Background: Former reports on amblyogenic refractive errors, amblyopia and binocular vision in congenital ptosis usually comprise all forms of ptosis without any differentiation. This study is an analysis of different kinds of ptosis.
Patients and methods: 154 eyes (98 ptotic eyes) of 77 patients with congenital ptosis aged > or = 1 year (56 unilateral ptoses: 45 simple, 1 with rectus superior paresis, 7 with Marcus Gunn's syndrome, 2 congenital oculomotor palsies, 1 unilateral fibrosis syndrome; 21 bilateral ptoses: 10 simple, 2 with bilateral double elevator paresis, 7 blepharophimosis syndromes and 2 bilateral fibrosis syndromes) were investigated concerning visual acuity, refractive error (94 % in cycloplegy), strabismus and stereo acuity. As amblyogenic refractive errors were defined: astigmatism > or = ldpt, anisometropia > or = 1 dpt (spherical equivalent) and hyperopia > or = 3 dpt; amblyopia was defined as visual acuity less than 1.0 or a difference between both eyes of at least 0.2.
Results: Altogether were found: Hyperopia > or = 3 dpt in 28.6 % (n = 28); astigmatism > or = 1 dpt in 63.3 % (n = 62), anisometropia in 27.3 % (n = 21), amblyopia in 65.3 % (n = 64), strabismus in 29.9 % (n = 23) and stereopsis in 76.6 % (n = 59). In unilateral simple ptosis, astigmatism of the fellow eye was found in 26.8 % (n = 14). In unilateral ptosis, esotropia was 21.4 % (n = 12), in bilateral ptosis, exotropia 19 % (n = 4), as well as astigmatism > or = 3 dpt 26.2 % (n = 11). As was to be expected, ptosis groups with motility disorders were associated with higher rates of strabismus and amblyopia. The blepharophimosis syndrome could be differentiated by the typical lid anomalies.
Conclusion: The subgroups of congenital ptosis differ in frequency of amblyogenic factors. In unilateral ptosis these are also frequent in the fellow eye.