Role of pars plana vitrectomy and membrane peel in vitreomacular traction associated with retinal vasoproliferative tumors.

To report a case of retinal vasoproliferative tumor (VPT) with secondary epiretinal membrane (ERM) formation and vitreo-macular traction managed by pars plana vitrectomy (PPV) and membrane peel. A 29-year-old male was referred for management of decreased vision in the right eye (OD) for 1 week. Presenting visual acuity was 20/50 Snellen feet (ft) OD, and fundus examination showed an ERM associated with a reddish-yellow mass in the inferotemporal quadrant with overlying exudation, hemorrhage, and subretinal fluid consistent with VPT, and cryotherapy was recommended. Two months later, there was complete tumor regression, but there was decreased vision from progressive vitreomacular traction to 20/400 ft. PPV with combined ERM and internal limiting membrane (ILM) peel were performed with resolution of vitreomacular traction and improvement of visual acuity to 20/50 ft at 6 months. PPV with combined ERM and ILM peel is effective for vision loss secondary to ERM and vitreomacular traction associated with retinal VPT.

Introduction

Epiretinal membrane (ERM) is a frequent cause of decreased vision. Although surgical removal alone can achieve visual recovery in most cases, some ERMs require management of an underlying pathology prior to improvement in vision.[1] Secondary ERM can be associated with inflammatory conditions, diabetic retinopathy, or intraocular tumors, particularly those associated with exudation into the retina and vitreous cavity. Vasoproliferative tumor (VPT) is a benign retinal tumor that can lead to macular ERM in 50 of 252 patients (13%) of primary cases and in 15 of 82 patients (7%) of secondary cases.[2] Typically, this tumor appears as a reddish-pink, elevated mass located in the pre-equatorial region with mildly dilated retinal feeder vessels and often causing vision-threatening complications from lipid exudation, cystoid macular edema (CME), vitreous hemorrhage, retinal detachment, and ERM formation.[23] Treatment of VPT is focused toward tumor involution with resolution of these findings and visual recovery.[234] Methods of treatment include laser photocoagulation, photodynamic therapy, thermoablation, cryotherapy, plaque radiotherapy, and intravitreal steroid or anti-vascular endothelial growth factor (VEGF) injections alone or in combination. The most suitable choice depends on the tumor size and location as well as the related features.

Herein, we describe a case of VPT with secondary ERM, treated by trans-scleral cryotherapy for tumor control and pars plana vitrectomy (PPV) with ERM peeling to rehabilitate the foveola. We discuss the pathogenesis of ERM formation and its implications on management.

Case Report

A 29-year-old caucasian male was referred for management of 1 week vision loss. Visual acuity was 20/50 in the affected right eye (OD) and 20/25 in the left eye (OS). Intraocular pressure and anterior segment examination of both eyes were normal. Posterior segment examination was normal OS, whereas OD revealed an ill-defined reddish-yellow intraretinal mass with overlying exudation, hemorrhage, and subretinal fluid (SRF) along the inferotemporal periphery [Figure 1a–c]. Ultrasonography showed a dense intraocular mass measuring 1.7 mm in thickness with SRF and attached posterior hyaloid, whereas fluorescein angiography showed peripheral nonperfusion with hyperfluorescence of the lesion and late leakage, consistent with a retinal VPT. Macular optical coherence tomography (OCT) revealed an ERM, with vitreomacular traction, mild macular edema, and distortion of the normal foveal contour [Figure 1d and e]. Treatment options at that time included laser photocoagulation, photodynamic therapy, or cryotherapy, and considering small size, peripheral location, and presence of an ERM, trans-scleral cryotherapy was provided.

