Philadelphia, Pa. (April 1, 2013) – By middle age, most people have age-related declines in near vision (presbyopia) requiring bifocals or reading glasses.  An emerging technique called hyperopic orthokeratology (OK) may provide a new alternative for restoring near vision without the need for glasses, according to a study, “Refractive Changes from Hyperopic Orthokeratology Monovision in Presbyopes”, appearing in the April issue of Optometry and Vision Science, official journal of the American Academy of Optometry.  The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.

For middle-aged patients with presbyopia, wearing OK contact lenses overnight can restore up-close vision in one eye, according to the study by Paul Gifford, PhD, FAAO, and Helen A Swarbrick, PhD, FAAO, of University of New South Wales, Sydney.  “The authors have shown the feasibility of correcting one eye for near vision through OK, in which overnight contact lens wear shapes the cornea of one eye to allow in-focus near vision for reading,” comments Anthony Adams, OD, PhD, Editor-in-Chief of Optometry and Vision Science.

Overnight OK Lens Wear Restores Near Vision in One Eye

The study included 16 middle-aged patients (43 to 59 years) with age-related loss of near vision, or presbyopia.  Presbyopia is caused by age-related loss of flexibility in the cornea—the transparent front part that lets light into the eye.

Orthokeratology is a clinical technique to correct vision using specially designed rigid contact lenses to manipulate the shape of the cornea.  Dr Adams likens OK therapy to orthodontic treatment using braces to change the alignment of the teeth.

Drs Gifford and Swarbick evaluated a “monocular” technique, with patients wearing a custom-made OK lens in one eye overnight for one week.  To preserve normal distance vision, the other eye was left untreated.

In all patients, the monocular OK technique was successful in restoring near vision in the treated eye.  The improvement was apparent on the first day after overnight OK lens wear, and increased further during the treatment week.  Eye examination confirmed that the OK lenses altered the shape of the cornea, as they were designed to do.

Nightly Lens Wear Needed to Retain Correction

Vision in the untreated eye was unaffected, and all patients retained normal distance vision with that eye; essentially this gives the patient the dequivalent of ‘monovision’ that is usually done with contact lenses or surgery.  To retain the correction in near vision, patients had to continue wearing their OK lenses every night. Dr Adams likens this ongoing treatment to the “retainer” that orthodontic patients have to wear nightly.  As expected, when patients stopped wearing their OK lens after the treatment week, presbyopia rapidly returned.

By about age 45 to 50, most people need bifocals or some other form of vision correction to restore vision for reading and other up-close tasks. Alternatives for presbyopia have been introduced, including fitting a contact lens for distance vision in one eye and a lens for near vision in the other eye.  This is the so called monovision, now the authors show it can be achieved without the need to wear a contact lens during the day. “However, the chief problem with monovision for many people is that their stereoscopic 3D vision is degraded and many find that hard to tolerate,” according to Dr Adams.

Although overnight OK is not a new technique, it has been mainly used to reduce nearsightedness (myopia) in younger patients.  The new study shows that OK is similarly effective in changing corneal shape, and achieving desired correction in near vision, in older patients with presbyopia.

The new study suggests that overnight OK lenses are a feasible alternative for correction of presbyopia, “sufficient to provide functional near vision correction white retaining good distance visual acuity,” Drs Gifford and Swarbick write.   The technique is safe, with the cornea returning to its previous shape about a week after the patient stops wearing the lenses.

“This study demonstrates that OK is quite viable as a nonsurgical option for monovision that does not require wearing contact lenses during the day, although it does require ‘retainer’ orthokeratology contact lenses to be worn overnight,” Dr Adams adds.  “This possibility will certainly appeal to many people, especially since the changes in the corneal curvature of the treated eye are fully reversible.”

To read the article, “Refractive Changes from Hyperopic Orthokeratology Monovision in Presbyopes”, please visit http://journals.lww.com/optvissci/Fulltext/2013/04000/Refractive_Changes_From_Hyperopic_Orthokeratology.3.aspx

About Optometry and Vision Science

Optometry and Vision Science, official journal of the American Academy of Optometry, is the most authoritative source for current developments in optometry, physiological optics, and vision science. This frequently cited monthly scientific journal has served primary eye care practitioners for more than 75 years, promoting vital interdisciplinary exchange among optometrists and vision scientists worldwide.

About the American Academy of Optometry

Founded in 1922, the American Academy of Optometry is committed to promoting the art and science of vision care through lifelong learning.  All members of the Academy are dedicated to the highest standards of optometric practice through clinical care, education or research.

About Lippincott Williams & Wilkins

Lippincott Williams & Wilkins (LWW) is a leading international publisher of trusted content delivered in innovative ways to practitioners, professionals and students to learn new skills, stay current on their practice, and make important decisions to improve patient care and clinical outcomes.

LWW is part of Wolters Kluwer Health, a leading global provider of information, business intelligence and point-of-care solutions for the healthcare industry. Wolters Kluwer Health is part of Wolters Kluwer, a market-leading global information services company with 2012 annual revenues of €3.6 billion ($4.6 billion).

Contacts:

Robert Dekker
Director of Communications
Wolters Kluwer Health
+1 (215) 521-8928
Robert.Dekker@wolterskluwer.com

Connie Hughes
Director, Marketing Communications
Wolters Kluwer Health Medical Research
+1 (646) 674-6348
Connie.Hughes@wolterskluwer.com

Philadelphia, Pa. (March 04, 2013) – A contact lens technique called overnight orthokeratology (OK) brings rapid improvement in vision for nearsighted patients.  Now a new study shows that OK treatment works mainly by flattening the front of the cornea, reports a recent study, “Posterior Corneal Shape Changes in Myopic Overnight Orthokeratology”, appearing in the March issue of Optometry and Vision Science, official journal of the American Academy of Optometry.  The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.

