RESUMO
AIM: (1) To compare optical coherence tomography (OCT) parameters between amblyopic eyes and fellow eyes in patients presenting with anisometropic amblyopia. (2) To find OCT factors predicting the outcomes of occlusion therapy. MATERIALS AND METHODS: This prospective study was conducted in a tertiary eye care center for a period of 20 months. Fifty-four children diagnosed with anisometropic amblyopic were included in the study. After complete ophthalmic and OCT examination, patients were advised to undergo occlusion therapy with large spectacle patch. Patients were reviewed after 6 months to record improvement in visual acuity and analyze their OCT parameters. Statistical tests used were paired "t" test and independent "t" test. RESULTS: The mean age of 54 study patients was 9.24 ± 2.82 years. For comparison of OCT parameters, they were classified as myopic (22 patients), hypermetropic (24 patients), and astigmatic (8 patients) groups. In the anisomyopic amblyopia group, the mean inner macular thickness was significantly increased in fellow eyes (304.09 ± 11.06 µm) compared to amblyopic eyes (297.59 ± 14.16 µm). In the anisohyperopic amblyopia group, the outer macular thickness significantly increased in amblyopic eyes (286.43 ± 18.63 µm) when compared to fellow eyes (272.62 ± 14.90 µm). In the follow-up visit, 28 patients showed improvement and 6 patients did not show improvement in final best-corrected visual acuity, and the OCT parameters in amblyopic eyes of these two groups did not differ significantly. CONCLUSION: Abnormal experience in early life does not affect the maturation process of retinal layers as evident by OCT parameters, and these parameters cannot predict the outcomes of occlusion therapy.
RESUMO
Purpose: To describe the influence of corrected refractive error on measured torsional fusional amplitudes (TA) by comparing the TA between emmetropes and spectacle corrected myopes, using the after-image slides of the synoptophore, as targets. Methods: Fifty emmetropes (Group I) and 50 myopes (Group II) with best-corrected acuity of 6/6 in each eye were included in the study. Near point of convergence (NPC), near point of accommodation (NPA), and horizontal fusional amplitudes (HFA) were assessed in all the subjects. After-image slides, both horizontally aligned, were used as targets (without the bright flashes). One of the slides was rotated inwards, till cyclo-diplopia was reported by the subject; the procedure was repeated with the slide rotated outwards. The sum of the two readings was taken as TA. NPC, NPA, HFA, and TA were analyzed. Results: There was no significant difference in the NPC, NPA, and HFA between the two groups. The emmetropic subjects had significantly better torsional amplitude (8.4 ± 1.4 degrees) compared to myopes (7.7 ± 1.5 degrees, P = 0.03). We postulate that this difference may be due to perceived image minification, which brings the edges of retinal image of the targets closer to the fovea, thus rendering the myopes lesser tolerant to cyclodiplopia than emmetropes. Conclusion: Refractive error, corrected with spectacles, influences the measured TA. Myopic subjects have lesser torsional fusional amplitude than emmetropes.
