Sir,

Choroidal neovascularization (CNV) secondary to colobomas are rare and have been treated with laser photocoagulation, photodynamic therapy (PDT), or merely observed.1, 2, 3, 4 To the best of our knowledge, this is the first report of treatment of CNV secondary to a coloboma with intravitreal anti-vascular endothelial growth factor therapy.

Case report

A 36-year-old man presented with reduced vision in the right eye of 1-month duration. The left eye had microphthalmos. His best-corrected visual acuity (BCVA) was 6/36 OD. Clinical evaluation of the right eye revealed an inferior retinochoroidal coloboma, extending up to the inferior disc margin and macula. Active subfoveal CNV with submacular haemorrhage was noted (Figure 1a), which was further evidenced by fluorescein angiography (FA) (Figure 1b) and optical coherence tomography (OCT) (Figure 1c). The patient opted for and was administered 1.25 mg of intravitreal bevacizumab (Avastin, Genentech, San Francisco, CA, USA).

Figure 1
figure 1

(a) Fundus photograph of the patient showing an inferior retinochoroidal coloboma with an active choroidal neovascular membrane (CNV); (b) late-phase angiogram showing the leak of the CNV surrounded by blocked fluorescence of the subretinal haemorrhage; and (c) vertical optical coherence tomogram (OCT) through the macula and coloboma showing the submacular neovascular tissue. (d) A year later, after two consecutive monthly injections of intravitreal bevacizumab, the fundus picture shows regression of the CNV, with (e) staining evident on the angiogram and (f) complete resolution of the lesion evident on OCT.

Full size image

One month later, the patient presented with an improved BCVA of 6/24 OD. Fundus examination, FA, and OCT revealed partially regressed CNV, and the patient was re-treated by injecting intravitreal bevacizumab in the right eye. At the final review, a year later, his BCVA was 6/9 OD and the CNV was noted to have completely regressed clinically, angiographically, and tomographically (Figures 1d–f).

Comment

CNV, a rare complication, usually develops at the junction between the normal retina and the coloboma, as also observed in our case.1 Bruch's membrane disruption and retinal pigment epithelium displacement at the margin of the coloboma allow migration of choroidal neovascular tissue into the subretinal space at this site.1 The paucity of reports coupled with the age at presentation varying from the first to the seventh decade has led to the specific trigger for neovascularization remaining unestablished.1

Of the five eyes treated with laser photocoagulation, two showed improvement in vision, with the rest remaining at the same level.1 PDT improved the vision in a child.4 Only one of the four conservatively managed cases reported stabilization of vision.1, 3 Bevacizumab has been used off-label, as intravitreal therapy for CNV, successfully.5 We report on the regression of CNV associated with a retinochoroidal coloboma in a uni-ocular patient, who received two injections of intravitreal bevacizumab and showed significant visual improvement over a year.