Silicone oil in the repair of complex retinal detachments. A prospective observational multicenter study.

OBJECTIVE: This study aimed to report anatomic and visual acuity outcomes and complications after 1000-centistoke silicone oil was used as a retinal tamponade for the treatment of complex retinal detachments. DESIGN: Prospective observational multicenter study conducted at community and university-based ophthalmology clinics. PARTICIPANTS: The study cohort consisted of 2439 patients (2573 eyes) treated for complex retinal detachments associated with cytomegalovirus (CMV) necrotizing retinitis or a non-CMV etiology, including proliferative diabetic retinopathy, giant retinal tears, proliferative vitreoretinopathy, or ocular trauma. INTERVENTION: Vitrectomy surgery was performed for complex retinal detachment with 1000-centistoke silicone oil as the retinal tamponade. MAIN OUTCOME MEASURES: Anatomic outcomes were complete retinal attachment and macular attachment. Visual acuity outcomes were ambulatory vision (> or = 4/200) and preservation of preoperative visual acuity. Complications were rates of secondary intraocular pressure elevation (> or = 30 mmHg), hypotony (< or = 5 mmHg), corneal opacification (including band keratopathy, corneal edema, and corneal abrasions), oil emulsification, and cataract. Outcomes were assessed 6, 12, and 24 months after surgery. RESULTS: At the 6-month examination, the retina was completely attached in 178 (78%) of 228 CMV eyes and in 855 (70%) of 1219 non-CMV eyes. The macula was attached in 216 (95%) of 228 and 1062 (89%) of 1189 CMV and non-CMV eyes, respectively. Ambulatory vision was noted in 151 (65%) of 234 CMV eyes and in 480 (38%) of 1251 non-CMV eyes. Visual acuity was preserved in 106 (46%) of 230 and 1035 (84%) of 1229 CMV and non-CMV eyes, respectively. The corresponding rates of complications for CMV and non-CMV eyes were: elevated intraocular pressure, 0 (0%) of 196 and 35 (3%) of 1196; hypotony, 11 (6%) of 196 and 228 (19%) of 1196; corneal opacity, 13 (6%) of 229 and 326 (26%) of 1248; emulsification, 3 (1%) of 211 and 29 (3%) of 959; and cataract in phakic eyes, 118 (64%) of 185 and 50 (63%) of 80. CONCLUSIONS: Retinal reattachment was achieved in the majority of eyes using vitrectomy and silicone oil retinal tamponade. Complication rates generally were less frequent in CMV eyes, but follow-up was shorter in this group of patients, largely because of reduced life expectancy. Cataract frequently developed in phakic eyes of study patients. Use of 1000-centistoke silicone oil can be considered in the management of complex retinal detachments associated with multiple etiologies.

Detection of air emboli in radiographic contrast media by microwave radiometry.

To evaluate the efficacy of a microwave radiometry system in detecting in-line air emboli in radiographic contrast media, air emboli ranging in volume from 0.1 to 0.005 ml were introduced into ionic (ioxaglate) and nonionic (iohexol) contrast media at 22 or 37 degrees pumped at flow rates of 16.7, 180 or 300 ml/min through polyvinlychloride tubing with an inner diameter of 0.100 inches (2.54 mm) over which was fitted a radiometer antenna connected to a Microwave Medical System F+ radiometer and a computerized data acquisition system. A total of 400 determinations were run, with 10 replicate determinations for each unique set of experimental conditions. The success of air emboli detection was not significantly related to contrast media (p = 0.73) or contrast temperature (p = 0.68). Embolus volume (p < 0.0001) and pump speed (p < 0.0001) were significant factors affecting system performance. The system could reliably detect small (0.005 ml) emboli in both ionic and nonionic low-osmolar contrast media.