Unintentional Displacement of the Retina after Standard Vitrectomy for Rhegmatogenous Retinal Detachment

Objective: To study unintentional displacement of the retina after standard vitrectomy for rhegmatogenous retinal detachment (RRD). Design: Prospective interventional case series. Participants: Forty- three eyes of 43 consecutive patients with cystic RRD involving 1 or more quadrants underwent successful standard vitrectomy with 20% sulfur hexafluoride gas injection. Neither scleral buckling nor retinotomy was performed. Methods: Fundus autofluorescence (FAF) imaging was subsequently recorded to detect displacement of the retina using the Topcon TRC- 50DX (Topcon, Tokyo, Japan) at 10 days and 1, 3, and 6 months postoperatively. Fluorescein angiography was also recorded using standard techniques for patients with abnormal FAF findings. Cyclotorsion and vertical deviation were measured postoperatively. Main Outcome Measures: The proportion of eyes with postoperative retinal displacement detected by FAF imaging. Results: The mean age of these 43 patients was 60 years with a range of 39 to 77 years. Of the 43 eyes, retinal detachment involved 1 quadrant in 2 eyes, 2 quadrants in 31 eyes, 3 quadrants in 8 eyes, and 4 quadrants in 2 eyes. After complete reattachment of the retina, FAF photography demonstrated hyperfluorescent lines superiorly parallel to retinal vessels within the vascular arcade in 27 of the 43 eyes (62.8%). Fluorescein angiography did not demonstrate any abnormalities corresponding to the linear autofluorescence. This autofluorescence was hypothesized to originate from increased metabolic activity of the retinal pigment epithelium that had been preoperatively located under the major retinal vessels and was postoperatively exposed to light because of downward displacement of the retina. Of the 27 eyes with retinal displacement, 1 to 5 degrees of extorsion were seen in 16 eyes (59.3%), and 1 to 4 degrees of vertical deviation were seen in 13 eyes (48.1%). None of the 27 patients had diplopia or slant. The extent of retinal detachment (P = 0.019) and the macular status (on or off) (P = 0.016) were significantly associated with postoperative displacement of the retina. Conclusions: In eyes with RRD treated with standard vitrectomy and gas injection, the retina may move downward after the surgery. If the extent of retinal detachment is large, or macular detachment is present, unintentional postoperative retinal translocation may easily occur.