Abnormal Vitreoretinal Interface Leading to Macular Hole–Associated Retinal Detachment in Straatsma Syndrome

Abstract

Introduction: To report a case of macular hole (MH)–associated retinal detachment (RD) with Straatsma syndrome. Methods: A clinical case was retrospectively reviewed. Results: A 39-year-old woman with Straatsma syndrome was treated for an MH-associated RD. The MH was closed with vitrectomy and internal limiting membrane peeling, during which an unusually strong vitreoretinal adhesion was encountered in the area of myelinated nerve fibers. One day postoperatively, the patient developed serous choroidal effusions and a serous RD, which resolved by postoperative week 1. The patient’s vision ultimately returned to baseline. Conclusions: The presence of an unusually strong vitreoretinal adhesion in the area of myelinated nerve fibers and the development of a postoperative serous RD suggest that myelination may contribute to vitreoretinal adhesion and the development of MHs in Straatsma syndrome.

Introduction

Straatsma syndrome was first described in 1979 in 4 patients with unilateral axial myopia, extensive myelinated nerve fibers, and amblyopia. ¹ Although strabismus was initially included as a fourth feature, it was not always present and has since been removed as a defining feature. The amblyopia is typically severe and responds poorly to occlusion therapy.

This syndrome is thought to be static without significant progression or impact on ocular anatomy after stabilization of the amblyopia. However, several cases of macular holes (MHs) in Straatsma syndrome have been reported without a clear explanation of how this pathology is related to the underlying syndrome beyond myopia as a risk factor.^{2 –4}

We report a case of an MH-associated retinal detachment (RD) in a patient with Straatsma syndrome in which myelination was thought to contribute to the vitreoretinal pathology.

Case Report

A 39-year-old woman presented with 3 days of floaters and a shadow in the central vision in the left eye. She had a history of amblyopia, with a best-corrected visual acuity (BCVA) of 20/200, axial myopia, and myelinated nerve fibers in the left eye, consistent with Straatsma syndrome. She had a retinal tear in the left eye that was treated with laser retinopexy 12 years previously.

The VA was 20/20 and counting fingers (CF) in the right eye and left eye, respectively. The intraocular pressure (IOP) was normal bilaterally. The left eye was phakic and had an attached hyaloid; a small, anomalous optic nerve; and 360-degree peripapillary myelinated nerve fibers extending to the midperiphery superonasally, superiorly, and superotemporally (Figure 1, A–C). There was a macular hole with an RD extending to the arcades. The previous superior retinal tear was well treated without surrounding subretinal fluid (SRF).

Figure 1.

Preoperative imaging. Fundus photographs of the right eye (A) and left eye (B) show extensive retinal nerve fiber myelination, a macular hole (MH), and a posterior detachment in the left eye. Arrows denote the margins of the retinal detachment (RD). (C) Optical coherence tomography confirms the presence of an MH and RD. (D) Intraoperative photograph shows an attached macula after internal limiting membrane peeling (central area of lighter pigmentation) and fluid–air exchange.

The patient underwent vitrectomy using triamcinolone to highlight the vitreous. A posterior vitreous detachment (PVD) was induced at the optic nerve and over the macula. In the area of myelinated nerve fibers, strong vitreoretinal adhesion made propagation of the PVD challenging. Despite repeated attempts, the PVD was not extended to the periphery in the superonasal area. The internal limiting membrane (ILM) was stained (Tissue Blue, Brilliant Blue G Ophthalmic Solution, 0.025%, DORC) and peeled around the hole. A fluid–air exchange was performed, draining SRF through the macular hole (Figure 1D), and air was exchanged with 14% perfluoropropane.

One day postoperatively, the VA remained CF with an IOP of 10 mm Hg. Shallow, circumferential, anterior serous choroidal effusions and inferior shifting serous SRF were present. No breaks were identified, and standard postoperative care was recommended. One week postoperatively, the VA remained CF and the choroidal effusions and the SRF had resolved. At 4 months, the MH remained closed and the VA had improved to 20/300–20/400 (Figure 2).

Figure 2.

Postoperative month 2 imaging. Fundus photograph (A) and optical coherence tomography (B) of the left eye show an attached retina and a closed macular hole.

