The prevalence of refractive errors and corneal topographic changes in unilateral congenital ptosis versus the fellow eye- A cross-sectional study

The drooping upper eyelid in ptosis induces pressure on the eyelid and the same has been implicated to induce refractive errors. Very limited literature is available on the actual prevalence of corneal topographic changes and refractive errors seen in ptosis. Aim of this study was done to examine the effect of pressure of the upper eyelid on refractive errors and corneal topography in ptotic eyes and its comparison with fellow normal eyes. This was a cross-sectional observational study and included 83 patients with unilateral congenital ptosis. The study was conducted at NavJyoti Eye Hospital, Gorakhpur, Uttar Pradesh from Jul 2021- Feb 2023. Only unilateral cases of simple congenital ptosis were included in the study. Ptosis was evaluated to classify it into mild, moderate and severe. Retinoscopic refraction and corneal mapping for topography were done to get keratometric data, refractive errors, astigmatism and topographic patterns. The observations in ptotic eyes were compared with those in fellow normal eyes. Data was analyzed using the Statistical Package for Social Sciences (SPSS) version 20. P- value of < 0.05 was considered significant. Around 18 (21.69%) patients were found to have mild ptosis, 30 (36.14%) showed moderate and 35 (42.17) participants had severe ptosis. 16 (19.28%) ptotic eyes had myopia as compared to 10 (12.05%) non-ptotic eyes. 14 (16.86%) ptotic eyes were hyperopic as compared to 2 (2.41%) non-ptotic eyes. 38 (45.78%) ptotic eyes showed significant astigmatism (refractive) as compared to 5 (6.02%) non-ptotic eyes. 48 (57.83%) of ptotic eyes had significant Sim K (topographic) astigmatism as compared to 24 (28.92%) non-ptotic eyes. The prevalence of refractive errors was found to increase with the severity of ptosis. The majority of ptotic eyes 44 (53.01%) showed symmetrical bow tie pattern on corneal imaging (topography) whereas the most common pattern seen in non-ptotic eyes was round 33 (39.76%). Pressure from the upper eyelid in congenital ptosis induces significant corneal topographic changes and errors of refraction. Meticulous refraction and corneal topography should be done in all cases of congenital ptosis to timely detect astigmatism and suitable corrective measures should be instituted to prevent the development of amblyopia.