Binocular Function Parameters in Elite Football Players.

BACKGROUND: To investigate the binocular function in elite football players, and to analyze the differences (i) between athletes who play in different positions and (ii) between players of different ethnicities. METHODS: We screened 102 professional football players from four teams. The screening consisted of the measurement of refractive error. The binocular function parameters evaluated were: horizontal and vertical ocular alignment for distance (DF) and near fixation (NF), the values of break and recovery for negative and positive fusional vergences at DF and NF, vergence facility at NF, monocular accommodative facility at NF, near point of convergence (NPC) (break and recovery points), and NF stereopsis. All the athletes were men with a mean age of 24.6 ± 4.1 years. RESULTS: No statistically significant differences were found based on the athletes' ethnicity, except for ametropia prevalence, negative fusional vergences at DF, and NPC. We verified a statistically significant difference for the value of the break of negative fusional vergence at DF. The values found for Arab athletes are higher by more than 2 prism diopters than athletes of other ethnicities (p = .021). Arab athletes also show NPC values more distant than other athletes (p = .019, and p = .002 for break and recovery, respectively). CONCLUSION: Arab athletes have some binocular function parameters better than the remaining athletes, in particular when compared to Caucasian athletes. When compared to reference studies, athletes' binocular function seems to be better than those of the general population.

Prevalence of binocular vision dysfunctions in professional football players.

CLINICAL RELEVANCE: The extent of binocular vision dysfunction in elite soccer players needs to be determined as it may impact performance. BACKGROUND: The purpose of the study was to investigate the prevalence of binocular vision dysfunctions in elite soccer players. METHODS: One hundred and seven professional soccer players were evaluated. Refractive error was measured and the following binocular vision parameters were assessed: horizontal and vertical phoria for distance and near vision, the values of break and recovery for negative and positive fusional vergences at distance and near vision, vergence facility at distance and near vision, monocular accommodative facility at near vision, and near point of convergence (break and recovery points). All the athletes were men with a mean age of 24.4 ± 4.8 years. RESULTS: No athlete was diagnosed with divergence excess, divergence insufficiency, or basic exophoria. About 13.0% of the athletes have binocular vision dysfunctions related to esophoria (0.9% with esophoria at near vision and 12.1% with esophoria at distance and near vision). About 10.3% have convergence insufficiency and 2.8% were diagnosed with fusional vergence dysfunction. The only accommodation-related parameter analysed was accommodative infacility, and 6.5% of the athletes had this dysfunction. Vertical phoria was present in 3.7% of the athletes. No statistically significant differences were found based on in athletes with respect to ethnicity, position occupied on the field, age, ametropia or laterality. CONCLUSION: The overall prevalence of binocular vision dysfunction in elite soccer players was 36.4%. The most prevalent dysfunctions are related to the presence of esophoria (13.0%). The values found point out the need to include binocular vision assessment protocols in the visual assessment routine for athletes.

Pigmented corneal ring associated with orthokeratology in Caucasians: case reports.

BACKGROUND: The aim was to report the appearance of a pigmented ring in both eyes of two patients undergoing overnight orthokeratology. METHODS: Two Caucasian patients, one male and one female, were fitted with orthokeratology lenses to correct myopia between -2.00 and -2.50 DS with Paragon corneal refractive therapy lenses worn overnight. Treatment was successful in both patients achieving uncorrected vision of 6/6 or better monocularly under high (100 per cent) and low (10 per cent) contrast conditions. RESULTS: At the six-month visit both patients presented with pigmented rings under slitlamp examination in both eyes. The location of the ring was consistent with the corneal area being flattened for myopic correction. Clinical examination was otherwise normal. CONCLUSIONS: Despite being initially reported in Asian patients from Hong Kong, a pigmented ring related to orthokeratology treatment is also present in Caucasian patients, reducing the potential role of an ethnic link. Further large-scale studies need to be done to estimate the actual incidence of this condition and the potential implications for corneal health.

Intraoffice variability of corneal biomechanical parameters and intraocular pressure (IOP).

PURPOSE: To evaluate the intraoffice hour variability of intraocular pressure (IOP) and in vivo biomechanical properties of the cornea, as measured with the Ocular Response Analyzer (ORA). METHODS: The right eye of each of 58 young healthy subjects (14 men, 44 women) was measured at 1-hour intervals from 9.00 a.m. until 7.00 p.m. with the ORA. Subjects' age ranged from 19 to 45 years (average +/- standard deviation, 25 +/- 6 years). RESULTS: Average intraoffice hour variability of IOP and corneal biomechanical parameters were not statistically significant, showing a stable profile during the hours of the day studied. An interesting finding was that although there were no significant diurnal variations in any of the parameters, minor changes in corneal-compensated IOP and a Goldmann-equivalent IOP were significantly correlated with the intraoffice hour variability of corneal biomechanical parameters corneal hysteresis (CH) and the corneal resistance factor (CRF). Corneal-compensated IOP changes were the most strongly associated with intraoffice hour variability in CH for all measurement times (r = 0.598; p < 0.001). Changes of Goldmann-equivalent IOP were strongly correlated with intraoffice hour variability of corneal resistance factor (r = 0.849; p < 0.001). CONCLUSIONS: The present study confirms that intraoffice hour values of CH and corneal resistance factor are quite stable among a population of young healthy adults. However, average changes in these parameters over time correlate well with the changes in IOP values obtained with the same instrument, suggesting that diurnal variations of IOP could be at least in part related with changes in the biomechanical behavior of the cornea against the mechanical stimuli used by current non-contact tonometers. The most stable period to measure IOP and biomechanical parameters with ORA was in the afternoon.

A comparison of two pachymetric systems: slit-scanning and ultrasonic.

PURPOSE: This article compares measurements of corneal thickness obtained with the Orbscan Topography System with those obtained with the ultrasonic pachymeter, when used to measure central-comeal thickness in normal subjects. METHODS: Slit-scan topography (Orbscan II system, version 3.0, Bausch & Lomb, Rochester, NY) and ultrasonic pachymetry (Ophthasonic A-Scan/ Pachometer III, Accutome, Malvern, PA) were used to measure central-corneal thickness in 92 right corneas of 92 healthy adult subjects. A correlation analysis was used to evaluate the relationship between both instruments. Measurements were also compared by plotting the difference between the methods against the average. The hypothesis of zero bias was examined by a paired t-test. The 95% limits of agreement also were calculated. RESULTS: The mean corneal thickness was 559.9 microm +/-3.73 SEM with the Orbscan system and 551.2 microm +/- 4.57 SEM with the ultrasonic pachymeter, values that were significantly different (paired t-test, P = 0.000). The coefficient of determination was 0.860 (y = -65.78 + 1.135 x; P = 0.000). The mean difference between the measurements from both devices was found to be significantly different from zero (mean: 8.74 microm; paired t-test; P = 0.000), with Orbscan being slightly higher than the Ophthasonic A-Scan. CONCLUSIONS: The Orbscan system measurements of central corneal thickness were greater than ultrasonic pachymeter measurements, a difference that was statistically significantly.