[Vitreoretinal surgery in Oman]

Abstract

Purpose: Vitreoretinal diseases in Middle Eastern countries currently rank in importance behind cataract, trachoma and glaucoma. This study reports on the most frequent causes of vitreoretinal diseases and the results of vitreoretinal surgery in Oman in order to gain insights into requirements in training and equipment.

Methods: Demographic data and biomicroscopic examinations were performed over a 5-year period. Pars plana vitrectomies were carried out with the Accurus 800CS (Alcon) and EyeLite® 532 nm Laser (Alcon), endotamponade with silicone oil 5600 cs (adatomed) or C₃F₈ Ispan (Alcon), oval silicone sponge scleral buckles 5.5 x 7.5 mm type 507 (Geuder®) in adults and oval silicone sponge scleral buckles 3.0 × 5.0 mm type 506 (Geuder®) in children (up to 12 years) were sutured with Mersilene parallel to the limbus. Patients were followed after 4 weeks and 1 year. Evaluation of data was done by descriptive statistics (Fisher exact and χ²-tests).

Results: From 2002 to 2006, 2,910 vitreoretinal surgeries were performed on 784 adult and 101 pediatric eyes. Main indications were proliferative diabetic vitreoretinopathy (PDVR) (229/784 eyes=29%), followed by trauma (166/784=21%), and PVR retinal detachment (112/784=14.3%) in adults and in children the main indication was trauma (73/101 eyes=73%). The postoperative vision in adults with trauma, PVR retinal detachment, epiretinal gliosis and IOL extraction was significantly different and better (p=0.003, p=0.044, p=0.029, p=0.001, respectively) and the postoperative vision in PDVR with uncontrolled diabetes mellitus II significantly different and worse (p=0.001). Of the eyes with PDVR in uncontrolled diabetes mellitus 165 out of 229 (72%) lost distance vision (p=0.00014). All patients with serious macular edema and an HbA(1c) of ≥9.5% lost 5 m distance in vision. The mean HbA(1c) in all patients who experienced postoperative blindness was 13.5%. Postoperative vision was significantly better in children operated for trauma complications (p=0.046) whereby patients with contusion of the globe had a significantly better final result (p=0.0302) than patients with penetrating injuries. Revision surgery was indicated most frequently after surgery for proliferative vitreoretinopathy due to prior retinal detachment surgery.

Conclusions: The most frequent causes of preventable retinal blindness in Oman are pediatric trauma and advanced diabetic vitreoretinopathy. Eyes operated for trauma had a better outcome than PDVR in patients with uncontrolled diabetes mellitus. The large number of eyes with PDVR in the final stages and sequelae of trauma legitimates preventive medical measures and an expansion of vitreoretinal services with supportive external training of specialists and allied health professions.