“This study appears to show that it is only, or primarily, the very front surface layers of the cornea that are altered by OK contact lens treatment,” comments Anthony Adams, OD, PhD, Editor-in-Chief of Optometry and Vision Science.  The study was performed by Jeong Ho Yoon, PhD, of University of Choonhae Health Science, Ulsan, Republic of Korea, and Helen A. Swarbick, PhD, FAAO, of University of New South Wales, Sydney, Australia.

Overnight Orthokeratology Works—But How?

Orthokeratology is a clinical technique to reduce nearsightedness (myopia) using specially designed rigid contact lenses to manipulate the shape of the cornea—the transparent front part that lets light into the eye.  Dr Adams likens OK therapy to orthodontic treatment using braces to change the alignment of the teeth.

He explains “Wearing these lenses overnight for about six hours is currently the treatment approach for most clinicians who use OK for the temporary correction of low to moderate myopia.”  But it has been unclear exactly how OK works to reduce myopia:  Do the contact lenses reshape just the front surface of the cornea, or do they bend and flatten the entire cornea?

To find out, Drs Yoon and Swarbick had 18 young adults with “low” (relatively mild) myopia wear OK lenses overnight for 14 days.  Using sophisticated techniques, the researchers made detailed measurements of corneal shape and thickness before, during, and after treatment.

As in previous studies, wearing OK contact lenses led to reduced myopia, thus improving vision.  The changes were significant after the first night wearing OK lenses, By 14 days, myopia was almost completely eliminated and the participants had near-normal uncorrected (without glasses) visual acuity.

Results ‘Achieved Primarily through Remodeling of Anterior Cornea’

These changes were linked to significant flattening of the anterior (front) portion of the cornea.  Like the vision changes, the change in corneal shape was significant after the first night wearing OK lenses.  Although corneal flattening continued throughout the 14-day treatment period, about 80 percent of the change occurred in the first four days.

In contrast, OK lenses caused only a small and temporary change in the shape of the posterior (rear) cornea, and only slight thinning of the central cornea.  “Overall, our results support the current hypothesis that the OK refractive effect is achieved primarily through remodeling of the anterior corneal layers, without overall corneal bending,” according to Drs Yoon and Swarbick.

Overnight OK contact lenses provide an effective treatment for relatively mild myopia.  It requires custom-made rigid contact lenses designed to accommodate the shape and desired change of the patient’s eye.  While OK lenses provide an alternative to LASIK surgery for correction of myopia, the patient must continue nightly contact lens wear to maintain the improvement.

The authors hope their results “will provide a more complete picture of overall corneal changes during myopic OK.”   In particular, the study demonstrates that overnight OK lenses don’t change the curvature of the posterior cornea—”at least in the first two weeks of lens wear.”

To read the article “Posterior Corneal Shape Changes in Myopic Overnight Orthokeratology”, please visit http://journals.lww.com/optvissci/fulltext/2013/03000/Posterior_Corneal_Shape_Changes_in_Myopic.3.aspx

About Optometry and Vision Science

Optometry and Vision Science, official journal of the American Academy of Optometry, is the most authoritative source for current developments in optometry, physiological optics, and vision science. This frequently cited monthly scientific journal has served primary eye care practitioners for more than 75 years, promoting vital interdisciplinary exchange among optometrists and vision scientists worldwide.

About the American Academy of Optometry

Founded in 1922, the American Academy of Optometry is committed to promoting the art and science of vision care through lifelong learning.  All members of the Academy are dedicated to the highest standards of optometric practice through clinical care, education or research.

About Lippincott Williams & WilkinsLippincott Williams & Wilkins (LWW) is a leading international publisher of trusted content delivered in innovative ways to practitioners, professionals and students to learn new skills, stay current on their practice, and make important decisions to improve patient care and clinical outcomes.

LWW is part of Wolters Kluwer Health, a leading global provider of information, business intelligence and point-of-care solutions for the healthcare industry. Wolters Kluwer Health is part of Wolters Kluwer, a market-leading global information services company with 2012 annual revenues of €3.6 billion ($4.6 billion).

Contacts:

Robert Dekker
Director of Communications
Wolters Kluwer Health
+1 (215) 521-8928
Robert.Dekker@wolterskluwer.com

Connie Hughes
Director, Marketing Communications
Wolters Kluwer Health Medical Research
+1 (646) 674-6348
Connie.Hughes@wolterskluwer.com

Comprehensive Visual Evaluation Needed after Any TBI, Suggests Study in Optometry and Vision Science

Philadelphia, Pa. (February 4, 2013) – Visual symptoms and abnormalities occur at high rates in people with traumatic brain injury (TBI)—including Iraq and Afghanistan War veterans with blast-related TBI, reports a study, “Mechanisms of TBI and Visual Consequences in Military and Veteran Populations,” in the February issue of Optometry and Vision Science, official journal of the American Academy of Optometry.  The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.

Vision problems are similar for military and civilian patients with TBI, and are common even after relatively mild brain injury, according to the report by Gregory L. Goodrich, PhD, of the VA Palo Alto (Calif.) Health Care System and colleagues.  “Comprehensive eye examinations are recommended following even mild traumatic brain injury,” comments Anthony Adams, OD, PhD, Editor-in-Chief of Optometry and Vision Science.

High Rate of Vision Problems in after TBI…

The researchers analyzed rates and types of vision problems in 50 Iraq and Afghanistan War veterans with blast-related TBI.  Blast-related TBI is a unique type of injury, with brain trauma caused by proximity to a blast or explosion, such as from an improvised explosive device.  “There is understandably a great deal of interest in the impact of war injuries on veterans and the eyes are among the most impacted of injuries to the body,” says Dr Adams.

The findings were compared to those of 50 patients, mainly civilians, with non-blast-related TBI—most commonly occurring in motor vehicle crashes.  (About one-third of the veterans with blast-related TBI also had direct head trauma, caused by events surrounding the blast.)

The results showed high rates of vision problems in both groups.  More than 65 percent had vision-related symptoms, including difficulty reading in about half of patients.  Patients with blast-related TBI were more likely to complain of light sensitivity—67 versus 77 percent.

