Internal Limiting Membrane Peeling For Primary Rhegmatogenous Retinal Detachment Repair

Abstract

The formation of macular pucker (MP) can limit functional visual recovery after rhegmatogenous retinal detachment (RRD) repair.1Katira R.C. Zamani M. Berinstein D.M. et al.Incidence and characteristics of macular pucker formation after primary retinal detachment repair by pars plana vitrectomy alone.Retina. 2008; 28: 744-748Crossref PubMed Scopus (64) Google Scholar The internal limiting membrane (ILM), composed of the footplate of Muller glia, has been considered a scaffold for proliferation of retinal glia, hyalocytes, and metaplastic retinal pigment epithelium after operative MP removal, contributing to recurrent MP.2Gandorfer A. Haritoglou C. Scheler R. et al.Residual cellular proliferation on the internal limiting membrane in macular pucker surgery.Retina. 2012; 32: 477-485Crossref PubMed Scopus (63) Google Scholar Peeling the ILM removes the posterior hyaloid and vitreous cortex, epiretinal membrane, and can relieve tractional forces, improve macular hole closure rate, and reduce secondary MP formation.3Brooks Jr, H.L. Macular hole surgery with and without internal limiting membrane peeling.Ophthalmology. 2000; 107: 1939-1948Abstract Full Text Full Text PDF PubMed Scopus (548) Google Scholar We report a nonrandomized, multisurgeon, retrospective, 2-arm clinical trial evaluating the incidence of postoperative MP after primary RRD repair with or without triamcinolone-acetonide (TA)-assisted ILM peeling. After a coding search of a database from a large retina referral practice (The Retina Institute, St. Louis, MO) of 708 eyes, we identified 62 eyes with primary RRD that underwent repair without ILM peeling (n = 32; group 1) or with TA-assisted ILM peeling (n = 30; group 2). Patients with a history of preoperative MP, RD surgery, tractional RD, proliferative vitreoretinopathy, silicone oil tamponade, choroidal detachment, trauma, retinal dialysis, cryoretinopexy, laser retinopexy, focal or grid or pan-retinal laser photocoagulation, proliferative retinopathy owing to retinovascular disease (e.g., diabetes mellitus), infectious retinitis, intraocular lens exchange, and aphakia were excluded. In all cases, RRD repair included standard 3-port vitrectomy pars plana vitrectomy, posterior vitreous detachment, endolaser or cryotherapy for retinopexy, internal drainage of subretinal fluid via retinotomy or preexisting break, fluid–air exchange, and instillation of intraocular gas tamponade. In all cases of ILM peeling (group 2), nondiluted TA (Kenalog-40, 40 mg/ml; Bristol Myers Squibb, Princeton, NJ) was injected intravitreally to visualize the posterior vitreous cortex, hyaloid, MP, and ILM, as described previously.4Schadlu R. Tehrani S. Shah G.K. et al.Long-term follow-up results of ILM peeling during vitrectomy surgery for premacular fibrosis.Retina. 2008; 28: 853-857Crossref PubMed Scopus (26) Google Scholar After membrane stripping of these structures, TA was completely removed by aspiration to ensure no residual TA was present before fluid–gas exchange (Video 1, available at http://aaojournal.org). Statistical comparisons were performed using the Fischer exact test, paired t test, Student t test, or Mann–Whitney U test, depending on the nature of the variable. The mean age ± standard deviation of patients was 66.1±10.5 years in group 1 and 67.5±10.2 in group 2 (P = 0.65; Table 1, available at http://aaojournal.org). Baseline (20/382 vs 20/256, P = 1.00) and postoperative (20/40 vs 20/58, P = 0.11) Snellen visual acuities were similar in both groups (P = 0.43; Table 1, available at http://aaojournal.org). The mean follow-up time ± standard deviation was 633±473 days in group 1 and 434±317 days in group 2 (P = 0.08; Table 1, available at http://aaojournal.org). In each group, there was a clinically and statistically significant improvement in Snellen visual acuity after RRD repair (group 1, 20/382 vs 20/40; group 2, 20/256 vs 20/58; P<10–3 in both groups; Table 2, available at http://aaojournal.org). There were no differences between the 2 groups with regard to gender, laterality, number of retinal breaks, macula status, duration from diagnosis to surgery, concomitant scleral buckling, or magnitude of visual acuity improvement after RRD repair. In group 1, 34.4% of eyes developed postoperative MP, with a mean Snellen acuity of 20/40. In contrast, 3.3% of eyes in group 2 developed pucker; visual acuity (n = 1) was 20/25 (P = 0.0027; Table 3, available at http://aaojournal.org). The number need to treat to prevent 1 postoperative MP is 4. Overall, 9.4% in group 1 underwent repeated surgery for removal of MP (mean preoperative acuity, 20/141 improving to a mean of 20/47 postoperatively; Table 4, available at http://aaojournal.org). No patients in group 2 underwent surgery for postoperative MP (non-clinically significant MP in 1 patient). The number need to treat to prevent 1 surgery for postoperative MP is 11. Limitations of this study