Spontaneous Progression of a Long-Standing Lamellar Macular Hole into a Full-Thickness Macular Hole

Introduction

First described by Gass in 1975¹ as a macular lesion resulting from cystoid macular edema, the term lamellar macular hole has been used to describe an “aborted” full thickness macular hole in which a complete posterior vitreous detachment (PVD) occurs, causing a partial thickness retinal defect. Such an occurrence results in a stable, round, and well-circumscribed reddish lesion in the macula, associated with good visual acuity (usually 20/40 or better).^2–4

Recently, optical coherence tomography (OCT) studies expanded the definition of lamellar macular hole on an anatomic basis, allowing a precise differentiation between lamellar, full thickness and macular pseudohole secondary to an epiretinal membrane.^3,5

Idiopathic macular holes are not typically associated with preexisting macular pathology. As suggested by Gass,⁴ they develop after the outer part of the vitreous cortex contracts, leading to the dehiscence of the retinal receptor layer at the umbo and centrifugal retraction of the retinal photoreceptors.

We report a case of a long-standing stable lamellar macular hole with good visual acuity that became a full thickness macular hole soon after uncomplicated cataract surgery.

Case Report

A 69-years-old male, with positive serology for the human immunodeficiency virus, was initially seen in 1995 for a routine eye examination. In his first examination, the corrected visual acuity was 20/20 with −6.25 spherical diopters in the right eye and 20/20 with −4.50 spherical diopters in the left eye. The anterior segment examination revealed a 1+ nuclear sclerosis in both eyes and fundus examination was completely normal in both eyes. In October 1998, his visual acuity suddenly dropped to 20/50 in the right eye, and a full thickness macular hole was diagnosed in this eye (Fig. 1). The hole was successfully treated with pars plana vitrectomy, epiretinal membrane peeling, and gas bubble infusion (Fig. 1). One year later, he underwent cataract extraction and posterior chamber intraocular lens (PCIOL) implantation in the right eye with improvement of the visual acuity (20/30 with correction). In June 2000, the patient noticed a small black spot in the vision of the left eye, without decreasing of the visual acuity (20/20). Clinical examination and OCT disclosed a lamellar macular hole (Fig. 2). The patient was observed annually and an epiretinal membrane (ERM) developed in both eyes, remaining stable without causing new problems (Figs. 1 and 2).

Figure 1. Optical Coherence Tomography (OCT) Scans Through the Right Macula During the Follow Up: (A) OCT 1 Scan Showing a Full Thickness Macular Hole and Intra-Retinal Cysts in the Borders of the Hole (1998). (B) OCT 1 Scan Showing the Closed Macular Hole (June 2000). (C) Stratus OCT Scan Showing the Presence of Epiretinal Membrane (ERM) Nasal to the Fovea (right in the Figure) (April 2006).

Figure 2. Optical Coherence Tomography (OCT) Scans Through the Left Macula During the Follow Up: (A) OCT 1 Scan Disclosed the Posterior Hyaloid Attached to the Foveola (arrowheads) Forming a Stage 0 Macular Hole (1998). (B) OCT 1 Scan Showing the Lamellar Macular Hole. Note that the Posterior Hyaloid Cannot be Identified (June 2000). (C) Stratus OCT Scan Demonstrates the ERM in Both Sides of the Fovea. Note the Sharp Borders of the Foveal Depression Secondary to the Contraction of the ERM Simulating a Macular Pseudohole, but the Thinning of the Central Fovea Due to the Disruption of the Outer Nuclear Layer is Compatible with the Lamellar Hole (April 2006). (D) Stratus OCT Scan Showing the Full Thickness Macular Hole 7 Weeks After the Cataract Surgery (May 2008). (E) Ultra-High Resolution OCT 3 Months After Full Thickness Macular Hole Repair Showing the Closed Hole, Intact External Limiting Membrane, and Irregular Inner Segment–Outer Segment Photoreceptor Junction.

In March 2008, the patient presented with corrected visual acuity of 20/30 in the right eye and 20/60 in the left, and the examination showed a 2+ nuclear sclerosis in the left eye. Fundus examination and OCT scan were stable in both eyes. The patient underwent cataract extraction and PCIOL implantation without complications, and 7 weeks after the surgery the patient suddenly noticed a central black spot in the vision of the left eye. His visual acuity had dropped to 20/300 and the fundus examination and the OCT disclosed a full thickness macular hole in the left eye (Fig. 2). Pars plana vitrectomy, epiretinal membrane peeling, and gas bubble injection were performed with successful closure of the macular hole (Fig. 2), and the visual acuity improved to 20/40 3 months after the surgery.

Discussion

Lamellar macular holes are widely thought to be stable and associated with good visual acuity. Takahashi et al.⁶ described the OCT findings in two cases of lamellar macular hole, one of them progressed to full thickness macular hole 4 months after development. Targino et al.⁷ described two cases of lamellar macular hole with complete vitreofoveal separation that progressed to full thickness macular hole a short time after they developed (6 weeks and 5 months). As far as we know, this is the first case in the literature to describe a long-term stable lamellar macular hole (8 years) with good visual acuity that progressed to a full thickness macular hole.

Lamellar macular hole is usually a stable condition, rarely progressing to full thickness macular hole. Targino et al.⁷ suggested that the progression of the lamellar hole in their cases could be explained by the recently proposed “hydration theory”, in which a defect in the inner retina with secondary accumulation of the fluid vitreous into the middle and outer retinal tissues may be responsible for the macular hole formation.⁸ Although this theory could be applied to cases in which the vitreofoveal separation was recent causing the disruption in the foveal tissue necessary to the influx of fluid vitreous, it is unlikely that this happened in our patient, because his lamellar hole was diagnosed 8 years before.

The Vitrectomy for Macular Hole Study Group demonstrated in one of their reports that cataract surgery increased the odds of ERM development.⁹ Although we were not able to clinically detect an increase in the ERM after the cataract surgery, another explanation for the progression of the lamellar hole to a full thickness hole could be the growth of the ERM after the surgery causing a tangential force on the fovea and leading to the disruption of the remaining photoreceptor layer. Similar mechanism has been proposed by some authors to cause the re-opening of successful surgically closed full thickness macular hole.¹⁰

Several non-idiopathic causes of full thickness macular hole have been described in the literature, such as hypertension, trauma (including post-Nd:YAG laser capsulotomy), lightning strike, diabetes, ERM, macular edema, optic pit, X-linked retinoschisis, infectious causes (fungal endophthalmitis and Bartonella henselae neuroretinitis), and idiopathic parafoveal telangiectasis. The present case report does not warrant the inclusion of lamellar macular hole in this list, but might suggest that patients with lamellar macular holes associated with ERM undergoing ocular procedures (like cataract surgery) should be followed closely due to the risk of destabilization of the lamellar macular hole and progression to full thickness macular hole.

In summary, we described one case of long-standing lamellar macular hole that progressed to a full thickness macular hole following an uncomplicated cataract surgery. The reasons for this progression remain unclear.