David G. Kirschen

Comparison of suppression, stereoacuity, and interocular differences in visual acuity in monovision and acuvue bifocal contact lenses.

PURPOSE The relationship between visual acuity and stereoacuity has been well documented: as binocular visual acuity increases, stereoacuity improves. We compared interocular differences in visual acuity and stereoacuity in two presbyopic soft contact lens modalities, monovision and a new soft bifocal contact lens, the Acuvue Bifocal. The Acuvue Bifocal is hypothesized to show a smaller interocular acuity difference, increased stereoacuity, and decreased suppression over monovision at distance and near. METHODS Monovision patients wearing Acuvue or Surevue soft contact lenses were tested for visual acuity, stereoacuity, and suppression at distance and near. Stereoacuity was tested with the Randot Stereotest (near) and the BVAT (distance). Suppression was evaluated with the Acuity Suppression Vectogram (near) and the BVAT (distance). Patients were then fit with the Acuvue Bifocal in each eye. After wearing the lenses for 1 week, the same tests of visual acuity, stereoacuity, and suppression were performed. RESULTS The mean interocular acuity difference (IAD) at distance with monovision was 0.712 logarithm of the minimum angle of resolution (logMAR) (SD = 0.275) and 0.188 logMAR (SD = 0.252) (p < 0.001) with the Acuvue Bifocal. At near, the mean IAD with monovision was 0.420 logMAR (SD = 0.183) and 0.137 logMAR (SD = 0.147) (p < 0.001) with the Acuvue Bifocal. Of the monovision subjects, 89% (17 of 19) demonstrated suppression at near while only 26% (5 of 19) did with the bifocal lenses (statistically significant at p < 0.001). Stereoacuity at near improved from a median of 200 sec arc with monovision to 50 sec arc with the bifocal lenses. CONCLUSIONS In this study, correcting presbyopia with the Acuvue Bifocal versus monovision resulted in a statistically significant decrease in the interocular difference in visual acuity at distance and near. The decreased interocular difference in visual acuity improved certain aspects of binocularity as demonstrated by a decrease in suppression and an increase in stereoacuity.

The Use of Botulinum Toxin in the Medical Management of Benign Essential Blepharospasm

Twenty-eight patients with mild or moderate cases of benign essential blepharospasm were treated with botulinum toxin Type A. Average follow-up was six months. The injection technique used on these patients is illustrated. The treatment was effective in virtually all patients treated, although transient; the mean interval of relief of spasm was approximately two and one-half months. Potential side effects include ptosis and epiphora. Botulinum toxin as an initial treatment or as an adjunct in postsurgical residual blepharospasm shows promise in this preliminary study.

The visual function of olympic-level athletes-an initial report.

Objective: To describe the visual functions of Olympic-level athletes and begin to describe any differences between sports. Methods: A commercially available testing system was used to evaluate 157 Olympic-level athletes. These sports vision evaluations were therefore performed under standardized conditions. Visual functions, tested at a distance, consisted of monocular visual acuity, contour and random dot stereoacuity, and contrast sensitivity. Results: Boxers and track-and-field athletes demonstrated mean logMAR visual acuities between −0.078 and −0.060. All others demonstrated results better than −0.121. There were statistically significant differences and suggestive trends in the visual acuity in the right and left eyes between the track-and-field and archery and track-and-field and softball, and between softball and boxing (range P=0.0005-0.0243). Mean distance contour stereoacuity of the archers was 62 arcsec, worse than the soccer, softball, and speed skaters. All athletes demonstrated similar contrast sensitivity results at low spatial frequencies, whereas at higher spatial frequencies, softball players performed better than did the speed skaters, track-and-field, and volleyball athletes. Conclusions and Application to Clinical Practice: There seems to be a unique set of visual skills that are common to athletes in certain sports. In addition, visual performance measures vary between sports at the Olympic level. The ability to identify the visual needs for an athlete who wishes to participate in a given sport, and to correct any deficits an athlete may have, could lead to more success, at the elite and amateur levels.

The role of sports vision in eye care today.

