Optical coherence tomography and confocal scanning laser tomography for assessment of macular edema.

PURPOSE

To compare optical coherence tomography (OCT) and confocal scanning laser tomography (cSLT) for quantitative retinal thickness mapping of the macula and their ability to detect macular edema.

DESIGN

Prospective, comparative, clinical observational study.

METHODS

The study population of 138 eyes (97 patients) was divided into a study group consisting of 45 (32.6%) eyes with macular edema and a control group consisting of 93 (67.4%) eyes without macular edema. All patients underwent OCT and cSLT of the macula. Retinal thickness measurements obtained by OCT were compared with signal width and edema index, determined by cSLT.

RESULTS

The OCT measurements and cSLT edema index were significantly (P <.001) correlated with each other. Correlation coefficients decreased (P <.001) with increasing diameter of the measurement circle. In the macular edema group, correlation coefficients were significantly (P <.001) higher than in the control group. To separate the study and control groups, receiver operator characteristic curves covered a larger area for OCT measurements than for cSLT measurements. Retinal thickness measurements and edema index correlate with visual acuity (correlation coefficient r = -.653 for OCT, r = -.608 for cSLT; P <.001).

CONCLUSIONS

Macular edema can be quantitatively mapped by OCT and cSLT. The retinal thickness and edema index measurements correlate with visual acuity. The fast and standard examination modes of OCT give similar measurements. Both OCT and cSLT can differentiate between eyes with and without macular edema, with OCT showing a higher predictive value.