Paediatric choroidal neovascular membrane secondary to toxoplasmosis treated successfully with anti-vascular endothelial growth factor.

The purpose of this report was to evaluate the role anti-VEGF in management of CNVM secondary to ocular toxoplasmosis. Young female diagnosed as a case of bilateral ocular toxoplasmosis presented with complaints of diminution of vision in the right eye. Fundus examination showed an active CNVM adjacent to toxoplasmosis scar. In view of active CNVM, patient was administered intravitreal ranibizumab. A total of 2 injections of intravitreal ranibizumab were given. Fundus showed a scarred CNVM adjacent to the toxoplasma scar with no clinical signs of activity. Anti-VEGF therapy has been successfully used to improve visual and anatomical outcome in juxtafoveal (deleted subfoveal)CNVM secondary to toxoplasmosis.

Introduction

Pediatric choroidal neovascular membranes (CNVM) are uncommon but important cause of visual impairment. These may be idiopathic or may be seen secondary to trauma, infection, inflammation or retinal dystrophies. The limited published data on their natural history, as well as delay in their presentation make the management of pediatric CNVMs difficult. There is no uniform consensus on the management of these cases because of lack of randomized or controlled clinical trials. CNVMs have been seen in patients with toxoplasmic chorioretinitis.[123] These patients have been managed by observation, anti-parasitic and/or anti-inflammatory medication, laser photocoagulation, surgical excision or photodynamic therapy, with variable outcomes.[4567] Very few reports have been published for treating inflammatory CNVM successfully with anti-vascular endothelial growth factor (anti-VEGF).[8] We report a case of congenital toxoplamosis that developed CNVM and was successfully treated with anti-VEGF therapy in a 13 year old.

Case Report

A 13-year-old female diagnosed to have bilateral toxoplasmosis presented to us with complaints of diminution of vision in the right eye since 5 days. On examination vision in the right eye was 6/15, N10 and in the left eye was 6/36, N10. Anterior segment examination revealed grade 1 cells in the right eye with no other obvious abnormality. Left eye anterior segment was within normal limits. Fundus examination of the right eye revealed a juxtafoveal scarred toxoplasmosis lesion with well-defined punched-out margins. There was a presence of subretinal hemorrhage with subretinal fluid at the foveal edge of the scar suggestive of CNVM. Fundus fluorescein angiography (FFA) revealed hyper fluorescence of the lesion at the edge of the scar with active leakage in late stages of the angiogram. Optical coherence tomography (OCT) also revealed a juxtafoveal CNVM superotemporal to fovea and subretinal fluid superior and subfoveal [Figures 1a and 2a]. Left eye fundus revealed a punched out toxoplasmosis scar at the macula with no signs of activity. In view of the active CNVM in the right eye the patient was advised intravitreal ranibizumab (RBZ) 0.05 ml under general anesthesia. The patient underwent the same along with antiparasitic treatment for toxoplasmosis chorioretinitis which included oral clindamycin 300 mg four times a day and oral sulfamethoxazole and trimethoprim twice daily dosage for 2 weeks along with oral steroids in tapering dose.

Figure 1

(a) FFA shows active leakage from the CNVM adjacent to toxoplasma scar (b) FFA shows persisting leakage from the CNVM at 2 month follow up (c) FFA shows scarred CNVM adjacent a toxoplasmosis scar with scar staining (d) FFA shows scarred CNVM with no active leakage

Figure 2

(a) OCT image along the vertical axis shows an active CNVM superior to fovea with surrounding sub-retinal hemorrhage. A small pigmentation is seen within the lesion causing shadowing. Sub-retinal fluid is seen at the fovea. Foveal depression is maintained (b) OCT image through the same location as the previous visit shows a partially regressed CNVM with minimal subretinal fluid and retinal thickening at the inferior edge of the lesion (c) Vertical OCT scan shows a well defined hyper reflective scarred CNVM with no evidence of activity (d) OCT scan shows scarring CNVM with complete resolution of SRF. Note the thinning of IS-OS junction at fovea

One month post intravitreal injection vision in the right eye improved to 6/12, N6. Anterior segment was within normal limits. Fundus examination showed reduced subretinal hemorrhage with regressing CNVM which was confirmed on OCT with decreasing subretinal fluid. FFA still showed active leakage from the CNVM [Figures 1b and 2b]. In view of the persisting active CNVM patient was administered a second dose of ranibizumab intravitreal injection and was followed up after a month. On her next visit, 1 month post second injection, vision in the right eye further improved to 6/9, N6. Fundus showed a scarred CNVM adjacent to the toxoplasma scar with resolving subretinal hemorrhage with no clinical signs of activity. OCT showed scarred a CNVM with no subretinal fluid [Figures 1c and 2c]. At her next follow up, 1 month later she had maintained stable vision with no signs of activity in the CNVM [Figures 1d and 2d]. On her last visit, 10 months post injection, vision in the right eye was 6/9, N6 and fundus showed a scarred CNVM. OCT showed a scarred subretinal lesion.

Comment

Anti-VEGF therapy has been successfully used to improve visual outcome in patients with subfoveal and juxtafoveal CNVM. It reduces concomitant tissue destruction to the neurosensory retina and choroid as seen in other treatment modalities like laser photocoagulation. Because active infectious retinitis may be obscured by hemorrhage and because intravitreal injections may reactivate chorioretinitis, concurrent therapy with oral anti-toxoplamosis medicine is also recommended in these cases.[8] Though photodyanamic therapy (PDT) has been shown to be effective by other authors[56] we did not advise it because cooperation during the procedure was questionable due to the younger age group of the patient. In our case only two injections resulted in resolution of the neovascular membrane and stabilization of visual acuity. The reduced number of treatments to achieve resolution of fluid and involution of CNVMs can be explained by the relative good health of the RPE pump in patients in younger age group compared with the RPE in adults with age-related macular degeneration.[89] We used adult dosage in this patient since the patient was 13 year old; adult dose in such cases has also been used in other case reports.[89] We also believe that fewer injections given on PRN basis may reduce the risk of systemic adverse effects also which may be a subject of concern especially in the paediatric age group. In our case, we did not observe any short-term adverse ocular or systemic side effects secondary to the treatment with intravitreal anti-VEGF agents.(Deleted reference9) However, long-term studies will be required to establish the safety of these injections in this age group.