On examination, patients with non-blast-related TBI were more likely to have problems related to eye movement (saccadic dysfunction)—85 versus 58 percent.  Other types of problems were similar between groups, including blurred vision caused by focusing problems (accommodative dysfunction) and problems moving the eyes together to focus on near objects (convergence insufficiency).  Visual field defects (blind spots) were less common.

The high rate of visual problems occurred even though most patients had normal visual acuity.  In both the blast-related and non-blast-related TBI groups, visual problems were similar after mild versus moderate to severe TBI.

…With Similar Rates Regardless of TBI Cause or Severity

Traumatic brain injury is a common problem, affecting an average of 1.7 million Americans each year.  “TBI can take place in any setting and can happen to anyone,” according to Dr Goodrich and coauthors.  Visual problems, especially oculomotor (eye movement) difficulties, are common after TBI.   The new study is one of the first to examine the rates and types of visual problems among military personnel with blast-related TBI.

The results show high rates of visual symptoms and abnormalities after blast-related TBI, similar to those found in non-blast-related TBI.  The similarities are despite the differing mechanisms of injury.  The higher rate of light sensitivity in the military group is consistent with previous studies reporting increased sensitivity to light and noise in patients with blast-related TBI.

Dr Goodrich and colleagues call for further studies to understand “the pathophysiologic and neurologic changes that occur in all types of acquired brain injury.”  Meanwhile, considering the high rates of vision problems after even mild TBI, they conclude, “[A] comprehensive vision examination should be conducted following brain injury, regardless of injury type or severity.”

To read the article “Mechanism of TBI and Visual Consequences in Military & Veteran Populations”, please visit http://journals.lww.com/optvissci/Fulltext/2013/02000/Mechanisms_of_TBI_and_Visual_Consequences_in.3.aspx

About Optometry and Vision Science

Optometry and Vision Science, official journal of the American Academy of Optometry, is the most authoritative source for current developments in optometry, physiological optics, and vision science. This frequently cited monthly scientific journal has served primary eye care practitioners for more than 75 years, promoting vital interdisciplinary exchange among optometrists and vision scientists worldwide.

About the American Academy of Optometry

Founded in 1922, the American Academy of Optometry is committed to promoting the art and science of vision care through lifelong learning.  All members of the Academy are dedicated to the highest standards of optometric practice through clinical care, education or research.

About Lippincott Williams & Wilkins
 
Lippincott Williams & Wilkins (LWW) is a leading international publisher of trusted content delivered in innovative ways to practitioners, professionals and students to learn new skills, stay current on their practice, and make important decisions to improve patient care and clinical outcomes.

LWW is part of Wolters Kluwer Health, a leading global provider of information, business intelligence and point-of-care solutions for the healthcare industry. Wolters Kluwer Health is part of Wolters Kluwer, a market-leading global information services company with 2011 annual revenues of €3.4 billion ($4.7 billion).

Contacts:

Robert Dekker
Director of Communications
Wolters Kluwer Health
+1 (215) 521-8928
Robert.Dekker@wolterskluwer.com

Connie Hughes
Director, Marketing Communications
Wolters Kluwer Health Medical Research
+1 (646) 674-6348
Connie.Hughes@wolterskluwer.com

Philadelphia, Pa. (January 7, 2012) – Abnormalities of eye movement and fixation may contribute to difficulty in perceiving and recognizing faces among older adults with age-related macular degeneration (AMD), suggests a study “Abnormal Fixation in Individuals with AMD when Viewing an Image of a Face” appearing in the January issue of Optometry and Vision Science, official journal of the American Academy of Optometry.  The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.

Unlike people with normal vision focus, those with AMD don’t focus on “internal features” (the eyes, nose and mouth) when looking at the image of a face, according to the study by William Seiple, PhD, and colleagues of Lighthouse International, New York.  They write, “Abnormal eye movement patterns and fixations may contribute to deficits in face perception in AMD patients.”

When Viewing Famous Face, AMD Patients Focus on External Features

The researchers used a sophisticated technique called optical coherence tomography/scanning laser ophthalmoscopy (OCT-SLO) to examine the interior of the eye in nine patients with AMD.  Age-related macular degeneration is the leading cause of vision loss in older adults.  It causes gradual destruction of the macula, leading to blurring and loss of central vision.

Previous studies have suggested that people with AMD have difficulty perceiving faces.  To evaluate the possible role of abnormal eye movements, Dr Seiple and colleagues used the OCT-SLO equipment to make microscopic movies of the interior of the eye (fundus, including the retina and macula) as the patients viewed one of the world’s most famous faces:  the Mona Lisa.

This technique allowed the researchers to record eye movements and where the patients looked (fixations) while looking at the face.  They compared the findings in AMD patients to a control group of subjects with normal vision.

The results showed significant differences in eye movement patterns and fixations between groups.  The AMD patients had fewer fixations on the internal features of the Mona Lisa’s face—eyes, nose, and mouth.  For controls, an average of 87 percent of fixations were on internal features, compared to only 13 percent on external features.  In contrast, for AMD patients, 62 percent of fixations were on internal features while 38 percent were on external features.

The normal controls also tended to make fewer and shorter eye movements (called saccades) than AMD patients.  The differences between groups did not appear to be related to the blurring of vision associated with AMD.

Some older adults with AMD report difficulties perceiving faces.  While the problem in “processing faces” is certainly  related to the overall sensory visual loss, the new  evidence suggests that specific patterns of eye movement abnormalities may also play a role.

Dr Seiple and colleagues note that “abnormal scanning patterns when viewing faces” have also been found in other conditions associated with difficulties in face perception, including autism, social phobias, and schizophrenia.  The authors discuss the possible mechanisms of the abnormal scanning patterns in AMD, involving the complex interplay between the eyes and brain in governing eye movement and interpreting visual information.

