EXTRAMACULAR DRAINAGE OF SUBRETINAL FLUID DURING VITRECTOMY FOR MACULAR HOLE RETINAL DETACHMENT IN HIGH MYOPIA HYE S. JEON, MD,*† IK S. BYON, MD,†‡ SUNG W. PARK, MD,*† JI E. LEE, MD, PHD,*† BOO S. OUM, MD, PHD*† Purpose: To compare surgical outcomes between subretinal fluid drainage through the macular hole (MH) and through sites other than the MH during vitrectomy for MH retinal detachment in highly myopic eyes. Methods: Retrospective analysis was performed on the medical records of 41 patients who underwent vitrectomy for MH retinal detachment in highly myopic eyes. Group M included eyes in which subretinal fluid was drained through MH. Group E included eyes in which subretinal fluid was drained through an extramacular break or retinotomy. Pre- and postoperative visual acuity, reattachment rate, and MH closure rate were investigated. Results: Primary retinal reattachment was achieved in 13 of 21 eyes (62%) in Group M and in 19 of 20 eyes (95%) in Group E (P = 0.020). The MH was closed more frequently in Group E (15 eyes) than in Group M (7 eyes; P = 0.012). Ambulatory vision of 20/400 or better was achieved in 16 eyes in Group E and in 10 eyes in Group M (P = 0.033). Conclusion: Extramacular drainage of subretinal fluid resulted in better outcomes than the conventional procedure of drainage through the MH. RETINA 34:1096–1102, 2014
M
In conventional treatment, the subretinal fluid in MHRD is drained through the MH. Several investigators have suggested that this procedure may damage the retinal pigment epithelium (RPE) and have an adverse effect on functional outcomes.11 Moreover, in our experience, the subretinal fluid is commonly viscous and tends to form a thick stream, which dilates the MH during drainage. We hypothesized that draining the subretinal fluid through the MH may damage the surrounding sensory retina and reduce the closure rate. In the current study, we drained the subretinal fluid through an extramacular break or retinotomy other than the MH and compared the postoperative outcomes with those in eyes that underwent conventional subretinal fluid drainage through the MH.
acular hole retinal detachment (MHRD) is an uncommon disease that usually affects highly myopic eyes. Vitrectomy and gas tamponade are considered the standard procedures for MHRD.1 Various adjunctive procedures, such as silicone oil filling,1–3 photocoagulation of the macula,4,5 and removal of epiretinal tissue or the internal limiting membrane,4,6–9 have also been introduced. However, anatomical and functional outcomes have been reported as worse than those in nonmyopic eyes with retinal detachment or macular hole (MH). The rate of hole closure was reported as low as 44%, even with peeling of the internal limiting membrane.10 From the *Department of Ophthalmology, School of Medicine, Pusan National University, Yangsan, South Korea; †Medical Research Institute, Pusan National University Hospital, Busan, South Korea; and ‡Research Institute for Convergence of Biomedical Science and Technology, Yangsan Busan National University Hospital, Yangsan, South Korea. None of the authors have any financial/conflicting interests to disclose. Reprint requests: Ji E. Lee, MD, PhD, Department of Ophthalmology, Pusan National University Hospital, 1-10 Ami-dong, Seo-gu, Busan 602-739, South Korea; e-mail: [email protected]
Methods A retrospective analysis was performed based on the medical records of patients who underwent primary vitreoretinal surgery for MHRD complicated in high myopic eyes between 2005 and 2011 at the Pusan 1096
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National University Hospital and were followed-up for at least 6 months after the surgical procedure. High myopia was defined as eyes with an axial length of 25 mm or longer or a refractive error of −6.0 diopters or greater.12 The diagnosis of MHRD was confirmed by ophthalmoscopic examination or intraoperative findings. Eyes in which other breaks presented and the MH was not considered the primary cause of retinal detachment were excluded based on the configuration of the subretinal fluid. Eyes with subretinal fluid confined to the macula were also excluded because drainage retinotomy could not be performed. All the consecutive cases were operated using pars plana vitrectomy. Those eyes that underwent combined buckling or encircling surgery were excluded. The collected preoperative data included age, gender, interval between symptom onset and surgical procedure, best-corrected visual acuity, refractive error, lens status, axial length, and the presence of staphyloma. The patients were divided into two groups based on the surgical technique used. Group M included eyes in which the subretinal fluid was drained through the MH conventionally, and Group E included eyes in which the subretinal fluid was drained through sites other than the MH. Extramacular drainage was used in the surgeries performed later than October 2008. In Group E, if there were any preexisting retinal breaks other than the MH, an attempt was made to drain the subretinal fluid through these breaks. Otherwise, retinotomy was performed to drain the subretinal fluid. The site for the retinotomy was chosen outside the macula to avoid chorioretinal atrophy. If a staphyloma was present, the retinotomy was performed at the edge of the staphyloma. One low barrier photocoagulation was performed surrounding the retinotomy. The internal limiting membrane was peeled after staining with indocyanine green. The MH was protected from the indocyanine green using heavy liquid under fluid or viscoelastics under air. The retina was tamponaded by gas or silicone oil in all patients. A nonexpanding concentration of SF6 or C3F8 was selected at the surgeon’s discretion. In more recent cases, a lower concentration (10–12%) of C3F8 was used instead of SF6. Silicone oil was used in patients who could not maintain a facedown position. Postoperatively, the patients were encouraged to maintain a strict facedown position for at least 3 days. For the statistical analysis, visual acuity measured by a Snellen acuity chart was transcribed to the logarithm of the minimum angle of resolution unit. The best postoperative visual acuity was defined as the best visual acuity during the follow-up period. Primary attachment was defined as reattachment of the retina without additional surgical procedure except for the