include the nonuniform use of OCT, and its retrospective nature. A possible confounder in this study is the use of intravitreal TA, which was not used in group 1, but was used in group 2 for improved visualization during ILM peeling. Although the possibility remains that TA itself may prevent postoperative MP formation, TA was fastidiously removed before fluid–gas exchange because the effects and concentration of remaining TA after fluid–gas exchange cannot be predicted. In addition, the relatively small number of secondary surgeries for removal of postoperative MP limited statistical comparisons on 2 variables: improvement of visual acuity after postoperative MP removal in group 1, and rate of secondary surgery between groups 1 and 2. Although the limitations of this retrospective study preclude concluding an advantage to ILM peeling for uncomplicated, primary RRD repair to reduce MP, this pilot analysis provides insight toward devising a larger, randomized, prospective clinical trial to assess whether ILM peeling remains beneficial in this context. Such a trial would include similar inclusion and exclusion criteria, as well as control and intervention groups. Pre- and postoperative OCT analyses to assess the presence of MP in each subject should be conducted. Intraoperatively, a similar amount of TA should be injected in each patient from both groups, with consistent TA removal before fluid–air exchange. The primary endpoints would be presence of postoperative MP by OCT and/or clinical biomicroscopy, as well as rate of secondary surgery for postoperative MP. Visual acuities would be a secondary endpoint. Given a confidence interval of 5%, an approximate incidence of 30 000 RRDs per year in the United States, a sample size of 380 patients for such a prospective trial would be appropriate. Previous work has demonstrated a reduction in postoperative MP formation after ILM peeling in proliferative vitreoretinopathy-related retinal detachment.5Aras C. Arici C. Akar S. et al.Peeling of internal limiting membrane during vitrectomy for complicated retinal detachment prevents epimacular membrane formation.Graefes Arch Clin Exp Ophthalmol. 2009; 247: 619-623Crossref PubMed Scopus (42) Google Scholar In this retrospective pilot series, for the first time we have demonstrated that ILM peeling during uncomplicated, primary RRD repair reduced postoperative MP. Although there was a trend toward lower MP removal rate, it was not significant. eyJraWQiOiI4ZjUxYWNhY2IzYjhiNjNlNzFlYmIzYWFmYTU5NmZmYyIsImFsZyI6IlJTMjU2In0.eyJzdWIiOiI4MWUwNjlkNTlhOTY4MzIwOTBlNzIxZjkyZTc2MzVmMyIsImtpZCI6IjhmNTFhY2FjYjNiOGI2M2U3MWViYjNhYWZhNTk2ZmZjIiwiZXhwIjoxNjY2MTY1OTcxfQ.QEv5kjk0Xa70Rh-Wr494VszL4D0WRBWTbPvQon7e6aDtYPwNPA1Q4JgavYKwhJKRKeAY-Eb7n1Jg_anWu0D-piatZ_QUN_Ac2AWnWRSjw7OMe6zLjjX7QtHFxP3mQ2_LKM1gnqVRJkx-NN7_XKtkJFVl_rbyXxOELyJXPpuZ35XdSExQiUvU5kDncbzXMJn4C31Wi8jjDHRUb2BhjnPpMwAY2Zy4o_LgGci1auNejH7cXloDmHJTxKSy8ebfAsJgT2xMyBFcTNGlVkDqtgqWSbm8yaoglAKD_HUxEe3fAVLgOY2zQYigA-pw_Q-5Bgyhqiwyt1eOpIfviwPYdYq2yQ Download .mp4 (4.97 MB) Help with .mp4 files Video 1VidClip of the internal limiting membrane (ILM) peel, which briefly shows ILM peeling during a macula-off rhegmatogenous retinal detachment.Table 1Baseline Characteristics of Group 1 and 2VariableGroup 1Group 2P-ValueNo. of patients3030No. of eyes3230Age at diagnosis (yrs)62.6±10.664.0±9.70.60Duration of followup (days)633±473434±3170.08Gender: F/M (no. of eyes)7/257/231.00Diabetes mellitus25% (8/32)20% (6/30)0.76Laterality: right/left14/189/270.30Lens: pseudophakic/phakic12/2021/90.04⁎Statistically significant. Statistically significant. Open table in a new tab Table 2Baseline Retinal Characteristics of Group 1 and 2VariableGroup 1Group 2P-ValueMacula status: on/off8/248/221.00Number of retinal breaks1.62±0.711.73±0.980.62Diagnosis to RRD repair (days)2.77±1.963.00±4.530.60Scleral buckling90.6% (29/32)80.0% (24/30)0.29Intraoperative cryotherapy9.4% (3/32)3.3% (1/30)0.61Preoperative visual acuity (LogMAR [Snellen])1.28±0.83 [20/382]1.11±0.89 [20/256]1.00Postoperative visual acuity (LogMAR [Snellen])0.31±0.33[20/41]0.46±0.41[20/58]0.11Visual acuity improvement after RRD repair (LogMAR)0.97±0.820.65±0.760.12P-Value of pre- vs post-operative visual acuities<0.001⁎Statistically significant.<0.001⁎Statistically significant. Statistically significant. Open table in a new tab Table 3ILM Peeling during Primary RRD Repair Reduces Postoperative MPVariableGroup 1Group 2P-ValuePostoperative MP rate34.3% (11/32)3.3% (1/30)0.0027⁎Statistically significant.Secondary MP removal rate9.4% (3/32)0% (0/30)0.24 Statistically significant. Open table in a new tab Table 4Characteristics of MPVariableGroup 1Group 2P-ValueVisual acuity of total patients with MP (LogMAR [Snellen])0.30±0.40 (11/32) [20/40]0.10 (1/30) [20/25]N/AVisual acuity of patients with clinically significant MP (LogMAR [Snellen])0.84±0.40 (3/32) [20/141]N/A (0/30)N/AVisual acuity after MP removal (LogMAR [Snellen])0.37±0.24 (3/32) [20/47]N/A (0/30)N/A Open table in a new tab