Juxtafoveal Choroidal Neovascularization Associated with Retinitis Pigmentosa Treated with Intravitreal Bevacizumab

Introduction

Choroidal neovascularization (CNV) may rarely complicate Retinitis Pigmentosa (RP) leading to further visual acuity deterioration.^1,2 We describe a case of juxtafoveal CNV occurring in a patient affected by RP, treated with intravitreal bevacizumab over a 12-month follow-up.

Case Report

A 66 year-old woman was referred to our center for visual acuity loss and metamorphopsia in the left eye (LE). The patient was diagnosed as having RP at the age of 32. Genetic characterization revealed a mutation in the ABCA4 gene (RP 19). Best-corrected visual acuity (BCVA) was 20/60 in the right eye and 20/200 in the LE. Anterior segment was normal. Fundus examination of both eyes revealed optic disk pallor, peripapillary atrophy, and typical bone spicules involving the mid peripheral retina (Fig. 1). Additionally, a grayish lesion with surrounding neurosensory detachment was visible in the macula of the LE. Fluorescein angiography revealed the presence of a classic juxtafoveal CNV in the LE, which was confirmed on indocyanine green angiography. Optical coherence tomography (OCT) showed a neurosensory detachment overlying the hyper-reflective lesion corresponding to the CNV. Visual field was greatly constricted, whereas the full-field electroretinogram testings showed severely diminished scotopic responses, with photopic responses decreased in amplitude and delayed in implicit time. The patient was advised to undergo an intravitreal injection of bevacizumab (1.25 mg), after signing a written informed consent. One month later, BCVA was 20/100, with a resolution of neurosensory detachment on OCT. The patient was regularly monitored every month. Over the subsequent 12-month follow-up, the patient experienced re-activation of the CNV, as documented by the detection of recurrent neurosensory detachment on OCT in association with BCVA deterioration, and was re-treated another 4 times. Visual field and electroretinogram responses turned out to be unchanged over the follow-up.

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FIG. 1.

Top Left: Composite Fluorescein angiography revealing the characteristics of the picture of retinitis pigmentosa associated with juxtafoveal choroidal neovascularization. Top Right: Indocyanine green angiography in early phases delineating the neovascular net of the juxtafoveal choroidal neovascularization. Bottom Left: Optical coherence tomography before the treatment showing a neurosensory detachment overlying the hyper-reflective lesion corresponding to the juxtafoveal choroidal neovascularization. Bottom Right: Optical coherence tomography 12 months after the treatments, with resolution of the neurosensory detachment.

At the end of the 12-month follow-up, BCVA was 20/100 with CNV stabilization.

Discussion

Management of CNV associated with RP is still uncertain. Owing to the rarity of the condition, limited experience has been accrued. Development of subfoveal CNV in RP leads to an additional functional impairment,^1,2 and, therefore, could be usefully treated in an attempt to save the remaining central visual function. A single case of RP presenting juxtafoveal CNV has been previously described. ² More specifically, the patient was simply observed without any treatment over a 14-year follow-up. Visual acuity progressively deteriorated up to 0.04, with severe macular damage. ² Recently, Malik et al. described a case of subfoveal CNV associated with RP, who was managed with intravitreal bevacizumab. ³ Even though no functional improvement was registered, CNV evolved into subretinal fibrosis after the therapy, showing an anatomical stabilization over the follow-up. In the present case with juxtafoveal CNV, we suggested that the patient undergo an intravitreal bevacizumab injection, worried that lazer treatment could further compromise the central visual field of the patient. Overall, the results turned out to be positive, with CNV stabilization and visual acuity improvement. Nevertheless, we may also comment that, although successful in limiting the CNV extension and avoiding the foveal extension, intravitreal bevacizumab required 5 injections to achieve the CNV stabilization in 12 months, providing evidence that even RP-related CNV can be difficult to stabilize. Moreover, intravitreal anti-vascular endothelial growth factor (VEGF) therapy may prove to be unsafe in the long term, especially for patients with RP, whose photoreceptors are just about leading to apoptosis. Some investigators have raised an alert for the safety of continuing intraocular VEGF neutralization, because endogenous VEGF maintains both retinal and choroidal circulation and is one of the key neurotrophic factors.^4,5

However, our findings showed that neither visual field nor electroculogram responses worsened, suggesting that a limited anti-VEGF therapy may not lead to further damage, at least over a 12-month follow-up.

Conclusions

The present case report indicates that intravitreal bevacizumab is effective in producing juxtafoveal CNV stabilization and visual acuity improvement in a patient affected by RP, over a 12-month follow-up. Future studies are required to ascertain the best therapeutic approach for CNV complicating RP.