Surgical Technique

Surgical Technique

Edited by George A. Williams

Perfluoro-n-Octane–Assisted Single-Layered Inverted Internal Limiting Membrane Flap Technique for Macular Hole Surgery

V

Pars plana vitrectomy was performed using the Constellation (Alcon Laboratories, Inc, Fort Worth, TX) sutureless 23-gauge vitrectomy system and a noncontact viewing system Resight 700 (Carl Zeiss Meditec AG, Jena, Germany). After removing vitreous

to the equator, the ILM was stained by injection of 0.025% Brilliant Blue G 250 (BBG; Sigma-Aldrich, St. Louis, MO) into the vitreous cavity over the macula area and following this with an immediate lavage. Viscous fluid in the hole base was aspirated passively during lavage. An ILM flap of about 1 disk diameter size was used to cover the macular hole from its superior margin considering gravity. A flap was made using 2 different techniques (Figure 1). First, a flap was made directly without removing the ILM. Second, a flap was made by removing the ILM except the area required for a flap (Figure 2). A specific order of ILM removal was required to create a flap (Figure 3). The ILM was first removed 1 disk diameter apart superiorly from the macular hole margin. Next, the temporal and nasal ILM was removed separately from inferior to superior, to remain the designated area for a flap. The ILM flap was gently flipped by inverting it using the intraocular forceps to cover the whole macular hole. A small amount of PFO (Perfluoron; Alcon Laboratories, Inc, Fort Worth, TX) was then gently introduced over the macula to keep the inverted ILM flap in the position during surgery. If displacement of the flap occurred during PFO injection, its position was adjusted using the forceps. After confirming the proper position of the flap, PFO was injected further to a total volume of 1 mL. Fluid– air exchange was started after removing peripheral

From the *Department of Ophthalmology, School of Medicine, Pusan National University, Yangsan, Korea; †Medical Research Institute, Pusan National University Hospital, Busan, Korea; and ‡Research Institute for Convergence of Biomedical Science and Technology, Yangsan Pusan National University Hospital, Yangsan, Korea. None of the authors have any financial/conflicting interests to disclose. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s Web site (www.retinajournal.com). Reprint requests: Ji Eun Lee, MD, PhD, Pusan National University Hospital, Ami dong 1-10, Seo-gu, Busan 602-739, Korea; e-mail: [email protected]

Fig. 1. The two different methods used to make an inverted ILM flap. A. An inverted flap was made without peeling of the ILM around the macular hole. B. The ILM was removed except the area for an inverted flap.

itrectomy became the standard treatment of macular hole after its introduction by Kelly and Wendel.1 Although progression of surgical techniques and diagnostic tools have improved the anatomical outcomes of macular hole surgery, postoperative visual recovery is usually limited.2–4 Furthermore, surgical closure is challenging in cases of long-lasting large macular holes5 or highly myopic eyes.6 Various surgical strategies have been introduced to improve postoperative outcomes for these cases.7–10 Recently, the inverted internal limiting membrane (ILM) flap technique was reported to have higher closure rate for large macular holes.10 The ILM around the macular hole is left to cover the macular hole during fluid–air exchange. However, their technique seemed like packing a macular hole with a folded ILM rather than covering it with a true flap. Here, the authors describe a modified technique for covering a macular hole with a single-layered flap of the ILM with the assistance of perfluoro-n-octane (PFO).

