Background: Age-related macular degeneration (AMD) is the leading cause of blindness in industrialized countries. In this study, we used optical coherence tomography for evaluation of patients with AMD.
Methods: Optical coherence tomography imaging is analogous to ultrasound, except that reflected light instead of sound is used. The analysis of the reflected light is processed with the technique of low-coherence interferometry. In this study, 33 patients with different stages of AMD were examined with optical coherence tomography. The classification of AMD was according to the guidelines as proposed by the "International ARM Epidemiological Study group".
Results: With this method we were able to identify drusen, alteration of the retinal pigment epithelium, and secondary retinal changes. Other structures such as basal laminar (linear) deposits could not be identified with this method. Choroidal neovascularization was evident in the tomogram. Classic choroidal neovascular membranes presented with well-defined boundaries on optical coherence tomography and occult choroidal neovascular membranes had a less delineable structure with optical coherence tomography.
Conclusion: Optical coherence tomography cannot replace conventional diagnostic techniques. This method provides no additional information in patients with non-exsudative AMD. In patients with choroidal neovascular membranes secondary to AMD optical coherence tomography may be able to characterize the relation of the membrane to the retinal pigment epithelium and imaging may be possible through hemorrhage. The interpretation of the optical coherence tomogram needs further studies including clinicopathologic correlation.