Quantitative Assessment of Macular Edema With Optical Coherence Tomography

OBJECTIVE: To evaluate optical coherence tomography, a new technique for high-resolution cross-sectional imaging of the retina, for quantitative assessment of retinal thickness in patients with macular edema. DESIGN: Survey examination with optical coherence tomography of patients with macular edema. SETTING: Referral eye center. PATIENTS: Forty-nine patients with the clinical diagnosis of diabetes or diabetic retinopathy and 25 patients with macular edema secondary to retinal vein occlusion, uveitis, epiretinal membrane formation, or cataract extraction. MAIN OUTCOME MEASURES: Correlation of optical coherence tomograms with slit-lamp biomicroscopy, fluorescein angiography, and visual acuity. RESULTS: Optical coherence tomograms of cystoid macular edema closely corresponded to known histopathologic characteristics. Quantitative measurement of retinal thickness is possible because of the well-defined boundaries in optical reflectivity at the inner and outer margins of the neurosensory retina. Serial optical coherence tomographic examinations allowed tracking of both the longitudinal progression of macular thickening and the resolution of macular edema after laser photocoagulation. In patients with diabetic retinopathy, measurements of central macular thickness with optical coherence tomography correlated with visual acuity, and optical coherence tomography was more sensitive than slit-lamp biomicroscopy to small changes in retinal thickness. CONCLUSIONS: Optical coherence tomography appears useful for objectively monitoring retinal thickness with high resolution in patients with macular edema. It may eventually prove to be a sensitive diagnostic test for the early detection of macular thickening in patients with diabetic retinopathy.