Glaucoma after pars plana vitrectomy and silicone oil injection for complicated retinal detachments

Objective: To determine the incidence and associations of glaucoma after pa rs plana vitrectomy (PPV) and silicone oil injection (SOI) for complicated retinal detachments and the response to treatment. Design: Retrospective noncomparative case series. Participants: A total of 150 eyes of 150 patients who had completed a minim um of 6 months of follow-up were included in this study. Analysis included clinical records of all consecutive cases of complicated retinal detachment that underwent PPV with SOI between July 1991 and February 1996. Intervention: Surgical intervention for vitreoretinal pathology included st andard three-port PPV and additional procedures as appropriate for the reti nal pathology, and SOI, Procedures for the control of glaucoma were silicon e oil removal (SOR), trabeculectomy with mitomycin C, cyclocryotherapy, sem iconductor diode laser contact transscleral cyclophotocoagulation (TSCPC) a nd anterior chamber tube shunt to encircling band (ACTSEB). Main Outcome Measures: Presence of glaucoma (predefined as intraocular pres sure [IOP] greater than or equal to 24 mmHg, which also was greater than or equal to 10 mmHg over the preoperative level, sustained for greater than o r equal to 6 weeks) and the result of medical and surgical management were the main outcome measures. Demographic, preoperative, intraoperative, and p ostoperative parameters including the age of the patient, etiology of retin al detachment, refractive status, preexisting glaucoma, aphakia, diabetes m ellitus, presence of silicone oil (SO) in the anterior chamber, emulsificat ion of SO, rubeosis iridis, and anatomic success were evaluated by univaria te and multivariate logistic regression analyses to assess their predictive Value in the causation of glaucoma and to determine factors prognosticatin g response to treatment. Results: The main indications for PPV+SOI were proliferative vitreoretinopa thy (57%; 85 of 150), proliferative diabetic retinopathy (15%; 23 of 150), and trauma (14%; 21 of 150). Glaucoma occurred in 60 eyes (40%) at 14 days median (range, 1 day-18 months). Elevation of IOP could be attributed direc tly to SO in 42 (70%) eyes. Glaucoma was controlled in 43 (72%) of 60 eyes on treatment (with medicines alone in 30%, SOR and medicines in 25%; trabec ulectomy with mitomycin C/ACTSEB/cyclocryotherapy or TSCPC in 17%); 28% (17 of 60) remained refractory. independent predictive factors for glaucoma on multivariate analysis were rubeosis iridis (odds ratio, 10.76), aphakia (o dds ratio, 9.83), diabetes (odds ratio, 6.03), SO in anterior chamber (odds ratio, 4.74), and anatomic failure (negative risk factor; odds ratio, 0.11 ). Poor prognostic factors for the control of glaucoma were SO emulsificati on (odds ratio, 15.34) and diabetes (odds ratio, 6.03). Conclusion: Glaucoma is a frequent and often a refractory complication of P PV with SO( and has a multifactorial etiology. Aggressive medical and surgi cal management with SOR, trabeculectomy with mitomycin C, glaucoma shunts, and cyclodestructive procedures shows modest success in controlling IOP.