Changes in the morphofunctional parameters of the eye in neovascular glaucoma on the after vitreoretinal surgery

Abstract

Purpose : to assess morphological and functional parameters of the eyeball in patients with neovascular glaucoma (NVG) and diabetic macular edema (DME) after vitreoretinal interventions. Material and methods . This study involved 60 patients (60 eyes), aged 59 ± 12 including 34 men and 26 women. The patients were divided into three groups: group 1 — 19 patients (19 eyes) with NVG and DME after a vitreoretinal surgery (VRS) for proliferative diabetic retinopathy performed no earlier than a year ago. If DME was found within 6 months after the surgery, a drug was administered intravitreally (3 loading injections given with monthly intervals). The patients’ history contained cataract phacoemulsification with an implantation of an intraocular lens (IOL). Group 2 (23 patients, 23 eyes) consisted of persons with stage III primary open-angle glaucoma (POAG) with the duration of the glaucomatous process of up to 5 years, who received no laser or surgical antiglaucomatous interventions. The history of these patients also contained phacoemulsification operations with IOL implantation. Group 3 (18 patients, 18 eyes), which was composed of patients with pseudophakia but no symptoms of glaucoma or other eye pathology, served as control. Results . The opening of the anterior chamber angle (ACA) in NVG (group 1) was 2.73 times smaller (p = 0.034) than in POAG (Group 2) and 3.69 times smaller than in the control group (p = 0.034). Neovascularization of the iris and the ACA could primarily be seen in patients with NVG (84 %). Goniosynechiae in the ACA of group 1 patients were seen 6.35 times more often than in group 2 patients and 14.45 times more often than in group 3 patients. Rubeosis occurred in group 1 patients 4.65 times as often as in group 2 and 6.64 times more often than in group 3 patients (p = 0.034). Statistically significant differences of morphometric parameters of the optic disc between groups 1 and 2, on the one hand, and group 3, on the other hand were found. Meanwhile, the figures for groups 1 and 2 were statistically comparable, which is explained by the same degree of severity of the glaucomatous process in these groups. The analysis of indices of computer perimetry MD, MS and sLV showed a developed glaucomatous process in groups 1 and 2. The revealed changes are based on pathognomonic factors. In particular, they may be caused by the prior surgical intervention affecting the vitreoretinal interface in group 1 patients. Conclusion . The onset of NVG is primarily caused by a grave course of proliferative diabetic and changes in the ACA profile, due to the formation of synechiae. Regardless of the risk factors, the result of surgical treatment depends on the condition of the ischemic retina and the anterior segment of the eye. Thus, the assessment of the morphofunctional parameters of the eye in patients with NVG and DME after VRS is of great interest. Changes in such parameters as the degree of openness of the ACA, distance from the iris to the IOL, the presence of rubeosis and synechia may be used to determine the methods and tactics of surgery, which will eliminate the pathophysiological factors of the onset and progression of CVH, and reduce postoperative complications.