A previous study suggested that drawing attention to specific characteristics—such as the internal facial features—may increase fixations on internal features and improve face perception.  Dr Seiple and coauthors conclude, “That report gives hope that eye movement control training and training of allocation of attention could improve face perception and eye scanning behavior in individuals with AMD.”

To read the article “Abnormal Fixation in Individuals with AMD when Viewing an Image of a Face”, please visit http://journals.lww.com/optvissci/Fulltext/2013/01000/Abnormal_Fixation_in_Individuals_With_Age_Related.10.aspx

About Optometry and Vision Science

Optometry and Vision Science, official journal of the American Academy of Optometry, is the most authoritative source for current developments in optometry, physiological optics, and vision science. This frequently cited monthly scientific journal has served primary eye care practitioners for more than 75 years, promoting vital interdisciplinary exchange among optometrists and vision scientists worldwide.

About the American Academy of Optometry

Founded in 1922, the American Academy of Optometry is committed to promoting the art and science of vision care through lifelong learning.  All members of the Academy are dedicated to the highest standards of optometric practice through clinical care, education or research.

About Lippincott Williams & WilkinsLippincott Williams & Wilkins (LWW) is a leading international publisher of trusted content delivered in innovative ways to practitioners, professionals and students to learn new skills, stay current on their practice, and make important decisions to improve patient care and clinical outcomes.

LWW is part of Wolters Kluwer Health, a leading global provider of information, business intelligence and point-of-care solutions for the healthcare industry. Wolters Kluwer Health is part of Wolters Kluwer, a market-leading global information services company with 2011 annual revenues of €3.4 billion ($4.7 billion).

Contacts:

Robert Dekker
Director of Communications
Wolters Kluwer Health
+1 (215) 521-8928
Robert.Dekker@wolterskluwer.com

Connie Hughes
Director, Marketing Communications
Wolters Kluwer Health Medical Research
+1 (646) 674-6348
Connie.Hughes@wolterskluwer.com

Philadelphia, Pa. (December 10, 2012) – For people using 30-day extended-wear/continuous-wear (EW/CW) contact lenses, replacing lenses at night doesn’t lower the risk of complications compared to changing lenses monthly, suggests a study – “The Effect of Daily Lens Replacement During Overnight Wear on Ocular Adverse Events”, appearing in the December issue of Optometry and Vision Science, official journal of the American Academy of Optometry.  The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.

In contrast, replacing lenses every morning reduces the overall rate of “ocular adverse events,” reports the study by Jerome Ozkan, BOptom of Brien Holden Vision Institute, Sydney, and colleagues.  The researchers write, “Contact lens wearers on an EW/CW schedule should be advised to minimize lens handling prior to sleep to reduce the risk of complications.”

Morning or Night versus Monthly Lens Replacement

The “proof of concept” study evaluated the effects of morning versus night replacement and lens handling in 215 patients using silicone hydrogel EW/CW contact lenses.  Extended/continuous wear lenses are designed to be worn continuously for up to a month, including overnight.  But in the study, patients put in fresh EW/CW lenses every day—either at night before going to sleep or in the morning after waking.

At regular clinic visits, adverse events were compared for patients who replaced their lenses in the morning or at night.  Adverse event rates were compared to those in a similar, previously studied group of patients who wore EW/CW lenses continuously for a month.

The results showed a lower overall adverse event rate for patients who replaced their lenses each morning:  about four percent, compared to nearly nine percent with one month of continuous wear.  Morning lens replacement was specifically associated with a lower rate of mechanical adverse events, such as scratches and abrasions of the cornea:  less than one percent, compared to a little over five percent with monthly replacement.

In contrast, the adverse event rate for patients who replaced their lenses nightly was about eight percent—not significantly different from the rate for monthly lens replacement.  Inflammatory adverse events (such as redness and irritation of the eye) were somewhat less common with morning lens replacement, although the difference was not significant.

Lens Handling Linked to Contamination

Microbiology studies in a subgroup of patients found that lenses were frequently colonized with Staph bacteria after handling.  In the one-month study, there were no major complications, including the rare but serious infection microbial keratitis.

Extended wear/continuous wear contact lenses are a convenient alternative to daily-wear lenses, avoiding the need for daily lens removal, cleaning, and replacement.  Although EW/CW lenses are generally safe, the risk of complications is higher than with daily-wear lenses.  Extended wear may provide more time for bacteria to colonize the lens and cause infections. 

“The benefit of a fresh lens at night might be partially negated by contamination of the contact lens due to lens handling prior to overnight eye closure,” comments Anthony Adams, OD, PhD, Editor-in-Chief of Optometry and Vision Science.  “At night, with closed eyes, there is less oxygen getting to the cornea and reduced ‘lid wiper’ cleaning effect on the lenses.”

The new study suggests that replacing lenses in the morning reduces complications related to EW/CW lens wear.  “Unfortunately, replacing lenses at night does not appear to have any beneficial effect, perhaps due to the side effects of handling lenses just prior to overnight eye closure,” Dr Ozkan and coauthors write.  They suggest that, when users do replace EW/CW lenses, they should do so in the morning—and in any case, should avoid handling lenses before they go to sleep at night. 

To read the article “The Effect of Daily Lens Replacement During Overnight Wear on Ocular Adverse Events”, please visit http://journals.lww.com/optvissci/Fulltext/2012/12000/The_Effect_of_Daily_Lens_Replacement_During.4.aspx 

About Optometry and Vision Science

Optometry and Vision Science, official journal of the American Academy of Optometry, is the most authoritative source for current developments in optometry, physiological optics, and vision science. This frequently cited monthly scientific journal has served primary eye care practitioners for more than 75 years, promoting vital interdisciplinary exchange among optometrists and vision scientists worldwide.

About the American Academy of Optometry

Founded in 1922, the American Academy of Optometry is committed to promoting the art and science of vision care through lifelong learning.  All members of the Academy are dedicated to the highest standards of optometric practice through clinical care, education or research.