removal of silicone oil. The final attachment rate was also evaluated at the last date of follow-up. If the silicone oil was not removed because of low intraocular pressure, it was considered a failure of reattachment, regardless of the presence of subretinal fluid. Closure of the MH was defined as the resolution of neurosensory retinal defects in optical coherence tomography (Cirrus HD-OCT; Carl-Zeiss, Dublin, CA). To verify the closure of the MH, all 128 B-scans were reviewed in a 512 · 128 cube scan. Results Forty-one eyes (41 patients) were included in the current study. Twenty-one patients were in Group M, and 20 cases were in Group E. The baseline characteristics are summarized in Table 1. Visual acuity (in logarithm of the minimum angle of resolution units) before the surgical procedure was 1.91 ± 0.64 in Group M and 2.02 ± 0.81 in Group E. There were no significant differences in the baseline characteristics between the two groups. Concurrent phacoemulsification was performed in 12 of 15 phakic eyes (80%) in Group M and 8 of 10 phakic eyes (80%) in Group E. After primary operations, three eyes in Group M and two eyes in Group E remained phakic, and there were no significant progression of cataract during follow-up. Drainage retinotomy was performed in 18 eyes in Group E (90.0%, Figures 1–3). Four eyes required drainage retinotomy, despite the presence of other breaks. In two of these eyes, the break was not connected to the subretinal fluid, and in one eye, the subretinal fluid was too viscous to be displaced peripherally using heavy liquid. In one eye, the break was in the macula (Figure 3). The vitreous was replaced with C3F8 Table 1. Baseline Characteristics of Patients Who Underwent Vitrectomy for MHRD With Drainage Through the MH (Group M) or Extramacular Drainage (Group E)
Number of eyes Sex (M:F) Age (years) Sx duration (weeks) Visual acuity (logMAR) Axial length (mm) Staphyloma (eyes) Lens (eyes) Phakic Pseudophakic Presence of breaks (eyes)
Group M
Group E
P
21 2:19 65.2 ± 7.7 8.3 ± 9.8 1.91 ± 0.64 28.1 ± 2.2 19 (82.6%)
20 2:18 64.3 ± 13.5 5.0 ± 7.5 2.02 ± 0.81 28.6 ± 2.2 20 (100%)
— 1 0.855 0.133 0.739 0.440 0.488 0.208
15 (71%) 6 (29%) 3 (14%)
10 (50%) 10 (50%) 6 (30%)
0.277
F, female; M, male; Sx, symptom; logMAR, logarithm of the minimum angle of resolution.
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2014 VOLUME 34 NUMBER 6
Fig. 1. Preoperative and postoperative findings of fundus (A and B) and optical coherence tomography (C and D) of Case 5 in Group E. A. A 57-year-old woman having high myopia with a spherical equivalent of −19.25 diopters and an axial length of 29.35 mm presented with MHRD localized posterior to the equator in her right eye. Her corrected visual acuity was 20/200. The patient underwent pars plana vitrectomy with the removal of the internal limiting membrane. B. Subretinal fluid was drained through the retinotomy made above the superotemporal arcade (arrow). The retina was tamponaded with 14% C3F8. After absorption of the gas, the retina remained reattached and optical coherence tomography confirmed macular hole closure (D). Three months after the surgical procedure, the patient’s visual acuity had increased to 20/100.
in 36 eyes (87.8%), SF6 in 3 eyes (7.3%), and silicone oil in 2 eyes (4.9%; Table 2). In some cases, small amount of subretinal fluid in the staphyloma was removed through the MH passively using a soft-tipped flute needle at the end of fluid–air exchange in Group E; however, residual fluid was so small and nonviscous that dilation of the MH was not observed during the procedure. Primary retinal reattachment was achieved in 13 of 21 patients (61.9%) in Group M and in 19 of 20 patients (95.0%) in Group E. The primary attachment rate was significantly higher in Group E (P = 0.020, Fisher’s exact test). Reattachment rate of the former and the latter half cases did not show significant differences in each group (70.0% vs. 54.5% in Group M; P = 0.659 and 100% vs. 90% in Group E; P = 1.000).
The cases with recurrent detachment were treated with vitrectomy and C3F8 gas or silicone oil. If there was proliferative vitreoretinopathy, encircling was combined. Two eyes in Group M failed to achieve anatomical success finally. Final reattachment was achieved in 19 of 21 patients (90.5%) in Group M and in 20 of 20 patients (100%) in Group E (P = 0.232). The MH was closed in 7 of 21 eyes (33.3%) in Group M and in 15 of 20 eyes (75.0%) in Group E. The rate of hole closure was significantly higher in Group E (P = 0.012, chi-square test). Once the retina was reattached, an additional operation was not performed to close the MH in the cases with the unclosed MH. No complications were associated with drainage retinotomy in Group E (Figures 1–3).
Fig. 2. An 80-year-old woman (Case 17 in Group E) visited the clinic with decreased visual acuity to hand motion in the right eye. A. Fundus examination revealed myopic degeneration, and retinal detachment complicated by macular hole in the posterior pole extended to inferior periphery. The axial length was 29.27 mm. During vitrectomy, retinotomy was performed superior to the superotemporal arcade at the edge of the staphyloma. C3F8 gas of 14% was used for the tamponade. After 2 months, the retina was reattached without recurrence (B) and closure of the MH was confirmed by optical coherence tomography (C). After 12 months, her visual acuity remained at 20/1000 because of severe chorioretinal atrophy involving the fovea.
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Fig. 3. A. A 76-year-old woman (Case 18 in Group E) who had undergone cataract surgery 3 years earlier presented with macular hole and localized subretinal fluid in the posterior pole. There was another break in the macula. Visual acuity was 20/1000, and the axial length was 30.39 mm. Pars plana vitrectomy was performed using 23-gauge instruments. B. A retinotomy was made at the edge of the staphyloma close to the supertemporal arcade (arrow), and the viscous subretinal fluid was drained through it. The internal limiting was removed, and the vitreous cavity was filled with 12% C3F8. After 3 months, both the MH hole and the other break had closed without recurrence of retinal detachment. Her final visual acuity was 20/400. Optical coherence tomography shows two breaks at presentation (C) and closure of both breaks after the surgical procedure (D).