Conclusions

We report the treatment of an MH-associated RD in the setting of Straatsma syndrome. The case was notable for a firmly adherent hyaloid to the underlying myelinated nerve fibers and an early choroidal effusion and exudative RD that spontaneously resolved.

Three cases have been reported that describe the development of an MH and RD in the setting of Straatsma syndrome, and all were treated with vitrectomy and ILM peeling. Two of these presented with a total RD.^2,3 In the first case, the posterior vitreous was attached and a PVD was induced at the time of surgery. ² In the second case, the status of the posterior vitreous was not noted, and the retina redetached 2 weeks postoperatively. ³ The nature of any adhesion of the hyaloid to the myelinated nerve fiber was not noted in either case. A third case of MH with partial RD had attached hyaloid at presentation. ⁴ A PVD was induced at the time of surgery, but it could not be released from the area of myelination. The description of the postoperative course was limited to 1 week. This firm adhesion was similar to that in the present case.

Gentile et al ⁵ described the pathophysiology of idiopathic MHs in 3 phases. In the initiating phase, vitreofoveal traction leads to dehiscence of the posterior hyaloid and an ILM defect. This is followed by the progression phase whereby fluid enters the ILM defect and hydrates the inner retinal layers, causing a lamellar hole. Once the external limiting membrane is breached, the retinal pigment epithelium (RPE) pump becomes overwhelmed and hydration of the outer retina leads to a full-thickness hole. Although tangential traction may contribute to this, it is not necessary for hole development at this stage. The third phase describes closure via glial migration to bridge the hole, allowing reconstitution of the fluid-barrier function of the retina and proper functioning of the RPE pump. The abnormal hyaloidal-myelinated nerve fiber attachment encountered in the current case may have transmitted tractional forces to the vitreofoveal interface, initiating the first phase of MH development. The similarity of this case to others in the literature suggests that this vitreofoveal traction from the macular retinal nerve fiber layer may be a common feature of Straatsma syndrome.

MHs can also develop in the setting of high myopia. Typically, this is associated with staphyloma, preexisting foveoschisis, and epiretinal membrane (ERM). ⁶ Inner retinal tension, balanced against ocular growth and staphyloma formation, generates posterior retinoschisis and subsequent MH development. ERMs can contribute to this tangential traction and elevate the edges of the MH to prevent closure and allow for detachment. In the current case, the status of the retina before presentation was unknown; however, the eye was staphylomatous and there were significant intraretinal cysts in the outer plexiform layer on presentation. Although myopia may have contributed to hole development, the abnormal vitreous adhesion at the myelinated nerve fibers likely generated traction on preexisting foveoschisis, yielding the MH.

The postoperative choroidal effusion and exudative RD observed in the current case may also be related to abnormal vitreoretinal adhesion. A similar finding was previously reported in treatment of an idiopathic MH. ⁷ In this report, a patient had vitrectomy for a stage 3 MH and was found to have 360-degree choroidal effusions and an inferior exudative bullous RD at postoperative week 1, despite normal IOPs. The choroidal effusion and RD spontaneously resolved after 2 weeks and 6 weeks, respectively. Notably, this patient was found to have an exceptionally adherent hyaloidal face at the optic nerve intraoperatively. It was proposed that the manipulation required to release this may have stimulated exudation. Alternatively, high myopia has been described as a risk factor for choroidal effusions associated with serous RD, or the effusions could have been the result of transient postoperative hypotension. ⁸ However, the similarities of manipulating firm vitreoretinal adhesions resulting in an unusual postoperative finding in the present case are consistent with this theory, and to our knowledge, this is the first report of Straatsma syndrome to observe this finding.

In conclusion, this case reinforces recent evidence that MHs may be a delayed feature of Straatsma syndrome and suggests that myelination may generate abnormal vitreoretinal traction that leads to these holes. Furthermore, exudative RDs and serous choroidal effusions may result from manipulation of such abnormal vitreoretinal adhesions. Patients with Straatsma syndrome should have regular ophthalmic evaluation because early MHs can develop asymptomatically in amblyopic eyes and further vision loss from RD can be avoided.