gms | German Medical Science

Background: The foveal pit is a depression of the retina in the region of the fovea with disputed functional significance. There is a controversial discussion in the literature about the effects of an absence of the foveal pit on central visual acuity.

Method: We report on four patients (5, 16, 18 and 47 years, all female) that visited our clinics due to an impaired vision and that revealed an absent foveal pit. Patients were examined by optical coherence tomography (OCT) and multifocal electroretinography (mfERG). We only included patients without further defects in the retina, such as oedema, epiretinal membranes or degenerations.

Results: Three patients had diseases not directly associated to the retina (Cornea guttata, optic nerve atrophy and neuritis nervi optici), and in one patient only foveal pit was absent without further defects. No patient was albinotic. All retinal layers could be identified in the OCT image. Visual acuity ranged between 0.6 and 0.08. Retinal function measured by mfERG was reduced in the fovea, leading to a reduction of the amplitude compared to normal values. In some cases, amplitude was reduced also in perimacular regions. Recorded mfERG amplitudes were decreased to a different extent, differed between the right and the left eyes and showed no correlation to visual acuity.

Conclusion: The absence of the foveal pit leads to a reduction of the electrophysiological activity of the foveal region of the retina. Visual acuity cannot be predicted based on these data.