Optical Coherence Tomography Angiography and Fundus Fluorescein Angiography in Myopic Choroidal Neovascularization

Background: High myopia refers to an axial length of the eye greater than 26 mm or by having a refractive error of more than - six diopters. The most frequent cause of Choroidal neovascularization (CNV) in patients less than 50 years old is pathologic myopia. CNV is a serious lesion of the retina and choroid leading to vision loss or blindness due to subretinal or intraretinal fluid, hemorrhage, and lastly scar.

Fundus biomicroscopy, fundus fluorescein angiography (FFA), and optical coherence tomography (OCT) are the most common methods used to diagnose myopic CNV. Optical coherence tomography angiography (OCTA) shows both the retinal and choroidal vasculature, so it is used to diagnose choroidal neovascular membrane.

Aim: Study the role of OCTA in the diagnosis of choroidal neovascularization in myopia and compare it with the findings of fundus fluorescein angiography (FFA).

Patient and Methods: our study included twenty eyes of twenty patients who had active myopic CNV in the Ophthalmology Department, Tanta University.

Results: Spherical Equivalent ranged from - 6.5 to - 16.0 diopters. The vessel density (VD) had a statistical significance higher in OCTA, compared to FFA (p < 0.001). The CNV area was significantly less in OCTA, compared to FFA (P = 0.012). There was Statistical significance between BCVA as regard CNV site on FFA (P =0.002). The BCVA is less in subfoveal CNV than in juxtafoveal CNV.

Conclusion: OCTA is a new imaging technique, non-invasive and safe with rapid image acquisition. The recent gold standard for the assessment of myopic CNV is FFA, where the existence of CNV is detected by dye leakage; although, FFA is invasive and may be accompanied by nausea, urticaria, and very rarely anaphylaxis.

For the diagnosis and follow-up of myopic CNV, OCTA is still frequently used in combination with FFA.