The mean visual acuity (logarithm of the minimum angle of resolution) after the surgical procedure was 1.55 ± 0.67, 1.57 ± 0.68, and 1.82 ± 0.69 at 3, 6, and 12 months, respectively, in Group M and 1.36 ± 0.47, 1.30 ± 0.45, and 1.56 ± 0.40, respectively, in Group E. The best visual acuity after the surgical procedure was 1.50 ± 0.68 in Group M and 1.15 ± 0.40 in Group E. The mean improvement in visual acuity was 0.41 ± 0.75 in Group M and 0.87 ± 0.77 in Group E (Figure 4). Visual acuity significantly improved after the surgical procedure in both the groups (P = 0.026 and P , 0.001,
Wilcoxon’s rank sum test). Postoperative visual acuity with ambulatory vision of 20/400 or better was achieved more frequently in Group E (16 of 20 eyes, 80.0%) than in Group M (10 of 21 eyes, 47.6%; P = 0.033, Fisher’s exact test). However, there were no significant differences in the best postoperative visual acuity or in the improvement in visual acuity between the 2 groups (P = 0.079 and 0.118, Mann–Whitney U test; Table 3). Discussion Retinal detachment from MH is rare in nonmyopic eyes because traction to MH is not strong enough to Table 2. Surgical Procedures in Vitrectomy for MHRD With Drainage Through the MH (Group M) or Extramacular Drainage (Group E) Group M (n = 21)
Fig. 4. Changes in visual acuity after vitrectomy for MHRD with drainage through the macular hole (Group M) or extramacular drainage (Group E) at postoperative months 3, 6, and 12.
Concurrent phacoemulsification, n (%) ILM peeling, n (%) Retinotomy, n (%) Tamponade, n (%) SF6 C3F8 Silicone oil, n (%)
Group E (n = 20)
P
12/15 (80)* 8/10 (80)
1.0
19 (90) — 3 (14) 17 (81) 1 (5)
*Phakic eyes. ILM, internal limiting membrane.
20 (100) 0.488 18 (90) — 0.082 0 (0) 19 (95) 1 (5)
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Table 3. Anatomical and Functional Outcomes After Vitrectomy for MHRD With Drainage Through the MH (Group M) or Extramacular Drainage (Group E)
Primary success (eyes), n (%) Final success (eyes), n (%) Hole closure (eyes), n (%) Best VA (logMAR), mean ± SD VA improvement (logMAR), mean ± SD VA changes (eyes), n (%) .2 lines increase +2 to −2 lines ,2 lines decrease VA distribution (eyes), n (%) $20/100 20/100 to 20/200 20/200 to 20/400 ,20/400
Group M (n = 21)
Group E (n = 20)
P
13 (61.9) 18 (85.7) 7 (33.3) 1.50 ± 0.68 0.41 ± 0.75
19 (95.0) 20 (100) 15 (75.0) 1.15 ± 0.40 0.87 ± 0.77
0.020 0.232 0.012 0.079 0.118 0.189
14 (66.7) 3 (14.3) 4 (19.0)
16 (80.0) 4 (20.0) 0 (0)
3 3 4 11
(14.3) (14.3) (19.0) (52.4)
5 5 6 4
(25.0) (25.0) (30.0) (20.0)
0.319* 0.139* 0.033*
*Compared with the number of eyes in the groups below the indicated level. VA, visual acuity; logMAR, logarithm of the minimum angle of resolution; SD, standard deviation.
pull the sensory retina from the RPE. The most common cause of MHRD is high myopia. Foveal detachment and surrounding retinoschisis are often observed in highly myopic eyes.13,14 Ikuno et al10 suggested that foveal detachment in myopic foveoschisis could be a predisposition to MHRD. Foveal detachment is thought to precede MH formation, which is followed by the extension of retinal detachment, instead of the development of retinal detachment from MH. This theory explains common surgical findings that old viscous subretinal fluid is drained even in recently symptomatic cases. This viscous fluid tends to coalesce, forming a thick stream during drainage, and the MH is dilated by the flow of the subretinal fluid. Although the MH seems to return to its original size after drainage, the macula in highly myopic eyes is thinner than that in nonmyopic eyes because of the degenerative changes, and therefore, it is prone to mechanical damage. Our hypothesis was that drainage through the MH damages not only the RPE but also the surrounding sensory retina, expanding the diameter of the MH and, consequently, lowering the closure rate of the hole. O’Driscoll et al15 reported a long-term MH closure rate of 31% in cases of rhegmatogenous retinal detachment accompanying MH. Although nonmyopic cases were included, the closure rate was much lower than that in idiopathic MH.16 They suggested that the low closure rate is caused by the internal drainage of viscous subretinal fluid through the MH, which can lead to the enlargement of the hole.15 Extramacular drainage of subretinal fluid has been previously reported. Wolfensberger and Gonvers5 reported the surgical outcomes of MHRD treated by vitrectomy combined with temporary silicone oil tamponade and laser photocoagulation. Although the subretinal
fluid was drained through the MH in most patients, fluid–perfluorocarbon liquid exchange was used to drain the subretinal fluid through a peripheral retinotomy that had been performed using a vitreous cutter in some cases. Differences in the surgical outcomes between the cases in which the subretinal fluid was drained through MH and through peripheral retinotomy were not presented. The MH closure was not evaluated because the study was conducted in the pre–optical coherence tomography era, and by ophthalmoscope, MH is barely visible in highly myopic eyes. Even using time-domain optical coherence tomography, the hole closure is occasionally unreliable because six radial scans may miss a small hole because of eccentric fixation in degenerative, highly myopic eyes. In the present study, hole closure was assessed by reviewing all the B-scans of the spectraldomain optical coherence tomographic raster scans. Closure of MH is thought to be a key in improving the anatomical success rate because it restores the normal anatomical configuration of the macula and eliminates the chances of recurrent detachment from the MH. In highly myopic eyes, unclosed MH is prone to redetachment of the retina because of the traction caused by staphyloma and weak adherence in the area of chorioretinal atrophy. The higher primary retinal reattachment rate in Group E could have resulted from the higher rate of hole closure. Final reattachment was achieved in all eyes in Group E. Extramacular drainage has another advantage that it avoids insults to the foveal RPE by suction through the MH. Kelly and Wendel17 suggested that changes in the RPE seem to be secondary to trauma to the RPE and photoreceptors during MH surgery and that they occur secondary to the precipitous suction removal of the thick subretinal fluid through MH. Charles11
EXTRAMACULAR DRAINAGE OF SRF FOR MHRD JEON ET AL