About Lippincott Williams & Wilkins

Lippincott Williams & Wilkins (LWW) is a leading international publisher of trusted content delivered in innovative ways to practitioners, professionals and students to learn new skills, stay current on their practice, and make important decisions to improve patient care and clinical outcomes. LWW is part of Wolters Kluwer Health, a leading global provider of information, business intelligence and point-of-care solutions for the healthcare industry. Wolters Kluwer Health is part of Wolters Kluwer, a market-leading global information services company with 2011 annual revenues of €3.4 billion ($4.7 billion).

Contacts:

Robert Dekker
Director of Communications
Wolters Kluwer Health
+1 (215) 521-8928
Robert.Dekker@wolterskluwer.com

Connie Hughes
Director, Marketing Communications
Wolters Kluwer Health Medical Research
+1 (646) 674-6348
Connie.Hughes@wolterskluwer.com

Philadelphia, Pa. (November 5, 2012) – Modern contact lens materials are prone to drying when exposed to air, which contributes to the buildup of deposits on contact lenses, according to a study – “The Impact of Intermittent Air Exposure on Lipid Deposition”, appearing in the November issue of Optometry and Vision Science, official journal of the American Academy of Optometry.  The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health

With significant differences between materials, the buildup of lipid deposits on contact lenses is affected by “intermittent air exposure” between blinks, according to Holly Loretz, PhD, and colleagues of the Centre for Contact Lens Research at University of Waterloo, Ont., Canada.  The findings may help in developing new materials that are less prone to drying and lipid deposition—thus increasing the chances of successful contact lens wear.

Air Exposure Leads to Increased Lipid Deposits on Contact Lenses

The researchers built a new experimental setup, called the “model blink cell,” to examine factors affecting the buildup of lipid (fatty) deposits on contact lenses.  The model blink cell was designed to cycle contact lens materials in and out of an artificial tear solution containing trace amounts of cholesterol or other lipids naturally present in tear fluid.

To mimic the effects of routine lens wear, six different contact lens materials were subjected to simulated blinks and eyelid motion for varying periods.  The researchers analyzed the effects of air exposure between “blinks” on the buildup of lipid deposits.

For most of the materials tested, air exposure led to increased lipid deposits.  Compared to lenses that remained submerged in the artificial tear solution, the amount of cholesterol deposited on lenses was about three times greater with air exposure.  For another type of lipid (phosphatidylcholine), lipid deposition was about 40 percent greater with intermittent air exposure.

Today’s sophisticated contact lens materials have molecular characteristics related to “wettability” that seem to contribute to a cycle of lipid deposition that is encouraged by repeated wetting and drying.  ”This wetting/de-wetting cycle can occur after every blink and therefore thousands of times a day, thus allowing lipid to continuously accumulate on and in the lens material,”  Dr Loretz and coauthors write.

What does it all mean for contact lens wearers?  “Contact lenses gather deposits during wear and contribute to discomfort and how successful the lenses are for the wearer,” explains Anthony Adams, OD, PhD, Editor-in-Chief of Optometry and Vision Science. “Dry eyes can also negatively affect the chances of successful contact lens wear.”

Although no laboratory model can fully simulate the effects of real-life contact lens wear, the model blink cell improves on previous approaches by accounting for the drying effects of intermittent air exposure.  The effects of drying on lipid deposition may be even more important with today’s sophisticated hydrophobic (“unwettable”) lens materials.

“The model blink cell device allows clinical researchers to move beyond the current relatively simple in vitro models for studying deposits to a more real-life modeling of a contact lens on the eye, particularly with today’s more hydrophobic silicon component hydrogel lenses,” Dr Adams adds.  “The authors are hopeful that this will allow  research that could be expected to provide improved comfort in contact lens wear.”

To read the article “The Impact of Intermittent Air Exposure on Lipid Deposition”, please visit http://journals.lww.com/optvissci/Fulltext/2012/11000/The_Impact_of_Intermittent_Air_Exposure_on_Lipid.6.aspx

Optometry and Vision Science for the iPad app is available as a free download from the iTunes App Store. For a limited time, all users will have free full content to the current issue. After the free introductory period, American Academy of Optometry members and subscribers will continue to enjoy full access via a simple login process. Each issue will be posted on the same schedule as the current online and print editions.

 About Optometry and Vision Science

Optometry and Vision Science, official journal of the American Academy of Optometry, is the most authoritative source for current developments in optometry, physiological optics, and vision science. This frequently cited monthly scientific journal has served primary eye care practitioners for more than 75 years, promoting vital interdisciplinary exchange among optometrists and vision scientists worldwide.

About the American Academy of Optometry

Founded in 1922, the American Academy of Optometry is committed to promoting the art and science of vision care through lifelong learning.  All members of the Academy are dedicated to the highest standards of optometric practice through clinical care, education or research.

About Lippincott Williams & Wilkins

Lippincott Williams & Wilkins (LWW) is a leading international publisher of trusted content delivered in innovative ways to practitioners, professionals and students to learn new skills, stay current on their practice, and make important decisions to improve patient care and clinical outcomes. LWW is part of Wolters Kluwer Health, a leading global provider of information, business intelligence and point-of-care solutions for the healthcare industry. Wolters Kluwer Health is part of Wolters Kluwer, a market-leading global information services company with 2011 annual revenues of €3.4 billion ($4.7 billion).

Contacts:

Robert Dekker
Director of Communications
Wolters Kluwer Health
+1 (215) 521-8928
Robert.Dekker@wolterskluwer.com

Connie Hughes
Director, Marketing Communications
Wolters Kluwer Health Medical Research
+1 (646) 674-6348
Connie.Hughes@wolterskluwer.com

Philadelphia, Pa. (October 3, 2012) – A simple test of eyelid sensitivity may help vision professionals in evaluating one of the most common eye-related symptoms:  dry eyes.  A new study linking increased eyelid sensitivity to decreased function of the eyelid margins is presented in the article – “Lid Margins: Sensitivity, Staining, Meibomian

Gland Dysfunction, and Symptoms”, appearing in the October issue of Optometry and Vision Science, official journal of the American Academy of Optometry.  The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.

