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Since Kelly and Wendell introduced macular hole surgery in the 1990s,1 numerous innovations and modifications have been introduced, particularly for advanced management of different hole types. This includes persistent or refractory holes, for which a subsequent surgery typically has a lower success rate than a primary attempt.2
In this case of a persistent macular hole that failed to close with a primary surgery, we deployed a combination of techniques to achieve anatomical success with improvement in visual acuity.
CASE REPORT
A 59-year-old woman presented for evaluation of a persistent macular hole in her left eye. A month earlier, she had undergone a pars plana vitrectomy (PPV) with peeling of the internal limiting membrane (ILM) with sulfur hexafluoride gas endo-tamponade without successful closure of the macular hole. Her ocular history also included cataract extraction with implantation of IOLs in both eyes and successful closure of a full-thickness macular hole in her right eye a few months prior.
The patient’s Snellen VA was 20/30 in the right eye and 20/100 in the left eye. Her IOPs were 16 mm Hg in both eyes. Slit-lamp examination revealed posterior chamber IOLs in both eyes with an open posterior capsule in the left eye. Dilated fundus examination revealed an avitric left eye with a full-thickness macular hole. OCT imaging of the left eye confirmed the presence of a macular hole with perifoveal cystoid macular edema. After discussion, the patient agreed to undergo a second surgical attempt to close the hole.
Trocars were placed in accordance with a standard 3-port 25-gauge PPV. Diluted triamcinolone was injected to identify retained vitreous, and a close shave of the vitreous base was performed. Diluted indocyanine green was then injected to identify the ILM and the extent of the previous peel, which had a radius of approximately 4.5 mm from the fovea, extending to the temporal edge of the optic nerve (Figure 1). Owing to the large peel area, a rotational pedicle flap was initiated with a FINESSE Flex Loop (Alcon), given the adherent nature of the ILM and the desire to produce a broad hinged flap. Grieshaber Advanced DSP Tip ILM Forceps (Alcon) were then used to propagate the flap along the arcades, taking care not to prematurely amputate or inadvertently narrow the flap width, until it was of adequate length to reach the extent of the hole (Figure 2). A Tano Diamond Dusted Membrane Scraper (Bausch + Lomb) was used to gently mobilize the edges around the macular hole to release any adhesions that might prevent its closure (Figure 3). To identify new peripheral pathology, 360º scleral depression was performed. The flap was then maneuvered into place, draping over and into the macular hole with the soft-tip cannula while weighing down the flap with a dispersive OVD. Additional OVD was then gently refluxed onto the flap over the hole to maintain the flap in good position (Figure 4). A careful fluid-air exchange was performed to avoid inadvertently dislocating or amputating the flap. An air-gas exchange was performed with octafluoropropane (C3F8) gas. The cannulas were removed, and the wounds were checked for watertight closure. Peribulbar antibiotics and steroids were provided at the end of the case.
Most recently, the patient followed up for her postoperative week 6 visit and was found to have anatomic success with closure of the macular hole. Her VA had improved to 20/70 from 20/100, albeit with residual superior intraocular gas.
We offer the following points that may improve success and facilitate the surgery:
- The use of triamcinolone to ensure that the posterior hyaloid membrane and the perifoveal cortical vitreous has been completely removed is important, as this residual material may produce horizontal tension on the hole and prevent its closure. Often, these eyes may exhibit vitreoschisis, which can provide a false sense of confidence that the posterior vitreous detachment was complete. Additionally, a peripheral shave may allow for increased intraocular volume of gas, and hence better endo-tamponade, particularly with shorter-acting gas types.
- Some holes, particularly if they exhibit any degree of chronicity, may form adhesions or scar tissue between the retina and the retinal pigment epithelium. Using gentle massage of the hole edges, as was used in this case, or even using subretinal blebs of BSS may help mobilize the hole edges by disrupting these adhesions and facilitate successful hole closure. Care must be taken to avoid injury to the fovea as this may lead to poor recovery of VA whether the hole closes or not.
- When using a flap, either free or pedicle, it is helpful to perform peripheral scleral depression before positioning the flap to ensure that any temporary deformation of the eye, including unintended redirection of the infusion, does not inadvertently dislodge the flap.
- OVD is helpful to keep the flap in place so that intraocular infusion currents do not move it from its intended location. Items such as perfluoro-n-octane (PFO) or autologous blood/serum also have been used in these cases to maintain the flap over or within a macular hole. These are helpful, as they may prevent any mechanical trauma caused by physically tucking the flap into the hole, and thus will reduce operative time spent in repositioning a flap.
- A careful fluid-air exchange is critical for two reasons: 1) to ensure that the flap does not move with the current of fluid, which may result in dislocation or even amputation of the flap; and 2) because retained fluid at the hole interface decreases the effectiveness of the endo-tamponade, which may prevent hole closure.
DISCUSSION
The first published use of a hinged flap was by Michalewska and colleagues, who used an inverted hinge ILM flap from the rim of the macular hole.3 The idea is that the ILM provides a scaffold for glial tissue to propagate and aid in bringing the edge of the hole together, restoring anatomical continuity of the photoreceptor layer.
Since then, multiple techniques to provide this scaffold have been described, such as rotational pedicle ILM flaps, free ILM flaps, placement of lens capsule, homologous amniotic membrane grafts, and autologous retinal transplantation. In this case, owing to the wide ILM peel, a rotational flap was created, given the additional difficulty of producing a temporal inverted hinge flap, which would have necessitated the creation of a broad flap at least 5 mm long in the equatorial retina.
CONCLUSION
A persistent or refractory macular hole presents many challenges to the surgeon, but there are multiple tools and techniques that may be used to improve the rate of anatomical closure and surgical success. Careful attention to each step of the procedure can shorten operative time and difficulty.
