Purpose: To evaluate topographic changes in choroidal thickness during development of choroidal neovascularization (CNV) in treatment-naive age-related macular degeneration (AMD) and to test the value of such changes as a predictive tool of CNV development.
Methods: This retrospective cohort included 86 eyes that developed CNV from intermediate AMD, 43 eyes with intermediate AMD, and 36 eyes without AMD. Patients with intermediate AMD underwent spectral domain optical coherence tomography using enhanced depth imaging mode every 6 months until CNV was detected. Choroidal neovascularization was localized to one of the subfields of Early Treatment of Diabetic Retinopathy Study grid on fluorescein angiography. Average choroidal thickness of each subfield was calculated.
Results: Choroidal thickness of the subfield where CNV developed at first clinical detection significantly increased compared with that 6 months before (P = 0.000 for central, P = 0.001 for superior parafoveal, P = 0.002 for temporal parafoveal, P = 0.002 for inferior parafoveal, and P = 0.001 for nasal parafoveal subfield). In eight patients who visited unexpectedly 3 months before CNV development in central subfield, choroidal thickness of central subfield increased significantly compared with that 6 months before CNV development (P = 0.001).
Conclusion: Choroidal neovascularization development accompanied choroidal thickening of the corresponding subfield. Regular measurement of choroidal thickness may assist in prediction of CNV.