Isabelle Jabert, OD, MPH, PhD, FAAO, and colleagues of The University of New South Wales, Sydney, used a test called esthesiometry to measure the sensitivity of the eyelid margins—the very edge of the upper and lower eyelids.  The test, easily performed in the optometrist’s office, provides an accurate measure of the lid margin’s sensitivity to touch.  The pilot study included 27 healthy adults, average age 31 years.

The researchers then looked at how eyelid sensitivity was related to the function of some specialized structures of the eyelid margin.  A special dye was also used to stain the innermost layer of the eyelid margin to assess the function of the meibomian glands, which secrete a specialized oil-like substance into the tear fluid.

The results showed some surprising differences between the upper and lower eyelids—including greater sensitivity of the lower-lid margin, compared to the upper lids.

And it was this increased lower lid sensitivity that was found to be related to hyperosmolarity of the tear film—that is, more concentrated tears.  The finding suggests the potential for a new approach to clinically assessing tear osmolarity via lower lid sensitivity measures.  Whereas past studies have shown a relationship between corneal sensitivity and osmolarity, none have addressed the possible lid sensitivity relationship. The ease with which the non-transparent lids can be accessed to measure sensitivity provides a potential clinical advantage over measuring sensitivity to touch on the cornea.

By comparison, the relationship between tear osmolarity and staining appears much more ambiguous.

The authors’ results emphasize clear differences in staining and sensitivity between the upper and lower lids; for example the upper lids appear to be less sensitive and they stain less.  Such findings may turn out to be important for interpretation of future studies of the dry eye condition. 

Increased osmolarity and decreased meibomian gland function have both been linked to symptoms related to dry eye:  one of the most common ocular complaints, especially in older people. 

Recent research has led to increased understanding of the delicate structure and function of the lid margin, and their contribution to common eye-related symptoms.  “There is renewed interest in the role of the eyelids in dry eye and meibomian gland dysfunction,” comments Anthony Adams, OD, PhD, Editor-in-Chief of Optometry and Vision Science.

The new results suggest that esthesiometry could provide optometrists with a simple test of lid margin sensitivity, providing evidence of tear osmolarity.  “This suggests a promising new tool for evaluating ocular health and effectiveness of treatment in dry eye disease and meibomian gland dysfunction,” Dr Adams adds.  The findings may provide “an expanded set of tools” for identifying problems leading to dry eye, and possibly for evaluating the effectiveness of new treatments.

To read the article Lid Margins: Sensitivity, Staining, Meibomian Gland Dysfunction, and Symptoms”, please visit http://journals.lww.com/optvissci/Fulltext/2012/10000/Lid_Margins___Sensitivity,_Staining,_Meibomian.5.aspx

Optometry and Vision Science for the iPad app is available as a free download from the iTunes App Store. For a limited time, all users will have free full content to the current issue. After the free introductory period, American Academy of Optometry members and subscribers will continue to enjoy full access via a simple login process. Each issue will be posted on the same schedule as the current online and print editions.

About Optometry and Vision Science

Optometry and Vision Science, official journal of the American Academy of Optometry, is the most authoritative source for current developments in optometry, physiological optics, and vision science. This frequently cited monthly scientific journal has served primary eye care practitioners for more than 75 years, promoting vital interdisciplinary exchange among optometrists and vision scientists worldwide.

About the American Academy of Optometry

Founded in 1922, the American Academy of Optometry is committed to promoting the art and science of vision care through lifelong learning.  All members of the Academy are dedicated to the highest standards of optometric practice through clinical care, education or research.

About Lippincott Williams & Wilkins

Lippincott Williams & Wilkins (LWW) is a leading international publisher of trusted content delivered in innovative ways to practitioners, professionals and students to learn new skills, stay current on their practice, and make important decisions to improve patient care and clinical outcomes. LWW is part of Wolters Kluwer Health, a leading global provider of information, business intelligence and point-of-care solutions for the healthcare industry. Wolters Kluwer Health is part of Wolters Kluwer, a market-leading global information services company with 2011 annual revenues of €3.4 billion ($4.7 billion).

Contacts:

Robert Dekker
Director of Communications
Wolters Kluwer Health
+1 (215) 521-8928
Robert.Dekker@wolterskluwer.com

Connie Hughes
Director, Marketing Communications
Wolters Kluwer Health Medical Research
+1 (646) 674-6348
Connie.Hughes@wolterskluwer.com

Philadelphia, Pa. (September 5, 2012) – Millions of Americans have poor vision that can’t be corrected by conventional glasses or contact lenses.  But many of them can benefit from new techniques to maximize their residual vision and thus enhance their daily living and mobility, according to a study – “The Berkeley Rudimentary Vision Test (BRVT)”, in the special September issue of Optometry and Vision Science, official journal of the American Academy of Optometry.  The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.

“In this feature issue of Optometry and Vision Science, we hope to showcase the many facets of low vision research, highlighting how recent advances in vision science can be applied to low vision research and patient care,” according to a guest editorial by an international team of experts led by Susana T.L. Chung, OP, PhD, FAAO, of University of California, Berkeley.

Beyond ‘Counting Fingers’—and Other Advances in Low Vision Research

Contributed by leading researchers from around the world, the 21 papers in the special issue provide a comprehensive update on new advances and future challenges in low vision research.  Recent years have seen increased research attention to the problem of low vision, driven by advances in understanding of the brain process in vision, a clearer understanding of visual search strategies, and an “explosion” of new technology.

“Most of the almost 3.5 million people in the United States with low vision have useful residual vision, even if they are among the 1 million who are legally blind,” comments Anthony Adams, OD, PhD, Editor-in-Chief of Optometry and Vision Science.  “So the challenge is to optimize that residual vision to improve the person’s quality of life or to meet work challenges.”

One key area is new approaches to assessing and measuring just how much potentially useful vision the patient has.  Historically, clinicians and researchers haven’t had readily available tools for measuring low vision.  Below a visual acuity of 20/200, residual vision has typically been described in terms of the ability to “count fingers” and “light perception.”