reported that RPE changes extending beyond the apparent rim of the subretinal fluid were observed in 6 of 24 cases that underwent MHRD surgery after subretinal fluid drainage through the MH. The above observations strongly support a mechanical pathogenesis for changes in RPE. Drainage retinotomy may be associated with postoperative complications, such as fibrosis, choroidal neovascularization, or recurrence.18,19 In a recent study that did not use drainage of subretinal fluid and silicone oil tamponade, Nadal et al20 reported high reattachment rates and MH closure in 51.9% of cases, which was slightly lower than the 75% in our results. As mentioned above, subretinal fluid of MHRD is commonly very viscous and may take a long time to absorb. The decreased function of the RPE in degenerative myopia would further delay absorption, leading to deterioration in the anatomical outcomes. If retinotomy could be performed safely, surgical drainage of the subretinal fluid would lead to improved outcomes. In the current study, no complication related to retinotomy was observed. The site of retinotomy in MHRD requires several considerations. The subretinal fluid in MHRD is commonly localized in the postequatorial retina. If retinal detachment is restricted to the macula, retinotomy should not be performed because postoperative expansion of scars related to the retinotomy may affect the fovea. Retinotomy in the area of chorioretinal atrophy should also be avoided because of the absence of a physiologic adhesive force and the risk of recurrence. If retinotomy is performed outside the staphyloma, too much subretinal fluid may remain after drainage through the retinotomy. In contrast, retinotomy inside staphyloma may promote recurrent retinal detachment. Macular hole closure was reported to be significantly correlated with final visual acuity.10 In the current study, no significant difference was detected in visual acuity at each postoperative time point, although there was a tendency toward greater improvement in Group E. However, Group E had a higher rate of ambulatory vision in the best visual acuity during follow-up. This parameter is more important in MHRD, in which visual acuity is generally very low. For example, improvement from hand motion to 20/800 is considered a significant improvement, but it is still worse than the ambulatory vision. It would be relevant to investigate the best visual acuity during the follow-up period to determine the efficacy of surgical treatment for MHRD in highly myopic eyes. Different tamponade materials and concentrations show various times to achieve the best visual acuity. In addition, visual acuity after surgical procedure may deteriorate gradually secondary to progressively
1101
degenerative changes, which are not uncommon in highly myopic eyes. Our study has several limitations: it is a retrospective series with a small number of cases. Because of the retrospective nature of the study, Group E includes more recent cases, and SF6 was used as tamponade only in Group M. However, these factors would not lead to a significant bias. All the procedures were performed by an experienced surgeon, and learning effects were not observed in each group. Tamponade gas was not reported to be a prognostic factor for primary attachment.21 In conclusion, extramacular drainage avoided adverse effects on the sensory retina and the RPE around the MH and improved success rates in MH closure, retinal reattachment, and visual outcome of vitrectomy for MHRD complicated in highly myopic eyes. A future study is required to compare results with extramacular drainage and without drainage of subretinal fluid. Key words: drainage retinotomy, high myopia, macular hole, macular hole retinal detachment, retinal detachment, staphyloma, vitrectomy. References 1. Nishimura A, Kimura M, Saito Y, Sugiyama K. Efficacy of primary silicone oil tamponade for the treatment of retinal detachment caused by macular hole in high myopia. Am J Ophthalmol 2011;151:148–155. 2. Cheung BT, Lai TY, Yuen CY, et al. Results of high-density silicone oil as a tamponade agent in macular hole retinal detachment in patients with high myopia. Br J Ophthalmol 2007;91:719–721. 3. Haut J, Van EG, Flamand M. Treatment of macular hole retinal detachment with silicone oil, with or without argon laser photocoagulation. Ophthalmologica 1983;187:25–28. 4. Yu J, Wang F, Cao H, et al. Combination of internal limiting membrane peeling and endophotocoagulation for retinal detachment related to high myopia in patients with macular hole. Ophthalmic Surg Lasers Imaging 2010;41:215–221. 5. Wolfensberger TJ, Gonvers M. Long-term follow-up of retinal detachment due to macular hole in myopic eyes treated by temporary silicone oil tamponade and laser photocoagulation. Ophthalmology 1999;106:1786–1791. 6. Ryan EH Jr, Bramante CT, Mittra RA, et al. Management of rhegmatogenous retinal detachment with coexistent macular hole in the era of internal limiting membrane peeling. Am J Ophthalmol 2011;152:815–819. 7. Shukla D, Rajendran A, Maheshwari R, Naresh KB. Early closure of macular hole secondary to rhegmatogenous retinal detachment with internal limiting membrane peeling. Ophthalmic Surg Lasers Imaging 2008;39:81–85. 8. Cho H, Choi A, Kang SW. Effect of internal limiting membrane removal in treatment of retinal detachment caused by myopic macular hole. Korean J Ophthalmol 2004;18:141–147. 9. Kadonosono K, Yazama F, Itoh N, et al. Treatment of retinal detachment resulting from myopic macular hole with internal limiting membrane removal. Am J Ophthalmol 2001;131: 203–207.
1102 RETINA, THE JOURNAL OF RETINAL AND VITREOUS DISEASES 10. Ikuno Y, Sayanagi K, Oshima T, et al. Optical coherence tomographic findings of macular holes and retinal detachment after vitrectomy in highly myopic eyes. Am J Ophthalmol 2003;136:477–481. 11. Charles S. Retinal pigment epithelial abnormalities after macular hole surgery. Retina 1993;13:176. 12. Curtin BJ. Physiologic vs pathologic myopia: genetics vs environment. Ophthalmology 1979;86:681–691. 13. Takano M, Kishi S. Foveal retinoschisis and retinal detachment in severely myopic eyes with posterior staphyloma. Am J Ophthalmol 1999;128:472–476. 14. Benhamou N, Massin P, Haouchine B, et al. Macular retinoschisis in highly myopic eyes. Am J Ophthalmol 2002;133: 794–800. 15. O’Driscoll AM, Goble RR, Kirkby GR. Vitrectomy for retinal detachments with both peripheral retinal breaks and macular holes. An assessment of outcome and the status of the macular hole. Retina 2001;21:221–225.
