Triple Procedure for Dense Cataractus Neovascular Glaucoma Patients

Introduction Ocular ischemia due to diabetic retinopathy (DR) and central retinal vein occlusion (CRVO) are the most common causes that contribute to the development of neovascular glaucoma (NVG). Ischemic retina derived factors like vascular endothelial growth factor (VEGF) that can affect the anterior segment and initiates neovascularization in the iris (NVI), neovascularization in the angle (NVA). Aqueous outflow is obstructed when neovascular fibrous tissues block the trabecular meshwork and leads to synechial angle closure, thus NVG develops. Intraocular pressure (IOP) rise due to NVG lowers the ocular perfusion leading to further retinal ischemia, and this in turn induces more neovascularization. The management of NVG is very difficult thus; the conventional treatments such as antiglaucoma drugs, trabeculectomy, cyclophotocoagulation and cyclocryotherapy have poor success rates. It is very important to reduce the ischemic drive promptly for the treatment of NVG. Pan-retinal photocoagulation (PRP) is a mandatory and effective in resolving the ischemic condition and decreasing the vasoproliferative factors production.[ This management is particularly difficult in eyes with dense cataract. However, it is possible to overcome this difficulty by doing phacoemulsification and pars plana vitrectomy (PPV) + PRP. Moreover, phacoemulsification combined with PPV enables us to apply PRP from the posterior pole to the ora serrata peripherally. It has been known that Mitomycin C (MMC) increase the success rate of trabeculectomy in patients with NVG. Therefore, in the current study, we performed Intravitreal bevacizumab (IVB) injection, phacoemulsification, PPV + PRP and trabeculectomy augmented with subconjunctival injection of MMC.

The aim of this study is to evaluate safety and efficacy of this combined surgical procedure to alleviate retinal ischemia, reduce IOP, and improve visual acuity in dense cataractus NVG patients.

Subjects and Methods

Twelve eyes of 12 patients with NVG associated with dense cataract enough to obscure fundus visualization (7 males, 5 females) were included in the study in the period from July 2016 to August 2019 at Ophthalmology Department, Faculty of Medicine, Minia University. The patient's age ranged from 47 to 66 years with a mean age of 57.25 ± 5.9 years. The underlying cause for NVG was diabetes mellitus (DM) in 8 eyes (75%) and CRVO in 4 eyes (33.33%). Vitreous hemorrhage was present in half (50%) of the patients. The study was approved by the Local Ethical Review Committee and adhered to the tents of Declaration of Helsinki as well as all patients singed a written consent after discussion of the potential benefits and risks of this triple surgical procedures.

Preoperative examinations: Routine ophthalmological examinations were done after history taking including, age, sex, laterality, etiology of NVG and number of used anti-glaucoma drugs. The ocular examination includes estimation of visual acuity, IOP measurement with Goldman applanation tonometer, slit lamp examination of anterior segment, gonioscopy examination of angle of anterior chamber, biometry and ultrasonography. The demographic data were registered as in (Table 1).