Abstract
Purpose :
To evaluate and compare the clinical signs of glaucoma seen with fundus photographs and optical coherence tomography (OCT) of healthy controls and glaucoma patients or suspects.
Methods :
44 glaucoma patients or suspects and 32 healthy controls, with refractive error between ± 6 diopters, were tested with digital color fundus photography and wide field 9 × 12-mm scans on swept-source OCT imaging (Topcon, Japan). Masked to clinical information, two glaucoma specialists evaluated fundus photos of the disc, while two OCT specialists evaluated a one-page report [1] generated from the wide-field cube scan. Both glaucoma and OCT specialists evaluated each photo or OCT report on a 6-point scale according to their level of suspicion for glaucoma (N, definitely normal; PN, probably normal; IN, if forced to guess, normal; IG, if forced to guess, glaucomatous; PG, probably glaucomatous; and G, definitely glaucomatous).
Results :
The pattern of clinical signs of glaucoma seen on fundus photographs was statistically different between glaucoma (P<0.01) and suspects (P<0.01) vs. controls. Compared with the suspect group, glaucoma eyes were more likely to have vertical cup-to-disc > 0.6 (65.4% vs. 27.8%, P <0.01), rim thinning (73.1% vs. 27.8%, P < 0.01), violation of the ISNT rule (69.2% vs. 19.4%, P < 0.01), and RNFL thinning (55.8% vs. 25%, P < 0.05). For the 26 glaucoma eyes, the glaucoma and OCT specialists differed on 4 (15.4%). In all 4, the discs did not appear glaucomatous (N to IN), while the OCT (Fig 1A) and VFs (Fig 2A) showed glaucomatous damage (G to IG). For the 18 suspects, they differed on 4 (22.2%). In all 4, the discs suggested glaucoma (G to IG), while the OCT was within normal limits (N to IN). For the 32 healthy eyes, they differed on 2 (6.3%). One disc was incorrectly evaluated as IG and IG, while the OCT was rated N and N. Another disc was evaluated as N and IN, while the OCT (Fig 1B) was incorrectly evaluated as PG and PG with normal VFs (Fig 2B).
Conclusions :
Clinical signs of glaucoma damage seen on fundus photographs often correlate with damage seen on OCT. In glaucomatous eyes, damage on VFs and OCT can be missed on photos. On the other hand, OCT may be inaccurately classified as glaucomatous when the RNFL is on the lower limits of normal. There is a role for combining the information of both. 1. Hood et al, TVST, 2016
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.