Purpose: To establish differences between the frequency of suspected deprivation myopia in unilateral and bilateral congenital ptosis with and without covered optical axis.
Methods: Ametropia was evaluated in both eyes of 95 patients with congenital ptosis. The amount of refraction was documented as spherical equivalent (100% cycloplegia). Statistical analysis was performed using the chi-square and sign tests.
Results: In unilateral ptosis, the frequency of myopia was lower (10/68: 15%) than that of hyperopia (58/68: 85%) in the ptotic eye (P <0.001). However, myopia occurred more often in the ptotic eye (10/68: 15%) than in the fellow eye (3/68: 4.4%). Myopic anisometropia was found only in the ptotic eye (5/68 vs 0/68), but was less frequent than hyperopic anisometropia (6/68 vs 8/68). In bilateral ptosis 7/54 myopia as compared with 47/54 hyperopia were observed and 1/27 myopic anisometropia vs 6/27 hyperopic anisometropia. Covered center of the pupil, in children < or = 8 years of age, was associated with myopia more frequently in bilateral than in unilateral ptosis (6/30 vs 1/27). We found a significantly higher rate of myopia <-1 diopter and hyperopia >2 diopter in comparison of children 5 to 7 years old with first-grade school children.
Conclusions: Two expected results were (1) compared with the normal population, an overall higher frequency of myopia in human congenital ptosis; (2) in unilateral ptosis, a higher frequency of myopia in the ptotic, than in the fellow eye.