Mapping of the retinal pigment epithelium in exudative age related macular degeneration.
OBJECTIVE
To evaluate a novel technique for three-dimensional mapping of the retinal pigment epithelium (RPE) layer in patients with subfoveal choroidal neovascularization (CNV) due to age-related macular degeneration.


METHODS
Scanning with a recent generation retinal thickness analyzer (RTA) was performed in consecutive patients undergoing fluorescein angiography. From a 3 x 3 mm area centered on the fovea, three-dimensional area maps of the RPE level were calculated by external spreadsheet software. Included were 18 eyes with classic CNV, 18 eyes with occult CNV and 18 eyes from age-matched normal subjects. Repeatability was assessed by measuring 17 eyes with CNV 3 times. In ten additional patients, RTA imaging results were compared with cross-sections obtained by optical coherence tomography.


RESULTS
By both methods, distinctive changes in RPE level maps were observed in classic and occult CNV. In classic CNV with the lesion extending over the RPE, only focal irregularities in the anteriorly displaced RPE surface were observed. In contrast, mapping of occult CNV showed a more irregular displacement of the RPE layer. The RPE map standard deviation indicating surface irregularity differed statistically significantly between the groups, with coefficients of variance of 5.9% for controls, 6.1% for classic and 8.8% for occult CNV (P < 0.001). Regarding repeatability, RPE level maps showed 1.2% coefficient of variance and an intra-class correlation coefficient of 0.87 for triplicate measurements in CNV patients.


CONCLUSIONS
Topographic mapping of CNV lesions offers a fast, reproducible method for obtaining three-dimensional morphometric information on the RPE level and to quantify changes.
Neubauer
Aljoscha S
AS
Department of Ophthalmology, Ludwig-Maximilians-University, Mathildenstr. 8, 80336, Muenchen, Germany. aljoscha.neubauer@med.uni-muenchen.de
Thiel
Martin
M
Priglinger
Siegfried
S
Chryssafis
Christos
C
Alge
Claudia
C
Welge-Lüssen
Ulrich
U
Kampik
Anselm
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020256:Choroidal Neovascularization / Q000175:diagnosis* / Q000209:etiology; D003941:Diagnostic Techniques, Ophthalmological; D005122:Exudates and Transudates; D005260:Female; D005451:Fluorescein Angiography; D006801:Humans; D021621:Imaging, Three-Dimensional; D008268:Macular Degeneration / Q000150:complications / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D010857:Pigment Epithelium of Eye / Q000473:pathology*; D015203:Reproducibility of Results; D041623:Tomography, Optical Coherence