Visual efficiency among teenaged athletes and non-athletes

AIM To compare visual efficiency, specifically accom-modation, vergence, and oculomotor functions among athletes and non-athletes. METHODS A cross-sectional study on sports vision screening was used to evaluate the visual skills of 214 elementary students (107 athletes, 107 non-athletes), aged between 13 and 16y. The visual screening assessed visual parameters such as ocular motor alignment, accommodation, and vergence functions. RESULTS Mean visual parameters were compared between age-group matched athletes (mean age 14.82±0.98y) and non-athletes (mean age 15.00±1.04y). The refractive errors of all participants were corrected to maximal attainable best corrected visual acuity of logMAR 0.0. Accommodation function assessment evaluated amplitude of accommodation and accommodation facility. Vergence functions measured the near point of convergence, vergence facility, and distance fusional vergence at break and recovery point. Ocular motor alignment was not statistically significant between both groups. Athletes had a statistically significant amplitude of accommodation for both the right eye (t=2.30, P=0.02) and the left eye (t=1.99, P=0.05). Conversely, non-athletes had better accommodation facility (t=-2.54, P=0.01) and near point of convergence (t=4.39, P<0.001) when compared to athletes. Vergence facility was found to be better among athletes (t=2.47, P=0.01). Nevertheless, non-athletes were significantly better for both distance negative and positive fusional vergence. CONCLUSION Although the findings are still inconclusive as to whether athletes had superior visual skills as compared to non-athletes, it remains important to identify and elucidate the key visual skills needed by athletes in order for them to achieve higher performance in their sports

Hubungan antara ujian TNO penataran biasa dan penataran songsang dengan Sstereopsis silang dan stereopsis tak silang

Persepsi tiga dimensi boleh dikategorikan kepada stereopsis silang apabila suatu objek kelihatan mendekati pemerhati dan sebagai stereopsis tak silang apabila suatu objek kelihatan menjauhi pemerhati. Keadaan ini boleh dikesan daripada ujian steropsis titik rawak TNO berdasarkan penataran plat ujiannya, iaitu penataran biasa memberi apresiasi objek kelihatan mendekati (stereopsis silang), manakala secara penataran songsang plat ujian yang memberi apresiasi objek kelihatan menjauhi pemerhati (stereopsis tak silang). Ini disokong oleh tanggapan umum bahawa stereopsis silang mempunyai nilai ambang yang lebih baik berbanding stereopsis tak silang. Kajian ini tidak menunjukkan perbezaan yang signifikan antara stereoakuiti penataran biasa dan stereoakuiti penataran songsang, sesi A: T = 7, p = 0.89 dan sesi B : T = 2, p = 0.27. Keputusan kajian juga menunjukkan tiada perbezaan yang signifikan antara stereoakuiti diukur dengan penataran biasa kali pertama diikuti oleh ukuran kali ke dua (T = 8, p = 0.6) dan stereoakuiti diukur dengan penataran songsang kali pertama diikuti ukuran kali ke dua (T = 6, p = 0.6). Hasil kajian ini merumuskan apresiasi stereopsis secara penataran biasa plat TNO tidak boleh dianggap sebagai stereopsis silang dan apresiasi stereopsis secara penataran songsang plat TNO tidak mewakili steropsis tak silang dengan alasan yang dinyatakan. Tiada kesan pembelajaran dikesan daripada ujian stereopsis titik rawak TNO

ORIGINAL ARTICLE - THE MAGNITUDE OF FOVEAL SUPPRESSION DURING FIXATION DISPARITY IN PRESBYOPIC PATIENTS

The characteristics of foveal suppression (FS) in fixation disparity (FD) due to visual stress were investigated and their relationship's between, age, symptoms, and the effect of temporary elimination of FD using prisms on the degree of the FS were analysed. Forty-five presbyopic subjects (15 without FD and 30 with stress related FD) participated in the study. The subjects underwent comprehensive optometric examination prior to the study. Their FS and FD were measured. The FD was later corrected with ophthalmic prisms, the power of which was equally divided between the eyes, and the FS was later verified. Age and FS had no significant correlation for subjects without FD (Spearman's rs = 0.17, p = 0.55,NS) and in subjects with FD (rs = 2.49, p = 0.19, NS), respectively. Correlation between the degree of FS and FD was weak (rs=0.38, p=0.07), however the magnitude of FD significantly increased with age (r=0.27, p=0.04). Subjects with FD had significantly larger degree of FS compared with subjects without FD (Wilcoxon's Z =-0.25, p=0.01). There was no significant difference in the magnitudes of FD (t = -0.38, p=0.07) and in their degrees of FS (Mann-Whitney U = 1.5, p=0.71) between subjects with and without symptoms. Correcting the FD with prisms generally reduced the degree of FS (Wilcoxon's Z =1.96, p=0.04), however, significant change in FS only occured in subjects with symptoms (Z=-1.97, p=0.03), but was not significant in subjects without symptoms (Z=-0.70, p=0.48)

