Quantitative analysis of diabetic macular edema after scatter laser photocoagulation with the scanning retinal thickness analyzer.
OBJECTIVE
To define the effect of scatter laser photocoagulation on foveal retinal thickness.


METHODS
A commercial scanning retinal thickness analyzer was used to measure retinal thickness. The foveal retinal thickness was measured at the central area of the fundus (0.4 x 0.4 mm). The method was applied to 20 consecutive patients (mean age, 52.4 +/-16.9 years) with diabetic retinopathy. Measurements were performed before and 6 weeks after scatter photocoagulation. Patients were examined by fluorescein angiography and slit-lamp biomicroscopy to detect macular edema.


RESULTS
Mean foveal thickness before scatter photocoagulation was 187+/-45 microm, increasing to 221+/-46 microm after the treatment (P = 0.0001). The foveal thickness increased in 12 eyes (60%). Laser treatment increased macular permeability in two eyes (10%). Biomicroscopic examination revealed central macular thickening in one eye (5%). Visual acuity was reduced in four eyes (20%).


CONCLUSIONS
Our results suggest that subclinical macular edema occurs after scatter laser photocoagulation. The retinal thickness analyzer is a sensitive tool for early detection of macular edema after laser treatment, because increases in retinal thickness as small as 34 microm cannot be assessed by slit-lamp biomicroscopy.
Tsujikawa
A
A
Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Japan.
Kiryu
J
J
Dong
J
J
Yasukawa
T
T
Suzuma
I
I
Takagi
H
H
Ogura
Y
Y
D002199:Capillary Permeability; D003924:Diabetes Mellitus, Type 2 / Q000150:complications; D003930:Diabetic Retinopathy / Q000503:physiopathology / Q000601:surgery*; D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation*; D004487:Edema / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D005451:Fluorescein Angiography; D005654:Fundus Oculi; D006801:Humans; D017075:Laser Coagulation / Q000009:adverse effects*; D008266:Macula Lutea / Q000473:pathology* / Q000503:physiopathology; D008875:Middle Aged; D012164:Retinal Diseases / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D012171:Retinal Vessels / Q000503:physiopathology; D014792:Visual Acuity