First Author: E.Kontou GREECE
Co Author(s): D. Alonistiotis N. karachalios N. Tsilimpokou A. Takis P. Stavrakas P. Theodossiadis 0 0 0 0 0 0 0 0 0
To study the incidence of Cystoid Macular Edema (CME) after phacoemulsification in non-diabetic patients that had prior undergone vitrectomy.
2nd Department of Ophthalmology, University of Athens, “Attikon” Hospital, Athens of Greece
Prospective, case series, interventional clinical study. 23 eyes that had previously undergone vitrectomy - 6 for Macular Hole (MH), 7 for Epiretinal Membrane (ERM), 10 for Retinal Detachment (RD) - and needed cataract surgery afterwards, were compared with 45 patients who underwent phacoemulsification only (control group, CG). Measurement of Visual Acuity (VA) and Optical Coherence Tomography (OCT, Stratus 3000, Zeiss) were performed before cataract surgery, one week and one month after phacoemulsification. Central Foveal Thickness (CFT) from the macular thickness map analysis was measured in both groups. Exclusion criteria were diabetus mellitus and other vascular and degenerative diseases of the retina. All patients underwent blood glucose level test for exclusion of undiagnosed diabetes.
From the study group 2/23 (8.7%) developed CME, against 1/45 (2.2%) from the CG (p<0.05). 2/23 (8.7%) vitrectomized eyes had ocular lens capsule rupture during phacoemulsification versus 2/45 (4.5%) from the CG. Both patients who developed CME from the study group had been previously operated for RD. None of the patients that had been previously operated for MH and ERM developed CME. Both vitrectomized patients developed CME 15 days postoperatively and had impressive improvement after one parabulbar injection of triamcinolone. The non-vitrectomized patient from the control group developed CME one month after surgery and had a good response to initial therapy but had recurrence of CME after one month and needed a second parabulbar injection.There was no statistically significant difference in the central foveal thickness between the 2 groups pre- and postoperatively. The total average visual acuity in the vitrectomized group was 0.27 before vitrectomy and 0.2 before phacoemulsification and 0.49 and 0.54 respectively post-operatively. In the CG the average visual acuity was 0.23 pre-operatively and 0.82 post-operatively. Visual acuity was statistically significantly higher postoperatively in both groups compared to preoperative VA and also higher postoperatively in the CG compared to the study group.
The absence of vitreous body predisposes for increased rates of complications during phacoemulsification. The incidence of CME in vitrectomized eyes undergoing phacoemulsification has not been adequately studied. In our study appears to be significantly higher compared to normal patients undergoing phacoemulsification. This is in agreement with other studies showing increased rate of CME in patients undergoing phacoemulsification after vitrectomy for ERM. To our knowledge, there has not been another recent study comparing all three types of vitrectomized non-diabetic patients to normal subjects undergoing cataract surgery. It seems that the absence of the biochemical barrier of the vitreous body predisposes to increased rates of postoperative CME, while at the same time the absence of mechanical traction to the macula reduces the severity of the CME and increases the response to standard therapy. Injury of the lens capsule during vitrectomy also predisposes to rupture at a later cataract surgery.