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16. Mester V, Kuhn F. Internal limiting membrane removal in the management of full-thickness macular holes. Am J Ophthalmol 2000;129:769–777. 17. Kelly NE, Wendel RT. Vitreous surgery for idiopathic macular holes. Results of a pilot study. Arch Ophthalmol 1991;109:654–659. 18. Richards SC, Maberley AL. Complications of retinotomies for subretinal fluid drainage. Can J Ophthalmol 1993;28:24–27. 19. McDonald HR, Lewis H, Aaberg TM, Abrams GW. Complications of endodrainage retinotomies created during vitreous surgery for complicated retinal detachment. Ophthalmology 1989;96:358–363. 20. Nadal J, Verdaguer P, Canut MI. Treatment of retinal detachment secondary to macular hole in high myopia: vitrectomy with dissection of the inner limiting membrane to the edge of the staphyloma and long-term tamponade. Retina 2012;32:1525–1530. 21. Nakanishi H, Kuriyama S, Saito I, et al. Prognostic factor analysis in pars plana vitrectomy for retinal detachment attributable to macular hole in high myopia: a multicenter study. Am J Ophthalmol 2008;146:198–204.
M
In conventional treatment, the subretinal fluid in MHRD is drained through the MH. Several investigators have suggested that this procedure may damage the retinal pigment epithelium (RPE) and have an adverse effect on functional outcomes.11 Moreover, in our experience, the subretinal fluid is commonly viscous and tends to form a thick stream, which dilates the MH during drainage. We hypothesized that draining the subretinal fluid through the MH may damage the surrounding sensory retina and reduce the closure rate. In the current study, we drained the subretinal fluid through an extramacular break or retinotomy other than the MH and compared the postoperative outcomes with those in eyes that underwent conventional subretinal fluid drainage through the MH.
acular hole retinal detachment (MHRD) is an uncommon disease that usually affects highly myopic eyes. Vitrectomy and gas tamponade are considered the standard procedures for MHRD.1 Various adjunctive procedures, such as silicone oil filling,1–3 photocoagulation of the macula,4,5 and removal of epiretinal tissue or the internal limiting membrane,4,6–9 have also been introduced. However, anatomical and functional outcomes have been reported as worse than those in nonmyopic eyes with retinal detachment or macular hole (MH). The rate of hole closure was reported as low as 44%, even with peeling of the internal limiting membrane.10 From the *Department of Ophthalmology, School of Medicine, Pusan National University, Yangsan, South Korea; †Medical Research Institute, Pusan National University Hospital, Busan, South Korea; and ‡Research Institute for Convergence of Biomedical Science and Technology, Yangsan Busan National University Hospital, Yangsan, South Korea. None of the authors have any financial/conflicting interests to disclose. Reprint requests: Ji E. Lee, MD, PhD, Department of Ophthalmology, Pusan National University Hospital, 1-10 Ami-dong, Seo-gu, Busan 602-739, South Korea; e-mail: [email protected]
Methods A retrospective analysis was performed based on the medical records of patients who underwent primary vitreoretinal surgery for MHRD complicated in high myopic eyes between 2005 and 2011 at the Pusan 1096
1097
EXTRAMACULAR DRAINAGE OF SRF FOR MHRD JEON ET AL
National University Hospital and were followed-up for at least 6 months after the surgical procedure. High myopia was defined as eyes with an axial length of 25 mm or longer or a refractive error of −6.0 diopters or greater.12 The diagnosis of MHRD was confirmed by ophthalmoscopic examination or intraoperative findings. Eyes in which other breaks presented and the MH was not considered the primary cause of retinal detachment were excluded based on the configuration of the subretinal fluid. Eyes with subretinal fluid confined to the macula were also excluded because drainage retinotomy could not be performed. All the consecutive cases were operated using pars plana vitrectomy. Those eyes that underwent combined buckling or encircling surgery were excluded. The collected preoperative data included age, gender, interval between symptom onset and surgical procedure, best-corrected visual acuity, refractive error, lens status, axial length, and the presence of staphyloma. The patients were divided into two groups based on the surgical technique used. Group M included eyes in which the subretinal fluid was drained through the MH conventionally, and Group E included eyes in which the subretinal fluid was drained through sites other than the MH. Extramacular drainage was used in the surgeries performed later than October 2008. In Group E, if there were any preexisting retinal breaks other than the MH, an attempt was made to drain the subretinal fluid through these breaks. Otherwise, retinotomy was performed to drain the subretinal fluid. The site for the retinotomy was chosen outside the macula to avoid chorioretinal atrophy. If a staphyloma was present, the retinotomy was performed at the edge of the staphyloma. One low barrier photocoagulation was performed surrounding the retinotomy. The internal limiting membrane was peeled after staining with indocyanine green. The MH was protected from the indocyanine green using heavy liquid under fluid or viscoelastics under air. The retina was tamponaded by gas or silicone oil in all patients. A nonexpanding concentration of SF6 or C3F8 was selected at the surgeon’s discretion. In more recent cases, a lower concentration (10–12%) of C3F8 was used instead of SF6. Silicone oil was used in patients who could not maintain a facedown position. Postoperatively, the patients were encouraged to maintain a strict facedown position for at least 3 days. For the statistical analysis, visual acuity measured by a Snellen acuity chart was transcribed to the logarithm of the minimum angle of resolution unit. The best postoperative visual acuity was defined as the best visual acuity during the follow-up period. Primary attachment was defined as reattachment of the retina without additional surgical procedure except for the
removal of silicone oil. The final attachment rate was also evaluated at the last date of follow-up. If the silicone oil was not removed because of low intraocular pressure, it was considered a failure of reattachment, regardless of the presence of subretinal fluid. Closure of the MH was defined as the resolution of neurosensory retinal defects in optical coherence tomography (Cirrus HD-OCT; Carl-Zeiss, Dublin, CA). To verify the closure of the MH, all 128 B-scans were reviewed in a 512 · 128 cube scan. Results Forty-one eyes (41 patients) were included in the current study. Twenty-one patients were in Group M, and 20 cases were in Group E. The baseline characteristics are summarized in Table 1. Visual acuity (in logarithm of the minimum angle of resolution units) before the surgical procedure was 1.91 ± 0.64 in Group M and 2.02 ± 0.81 in Group E. There were no significant differences in the baseline characteristics between the two groups. Concurrent phacoemulsification was performed in 12 of 15 phakic eyes (80%) in Group M and 8 of 10 phakic eyes (80%) in Group E. After primary operations, three eyes in Group M and two eyes in Group E remained phakic, and there were no significant progression of cataract during follow-up. Drainage retinotomy was performed in 18 eyes in Group E (90.0%, Figures 1–3). Four eyes required drainage retinotomy, despite the presence of other breaks. In two of these eyes, the break was not connected to the subretinal fluid, and in one eye, the subretinal fluid was too viscous to be displaced peripherally using heavy liquid. In one eye, the break was in the macula (Figure 3). The vitreous was replaced with C3F8 Table 1. Baseline Characteristics of Patients Who Underwent Vitrectomy for MHRD With Drainage Through the MH (Group M) or Extramacular Drainage (Group E)
Number of eyes Sex (M:F) Age (years) Sx duration (weeks) Visual acuity (logMAR) Axial length (mm) Staphyloma (eyes) Lens (eyes) Phakic Pseudophakic Presence of breaks (eyes)
Group M
Group E
P
21 2:19 65.2 ± 7.7 8.3 ± 9.8 1.91 ± 0.64 28.1 ± 2.2 19 (82.6%)
20 2:18 64.3 ± 13.5 5.0 ± 7.5 2.02 ± 0.81 28.6 ± 2.2 20 (100%)
— 1 0.855 0.133 0.739 0.440 0.488 0.208
15 (71%) 6 (29%) 3 (14%)
10 (50%) 10 (50%) 6 (30%)
0.277
F, female; M, male; Sx, symptom; logMAR, logarithm of the minimum angle of resolution.
