Enhanced Detection of Glaucoma Progression Using Widefield Swept-Source OCT.

PURPOSE

To examine the effectiveness of evaluating widefield swept-source OCT scans for detecting glaucoma progression compared with conventional circumpapillary retinal nerve fiber layer thickness (cpRNFLT) measurements.

DESIGN

Longitudinal study.

PARTICIPANTS

One hundred and fifty-six eyes with glaucoma from 115 participants.

METHODS

This study included individuals seen over ≥2 visits that were 12 months apart and those who were also scheduled for retest visits within ≤1 month at the baseline and 12-month visits. A circumpapillary circle scan on spectral-domain OCT and a widefield 15×15 mm OCT volume scan were acquired from each eye at each visit. A total of 286 and 284 unique visit pairs were thus available, where OCT scans were obtained 12 months and ≤1 month apart respectively, serving as the case and control groups respectively. Widefield OCT scans from these visit pairs were evaluated by 2 graders, who assessed the ganglion cell complex (GCC) thickness and thickness difference maps for glaucoma progression, masked to the time difference between the 2 scans.

MAIN OUTCOME MEASURES

Percentage of eyes deemed as progressing at 95% specificity.

RESULTS

Evaluation of widefield OCT scans identified >2 times as many eyes as progressing over a 12-month period (Grader 1 = 36.7%; Grader 2 = 38.1%) than cpRNFLT measurements from spectral-domain OCT (16.8%; P < 0.001 for both) at 95% specificity. For the subset of 96 (62%) eyes with a baseline visual field mean deviation (MD) ≥-6 dB, evaluation of widefield OCT scans identified ≥3 times as many eyes as progressing (Grader 1 = 41.1%; Grader 2 = 46.3%) compared with cpRNFLT measurements (13.7%; P < 0.001 for both). There was substantial between-grader agreement for the eyes identified as progressing on widefield OCT imaging (Gwet first-order agreement coefficient = 0.76). Evaluation of widefield OCT scans in a 2-arm trial seeking to detect a ≥30% treatment effect in 1 study eye, with 80% power, was estimated to reduce sample size requirements by 69% compared with cpRNFLT measurements, or by 80% when only including eyes with an MD ≥-6 dB.

CONCLUSIONS

Qualitative evaluation of widefield OCT scans showed an enhanced detection rate for structural progression than cpRNFLT measurements in glaucoma eyes. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.