A group led by Ian L. Bailey, OD, MS, FAAO, of University of California has developed a new tool for measuring residual vision at the very low end of the range.  Using a simple card system and very short test distances, the new test can make precise measurements of residual vision all the way down to 20/16,000.

The ability to make detailed assessments of such very low vision is an essential starting point for taking advantage of new techniques to maximize the use of residual vision.  At levels lower than 20/16,000, the test includes 13 steps to grade vision all the way to “light perception.”

Other topics in the special issue include new techniques and technologies for maximizing residual vision for critical functions like reading and mobility. Two studies highlight the impact of loss of contrast sensitivity on reading ability—not only in low-vision patients with glaucoma but even in the general population of older adults.  Dr Adams points out, “Fortunately, text presented digitally on a computer, tablet or smart phone can often dramatically increase accessibility to the written word in this group of people.”

The special issue also evaluates some newer new technologies and assessments that are—or are not—effective in maximizing residual vision for everyday functioning.  “Our goal for this feature issue is not simply to celebrate the most recent advances in the field, but also to stimulation ideas and questions for future research,” Dr Chung and coauthors conclude.  “More rigorous research can provide better patient care to the visually impaired.”

To read the article “The Berkeley Rudimentary Vision Test (BRVT)”, please visit http://journals.lww.com/optvissci/Fulltext/2012/09000/The_Berkeley_Rudimentary_Vision_Test.7.aspx

About Optometry and Vision Science

Optometry and Vision Science, official journal of the American Academy of Optometry, is the most authoritative source for current developments in optometry, physiological optics, and vision science. This frequently cited monthly scientific journal has served primary eye care practitioners for more than 75 years, promoting vital interdisciplinary exchange among optometrists and vision scientists worldwide.

About the American Academy of Optometry

Founded in 1922, the American Academy of Optometry is committed to promoting the art and science of vision care through lifelong learning.  All members of the Academy are dedicated to the highest standards of optometric practice through clinical care, education or research.

About Lippincott Williams & Wilkins

Lippincott Williams & Wilkins (LWW) is a leading international publisher of trusted content delivered in innovative ways to practitioners, professionals and students to learn new skills, stay current on their practice, and make important decisions to improve patient care and clinical outcomes. LWW is part of Wolters Kluwer Health, a leading global provider of information, business intelligence and point-of-care solutions for the healthcare industry. Wolters Kluwer Health is part of Wolters Kluwer, a market-leading global information services company with 2011 annual revenues of €3.4 billion ($4.7 billion).

Contacts:

Robert Dekker
Director of Communications
Wolters Kluwer Health
+1 (215) 521-8928
Robert.Dekker@wolterskluwer.com

Connie Hughes
Director, Marketing Communications
Wolters Kluwer Health Medical Research
+1 (646) 674-6348
Connie.Hughes@wolterskluwer.com

Philadelphia, Pa. (August 7, 2012) – Patients using cholesterol-lowering statin drugs may be at increased risk of developing age-related cataracts, according to a study - “Age-related Cataract Is Associated with Type 2 Diabetes and Statin Use”, in the August issue of Optometry and Vision Science, official journal of the American Academy of Optometry.  The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.

While further research is needed to understand the true nature of the association, the additional risk of cataracts in statin users appears similar to that associated with type 2 diabetes, according to the study by Carolyn M. Machan, OD, and colleagues of University of Waterloo, Ont., Canada.

Statins and Diabetes Both Increase Cataract Risk

The study included nearly 6,400 patients seen at the optometry clinic at the University of Waterloo in 2007-08.  Of these, 452 patients had type 2 diabetes.  Statin treatment and diabetes were evaluated as possible risk factors for age-related cataracts, controlling for other factors including sex, smoking, and high blood pressure.

Fifty-six percent of patients with type 2 diabetes were taking statins, compared to 16 percent of those without diabetes.  Both diabetes and statin use were significantly associated with an increased rate of age-related cataracts.

With adjustment for other factors, diabetes was associated with an 82 percent increase in cataract risk and statin use with a 57 percent increase.  Statistically, the increase in cataract risk associated with statins was similar to that associated with diabetes.

The associations differed for different types of cataracts.  For one specific type long linked to diabetes (posterior subcapsular cataract), the association with diabetes was no longer significant after adjustment for statin treatment.

Despite the high rate of statin use among patients with diabetes, the two risk factors appeared independent of each other.  At older ages, the risk of cataracts increased fastest in diabetic patients who took statins and slowest in nondiabetic patients who did not take statins.  On average, cataracts developed 5.6 years earlier in diabetic patients who took statins, compared to nondiabetic patients who did not take statins.

Type 2 diabetes is a known risk factor for the development of age-related cataracts—a common vision problem caused by clouding of the crystalline lens of the eye.  Studies in animals have shown a clear link between long-term treatment with statins (at high doses) and cataracts.

The new study suggests that statins may also be linked to cataracts in humans.  The authors emphasize that the study can’t prove that statins play any role in causing cataracts, but suggest that such a link is biologically plausible.

While further studies are needed, Dr Machan and colleagues emphasize that the known benefits of statin treatment for patients with type 2 diabetes probably outweigh any increased risk of cataracts.  They believe their results will help to increase awareness of the risks of treatments for type 2 diabetes, and may encourage the development of alternative cholesterol-lowering drugs that are not associated with an increased risk of cataracts.

Anthony Adams, OD, PhD, Editor-in-Chief of Optometry and Vision Science, comments, “Considering the increase in the prevalence of diabetes and the corresponding increase in the use of statins, the authors feel these findings serve to encourage further research on the long-term effect of statins on the human crystalline lens.”

