Inverted Flap Technique for Large Macular Hole Secondary to Chronic Uveitis.

Macular hole is a defect in the neurosensory retina at the center of the fovea, seen in 8.3% of the postuveitic cases. In such cases, macular holes tend to be large and are associated with structural damage in the outer retinal layers. Here, we report a case of bilateral chronic intermediate uveitis treated with sub-Tenon steroids that developed a full-thickness macular hole in the right eye. We treated it surgically with inverted flap technique of internal limiting membrane peeling. Postoperatively, the patient showed Type-1 closure of the hole with visual improvement.

Introduction

Macular hole, a defect in neurosensory retina at the center of the fovea, is most commonly idiopathic (58.3%), followed by posttraumatic (16.7%) and postuveitic (8.3%).[1] The pathophysiology of macular hole in postinflammatory cases differs from idiopathic ones. Although spontaneous closure may be seen in postuveitic macular holes,[2] chronic uveitic holes can become large in diameter with compromised photoreceptor function, making structural and functional improvement rather challenging. Although vitrectomy with internal limiting membrane (ILM) peeling with gas tamponade has become the standard treatment for macular hole closure, Lai et al.[3] suggested that complete ILM peeling may not be suitable for all types of macular holes. Incomplete ILM peeling with part of the ILM still attached to the macular hole edge with a flap reposited into the hole cavity as in the “inverted flap technique” is one of the modifications that have been used by surgeons for large macular holes. In this case report, we describe how inverted flap technique was useful in closure of a macular hole secondary to uveitis.

Case Report

A 30-year-old male presented to us with complaints of blurring of vision in both eyes (OU) during the past 6 months. He had been on and off topical as well as systemic steroids for recurrent episodes of bilateral chronic anterior uveitis in the past couple of years. Best-corrected visual acuity (BCVA) at presentation in the right eye (OD) and left eye (OS) was 6/18 N10 and 1/60 N6. He was also diagnosed to have idiopathic intermediate uveitis with chronic cystoid macular edema (CME) [Figure 1a and b] as well as complicated cataract in OU and was advised to systemic steroids with immunosuppressives. He was also given bilateral multiple posterior sub-Tenon's triamcinolone injections. Following treatment, there was resolution of CME [Figure 1c and d] with improvement in BCVA to 6/9 N6 in OD and 6/36 N10 in OS. Phacoemulsification with iris hooks with in-the-bag posterior chamber intraocular lens implantation in OU under steroid cover was done, following which vision improved to 6/7.5 N6 OU. However, 3 months after cataract surgery in OD, he reported a drop in visual acuity to 6/36 N12. Optical coherence tomography (OCT) confirmed the presence of a full-thickness macular hole (FTMH) [Figure 1e] with maximum basal diameter of 887 μ and minimum diameter between edges of 419 μ. Macular hole index (height/base) was 0.54. The patient was taken up for macular hole surgery involving pars plana vitrectomy (PPV) with inverted flap ILM peeling and injection of perfluoropropane (C3F8) under steroid cover.

Figure 1

(a) Optical coherence tomography of the right eye showing increased retinal thickness with intraretinal cystoid spaces. (b) Optical coherence tomography of the left eye showing chronic cystoid macular edema. (c) Optical coherence tomography of the right eye showing resolution of cystoid macular edema after posterior sub-Tenon triamcinolone. (d) Optical coherence tomography of the left eye showing resolution of cystoid macular edema after posterior sub-Tenon triamcinolone. (e) After cataract surgery, Stage-4 macular hole in the right eye. (f) Type-1 closure of macular hole in the right eye following inverted flap technique

Surgical procedure

25-gauge PPV with meticulous posterior vitreous separation was done. ILM was stained with brilliant blue under air; ILM edge was lifted superotemporal to fovea and ILM peeling was done with ILM forceps. ILM was left attached to about 1–2 clock hour of the edge of the macular hole. ILM was trimmed at very low suction using a microvit, and the flap thus made was inverted as a single layer onto the macular hole to fill the gap with the vitreal surface of the ILM now facing the RPE. Careful fluid–air exchange was done, not to disturb the flap and 14% C3F8 exchanged with air. The patient was followed up on the 1st and 3rd postoperative days and then 6 weeks later. He was advised to prone position for 3 weeks. As seen at 6 weeks, OD BCVA was 6/18 on distant Snellen's visual acuity chart, N8 at 25 cm with OCT confirming a Type 1 macular hole closure [Figure 1f].

Discussion

Gass introduced the classification and pathophysiology of macular hole pointing toward the key role of tangential and anteroposterior vitreomacular traction.[4] Inflammatory diseases of the eye affect macula often, and this may be a major cause of compromised vision. Chronic cystoid edema is a known precursor for the development of an FTMH in uveitic eyes as was seen in our case. Surgical treatment is the standard of care for closing macular holes in Stage 3 and Stage 4. Studies have recommended the use of inverted flap technique for macular hole closure. This technique has improved the anatomical and functional outcome of macular hole surgery, especially in difficult situations such as postvitrectomy holes, posttraumatic holes, myopic holes, and chronic and large holes.[5] Uveitic macular holes also present a challenge with up to 83% of operated eyes showing an open macular hole in spite of surgery with ILM peeling.[6] Inverted flap technique has been used with up to 100% efficacy in large or secondary macular holes. We report a case where this technique was successful in closure of a uveitic macular hole with good visual improvement. Stabilization of an ILM flap has been of concern. To prevent the loss of ILM flap, we kept the ILM attached to one edge of the MH and also did a slow fluid–air exchange to avoid any turbulence without the use of any perfluorocarbon to stabilize the flap. Using this technique, our anatomical result was excellent with good functional improvement as well. Long-term follow-up may show even better visual outcome.

ILM acts as a scaffold for the Muller cell growth and gliosis formation. The photoreceptors then follow and regrow in this defect and result in functional improvement. Using this method, we achieved not only a hole closure but also the hole closed in a “U-shaped” foveal configuration of a Type 1 closure which is associated with the best visual outcome.[7] BCVA improved from the preoperative value of 6/36 to 6/18 within 6 weeks.

Conclusion

We believe that the inverted flap technique is here to stay and can be very promising even in eyes with secondary macular holes due to underlying uveitis. Long-term follow-up as well as study of a larger case series may be necessary to emphatically support this.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.