Electrogenesis of Retina and Optic Nerve after Vitrectomy for the Primary Full-Thickness Macular Hole

Abstract

Purpose. To study the dynamics of electrophysiological parameters of the retina and optic nerve after vitrectomy for a primary fullthickness macular hole. Patients and Methods. Electrophysiological examination was performed in 40 patients (40 eyes) before vitrectomy, on the 1st, 3rd, 7th, 14th, 30th, 60th, 180th day after the operation. Three groups of patients were formed depending on the intraocular tamponade: the first group — air tamponade, the second group — gas (C3F8) tamponade, the third group — silicone oil tamponade. Results. In the first, second and third groups significant decrease in the retinal and optic nerve electrogenesis was revealed on the 1st day (p < 0.001) after vitrectomy. By the end of observation period all electrophysiological indices in the first, second and third groups recover to normal levels, excluding the retinal cone system and optic nerve parameters in the third group. Electrophysiological indices recovered twice as slow in the second group, compared to the first group, due to C3F8 gas tamponade inhibitory effect. In the first and second groups the photoreceptors recovered twice as fast as bipolar cells. Conclusions. Vitrectomy causes significant inhibition of photoreceptors, bipolar and ganglion cells electrogenesis. The duration of vitrectomy is a significant negative factor determining retinal and optic nerve electrogenesis inhibition in the postop. Intraocular C3F8 gas, silicon oil tamponade (compared to air tamponade) is a significant adverse factor affecting retinal and optic nerve electrogenesis inhibition in the postop. The primary full-thickness macular hole diameter is a significant factor in inhibiting electrogenesis of the retinal cone system. Photoreceptors have a greater rehabilitation ability than bipolar cells.

Keywords

• vitrectomy
• visual evoked potentials
• idiopathic macular hole
• electroretinogram
• electrophosphen