Abstract
Abstract: :
Purpose: Iatrogenic retinal breaks associated with 20–gauge pars plana vitrectomy (PPV) can have serious consequences. This study aimed to determine whether 25–gauge PPV system is associated with a different rate of retinal breaks in a major teaching center. Methods: We conducted retrospective, case–matched chart review of the first 50 consecutive eyes that underwent 25–gauge PPV for macular hole (18), epiretinal membrane (17), vitreomacular traction (5), lensectomy (2), vitreous hemorrhage (2), tractional retinal detachment (1), rhegmatagenous retinal detachment (1), endophthalmitis (1), branch retinal vein occlusion (1), asteroid hyalosis (1), and malignant glaucoma (1). These cases were matched with 50 eyes that underwent conventional 20–gauge PPV preceding the introduction of the 25–gauge system. The rate of iatrogenic retinal breaks in 25–gauge system was compared with the rate in 20–gauge system. All surgeries were supervised by a single vitreoretinal surgeon in the same institution. Results: The average age (69), indications and pre–operative risks factors for surgical complications were similar in both cohorts. The average initial visual acuity (VA) was 20/250 in the 20–gauge group and 20/300 in the 25–gauge group. In the 20–gauge group, 22% developed iatrogenic peripheral retinal breaks. Out of 11 eyes that developed breaks, 4 eyes had concurrent retinal detachment. 9 eyes were diagnosed intraoperatively and 2 eyes within 1 week of surgery. 4 eyes received laser retinopexy or cryopexy, 2 eyes were treated with pneumatic retinopexy, 4 eyes underwent scleral buckling and 1 eye required oil. Peripheral breaks most frequently occurred at the site of vitrectomy probe insertion. Macular hole surgery was associated with a significantly higher incidence of retinal breaks (27%) than epiretinal membrane peeling (14%). In the 25–gauge system, none of the 50 eyes had iatrogenic retinal breaks. At 1 month, the average VA was still worse than preoperative VA at 20/400 (p=0.06) in the 20–gauge cohort and slightly improved at 20/160 (p=0.025) in the 25–gauge cohort. At post–operative day 1 and week 1, the intraocular pressures were elevated to 24 mmHg (p < 0.0001) and 21 mmHg (p < 0.001) respectively in the 20–gauge cohort. The average postoperative intraocular pressures remained unchanged at 16 mmHg in the 25–gauge cohort. Conclusions: Based on these series, 25–gauge system PPV is safer than 20–gauge in a major teaching institution. This may partially be due to smaller size of instruments and the protective effect of trocars. The patients experienced faster recovery of vision and less perioperative elevation in intraocular pressure.
Keywords: vitreoretinal surgery • retinal detachment • retina