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Fig. 1. Preoperative and postoperative findings of fundus (A and B) and optical coherence tomography (C and D) of Case 5 in Group E. A. A 57-year-old woman having high myopia with a spherical equivalent of −19.25 diopters and an axial length of 29.35 mm presented with MHRD localized posterior to the equator in her right eye. Her corrected visual acuity was 20/200. The patient underwent pars plana vitrectomy with the removal of the internal limiting membrane. B. Subretinal fluid was drained through the retinotomy made above the superotemporal arcade (arrow). The retina was tamponaded with 14% C3F8. After absorption of the gas, the retina remained reattached and optical coherence tomography confirmed macular hole closure (D). Three months after the surgical procedure, the patient’s visual acuity had increased to 20/100.
in 36 eyes (87.8%), SF6 in 3 eyes (7.3%), and silicone oil in 2 eyes (4.9%; Table 2). In some cases, small amount of subretinal fluid in the staphyloma was removed through the MH passively using a soft-tipped flute needle at the end of fluid–air exchange in Group E; however, residual fluid was so small and nonviscous that dilation of the MH was not observed during the procedure. Primary retinal reattachment was achieved in 13 of 21 patients (61.9%) in Group M and in 19 of 20 patients (95.0%) in Group E. The primary attachment rate was significantly higher in Group E (P = 0.020, Fisher’s exact test). Reattachment rate of the former and the latter half cases did not show significant differences in each group (70.0% vs. 54.5% in Group M; P = 0.659 and 100% vs. 90% in Group E; P = 1.000).
The cases with recurrent detachment were treated with vitrectomy and C3F8 gas or silicone oil. If there was proliferative vitreoretinopathy, encircling was combined. Two eyes in Group M failed to achieve anatomical success finally. Final reattachment was achieved in 19 of 21 patients (90.5%) in Group M and in 20 of 20 patients (100%) in Group E (P = 0.232). The MH was closed in 7 of 21 eyes (33.3%) in Group M and in 15 of 20 eyes (75.0%) in Group E. The rate of hole closure was significantly higher in Group E (P = 0.012, chi-square test). Once the retina was reattached, an additional operation was not performed to close the MH in the cases with the unclosed MH. No complications were associated with drainage retinotomy in Group E (Figures 1–3).
Fig. 2. An 80-year-old woman (Case 17 in Group E) visited the clinic with decreased visual acuity to hand motion in the right eye. A. Fundus examination revealed myopic degeneration, and retinal detachment complicated by macular hole in the posterior pole extended to inferior periphery. The axial length was 29.27 mm. During vitrectomy, retinotomy was performed superior to the superotemporal arcade at the edge of the staphyloma. C3F8 gas of 14% was used for the tamponade. After 2 months, the retina was reattached without recurrence (B) and closure of the MH was confirmed by optical coherence tomography (C). After 12 months, her visual acuity remained at 20/1000 because of severe chorioretinal atrophy involving the fovea.
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EXTRAMACULAR DRAINAGE OF SRF FOR MHRD JEON ET AL
Fig. 3. A. A 76-year-old woman (Case 18 in Group E) who had undergone cataract surgery 3 years earlier presented with macular hole and localized subretinal fluid in the posterior pole. There was another break in the macula. Visual acuity was 20/1000, and the axial length was 30.39 mm. Pars plana vitrectomy was performed using 23-gauge instruments. B. A retinotomy was made at the edge of the staphyloma close to the supertemporal arcade (arrow), and the viscous subretinal fluid was drained through it. The internal limiting was removed, and the vitreous cavity was filled with 12% C3F8. After 3 months, both the MH hole and the other break had closed without recurrence of retinal detachment. Her final visual acuity was 20/400. Optical coherence tomography shows two breaks at presentation (C) and closure of both breaks after the surgical procedure (D).
The mean visual acuity (logarithm of the minimum angle of resolution) after the surgical procedure was 1.55 ± 0.67, 1.57 ± 0.68, and 1.82 ± 0.69 at 3, 6, and 12 months, respectively, in Group M and 1.36 ± 0.47, 1.30 ± 0.45, and 1.56 ± 0.40, respectively, in Group E. The best visual acuity after the surgical procedure was 1.50 ± 0.68 in Group M and 1.15 ± 0.40 in Group E. The mean improvement in visual acuity was 0.41 ± 0.75 in Group M and 0.87 ± 0.77 in Group E (Figure 4). Visual acuity significantly improved after the surgical procedure in both the groups (P = 0.026 and P , 0.001,
Wilcoxon’s rank sum test). Postoperative visual acuity with ambulatory vision of 20/400 or better was achieved more frequently in Group E (16 of 20 eyes, 80.0%) than in Group M (10 of 21 eyes, 47.6%; P = 0.033, Fisher’s exact test). However, there were no significant differences in the best postoperative visual acuity or in the improvement in visual acuity between the 2 groups (P = 0.079 and 0.118, Mann–Whitney U test; Table 3). Discussion Retinal detachment from MH is rare in nonmyopic eyes because traction to MH is not strong enough to Table 2. Surgical Procedures in Vitrectomy for MHRD With Drainage Through the MH (Group M) or Extramacular Drainage (Group E) Group M (n = 21)
Fig. 4. Changes in visual acuity after vitrectomy for MHRD with drainage through the macular hole (Group M) or extramacular drainage (Group E) at postoperative months 3, 6, and 12.
