Wide-based foveal pit: a predisposition to idiopathic epiretinal membrane

Purpose: To report the anatomical characteristics of wide-based foveal pit and its possible associations with macular diseases.

Methods: Wide-based foveal pit was defined as a foveal base width (FBW) larger than the mean value plus one standard deviation of the normal population. Eyes with a wide-based foveal pit were retrospectively collected as the study group, and age- and sex-matched subjects with a normal FBW were recruited as the control group. FBW, area of foveal avascular zone (FAZ), and retinal artery trajectory (RAT) were compared between the two groups. The characteristics of the fellow eyes in the study group were also described.

Results: Fifty-two eyes from 52 patients were identified as having a wide-based foveal pit; 43 (82.7%) were female. Both their FBW (474.7 ± 84.6 μm) and area of FAZ (0.50 ± 0.11 mm²) were significantly larger than in the control group (297.6 ± 42.3 μm and 0.29 ± 0.10 mm², respectively; p < 0.001 for both), and they also had a wider RAT than the control group (p < 0.001). During follow-up, three eyes had developed idiopathic epiretinal membrane. As for their fellow eyes, they either also had a wide-based foveal pit (11 eyes) or had various macular diseases including idiopathic epiretinal membrane (27 eyes), macular hole (5 eyes), and others (16 eyes).

Conclusions: Eyes with a wide-based foveal pit had a large FAZ and a wide RAT, and they might have a predisposition to idiopathic epiretinal membrane formation. Their fellow eyes also had a predisposition to epiretinal membrane and macular hole.