To read the article “Age-related Cataract Is Associated with Type 2 Diabetes and Statin Use”, please visit http://journals.lww.com/optvissci/Fulltext/2012/08000/Age_Related_Cataract_Is_Associated_with_Type_2.12.aspx 

About Optometry and Vision Science

Optometry and Vision Science, official journal of the American Academy of Optometry, is the most authoritative source for current developments in optometry, physiological optics, and vision science. This frequently cited monthly scientific journal has served primary eye care practitioners for more than 75 years, promoting vital interdisciplinary exchange among optometrists and vision scientists worldwide.

About the American Academy of Optometry

Founded in 1922, the American Academy of Optometry is committed to promoting the art and science of vision care through lifelong learning.  All members of the Academy are dedicated to the highest standards of optometric practice through clinical care, education or research.

About Lippincott Williams & Wilkins

Lippincott Williams & Wilkins (LWW) is a leading international publisher of trusted content delivered in innovative ways to practitioners, professionals and students to learn new skills, stay current on their practice, and make important decisions to improve patient care and clinical outcomes. LWW is part of Wolters Kluwer Health, a leading global provider of information, business intelligence and point-of-care solutions for the healthcare industry. Wolters Kluwer Health is part of Wolters Kluwer, a market-leading global information services company with 2011 annual revenues of €3.4 billion ($4.7 billion).

Contacts:

Robert Dekker
Director of Communications
Wolters Kluwer Health
+1 (215) 521-8928
Robert.Dekker@wolterskluwer.com

Connie Hughes
Director, Marketing Communications
Wolters Kluwer Health Medical Research
+1 (646) 674-6348
Connie.Hughes@wolterskluwer.com

Philadelphia, Pa. (July 2, 2012) – Watching 3D movies can “immerse” you in the experience—but can also lead to visual symptoms and even motion sickness, reports a study – “Stereoscopic Viewing and Reported Perceived Immersion and Symptoms”, in the July issue of Optometry and Vision Science, official journal of the American Academy of Optometry.  The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.

Symptoms related to 3D viewing are affected by where you sit while watching, and even how old you are.  “Younger viewers incurred higher immersion but also greater visual and motion sickness symptoms in 3D viewing,” according to the authors, led by Shun-nan Yang, PhD, of Pacific University College of Optometry, Forest Grove, Ore.  “Both [problems] will be reduced if a farther distance and a wider viewing angle are adopted.”

Greater ‘Immersion’ in 3D Also Associated With Increased Symptoms

The researchers performed experiments in which adults, from young adult to middle-aged, were invited to watch a movie (Cloudy with a Chance of Meatballs) in 2D or 3D while sitting at different angles and distances.   Visual and other symptoms were assessed—including the role of factors including age, seating position, and level of “immersion” in the movie.

Twenty-one percent of participants reported symptoms while watching the movie in 3D, compared to twelve percent with 2D viewing.   For younger study participants blurred vision, double vision, dizziness, disorientation, and nausea were all more frequent and severe when watching the movie in 3D.

3D viewing also led to a greater sense of immersion—”a greater sense of object motion and motion of the viewer in space”—compared to 2D viewing.  Subjects sitting in more central or closer positions reported greater immersion as well as increased symptoms of motion sickness—that is, nausea.  Sitting at an angle to the screen was associated with less immersion as well as reduced motion symptoms.

There were some differences by age, including a lower rate of blurred vision in older viewers (age 46 and older).  Older viewers had more visual and motion sickness symptoms in 2D viewing, while younger viewers (age 24 to 34) had more symptoms in 3D viewing.  The same age-related changes leading to lower rates of blurred vision in older viewers may also explain their lower rates of symptoms during 3D vision.

As 3D movies become more common, including on home screens, there are reports of visual and other symptoms among 3D viewers.  Vision and orientation symptoms related to 3D viewing may be related to a “mismatch” between focusing and converging the eyes. Anthony Adams, OD, PhD, Editor-in-Chief of Optometry and Vision Science notes “the technology for reducing mismatch between where the eyes converge and where they focus is likely to improve rapidly.”

The study identifies several factors associated with symptoms during 3D viewing.  “3D viewing is quite specific in causing blurred vision and double vision, and the resultant symptoms are greater for younger adults,” Dr Yang and colleagues write.  3D produces a greater sense of immersion than 2D viewing, which leads to more symptoms of motion sickness—especially for younger adults and when viewing from a closer distance and a more direct angle.

The study will help optometrists and other eye care professionals in talking to patients about visual and other symptoms related to today’s sophisticated 3D video setups.

 To read the article “Stereoscopic Viewing and Reported Perceived Immersion and Symptoms”, please visit http://journals.lww.com/optvissci/Fulltext/2012/07000/Stereoscopic_Viewing_and_Reported_Perceived.17.aspx

About Optometry and Vision Science

Optometry and Vision Science, official journal of the American Academy of Optometry, is the most authoritative source for current developments in optometry, physiological optics, and vision science. This frequently cited monthly scientific journal has served primary eye care practitioners for more than 75 years, promoting vital interdisciplinary exchange among optometrists and vision scientists worldwide.

About the American Academy of Optometry

Founded in 1922, the American Academy of Optometry is committed to promoting the art and science of vision care through lifelong learning.  All members of the Academy are dedicated to the highest standards of optometric practice through clinical care, education or research.

About Lippincott Williams & Wilkins

Lippincott Williams & Wilkins (LWW) is a leading international publisher of trusted content delivered in innovative ways to practitioners, professionals and students to learn new skills, stay current on their practice, and make important decisions to improve patient care and clinical outcomes. LWW is part of Wolters Kluwer Health, a leading global provider of information, business intelligence and point-of-care solutions for the healthcare industry. Wolters Kluwer Health is part of Wolters Kluwer, a market-leading global information services company with 2011 annual revenues of €3.4 billion ($4.7 billion).

Contacts:

Robert Dekker
Director of Communications
Wolters Kluwer Health
+1 (215) 521-8928
Robert.Dekker@wolterskluwer.com

Connie Hughes
Director, Marketing Communications
Wolters Kluwer Health Medical Research
+1 (646) 674-6348
Connie.Hughes@wolterskluwer.com