Concurrent phacoemulsification, n (%) ILM peeling, n (%) Retinotomy, n (%) Tamponade, n (%) SF6 C3F8 Silicone oil, n (%)
Group E (n = 20)
P
12/15 (80)* 8/10 (80)
1.0
19 (90) — 3 (14) 17 (81) 1 (5)
*Phakic eyes. ILM, internal limiting membrane.
20 (100) 0.488 18 (90) — 0.082 0 (0) 19 (95) 1 (5)
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Table 3. Anatomical and Functional Outcomes After Vitrectomy for MHRD With Drainage Through the MH (Group M) or Extramacular Drainage (Group E)
Primary success (eyes), n (%) Final success (eyes), n (%) Hole closure (eyes), n (%) Best VA (logMAR), mean ± SD VA improvement (logMAR), mean ± SD VA changes (eyes), n (%) .2 lines increase +2 to −2 lines ,2 lines decrease VA distribution (eyes), n (%) $20/100 20/100 to 20/200 20/200 to 20/400 ,20/400
Group M (n = 21)
Group E (n = 20)
P
13 (61.9) 18 (85.7) 7 (33.3) 1.50 ± 0.68 0.41 ± 0.75
19 (95.0) 20 (100) 15 (75.0) 1.15 ± 0.40 0.87 ± 0.77
0.020 0.232 0.012 0.079 0.118 0.189
14 (66.7) 3 (14.3) 4 (19.0)
16 (80.0) 4 (20.0) 0 (0)
3 3 4 11
(14.3) (14.3) (19.0) (52.4)
5 5 6 4
(25.0) (25.0) (30.0) (20.0)
0.319* 0.139* 0.033*
*Compared with the number of eyes in the groups below the indicated level. VA, visual acuity; logMAR, logarithm of the minimum angle of resolution; SD, standard deviation.
pull the sensory retina from the RPE. The most common cause of MHRD is high myopia. Foveal detachment and surrounding retinoschisis are often observed in highly myopic eyes.13,14 Ikuno et al10 suggested that foveal detachment in myopic foveoschisis could be a predisposition to MHRD. Foveal detachment is thought to precede MH formation, which is followed by the extension of retinal detachment, instead of the development of retinal detachment from MH. This theory explains common surgical findings that old viscous subretinal fluid is drained even in recently symptomatic cases. This viscous fluid tends to coalesce, forming a thick stream during drainage, and the MH is dilated by the flow of the subretinal fluid. Although the MH seems to return to its original size after drainage, the macula in highly myopic eyes is thinner than that in nonmyopic eyes because of the degenerative changes, and therefore, it is prone to mechanical damage. Our hypothesis was that drainage through the MH damages not only the RPE but also the surrounding sensory retina, expanding the diameter of the MH and, consequently, lowering the closure rate of the hole. O’Driscoll et al15 reported a long-term MH closure rate of 31% in cases of rhegmatogenous retinal detachment accompanying MH. Although nonmyopic cases were included, the closure rate was much lower than that in idiopathic MH.16 They suggested that the low closure rate is caused by the internal drainage of viscous subretinal fluid through the MH, which can lead to the enlargement of the hole.15 Extramacular drainage of subretinal fluid has been previously reported. Wolfensberger and Gonvers5 reported the surgical outcomes of MHRD treated by vitrectomy combined with temporary silicone oil tamponade and laser photocoagulation. Although the subretinal
fluid was drained through the MH in most patients, fluid–perfluorocarbon liquid exchange was used to drain the subretinal fluid through a peripheral retinotomy that had been performed using a vitreous cutter in some cases. Differences in the surgical outcomes between the cases in which the subretinal fluid was drained through MH and through peripheral retinotomy were not presented. The MH closure was not evaluated because the study was conducted in the pre–optical coherence tomography era, and by ophthalmoscope, MH is barely visible in highly myopic eyes. Even using time-domain optical coherence tomography, the hole closure is occasionally unreliable because six radial scans may miss a small hole because of eccentric fixation in degenerative, highly myopic eyes. In the present study, hole closure was assessed by reviewing all the B-scans of the spectraldomain optical coherence tomographic raster scans. Closure of MH is thought to be a key in improving the anatomical success rate because it restores the normal anatomical configuration of the macula and eliminates the chances of recurrent detachment from the MH. In highly myopic eyes, unclosed MH is prone to redetachment of the retina because of the traction caused by staphyloma and weak adherence in the area of chorioretinal atrophy. The higher primary retinal reattachment rate in Group E could have resulted from the higher rate of hole closure. Final reattachment was achieved in all eyes in Group E. Extramacular drainage has another advantage that it avoids insults to the foveal RPE by suction through the MH. Kelly and Wendel17 suggested that changes in the RPE seem to be secondary to trauma to the RPE and photoreceptors during MH surgery and that they occur secondary to the precipitous suction removal of the thick subretinal fluid through MH. Charles11
EXTRAMACULAR DRAINAGE OF SRF FOR MHRD JEON ET AL
reported that RPE changes extending beyond the apparent rim of the subretinal fluid were observed in 6 of 24 cases that underwent MHRD surgery after subretinal fluid drainage through the MH. The above observations strongly support a mechanical pathogenesis for changes in RPE. Drainage retinotomy may be associated with postoperative complications, such as fibrosis, choroidal neovascularization, or recurrence.18,19 In a recent study that did not use drainage of subretinal fluid and silicone oil tamponade, Nadal et al20 reported high reattachment rates and MH closure in 51.9% of cases, which was slightly lower than the 75% in our results. As mentioned above, subretinal fluid of MHRD is commonly very viscous and may take a long time to absorb. The decreased function of the RPE in degenerative myopia would further delay absorption, leading to deterioration in the anatomical outcomes. If retinotomy could be performed safely, surgical drainage of the subretinal fluid would lead to improved outcomes. In the current study, no complication related to retinotomy was observed. The site of retinotomy in MHRD requires several considerations. The subretinal fluid in MHRD is commonly localized in the postequatorial retina. If retinal detachment is restricted to the macula, retinotomy should not be performed because postoperative expansion of scars related to the