Abstract
To investigate whether correction for atypical birefringence pattern (ABP) using scanning laser polarimetry with enhanced corneal compensation (SLP-ECC) reduces the severity of ABP compared with variable corneal compensation (SLP-VCC) and improves the correlation with visual function.
Prospective observational study.
Normal and glaucomatous eyes enrolled from four clinical sites underwent complete examination, automated perimetry, SLP-ECC, and SLP-VCC. Eyes were characterized in three groups based upon the typical scan score (TSS): normal birefringence pattern (NBP) was defined as TSS ≥ 80, mild ABP as TSS 61 to 79, and moderate-severe ABP as TSS ≤ 60. For each of four SLP parameters, the area under the ROC curve (AUROC) was calculated to compare the ability of SLP-ECC and SLP-VCC to discriminate between normal and glaucomatous eyes.
Eighty-four normal volunteers and 45 glaucoma patients were enrolled. Mean TSS was significantly (
P < .001) greater using SLP-ECC (98.0 ± 6.6) compared with SLP-VCC (83.4 ± 22.5). The frequency of moderate-severe ABP images was significantly (
P < .001, McNemar test) higher using SLP-VCC (18 of 129, 14%) compared with SLP-ECC (one of 129, 0.8%). Two SLP-ECC parameters (temporal superior nasal inferior temporal [TSNIT] average and inferior average) had significantly (
P = .01,
P < .001) higher correlation (r = .45, r = .50, respectively) with MD compared with SLP-VCC (r = .34, r = .37). Among eyes with moderate-severe ABP (n = 18), inferior average obtained using SLP-ECC had significantly (
P = .03) greater AUROC (0.91 ± 0.07) compared with SLP-VCC (0.78 ± 0.11).
SLP-ECC significantly reduces the frequency and severity of ABP compared with SLP-VCC and improves the correlation between RNFL measures and visual function.
