Korean J Ophthalmol Vol.25, No.6, 2011 nade was used during the primary surgery. Perfluorocarbon was used in 48 of the 92 eyes during the vitrectomy. Post-operatively, 24 eyes (22.6%) underwent re-operation due to recurrence of RD. Ten eyes had repeat vitrectomies, eight eyes had vitrectomies with silicone oil tamponade, and six of the eyes had fluid-gas exchange. Silicone oil was used for the long-standing tamponade according to the surgeon’s preference and the removal of the silicone oil was performed in four of the eyes one year from the date of the last surgery. Three of the four eyes that underwent silicone oil removal achieved final and complete retinal attachment. The remain- ing eye that had the silicone oil removal received a sili- cone-oil re-injection due to a recurrence of the RD. At the time of the last follow-up, silicone oil tamponade was con- tinued in eight eyes including the cases that received further silicone oil injections. There were no significant silicone oil-related complications in the silicone oil-filled eyes throughout the follow-up period except for controlled IOP elevation. In addition, one eye with permanent silicone tam- ponade and one eye receiving further fluid-gas exchange pre- sented complete retinal attachment at the time of the patient’s last follow-up. Thus, among the 24 eyes that were re-oper- ated on, five of them (20.8%) achieved retinal reattachment. The final visual acuities of the recurrent RD cases were 1.80 ± 0.25 (range, 0 to 3), which were worse than the 0.63 ± 0.55 of the eyes without recurrence (p = 0.045) (Table 2). The major complications after surgery were macular puck- er, which occurred in four of the eyes, and IOL dislocation, which occurred in another four eyes. Visually significant macular pucker was diagnosed approximately 3 to 6 months after surgery in three of the eyes and all of these eyes under- went a subsequent removal of the epiretinal membrane. Four eyes began to develop IOL dislocation, and thus two of these eyes underwent one or two point IOL fixation and the other two eyes underwent IOL repositioning. There were no other major complications. Table 2. Characteristics of eyes with recurrence of retinal detachment after the primary operation Variables Initial visual acuity* Primary operation Vitrectomy Scleral buckling Vitrectomy + scleral buckling Second operation Vitrectomy + gas tamponade Vitrectomy + silicone oil tamponade Fluid-gas exchange Final visual acuity Complete retinal attachment at last follow-up 10 8 6 1.80 ± 0.25 5 (20.8%) *Logarithm of the minimum angle of resolution best-corrected visual acuity. Eyes undergoing re-operation (n = 24) 1.36 ± 1.27 4 2 18 396 Intra-operative findings Intra-operatively, the macula was already detached in 58 of the eyes (54.7%). Twenty-eight eyes (26.4%) had a de- fect in the posterior lens capsule and the remaining 78 eyes had an intact posterior lens capsule. During surgery, a reti- nal break was not identified in 30 of the eyes (28.3%), even though the surgeon performed a careful examination with 360 indentations. In regards to the number of retinal breaks that occurred in 76 eyes, 50 of the eyes had on break, 14 eyes had two breaks, eight of the eyes had more than three breaks present, and four eyes presented with retinal dialysis <1 quadrant. Retinal breaks were predominately small horse-shoe tears that were often located anterior to the equator, near the ora serrata. Breaks were found in the superotemporal quadrant in 32 of the eyes, the superonasal quadrant in 16 of the eyes, the in- ferotemporal quadrant in 14 of the eyes, the inferonasal quadrant in 12 of the eyes, and the perimacular area in two of the eyes (Table 1). Anatomical results The retina was attached in 82 of the eyes (77.3%) after pri- mary surgery and in 87 of the eyes (82.1 %) at the time of the last follow-up. Multivariate analysis did not show any stat- istically significant differences between anatomic success and the following pre-operative variables: baseline visual acuity; gender; age; laterality; presence of systemic compli- cations; the time of RD evolution; the time between the onset of RD and surgery; an intact lens capsule; the location of the intraocular lens; and a lower IOP. An inability to indentify retinal breaks was associated with a significantly lower ana- tomic success rate (p = 0.002). The other analyzed intra-operative factors and surgical factors were not associated with different reattachment rates (Table 3). In eyes with unidentified retinal breaks, the retinal attach- ment rate after the primary surgery was performed was 15 (50%) out of 30 eyes. Fifteen (50%) of 30 eyes had a re-oper- ation and tiny retinal breaks were identified in three eyes dur- ing the re-operation. The final retinal attachment rate was 20 (66.6%) of 30 eyes, which is significantly lower than the eyes with identified breaks (p = 0.02) (Table 4). Functional results The final visual acuities (logMAR) were improved from the baseline of 1.51 ± 1.14 (range, 0.1 to 3) to 0.65 ± 0.49 (range, 0 to 3) (p < 0.001). There was no correlation between the baseline and the final visual acuity (r = 0.128, p = 0.463). At the last follow-up, 50 of the eyes (47.1%) had a visual acuity of 20/50 or better and 42 of the 106 eyes (39.6%) ach- ieved a visual acuity of 6 / 18 or better. Based on multivariate analysis, the characteristics asso- ciated with a worse final visual acuity were an inability to