Optometry and Vision Science (OVS) Announces Preview - April 2015
Coming in the April 2015 Optometry & Vision Science
Here are brief highlights. The online and printed copy will be available early-April. E-Publication Ahead-of-Print now available for all these articles at http://journals.lww.com/optvissci
Anthony J. Adams, OD, PhD, FAAO Editor-in-Chief
Driving Experience Before Bioptic Telescope Spectacle Use is Critical
Bioptic telescopic spectacles (BTS) can be used by people with central visual acuity loss that does not meet state standards to obtain a driver's license in 43 states. But little is known about what visual or demographic factors are related to driving performance or safety in these drivers. In a retrospective study of 74 licensed bioptic drivers in Ohio, the authors found that lack of previous (non-bioptic) driving experience before road testing for licensure was related to poorer Highway Patrol road test results. Surprisingly, vision level was not related to road test results. Whether these poorer road test results predict post-licensure crashes in bioptic drivers remains to be studied.
Driving While Corrected for Astigmatism
Contact lens patients with mild uncorrected astigmatism drive regularly. Does their vision have an impact on driving performance? In simulated driving studies the authors found 11 young adults with mild astigmatism (between 0.75 and 1.75D) improved driving performance with toric lens wear correction versus no correction. Surprisingly, performance did not differ between toric and spherical contact lens wear conditions, perhaps due to the small sample size and the mild astigmatism levels.
Peripheral Prism Glasses in Homonymous Hemianopia
Unilateral peripheral prisms for homonymous hemianopia (HH) expand the visual field through peripheral binocular visual confusion, but can be a stimulus for binocular rivalry that could lead to reduced predominance (partial local suppression) of the prism image and limit device functionality. Using natural-scene images and motion videos in the laboratory, the authors found detection was reduced in binocular compared to monocular viewing, but only for relatively small targets; real-world situations are needed to confirm this.
Predicting Scotomas with Inexpensive Equipment
The unpredictability of random word and letter sequences renders reading performance highly dependent on eyesight and less dependent on reading skill and educational level. In 140 participants with maculopathy, recurrent right or left errors were able to indicate the presence and location of a scotoma. This was accomplished with inexpensive equipment having good test-retest reliability (SKread). This knowledge can be used to teach patients about how the scotoma can interfere with their vision.
Vision Quality And Center Optical Zone Size in Bifocal Contact Lenses
Our authors studied subjective image clarity with simultaneous focus multifocal contact lenses. Distance +2D to -4D computer images were generated with +2.50 addition lenses. The diameter of the center-near optical zone was varied, to cover from 0% to 90% of the pupil area. Judgments of image clarity varied greatly across their 14 participants, with central rays playing a much greater role than peripheral rays in determining subjective image clarity. This may also be relevant to multifocal IOLs.
Comparing SD-OCT Instrument Data with Caution
With increasing myopia, choroidal thickness at the fovea decreased and scleral canal width increased with two SD-OCT instruments compared in 72 eyes of healthy participants. Albeit small, statistically significant differences were found between Cirrus and Bioptigen OCT instruments. This suggests caution when comparing results collected with different instruments.
Post LASIK Differences Between Corneal and Whole Eye Measures of Corneal Optics
When measuring the change in higher order aberrations induced by LASIK, corneal front surface aberrometry measurement were not interchangeable with whole eye ocular aberrometry measurements. This was a retrospective case series from 150 consecutive patients treated with LASIK. Corneal front surface wavefront was obtained from a placido based corneal topography system (Atlas) and whole eye wavefront by Hartman-Shack aberrometry (WASCA) before and at least 3 months after surgery. All aberrations were calculated up to the 4th order for the 6-mm pupil diameter.
Self Refraction in Teenage Ghana School Children
In a study of 203 myopic teenage school children in a fishing community in Ghana self-refraction with Focusspecs adjustable spectacles revealed that just over 90% of the school children got within 1D of their actual cycloplegic refractive error. The authors see a place for this approach in underserved populations.
Age-Related Cataract and Alcohol Use
A PubMed and Embase driven random effects model meta-analysis of 10 studies (5 case-controlled, 5 cohort) indicated that moderate alcohol intake may possibly be protective but heavy alcohol intake is clearly a risk factor for age-related cataract.
Biometry Changes and Decreased IOP Following Cataract Surgery
Ocular biometric parameters change and intraocular pressure decreased after uncomplicated cataract surgery in a study of 119 normotensive eyes. The authors believe this is the first study correlating changes in ocular biometry to decreases in intraocular pressure as measured by Goldmann tonometry after uneventful phacoemulsification.
A New Computer-Based Color Vision Test
A new computer-based color vision test performed as well as traditional color vision book tests as a screening test and was also accurate with regard to diagnostic type. Such computer-based tests may replace traditional book tests in the future.
New Screening Test for Dyslexia?
The Decoding-Encoding Screener for Dyslexia (DESD) was developed to identify children who may have reading difficulties. The authors evaluated the validity of the DESD against two standardized tests of reading ability in 31 school-aged (9 to15) children. The low correlation between the DESD Reading Test and the Word Reading subtest, but not the Spelling subtest, indicates that some caution should be used when interpreting the results of the DESD Reading Test. The authors feel practitioners may find the DESD Spelling Scale a more useful tool than the DESD Reading Test in identifying children who may have reading difficulties.
Can Acuity be Better Than Optical Blur Predicts?
Our authors found that reduction in equivalent intrinsic blur (derived from their model) was greater than reduction in optical blur (using adaptive optics correction of wavefront error). They believe this implies that visual acuity in participants with high equivalent intrinsic blur can be improved beyond that expected from the reduction in optical blur alone.
Images Compared for Retinal Nerve Fiber Layer Detection
One hundred sets of color fundus photography, typical red-free RNFL photography, and blue reflectance RNFL photography with confocal scanning laser ophthalmoscopy (CLSO) of 9 normals, 16 glaucoma suspects and 75 glaucoma patients, were presented to evaluators. Consequently a total of 300 images were rated twice in random order by the five independent evaluators who were masked to the patient characteristics. The RNFL images produced using blue reflectance with CSLO showed the best performance for the detection of RNFL defects, especially in cases with wedge defects and advanced glaucoma stage.
Antimicrobials Effectiveness for Biofilms of Achromobacter and Pseudomonas
Achromobacter and Pseudomonas biofilms can develop in ophthalmic products and accessories such as contact lens cases, leading to the development of ocular infections. Our authors evaluated the efficacy of ophthalmic antimicrobial preservatives against these biofilms. Achromobacter was more resistant than Pseudomonas to the antimicrobial effects of ophthalmic preservatives. Because of growing interest in the role of pathogens such as Achromobacter, which may contaminate lens cases and cause rare but significant cases of keratitis, effective ophthalmic formulations should be developed in ophthalmic products.
Major Barrier to Optometry Educators in Teaching Evidence-Based Practice
Evidence-Based Practice (EBP) is recognized as key to delivery of optimal health care. Like medicine, our profession has recognized this and incorporated teaching of Evidence-Based Practice skills in optometry programs around the world. This pilot workshop aimed to study the perspectives of optometric educators who were positive about Evidence-Based Practice but identified lack of time as an important barrier to its practice.