The Relationship Between Macular Sensitivity and Retinal Thickness in Eyes With Diabetic Macular Edema ELHAM HATEF, ELIZABETH COLANTUONI, JIANMIN WANG, MOHAMED IBRAHIM, MATTHEW SHULMAN, FATIMA ADHI, YASIR JAMAL SEPAH, ROOMASA CHANNA, AFSHEEN KHWAJA, QUAN DONG NGUYEN, AND DIANA V. DO ● PURPOSE: To investigate relationship between macular sensitivity and retinal thickness in diabetic macular edema (DME). ● DESIGN: Prospective observational study. ● METHODS: SETTINGS: University-based retina practice. PATIENTS: Twenty-two eyes of 11 patients with DME. PROCEDURE: Fundus microperimetry and retinal thickness tomography were performed simultaneously using an automatic fundus perimetry/tomography system. MAIN OUTCOME MEASURES: Quantification of macular sensitiv- ity, fixation pattern, and relationship between macular sensitivity and retinal thickness. ● RESULTS: Fixation stability revealed that 21 eyes (95.4%) had stable fixation (>75% within central 2 degrees of point of fixation) and 1 eye (4.5%) had relatively unstable fixation (<75% of fixation points located within 2 degrees, >75% located within 4 de- grees). Evaluation of fixation location revealed that 15 eyes (68.2%) had central (>50% of fixation points within 0.5 mm of fovea), 3 eyes (13.6%) pericentral (25% to 50% within 0.5 mm of fovea), and 4 eyes (18.2%) eccentric (<25% of fixation points within 0.5 mm of fovea) fixation location. Macular sensitivity in- creased by an average of 0.03 decibel (dB) (95% confi- dence interval [CI]: 0.00, 0.06) per 1-micron (m) increase in retinal thickness for thickness values <280 m measured with the OPKO/OTI spectral-domain OCT. The macular sensitivity decreased by an average 0.05 dB (95% CI: 0.08, 0.02) per 1-m increase in thickness for thickness values >280 m. ● CONCLUSIONS: In this pilot study, the majority of eyes with DME had stable, central fixation. Macular sensitiv- ity varied depending on the thickness of the retina. Additional studies are needed to determine the role of microperimetry in eyes with DME. (Am J Ophthalmol 2011;152:400 – 405. © 2011 by Elsevier Inc. All rights reserved.) D IABETIC MACULAR EDEMA (DME) IS A MAJOR health problem and is the leading cause of visual impairment in developed countries among the working-age population. 1 Despite significant progress in the techniques to image the retina and connect the in vivo histologic diagnosis with the clinical diagnosis, physicians as well as patients still experience discrepancy between the microanatomy and visual function. Visual acuity is usually considered the gold standard for determination of damage attributable to DME; however, visual acuity may be inadequate to de- scribe the functional impairment caused by DME. 1,2 Microperimetry has made it possible to evaluate macular sensitivity in areas of macular edema. 1–3 The deterioration of macular sensitivity in patients with DME has been reported in previous studies. 1 In the present study, we investigate the relationship between macular sensitivity, retinal thickness, and associated factors in DME patients, quantified with an automatic fundus perimetry/tomogra- phy system (scanning laser ophthalmoscope/spectral-do- main optical coherence tomography [SLO/OCT]; OPKO/ OTI, Toronto, Ontario, Canada). METHODS ADULT PATIENTS WITH DME WHO WERE EVALUATED AT THE Wilmer Eye Institute, Johns Hopkins University (Baltimore, Maryland, USA) were eligible for participation. The diagno- sis of DME was made by 2 retina specialists (D.V.D. and Q.D.N.) using contact lens biomicroscopy and confirmed with optical coherence tomography (OCT). Additional study assessments included Early Treatment Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity (BCVA) and fluorescein angiography. The level of Hb A1C was obtained from subjects’ medical records. OCT imaging was performed with the spectral-domain OCT module integrated in the OPKO/OTI device. The Spectral OCT/SLO module of the device generated 3-dimen- sional (3D) retinal maps. It captured 28 000 A-scans per second, which enabled the acquisition of up to 128 longitu- dinal OCT scans in 2 seconds over a 5-mm area in the macula. Retinal thickness was defined as the distance be- tween the retinal nerve fiber layer and the hyporeflective line Accepted for publication Feb 24, 2011. From the Retinal Imaging Research and Reading Center (RIRRC), Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland (E.H., J.W., M.I., M.S., F.A., Y.J.S., R.C., A.K., Q.D.N., D.V.D.); Department of Biostatistics, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland (E.C.); and Department of Ophthalmology, The Second Hospital of Hebei Medical University Shijiazhuang, Hebei Province, China (J.W.). Inquiries to Diana V. Do, Johns Hopkins Hospital, 600 North Wolfe St, Maumenee 745, Baltimore, MD 21287; e-mail: ddo@jhmi.edu © 2011 BY ELSEVIER INC.ALL RIGHTS RESERVED. 400 0002-9394/$36.00 doi:10.1016/j.ajo.2011.02.024