Korean J Ophthalmol Vol.25, No.6, 2011 pseudophakic and aphakic RDs. Thus, a retinal break is not identified in 9% to 20% of pseudophakic RDs, which would be a risk factor for surgical failure [11-17]. Cases with un- identified retinal breaks have traditionally been managed us- ing SB and broad application cryopexy, which has a reported primary success rate of 53% to 70% [18,19]. We think an in- ternal approach with vitrectomy offers some advantages that might result in the detection of these breaks. Scleral external indentation together with endoillumination and magnifica- tion during the vitrectomy may help locate previously un- detected breaks [20]. Also during vitrectomy, breaks can be searched for with an aspirating instrument or by using per- fluorocarbon liquids that may identify a stream of fluid that is exiting the subretinal space via the hole [21]. We performed vitrectomy combined with either segmental or encircled SB in all 30 of the eyes that had unidentified breaks with a final anatomical success rate of 66%. Previous case series have re- ported that the anatomical success rate of vitrectomy when combined with SB was superior to SB alone [19,22-24]. In contrast, some authors have found that vitrectomy was not of additional value in terms of a better success rate [25,26]. A larger prospective randomized trial is needed in order to de- termine an accurate surgical method for RDs with unidentified breaks. As mentioned above, we indicated that identifying a retinal break is an important factor for both anatomic and functional outcomes for pseudophakic RD repair. The area of the retinal break was most frequently found in the superotemporal area. One of the most important changes in the posterior segment after cataract surgery is anomalous posterior vitreous detach- ment, which would induce a retinal tear [27-29]. Although the reasons for an increased incidence of posterior vitreous detachment after cataract surgery remain unknown, it is thought that the anterior movements of the vitreous during surgery might play a role in the development of posterior vitreous detachment [30,31]. We believe that it is possible that the in- sertion of an instrument during surgery via the main incision could produce vitreous movement and the subsequent vitre- ous traction may then result. In the current cases, the main in- cision for the cataract surgery was via a temporal approach and the eyes with an undetermined incisional approach may have undergone a temporal corneal approach. Although it is not clear why retinal breaks occur more frequently in the su- periotemporal quadrant, meticulous examinations of the su- periotemporal area during surgery are important to identify these retinal breaks. It has been reported that the previously mentioned neg- ative prognostic variables for anatomical outcomes are also associated with worse visual outcomes [5-13]. Among these variables, a lower IOP, unidentified retinal breaks, and the re- currence after primary surgery were associated with poorer final visual acuity in the current study. A lower IOP was re- lated to a poor final visual acuity and this relationship has previously been reported [32-35]. This finding might reflect a more bullous RD, a pre-operative choroidal detachment or 398 surgical difficulty. These factors are related with retinal glial cell up-regulation and retinal pigment epithelium dispersion, which resulted in a delayed morphologic recovery including that of the photoreceptor reposition of the reattached retina [36,37]. It is thought that the visual results of pseudophakic detach- ment depend on the pre-operative macula status and approx- imately 80% of pseudophakic RD typically presents with the macula detached [12-14]. However, 45% of the RDs in this study were macula-on at the time of surgery. We showed that the macula-off RD is not more highly related to poorer out- come, in spite of the worse baseline visual acuity, and that pseudophakic detachment is not present more often with the macula detached. We believe that patients tend to have accu- rate and frequent eye examinations, which would lead to an earlier diagnosis before there is macular involvement and this is reflected in our final results. In addition, both vitreous loss at the time of the cataract surgery and Nd:YAG posterior capsulotomy appear to in- crease the risk of RD when performed after cataract surgery [14]. A defect in the lens capsule may be related to more vit- reous involvement and reflect more complex intraocular manipulations. We investigated the defects in the lens capsu- les and the IOL position, but defects in the lens capsules and the IOL position were not prognostic factors for post-oper- ative outcomes. Although earlier reports suggested that vitrectomy without SB, the use of perflurocarbon liquids during vitrectomy, and the performance of a drainage retinotomy were associated with the existence of more complex RDs, and consequently poorer functional results [38-40], more recent reports have shown that the surgical outcomes appear to be independent of the surgical procedure that is chosen to resolve the RD [41,42]. In the current study, the type of surgical procedure (vitrectomy or SB) and intra-operative factors were not asso- ciated with the post-operative results. Thus, these results sug- gest that surgical outcomes are independent of the methods or complexity of the surgery. This study has some limitations. This retrospective series had a relatively small sample size within one retinal center and the surgical procedures that were used were heterogeneous. We did not describe the size of the retinal breaks, vitreous status, or the intra-operative events that occurred during the cataract surgery. A large, multicenter study is needed to evaluate the precise prognostic factors for surgical outcomes in patients with pseudophakic RDs. However, the surgical treatment of all the patients in this study was performed by one experienced retinal specialist. We believe this report is of importance to clinicians who perform surgery for RDs in pseudophakic patients. Consequently, retinal breaks that were not identified dur- ing surgery were related to poor anatomic and functional outcomes. Clinicians should perform careful examinations in the superotemporal quadrant to find retinal breaks when visible breaks are not identified. A poorer pre-operative state, includ- ing a worse pre-operative visual acuity, the macula-off RD, a