Figure 1

A 29-year-old man with inferotemporal vasoproliferative tumor (a) showing focal leakage on fluorescein angiography (b). After cryotherapy, vasoproliferative tumor was completely regressed (c) with residual epiretinal membrane (d). Optical coherence tomography showed attached posterior hyaloid (arrow), surface wrinkling, and macular edema (e) with 20/50 vision. Two months later, vision was 20/400 from progressive vitreomacular traction (arrows) and foveal distortion (f and g) requiring vitrectomy and membrane peel. Six months after surgery, visual acuity was 20/50 and foveal anatomy was restored (h and i)

Two months following cryotherapy, the tumor showed regression, but vision worsened to 20/400 secondary to progressive vitreomacular traction and CME [Figure 1f and g]. At this time, options included intravitreal steroid injections, anti-VEGF injections, or PPV with membrane peel. After discussion of the risks and benefits, the patient elected PPV with combined ERM and internal limiting membrane (ILM) peel. Six months postoperatively, vision returned to 20/50, and OCT showed resolution of vitreomacular traction with mild residual extrafoveal CME, slight flattening of the foveal contour, and mild ellipsoid irregularity on OCT [Figure 1h and i].

Discussion

The overall prevalence of ERM in histopathologic studies based on postmortem eyes is about 1.7% (27 patients in 1612 postmortem eyes).[5] The vast majority of ERMs are secondary to prior ocular surgery or trauma and less often ocular inflammation or intraocular tumors.[5] ERMs are composed of various combinations of retinal pigment epithelial cells, macrophages, fibrous astrocytes, and myofibroblasts that allow contractile properties causing distortion of normal retinal contour.[56] The precise relationship between VPT and ERM is unclear, but several possibilities exist. In a histopathological study, a similar case of ERM was associated with VPT in a healthy 34-year-old female managed by surgical removal because of worsening of vision after cryotherapy. The peeled specimen comprised a hyaline membrane with positive staining for type IV collagen and GFAP.[7] Further, capillary vessels resembling surface neovascularization similar to proliferative diabetic retinopathy were also found.[7] It is quite possible that cryotherapy-induced vitreous liquefaction, as seen in animal studies, could lead to vitreous detachment in a young patient, causing worsening of epiretinal traction where it is more densely bonded.[8] It should be realized that VPTs and ERMs could be coincidental, as both can occur in older patients.[234] Finally, the occurrence of remote macular edema associated with VPT presumably results from the release of inflammatory cytokines that can also induce secondary inflammation-mediated ERM formation, similar to pars planitis and other uveitic conditions.[5]

ERMs can be a significant cause of vision loss in eyes with VPT.[2] If completely asymptomatic and without leakage, observation is advised. For those with leakage, we recommend treating the tumor first with cryotherapy or other methods, as this can cause tumor involution as well as release of vitreomacular traction, presumably from induction or completion of posterior vitreous detachment, and prevent recurrence of macular edema or re-proliferation of ERMs by inhibition of vasoactive and inflammatory material from the VPT.[9]

Our case also illustrates the secondary role of PPV in the management of ERMs associated with VPT. Secondary ERMs have worse vision and greater central macular thickness compared to idiopathic ones.[10] Intraoperatively, secondary ERMs may behave differently, which can increase the risk of surgical complications such as vitreous hemorrhage, retinal holes, and detachment.[10] This may be attributable to tighter vitreomacular adhesions and thickening in cases of secondary ERM, as reported by one group that, in turn, proposed the use of pharmacologic vitreolysis to facilitate membrane peeling.[10] In addition to peeling of the ERM, removal of the ILM may help to prevent recurrence of ERM due to elimination of the scaffold on which glial cells and other fibrocytes proliferate, though this remains a subject of debate, and its role in the management of VPT-associated ERM is uncertain.[11] In our case, the ILM was peeled in view of the severe macular thickening and edema, and there has been no evidence of ERM recurrence 6 months after surgery.

Conclusion

VPTs can cause severe vision loss due to secondary involvement of the vitreoretinal interface. Although cryotherapy can effectively induce tumor regression and occasional release of vitreomacular traction, this therapy can occasionally cause worsening vision. In these cases, we believe that PPV and ERM peel is a viable option for management and can result in good anatomic and functional outcomes.

Financial support and sponsorship

Eye Tumor Research Foundation, Philadelphia, PA (CLS). The funders had no role in the design and conduct of the study, in the collection, analysis, and interpretation of the data, and in the preparation, review, or approval of the manuscript. Carol L. Shields, M.D. has had full access to all the data in the study and took responsibility for the integrity of the data and the accuracy of the data analysis.

Conflicts of interest

There are no conflicts of interest.