Types of diabetic macular edema assessed by optical coherence tomography.

Types of diabetic macular edema assessed by optical coherence tomography.

Koleva-Georgieva DN, Sivkova NP.
Department of Ophthalmology, Medical University, Plovdiv, Bulgaria.

AIM: To assess the types of diabetic macular edema (DME) in patients with type 2 diabetes mellitus by analyzing retinal thickness, morphology and presence of macular traction using optical coherence tomography (OCT).

PATIENTS AND METHODS: This prospective study included 74 diabetics with diabetic retinopathy (DR) (141 eyes), 29 diabetics without DR (57 eyes) and 25 healthy volunteers (39 eyes). The ophthalmic examination included best corrected visual acuity, stereo-ophthalmoscopy, fluorescein angiography and OCT. DME assessment was based on the analysis of several OCT features: macular thickness, retinal morphology and presence of macular traction--vitreomacular and/or from epiretinal membranes. Four OCT types of DME were suggested: type 1--early, type 2--simple, type 3--cystoid (3a--mild, 3b--intermediate, 3c--severe) and type 4--serous macular detachment. The distribution of the DME types and their correlation with retinal thickness and visual acuity were analyzed.

RESULTS: The distribution of eyes with DME was: type 1--14.1%, type 2--30.4%, type 3--45.7% (3a--14.1%, 3b--12%, 3c--19.6%) and type 4--9.8%. Macular traction with retinal distortion was detected in 31.5% of the eyes with DME. Retinal thickness at the fixation point was 176 +/- 16.8 microm (116 microm / 210 microm) in healthy eyes and 182.2 +/- 19.6 microm (138 microm / 212 microm) in eyes without DR. There was no statistically significant difference between the two groups (Independent samples test, P less then 0.05). The retina was significantly thicker in eyes with early DME (232.9 plus/minus 7.9 microm) than in healthy eyes and eyes without DR (Independent samples test, F = 16.274 and F = 13.100, P less then f equals 16.692.

CONCLUSION: OCT precisely differentiated 4 types of DME: early, simple, cystoid and serous macular detachment, as well as determined the presence of macular traction. The early diagnosis, high precision in retinal thickness measurement, assessment of the morphologic types and macular traction are of uppermost importance in determining the therapeutic approach, prognosis and the effect of treatment.

PMID: 19009748 [PubMed - in process]

Ranibizumab for macular edema due to retinal vein occlusions: implication of VEGF as a critical stimulator

Ranibizumab for macular edema due to retinal vein occlusions: implication of VEGF as a critical stimulator

Mol Ther. 2008 Apr

Campochiaro PA, Hafiz G, Shah SM, Nguyen QD, Ying H, Do DV, Quinlan E, Zimmer-Galler I, Haller JA, Solomon SD, Sung JU, Hadi Y, Janjua KA, Jawed N, Choy DF, Arron JR.
Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-9277, USA. pcampo@jhmi.edu

Macular edema is a major cause of vision loss in patients with central retinal vein occlusion (CRVO) or branch retinal vein occlusion (BRVO). It is not clear how much of the edema is due to hydrodynamic changes from the obstruction and how much is due to chemical mediators. Patients with macular edema due to CRVO (n = 20) or BRVO (n = 20) were randomized to receive three monthly injections of 0.3 or 0.5 mg of ranibizumab. At the primary endpoint, month 3, the median improvement in letters read at 4 m was 17 in the 0.3-mg group and 14 in the 0.5-mg group for CRVO, and 10 and 18, respectively for the BRVO group. Optical coherence tomography (OCT) showed that compared to injections of 0.3 mg, injections of 0.5 mg of ranibizumab tended to cause more rapid reductions of central retinal thickening that lasted longer between injections, but in 3 months, excess central retinal thickening which is a quantitative assessment of the macular edema, was reduced by approximately 90% in all four treatment groups. There was no correlation between the amount of improvement and duration of disease or patient age at baseline, but there was some correlation between the aqueous vascular endothelial growth factor (VEGF) level at baseline and amount of improvement. These data indicate that excess production of VEGF in the retinas of patients with CRVO or BRVO is a major contributor to macular edema and suggest that additional studies investigating the efficacy of intraocular injections of ranibizumab are needed.

Nature