Surgical Technique

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2014 VOLUME 34 NUMBER 9

Fig. 2. Intraoperative view of the creation of a singlelayered inverted ILM flap. A. The ILM was peeled remaining the area for a flap. B. The remained ILM was flipped over using an intraocular forceps. C. Perfluoron-octane was injected gently over the macula to keep the inverted ILM flap in position. D. The inverted flap was kept in position at the end of fluid–air exchange.

vitreous and was performed slowly enough to allow time for the viscous fluid to migrate posteriorly. The remnant fluid was removed as completely as possible

Fig. 3. Diagrammatic representation of surgical technique to make a single-layered inverted ILM flap. A. A 0.025% brilliant blue G (BBG) was injected into the vitreous cavity to stain the ILM. B. The ILM at the upper side of a flap was peeled horizontally 1 disk diameter (DD) apart from the upper margin of the macular hole. C and D. The temporal and nasal ILM was peeled separately from inferior to superior to make a 1 DD-sized flap. E. The ILM peeling was extended to 3 to 4 DD size. F. A single-layered inverted ILM flap was maintained during fluid–air exchange using perfluoro-n-octane.

before removing the PFO because delayed flow of fluid can cause rolling or displacement of the inverted ILM flap without the support provided by the heavy liquid.

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20/40 20/60 20/60 Yes Yes Yes Facedown Facedown Facedown

20/160 20/125 20/200 SF6 Air Air Yes Yes Yes 483 464 476 438 632 752 62 60 64 10 11 12

Female Female Female

73 67 71 72 66 63 65 69 65 1 2 3 4 5 6 7 8 9

C3F8, perfluoropropane; SF6, sulfur hexafluoride.

20/125 20/50 20/50 20/125 20/80 20/60 20/50 20/30 20/40 20/125 20/300 20/125 20/200 20/125 20/50 20/300 20/160 20/200 Yes Yes Yes Yes Yes No Yes Yes No Head-up Head-up Head-up Head-up Head-up Facedown Head-up Head-up Head-up C3F8 SF6 SF6 SF6 SF6 Air Air Air Air Yes Yes Yes Yes No No No Yes Yes 270 445 370 493 469 446 411 467 320 645 489 445 727 674 610 636 610 320

Retinitis pigmentosa Idiopathic Idiopathic Idiopathic Idiopathic Idiopathic Idiopathic Idiopathic Branch retinal vein occlusion Idiopathic Idiopathic Idiopathic

Conditions Age

Sex

Air was flushed gently for 3 minutes to evaporate the PFO at the end of the fluid–air exchange. During this process, fluid on the disk was removed continually to avoid its accumulation in the posterior pole, which resulted in flap displacement. In early cases, a macular hole was tamponaded using a long-acting gas (either SF6 or C3F8), and patients were instructed to keep a head-up position after the operation. In later cases, after failure to close the macular hole due to inferior migration of the flap, room air was used and patients were instructed to maintain a facedown position for the day after the operation. Closure of macular hole was assessed using spectral domain optical coherence tomography (Cirrus HD-OCT; Carl Zeiss Meditec Inc, Dublin, CA). Supplemental Digital Content, http://links.lww.com/IAE/A306.

Results

Case

Female Female Female Female Male Female Female Female Male

Postoperative Hole At 6 Posture Closure Preoperatively Months Intraocular Gas Tamponade Concurrent ILM Peeling

Hole Height, mm Hole Diameter, mm

Table 1. Characteristics of Patients Underwent Single-Layer Inverted ILM Flap for a Large Macular Hole

Visual Acuity (Snellen)

SURGICAL TECHNIQUE

One surgeon performed this technique in 12 consecutive patients. All cases are summarized in Table 1. No intraoperative or postoperative complications related to the inverted flap technique were noted. Of the 12 eyes, 10 (83%) showed initial macular hole closure after primary surgery using a single-layered inverted ILM flap technique. One case (Case 6; Figure 4, A and B) showed an open macular hole, which had an elevated margin covered by the single-layered ILM flap in the postoperative optical coherence tomography. The ILM had not been removed in this case. After this case, the technique was modified to remove the ILM in the macula to 3 to 4 disk diameter size except the ILM flap. The other case showed migration of the ILM flap in optical coherence tomography (Case 9; Figure 4, C and D). Migration was not noted in patients who kept a postoperative facedown position for 1 day. In both cases mentioned above, the macular hole was closed after second operation in which the ILM was removed to 4 disk diameter size and 14% C3F8 gas was used as a tamponade. The mean visual acuity improved significantly from logarithm of the minimum angle of resolution (logMAR) 0.9 ± 0.21 at baseline to 0.48 ± 0.19 at 6 months (P = 0.004). Visual acuity of 20/40 or better was achieved in 3 eyes (25%). Representative cases (Cases 1 and 8; Figure 4, E–H) had a normal foveal configuration after surgical closure. The ILM flap was noted over the foveal depression in 5 cases (42%). Restoration of the inner and outer segment junction signal was noted in 5 eyes at 3 months and 6 months postoperatively (Figure 4H). Residual PFO was not found in any case.