retinotomy may affect the fovea. Retinotomy in the area of chorioretinal atrophy should also be avoided because of the absence of a physiologic adhesive force and the risk of recurrence. If retinotomy is performed outside the staphyloma, too much subretinal fluid may remain after drainage through the retinotomy. In contrast, retinotomy inside staphyloma may promote recurrent retinal detachment. Macular hole closure was reported to be significantly correlated with final visual acuity.10 In the current study, no significant difference was detected in visual acuity at each postoperative time point, although there was a tendency toward greater improvement in Group E. However, Group E had a higher rate of ambulatory vision in the best visual acuity during follow-up. This parameter is more important in MHRD, in which visual acuity is generally very low. For example, improvement from hand motion to 20/800 is considered a significant improvement, but it is still worse than the ambulatory vision. It would be relevant to investigate the best visual acuity during the follow-up period to determine the efficacy of surgical treatment for MHRD in highly myopic eyes. Different tamponade materials and concentrations show various times to achieve the best visual acuity. In addition, visual acuity after surgical procedure may deteriorate gradually secondary to progressively
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degenerative changes, which are not uncommon in highly myopic eyes. Our study has several limitations: it is a retrospective series with a small number of cases. Because of the retrospective nature of the study, Group E includes more recent cases, and SF6 was used as tamponade only in Group M. However, these factors would not lead to a significant bias. All the procedures were performed by an experienced surgeon, and learning effects were not observed in each group. Tamponade gas was not reported to be a prognostic factor for primary attachment.21 In conclusion, extramacular drainage avoided adverse effects on the sensory retina and the RPE around the MH and improved success rates in MH closure, retinal reattachment, and visual outcome of vitrectomy for MHRD complicated in highly myopic eyes. A future study is required to compare results with extramacular drainage and without drainage of subretinal fluid. Key words: drainage retinotomy, high myopia, macular hole, macular hole retinal detachment, retinal detachment, staphyloma, vitrectomy. References 1. Nishimura A, Kimura M, Saito Y, Sugiyama K. Efficacy of primary silicone oil tamponade for the treatment of retinal detachment caused by macular hole in high myopia. Am J Ophthalmol 2011;151:148–155. 2. Cheung BT, Lai TY, Yuen CY, et al. Results of high-density silicone oil as a tamponade agent in macular hole retinal detachment in patients with high myopia. Br J Ophthalmol 2007;91:719–721. 3. Haut J, Van EG, Flamand M. Treatment of macular hole retinal detachment with silicone oil, with or without argon laser photocoagulation. Ophthalmologica 1983;187:25–28. 4. Yu J, Wang F, Cao H, et al. Combination of internal limiting membrane peeling and endophotocoagulation for retinal detachment related to high myopia in patients with macular hole. Ophthalmic Surg Lasers Imaging 2010;41:215–221. 5. Wolfensberger TJ, Gonvers M. Long-term follow-up of retinal detachment due to macular hole in myopic eyes treated by temporary silicone oil tamponade and laser photocoagulation. Ophthalmology 1999;106:1786–1791. 6. Ryan EH Jr, Bramante CT, Mittra RA, et al. Management of rhegmatogenous retinal detachment with coexistent macular hole in the era of internal limiting membrane peeling. Am J Ophthalmol 2011;152:815–819. 7. Shukla D, Rajendran A, Maheshwari R, Naresh KB. Early closure of macular hole secondary to rhegmatogenous retinal detachment with internal limiting membrane peeling. Ophthalmic Surg Lasers Imaging 2008;39:81–85. 8. Cho H, Choi A, Kang SW. Effect of internal limiting membrane removal in treatment of retinal detachment caused by myopic macular hole. Korean J Ophthalmol 2004;18:141–147. 9. Kadonosono K, Yazama F, Itoh N, et al. Treatment of retinal detachment resulting from myopic macular hole with internal limiting membrane removal. Am J Ophthalmol 2001;131: 203–207.
1102 RETINA, THE JOURNAL OF RETINAL AND VITREOUS DISEASES 10. Ikuno Y, Sayanagi K, Oshima T, et al. Optical coherence tomographic findings of macular holes and retinal detachment after vitrectomy in highly myopic eyes. Am J Ophthalmol 2003;136:477–481. 11. Charles S. Retinal pigment epithelial abnormalities after macular hole surgery. Retina 1993;13:176. 12. Curtin BJ. Physiologic vs pathologic myopia: genetics vs environment. Ophthalmology 1979;86:681–691. 13. Takano M, Kishi S. Foveal retinoschisis and retinal detachment in severely myopic eyes with posterior staphyloma. Am J Ophthalmol 1999;128:472–476. 14. Benhamou N, Massin P, Haouchine B, et al. Macular retinoschisis in highly myopic eyes. Am J Ophthalmol 2002;133: 794–800. 15. O’Driscoll AM, Goble RR, Kirkby GR. Vitrectomy for retinal detachments with both peripheral retinal breaks and macular holes. An assessment of outcome and the status of the macular hole. Retina 2001;21:221–225.
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16. Mester V, Kuhn F. Internal limiting membrane removal in the management of full-thickness macular holes. Am J Ophthalmol 2000;129:769–777. 17. Kelly NE, Wendel RT. Vitreous surgery for idiopathic macular holes. Results of a pilot study. Arch Ophthalmol 1991;109:654–659. 18. Richards SC, Maberley AL. Complications of retinotomies for subretinal fluid drainage. Can J Ophthalmol 1993;28:24–27. 19. McDonald HR, Lewis H, Aaberg TM, Abrams GW. Complications of endodrainage retinotomies created during vitreous surgery for complicated retinal detachment. Ophthalmology 1989;96:358–363. 20. Nadal J, Verdaguer P, Canut MI. Treatment of retinal detachment secondary to macular hole in high myopia: vitrectomy with dissection of the inner limiting membrane to the edge of the staphyloma and long-term tamponade. Retina 2012;32:1525–1530. 21. Nakanishi H, Kuriyama S, Saito I, et al. Prognostic factor analysis in pars plana vitrectomy for retinal detachment attributable to macular hole in high myopia: a multicenter study. Am J Ophthalmol 2008;146:198–204.
