PURPOSE: The purpose of our study was to assess the macular thickness and the electrophysiological changes in keratoconic patients without any systemic or ocular disorders. METHODS: 64 eyes of 32 keratoconus patients as well as 60 eyes of 30 controls participated in the study. All participants underwent a complete ophthalmological examination, including best-corrected visual acuity (BCVA) assessment, color vision testing, fundus examination, intraocular pressure measurement, central foveal thickness (CFT) measurement by optical coherence tomography (OCT) scan, and multifocal-electroretinogram (mf-ERG) recording. CFT, retinal response density (RRD) and P1 latency were measured. RESULTS: There was no statistically significant difference between the two groups concerning CFT and P1 latency in mf-ERG. The RRD in mf-ERG differed significantly between keratoconus patients and controls. Of note, BCVA was positively associated with RRD in keratoconus patients. CONCLUSION: In some cases of keratoconus, a macular dysfunction not visible ophthalmoscopically may coexist and the low visual acuity could be due not only to the corneal abnormality, but also to the photoreceptor dysfunction. As a result, the preoperative electrophysiological study of patients with keratoconus is crucial to avoid a needless corneal transplantation.
PURPOSE: The purpose of our study was to assess the macular thickness and the electrophysiological changes in keratoconic patients without any systemic or ocular disorders. METHODS: 64 eyes of 32 keratoconus patients as well as 60 eyes of 30 controls participated in the study. All participants underwent a complete ophthalmological examination, including best-corrected visual acuity (BCVA) assessment, color vision testing, fundus examination, intraocular pressure measurement, central foveal thickness (CFT) measurement by optical coherence tomography (OCT) scan, and multifocal-electroretinogram (mf-ERG) recording. CFT, retinal response density (RRD) and P1 latency were measured. RESULTS: There was no statistically significant difference between the two groups concerning CFT and P1 latency in mf-ERG. The RRD in mf-ERG differed significantly between keratoconus patients and controls. Of note, BCVA was positively associated with RRD in keratoconus patients. CONCLUSION: In some cases of keratoconus, a macular dysfunction not visible ophthalmoscopically may coexist and the low visual acuity could be due not only to the corneal abnormality, but also to the photoreceptor dysfunction. As a result, the preoperative electrophysiological study of patients with keratoconus is crucial to avoid a needless corneal transplantation.