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Fig. 4. A and B. Case 6 without concurrent ILM peeling. Optical coherence tomography (OCT) at 1 week postoperatively displayed an open macular hole with an elevated margin. The macular hole was covered with a single-layered inverted ILM flap (arrowheads). C and D. Case 9 with a macular hole and branch retinal vein occlusion who kept a postoperative head-up posture. A vertical image of OCT showed inferior migration of the flap (arrowheads) without hole closure at 1 month postoperatively. E and F. Case 1 with large-sized macular hole and retinitis pigmentosa. At 6 months after operation, the macular hole was successfully closed. G and H. Case 8: patient with preoperative hole size of 610 mm, showed restoration of the inner and outer segment junction line in OCT at 6 months after surgery. Visual acuity improved from 20/160 to 20/30.

Discussion Michalewska et al10 reported a higher macular hole closure rate after vitrectomy using an inverted ILM flap and suggested that the inverted ILM flap might

stimulate the proliferation of glial cells that fill macular holes. However, their technique seemed like packing the macular hole with a folded ILM and resulted in a multilayered membrane observed in postoperative optical coherence tomography. We considered that

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SURGICAL TECHNIQUE Table 2. Summary of the Surgical Technique for a SingleLayered Inverted ILM Flap in Macular Hole Surgery Stain the ILM using 0.025% BBG after removing vitreous to the equator A 1 disk diameter-sized flap is made by removing the surrounding ILM. Remove the superior area horizontally, and then the temporal and the nasal side from inferior to superior. Keep the designated area attached during removal Flip the flap to cover the macular hole using an intraocular forceps. The margin should be preserved as attached Inject a small amount of PFO gently over the inverted flap. If the flap is displaced during injection, reposition the flap using the forceps under PFO. After confirming proper flap position, inject more PFO to a total of 1 mL Remove the peripheral vitreous while confirming the absence of retinal breaks or detachment Exchange the fluid with air slowly, allowing enough time for the fluid to migrate posteriorly. Place the tip of the extrusion needle at several places in the periphery. Remove the remnant fluid as completely as possible before removing the PFO Flush air gently for 3 minutes for PFO to evaporate. Aspirate fluid on the disk continually Finish the operation, as the vitreous cavity filled with air, and maintain postoperative facedown position for the day after the operation in case of uncomplicated surgery BBG, brilliant blue G; ILM, internal limiting membrane; PFO, perfluoro-n-octane.

a single-layered ILM would be more physiological, provide a more regular structure for glial proliferation, and thus, aid macular hole closure and regeneration of the retinal structure. We had experienced several trial-and-errors for the development of our technique. Making a flap was the first part. Creating a flap without removing the ILM is simpler, but it was failed to close the macular hole in Case 6. Two reasons were suggested, that is, failure to relieve tangential traction by the remaining ILM and sequestration of the viscous fluid in the hole base by the ILM flap. The fluid in the hole base cannot be aspirated during fluid–air exchange in our technique, which was modified to aspirate the hole base fluid during the removal of BBG. The most difficult part of the single-layered ILM flap technique is maintaining the flap position until the completion of fluid–air exchange. Perfluoro-n-octane was chosen among various heavy liquids because it has a low vapor pressure, and thus, could be removed by evaporation without lavage, which might displace the flap. It is important that fluid should be removed as completely as possible before PFO. The fluid–air exchange should be performed slowly to minimize turbulence, which may displace the PFO bubble and thereby dislocate the ILM flap. Fluid thread between extrusion needle and the fluid surface