ORIGINAL ARTICLE - THE MAGNITUDE OF FOVEAL SUPPRESSION DURING FIXATION DISPARITY IN PRESBYOPIC PATIENTS

The characteristics of foveal suppression (FS) in fixation disparity (FD) due to visual stress were investigated and their relationship's between, age, symptoms, and the effect of temporary elimination of FD using prisms on the degree of the FS were analysed. Forty-five presbyopic subjects (15 without FD and 30 with stress related FD) participated in the study. The subjects underwent comprehensive optometric examination prior to the study. Their FS and FD were measured. The FD was later corrected with ophthalmic prisms, the power of which was equally divided between the eyes, and the FS was later verified. Age and FS had no significant correlation for subjects without FD (Spearman's rs = 0.17, p = 0.55,NS) and in subjects with FD (rs = 2.49, p = 0.19, NS), respectively. Correlation between the degree of FS and FD was weak (rs=0.38, p=0.07), however the magnitude of FD significantly increased with age (r=0.27, p=0.04). Subjects with FD had significantly larger degree of FS compared with subjects without FD (Wilcoxon's Z =-0.25, p=0.01). There was no significant difference in the magnitudes of FD (t = -0.38, p=0.07) and in their degrees of FS (Mann-Whitney U = 1.5, p=0.71) between subjects with and without symptoms. Correcting the FD with prisms generally reduced the degree of FS (Wilcoxon's Z =1.96, p=0.04), however, significant change in FS only occured in subjects with symptoms (Z=-1.97, p=0.03), but was not significant in subjects without symptoms (Z=-0.70, p=0.48)

The Changes of Tear Status after Conventional and Wavefront-Guided IntraLASIK

Background: IntraLASIK is a LASIK surgery that involved IntraLase femtosecond laser for the corneal flap creating. The objective of this research was to investigate and compare the changes in tear status at 1 and 3 months after undergoing conventional IntraLASIK with Bausch & Lomb PlanoScan (PS) algorithm, Bausch & Lomb Zyoptix Tissue Saving (ZTS) algorithm, and wavefront-guided (WG) IntraLASIK with VISX CustomVue. Methods: Tear status of 36 patients who were divided into 3 groups depending on the type of IntraLASIK they underwent (PS, n = 13; ZTS, n = 9; WG, n = 14) was evaluated. Tear status was determined by classifying the category of the thickness of pre-corneal tear lipid layer, non-invasive tear break-up time, and tear meniscus height. Repeated measures analysis of variance (ANOVA) and one way ANOVA were used for the statistical analyses. Results: The category of the thickness of tear lipid layer, non-invasive tear break up time and tear meniscus height were neither significantly changed after IntraLASIK for all groups nor showed significant difference among groups at 1 and 3 months post-IntraLASIK (P > 0.05). Blinking rate and palpebral aperture also had no significant changed after IntraLASIK. Conclusion: Both conventional (PS and ZTS) and WG IntraLASIK did not affect tear status up to 3 months post-IntraLASIK. WG IntraLASIK did not show superiority in preserving tear status 1 and 3 months post-surgery compared with conventional IntraLASIK

Macular thickness as determined by optical coherence tomography in relation to degree of myopia, axial length and vitreous chamber depth in Malay subjects.

PURPOSE: This study aimed to determine the relationship between macular thickness and spherical equivalent refraction (SER), axial length (AL) and vitreous chamber depth (VCD) in Malay subjects. METHODS: Sixty-three subjects (aged 19-24 years) with a mean SER of -1.79 ± 2.24 D, mean axial length of 24.26 ± 1.35 mm and mean vitreous chamber depth of 17.02 ± 1.33 mm were included in this clinical cross-sectional study. Stratus optical coherence tomography (Time Domain optical coherence tomography) was used to determine the thickness of the outer macular (perifovea) and inner macular (parafovea) at four different locations, that is, temporal, superior, nasal and inferior quadrants and also the fovea itself. RESULTS: Positive correlations were found between the outer macular (perifovea) thickness and SER at the temporal (R = 0.47, p \u3c 0.05), superior (R = 0.36, p \u3c 0.05) and inferior (R = 0.31, p \u3c 0.05) quadrants. Foveal thickness was also positively correlated with AL (R = 0.34, p \u3c 0.05) and VCD (R = 0.32, p \u3c 0.05). Negative correlations were found between outer macular thickness and axial length at the temporal (R = -0.46, p \u3c 0.05), superior (R = -0.27, p \u3c 0.05), nasal (R = -0.25, p \u3c 0.05) and inferior (R = -0.36, p \u3c 0.05) quadrants. Negative correlations were also found between outer macular thickness and VCD at the temporal (R = -0.51, p \u3c 0.05), superior (R = -0.32, p \u3c 0.05), nasal (R = -0.31, p \u3c 0.05) and inferior (R = -0.40, p \u3c 0.05) quadrants. CONCLUSIONS: This study shows that the degree of myopia and elongation of the globe are associated with thinning of most areas of the perifovea. A trend for foveal thickening in the high myopia group is also inferred, although this does not apply to the low and moderate myopia groups