Vitrectomy with Internal Limiting Membrane Peeling with Intravitreal Ranibizumab Injection for Patients with Central retinal Vein Occlusion with Combined Epiretinal Membrane

INTRODUCTION

A macular hole is a common macular disorder that Central retinal vein occlusion (CRVO) is one of the most common causes of visual loss in general population especially in middle age and elderly people. There are two types of vein occlusion, ischemic and non ischemic . ¹

The main complications of CRVO are cystoid macular edema (ME), ocular neovascularization and vitreous hemorrhage.² Cystoid macular edema may lead to severe visual loss the treatment of which depends mainly on anti-VEGF injections. ³

Epiretinal membranes (ERM) are formed by cellular migration and proliferation over the vitreoretinal interface. One of the causes of secondary ERM is retinal vein occlusion. ⁴

Anti VEGF injection can cause vascular endothelial cells hypoxia and increase connective tissue expression which might lead to tissue fibrosis and epiretinal membrane proliferation. ⁵ Also, ERM works like a barrier leading to a decrease in anti VEGF penetration.⁶

Depending on the above data, the usual regimen in management of CRVO represented in anti-vegf injections mayn't be efficient in patients who have

also combined ERM or even may lead to aggravation of ERM with finally fewer visual outcomes. This study discusses the role of vitrectomy with internal limiting membrane (ILM) peeling with intravitreal ranibizumab injection in patients with CRVO with combined ERM.

PATIENTS AND METHODS

A prospective cohort study conducted at Ophthalmology Department, Al-Azhar university Hospital, Egypt during the period from August 2019 till December 2020 and involved eleven patients with central retinal vein occlusion with coexisting ERM.

All participants enrolled in the research were given written consent. The approval of the research was achieved from Al-Azhar Faculty of Medicine (Research Ethics Committee (REC).

Eyes with vitreous hemorrhage, dense cataract, vitreomacular traction, previous vitreoretinal surgery, previous macular grid laser photocoagulation, uncontrolled glaucoma and other ocular lesions that could cause a decrease in vision were excluded from the study.

Methods:

preoperatively, all participants had undergone ophthalmic assessment involving BCVA converted to logMAR, anterior segment examination and fundus examination.

Fundus Fluorescein angiography and OCT assessing central macular thickness were done.

Postoperatively, the patients were examined 1 week and 1 month for BCVA in logMAR and full ophthalmic examination. OCT was done one month postoperatively.

Vitrectomy technique:

All participants underwent a standard 23 gauge vitrectomy, starting with insertion of three trocars, after that core vitrectomy was done then vitreous staining with triamcinolone acetonide followed by posterior vitreous detachment induction, then ILM staining using Brilliant Blue G together with ILM peeling reaching the vascular arcades (figure 1), then complete shaving, then pan retinal photocoagulation (PRP) (figure 2) and finally ranibizumab  injection  (0.5 mg/0.05 ml) through the trocar leaving the patient without tamponade with massaging on sclerotomies

Fig. 1:  Internal limiting membrane peeling

Fig. 2: Panretinal photocoagulation.

Statistical analysis:

Statistical Package for Social Sciences (SPSS) (version 23.0, IBM, Armonk, NY) was used to analyze data of the study. According to the type of data qualitative represented as number and percentage, quantitative represented by mean ± SD and comparison between groups was done by using Wilcoxon Test (Z). Level of significance was at p < 0.05.

RESULTS

A total of 11 eyes of 11 patients with central retinal vein occlusion with coexisting ERM were involved. Four eyes belonged to males 4(36.4%) and Seven eyes belonged to females 7(63.6%). Their age ranged from 30 to 73 years with a mean of 58.27 ± 12.83. The eleven eyes were 7(63.6%) right, and 4(36.4%) left (Table 1).

Table 1: Demographic data of patients

Regarding co-morbidity, there was ten patients (90.9%) had hypertension and two (18.2%) had diabetes mellitus (Table 2).

Table 2: Distribution of comorbidities in patients

There was a decrease in the 1-Week postoperative IOP (18.82±1.471) than preoperative IOP (19.09± 1.375), IOP continued to decrease progressively until the end of the 4-Week follow-up period (11.09 ± 1.30) that was lower than preoperative and one-week postoperative. However, the decrease in the IOP preoperatively and postoperatively wasn’t statistically significant (Table 3).

Z1, P1: Preoperative VS 1Week post, Z2, P2: Preoperative VS 4 Week post, Z3, P3: 1Week post VS 4 Week post

Table 3: Preoperative IOP versus one week and four weeks postoperatively

There was a significant reduction in one-week postoperative BCVA in log Mar (1.064±0.258) than preoperative (1.245±0.221) (𝑃=0.003). BCVA in log Mar continued to improve progressively until the end of the four-week follow-up period (0.718±0.316) that was statistically significantly lower than preoperative (𝑃 = 0.003) and one-week post-operative (𝑃 = 0.003) (Table 4), (figure3).

Z1, P1: Preoperative VS 1Week post, Z2, P2: Preoperative VS 4 Week post, Z3, P3: 1Week post VS 4 Week post

*: p value

Table 4: Preoperative BCVA in log Mar versus one week and four weeks postoperatively

Fig. 3: Preoperative BCVA in log Mar versus one week and four weeks postoperatively

There was a statistically significant decrease in the four-week postoperative CMT (357.73±133.094) than preoperative CMT (497.27±225.420) (𝑃=0.003) (Table 5), (figure 4).

*: p value

Table 5: Preoperative CMT versus four weeks postoperatively

Fig. 4: Preoperative CMT versus four weeks postoperatively

Fig. 5: Case 1: (A); Preoperatively, patient with CRVO with ERM together with macular edema. (B); Postoperatively, the macular edema markedly regressed.