during fluid–air exchange substantiate the presence of the viscous fluid, which can be removed best by placing the tip of an extrusion needle at the periphery of vitreous cavity. The next issue was postoperative posture. The headup posture was instructed after surgery in early series. However, the macular hole failed to be closed in one of these cases because of postoperative flap displacement. Finally, the protocol was modified to keep a facedown posture during the day of surgery to position the flap over the macular hole, and there were no more cases of failure. Our final surgical technique is summarized in Table 2. Two cases of closure after the second operation indicated that our cases would have been closed with a standard operation. However, compared with previous studies,10,11 on an inverted flap using remnant ILM after circumferential ILM peeling, our single-layered inverted ILM flap showed more normal configuration of fovea without folded membrane. Although more delicate procedures were required, we demonstrated that this alternative method is a definite technique for making a single-layered inverted ILM flap. Furthermore, short postoperative facedown positioning and air tamponade without using long-acting gas were sufficient for hole closure and would result in faster visual recovery. This novel technique would be beneficial for the treatment of large macular holes, and the efficacy should be evaluated in a large-scale case study. Key words: macular hole, inverted internal limiting membrane flap. MIN KYU SHIN, MD*† KEUN HEUNG PARK, MD* SUNG WHO PARK, MD*† IK SOO BYON, MD*‡ JI EUN LEE, MD, PHD*† References 1. Kelly NE, Wendel RT. Vitreous surgery for idiopathic macular holes. Results of a pilot study. Arch Ophthalmol 1991;109: 654–659. 2. Imai M, Iijima H, Gotoh T, Tsukahara S. Optical coherence tomography of successfully repaired idiopathic macular holes. Am J Ophthalmol 1999;128:621–627. 3. Michalewska Z, Michalewski J, Nawrocki J. Diagnosis and evaluation of macular hole with the HRT 2 retina module [in German]. Ophthalmologe 2007;104:881–888. 4. Michalewska Z, Michalewski J, Cisiecki S, et al. Correlation between foveal structure and visual outcome following macular hole surgery: a spectral optical coherence tomography study. Graefes Arch Clin Exp Ophthalmol 2008;246:823–830. 5. Salter AB, Folgar FA, Weissbrot J, Wald KJ. Macular hole surgery prognostic success rates based on macular hole size. Ophthalmic Surg Lasers Imaging 2012;43:184–189.

1910 RETINA, THE JOURNAL OF RETINAL AND VITREOUS DISEASES 6. Suda K, Hangai M, Yoshimura N. Axial length and outcomes of macular hole surgery assessed by spectral-domain optical coherence tomography. Am J Ophthalmol 2011;151: 118–127. 7. Couvillion SS, Smiddy WE, Flynn HW Jr, et al. Outcomes of surgery for idiopathic macular hole: a case-control study comparing silicone oil with gas tamponade. Ophthalmic Surg Lasers Imaging 2005;36:365–371. 8. Alpatov S, Shchuko A, Malyshev V. A new method of treating macular holes. Eur J Ophthalmol 2007;17:246–252.


9. Kuriyama S, Hayashi H, Jingami Y, et al. Efficacy of inverted internal limiting membrane flap technique for the treatment of macular hole in high myopia. Am J Ophthalmol 2013;156: 125–131. 10. Michalewska Z, Michalewski J, Adelman RA, Nawrocki J. Inverted internal limiting membrane flap technique for large macular holes. Ophthalmology 2010;117:2018–2025. 11. Mahalingam P, Sambhav K. Surgical outcomes of inverted internal limiting membrane flap technique for large macular hole. Indian J Ophthalmol 2013;61:601–603.