Abstract

VISUAL EVOKED POTENTIALS AFTER GLAUCOMA FILTRATION SURGERY

*Dua'a T. Daradkeh, MD, Mohannad Q. Al-Bdoor MD, Ahmed E. Khatatbeh, MD, Mousa V. Madani, MD and Feda’ A. Al Smadi, MD

ABSTRACT

Aim: to determine if there is functional improvement in optic nerve function manifested as change in visual evoked potentials (VEP) after glaucoma surgery. Methods: this is a prospective study performed at King Hussein Medical Center. All patients known to have open angle glaucoma and planned for surgery were included in the study. After taking detailed history including demographic features of the patients and past medical and ocular history, ocular exam was performed including visual acuity, anterior and posterior segment exam and intra ocular pressure measurement. VEP and OCT of the optic nerve was performed immediately before surgery and at 1,3- and 6-months post-surgery. Patients with retinal and optic nerve diseases not related to glaucoma were excluded from the study. Patients with IOP reduction not exceeding 40% of the original IOP were excluded from the study as well. The results will be compared with each other and analyzed. Results: One hundred patients aged between 45 and 74 years (mean 54±12 years) were included in the study. 58% of them were males. The mean IOP before surgery was 36 mmHg which improved to 19, 16 and 14 at 1,3 and 6 months respectively. The mean N75 and P100 latency was 79.1 and 108.0 before surgery and 79.9 and 108.6 at 6 months after surgery respectively. In patients with advanced cupping mean N75 and P100 latency was 82.1 and 110.9 before surgery and 84.2 and 114.7 at 6 months after surgery respectively. Conclusion: There was no significant improvement in VEP parameters after filtration surgery. Degree of cupping was a good indicator of severity of ganglion cells damage and VEP showed worsening of its parameters in patients with advanced cupping.

Keywords: Filtration surgery, Glaucoma, VEP.