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SD-OCT shows risk factors for retinal pigment epithelium tears
Disparate theories have been proposed to explain the association between RPE tears and anti-VEGF injections.
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Even though risk of a retinal pigment epithelium tear would not be reduced, it is still crucial to document a pigment epithelial detachment at high risk for RPE tear and to discuss with the patient the possibility of major vision loss after anti-VEGF injection, according to one researcher.
To that end, David Sarraf, MD, and colleagues performed high-quality spectral-domain optical coherence tomography scans on eight eyes that developed retinal pigment epithelium (RPE) tears after anti-VEGF injection for neovascular age-related macular degeneration in a retrospective case series. Both pre-tear and post-tear images were compared to better understand the mechanisms by which RPE tears occur in this setting.
“In all of the eyes, contractile properties of the type 1 choroidal neovascular (CNV) membrane could be identified prior to and after intravitreal anti-VEGF injection by using SD-OCT imaging,” Sarraf told Ocular Surgery News. “In each eye, these contractile characteristics were noted to progress using SD-OCT and to be a critical element in the development of an RPE tear after anti-VEGF therapy.”
Properties of contraction identified with SD-OCT analysis included a peaked and corrugated pigment epithelial detachment (PED) associated with type 1 CNV and bowing of the underlying Bruch’s membrane complex.
Contributing factors
“It should be noted that while contractile elements of the type 1 CNV are critical, the nature of the PED may also be significant in the development of an RPE tear,” Sarraf said. “The size of the PED, specifically the height of the PED, has been shown to be an important element in the development of an RPE tear, and therefore, hydrostatic mechanisms may also be involved and may contribute to the development of a PED at risk and create a platform whereby contractile mechanisms may operate to create an RPE tear.”
Sarraf has been studying RPE tears for many years and has published close to 10 papers on the subject, including the current study of eight eyes that appeared in the American Journal of Ophthalmology.
“The mechanism of an RPE tear has been debated for many decades,” he said. “In the anti-VEGF era, there has been an explosion of reports of RPE tears after anti-VEGF injection and growing consensus that anti-VEGF therapy may cause or at least accelerate the development of RPE tears. Disparate theories have been proposed to explain this association. This report is one of the first to document the importance of contraction of the type 1 CNV, which can progress under the influence of the anti-VEGF agent.”
Patients should be appropriately prepared for an adverse outcome, Sarraf said.
“Should an RPE tear develop, the anatomical and visual prognosis significantly declines,” Sarraf said. “However, continued anti-VEGF therapy can have anatomical and visual benefit, especially in eyes with lower grade tears — grade 2 and sometimes even grade 3 tears.”
One of Sarraf’s previous prospective studies on the development of RPE tears after anti-VEGF injection found that high-dose Lucentis (ranibizumab, Genentech) had a fourfold greater risk for RPE tear than standard treatment.
“While our overall numbers were small, it still raised concern about the use of high-dose therapy in PEDs at high risk of an RPE tear,” he said. “On the basis of this prospective study, some have suggested using lower doses of anti-VEGF agents in eyes at very high risk of developing an RPE tear. But this theory awaits support by a clinical trial.”
Sarraf and colleagues have collected data on approximately 50 eyes with RPE tears, many that developed after anti-VEGF therapy.
“We are now studying the long-term anatomical and visual prognosis after continued anti-VEGF injections,” he said. “Although the overall prognosis is poor, there are isolated eyes that can have an outstanding visual outcome even with high-grade tears many years after the development of an RPE tear with continued anti-VEGF injections.”
Sarraf credited first author Aaron Nagiel, MD, for analysis of the eight cases in the study. – by Bob Kronemyer