Sports vision as an academic discipline is in its infancy. This review traces its history on many different fronts: early work, research, organizations, literature, cultural environment, sports injuries, and a view of the future. This article was presented as the opening remarks to the first-ever academic sports vision meeting held at Fenway Park in Boston, Massachusetts, in January 2010.

Optical aberrations in professional baseball players

PURPOSE: To determine the presence, type, and size of optical higher‐order aberrations (HOAs) in professional athletes with superior visual acuity and to compare them with those in an age‐matched population of nonathletes. SETTING: Vero Beach and Fort Myers, Florida, USA. METHODS: Players from 2 professional baseball teams were studied. Each players optical aberrations were measured with a naturally dilated 4.0 mm pupil using a Z‐Wave aberrometer and a LADARWave aberrometer. RESULTS: One hundred sixty‐two players (316 eyes) were evaluated. The HOAs were less than 0.026 μm in all cases. Spherical aberration C(4,0) was the largest aberration with both aberrometers. There were small but statistically significant differences between the aberrometers in mean values for trefoil C(3,3) and C(3,−3) and secondary astigmatism C(4,2). Although statistically significant, the differences were clinically insignificant, being similar at approximately 0.031 diopter (D) of spherical power. A statistically significant difference was found between the professional baseball players and the control population in trefoil C(3,−3). These differences were clinically insignificant, similar to 0.071 D of spherical power. CONCLUSIONS: Professional baseball players have small higher‐order optical aberrations when tested with naturally dilated pupils. No clinically significant differences were found between the 2 aberrometers. Statistically significant differences in trefoil were found between the players and the control population; however, the difference was clinically insignificant. It seems as though the visual system of professional baseball players is limited by lower‐order aberrations and that the smaller HOAs do not enhance visual function over that in a control population. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

The effectiveness of an autorefractor with eye-tracking capability in pediatric patients

PURPOSE To study the diagnostic accuracy and effectiveness in children of a new autorefractor with eye-tracking capability. METHODS Children aged 3-17 years were tested with a Marco Nidek ARK-560A autorefractor before and after cycloplegia. Cycloplegic manifest refractions were conducted on the more cooperative children. Measurements were converted to vector representations M (sphere), J0, and J45 (cylinder) by Fourier analysis and compared before and after cycloplegia for autorefractor measurements and clinical manifest and retinoscopic determinations. RESULTS A total of 88 subjects were included. Autorefractor measurements were successfully obtained on all subjects. Before cycloplegia the mean spherical portion of the refractive error by autorefractor measurement (AR Dry) averaged 0.29 ± 0.75 D less hyperopia than the clinical manifest refraction (P < 0.005). After cycloplegia, mean autorefractor measurements (AR Wet) demonstrated 1.03 ± 0.84 D more hyperopia in the spherical component than AR Dry (P < 0.001). The spherical component of autorefraction and clinical measurements after cycloplegia were not statistically different, but the J0 astigmatic findings differed by 0.13 D ± 0.25 (P < 0.0003). For the 27 children under 8 years of age, precycloplegic autorefractor findings differed from manual cycloplegic retinoscopy by 1.48 D ± 1.13 for sphere (P < 0.001) but were not statistically different for astigmatic parameters. CONCLUSIONS Autorefractors can estimate manual retinoscopy values in children and may prove useful in the office setting in evaluating pediatric patients. Autotracking allowed successful acquisition of measurements in all subjects.

Thoughts on ocular dominance-is it actually a preference?

Background: Ocular dominance has been studied for many years, and there have been many attempts to correlate eye dominance with athletic performance. Although many reports have failed to show a correlation, some reports have shown a relationship between sports performance and eye dominance. Methods: This report reviews some of those studies and the tests of eye dominance used in the reports. Additionally, we review the physical basis of eye dominance and the role of the binocular visual system in its determination. Lastly, a review of common facts and fallacies relating to ocular dominance is provided. Results/Conclusion: It is suggested that the visual system is designed as a binocular system, and only tests that allow for maintenance of binocular vision during the determination of ocular preference should be used if an accurate evaluation is to be made.