Photography of the nerve fibre layer may support the diagnosis glaucoma.
Study 1
The agreement of angular locations of retinal nerve fiber layer (RNFL) defect margins in glaucomatous eyes using red-free fundus photographs were compared to Cirrus high-definition optical coherence tomography (OCT) RNFL deviation and thickness maps. 380 RNFL defects with clear margins in red-free fundus photographs were overlaid on the OCT deviation and thickness maps. A reference line was drawn between the disc center and the macular center. Lines were also drawn between the optic disc center and the point where the RNFL defect margins crossed the OCT scan circle. The angle between the reference and defect-margin lines defined the angular location of the defect margin.
The angular locations of proximal and distal RNFL defect margins on OCT thickness maps showed good agreement with red-free fundus photographs. However, OCT deviation maps showed greater angular locations for both proximal and distal RNFL defect margins compared with red-free fundus photographs, especially in eyes with higher myopia (p < 0.05). This finding should be considered when evaluating RNFL defects using OCT maps «Hwang YH, Kim YY, Kim HK ym. Agreement of retinal ...»1.
Study 2
The ability of clock-hour, deviation, and thickness maps of Cirrus high-definition spectral-domain optical coherence tomography (HD-OCT) in detecting retinal nerve fiber layer (RNFL) defects identified in red-free fundus photographs in eyes with early glaucoma (mean deviation >-6.0 dB) was investigated ina ross-sectional study. 295 eyes with glaucomatous RNFL defects with clear margins observed in red-free fundus photographs and 200 age-, sex-, and refractive error-matched healthy eyes were enrolled.
The width and location of RNFL defects were evaluated by using the red-free fundus photograph. When a RNFL defect detected by red-free fundus photograph did not present as (1) yellow/red codes in the clock-hour map, (2) yellow/red pixels in the deviation map, or (3) blue/black areas in the thickness map, the event was classified as a misidentification of a photographic RNFL defect by Cirrus HD-OCT. In healthy eyes, the presence of false-positive RNFL color codes of Cirrus HD-OCT maps was investigated.
The prevalence of and factors associated with the (1) misidentification of photographic RNFL defects by Cirrus HD-OCT in eyes with glaucoma and (2) false-positive RNFL color codes of Cirrus HD-OCT maps in healthy eyes were assessed.
Among the 295 red-free fundus photographic RNFL defects from 295 eyes with glaucoma, 83 (28.1%), 27 (9.2%), and 0 (0%) defects were misidentified in the clock-hour, deviation, and thickness maps of Cirrus HD-OCT, respectively. Fifty-six defects (19.0%) were misidentified only in the clock-hour map and 27 (9.2%) in both the clock-hour and deviation maps. The misidentification of photographic RNFL defects by Cirrus HD-OCT was associated with a narrower width and a temporal location of RNFL defects (P<0.05). Among the 200 healthy eyes, 25 (12.5%), 30 (15.0%), and 12 (6.0%) eyes had false-positive RNFL color codes in clock-hour, deviation, and thickness maps of Cirrus HD-OCT, respectively.
Among the clock-hour, deviation, and thickness maps obtained with Cirrus HD-OCT, the thickness map showed the best diagnostic ability in detecting photographic RNFL defects. The RNFL thickness map may be a useful tool for the detection of RNFL defects in eyes with early glaucoma «Hwang YH, Kim YY, Kim HK ym. Ability of cirrus hig...»2.
Study 3
The objective of the cross-sectional, observational study was to determine whether focal abnormalities of the lamina cribrosa are present in glaucomatous eyes with localized retinal nerve fiber layer (RNFL) defects. 20 eyes of 14 subjects with localized RNFL defects detected by stereophotographs and 40 eyes of 25 age-matched healthy subjects had stereoscopic optic disc photography and in vivo lamina cribrosa imaging using enhanced depth imaging optical coherence tomography (EDI-OCT).
Of 20 eyes with a localized RNFL defect, 15 (75%) had ≥ lamina criborosa defect compared with only 1 of 40 healthy eyes (3%). The largest area lamina cribros adefect was present in a radial line EDI-OCT scan corresponding with a localized RNFL defect in 13 of 15 eyes (87%). There was good agreement between graders as to whether an eye had an LC defect (kappa = 0.87; 95% confidence interval [CI], 0.73-1.00; P<0.001) and the location of the largest defect (kappa = 0.72; 95% CI, 0.44-1.00; P<0.001) «Tatham AJ, Miki A, Weinreb RN ym. Defects of the l...»3.
Study 4
39 patients (48 eyes) with localized RNFLDs by fundus photography and 48 age-matched control individuals were included into the study. The individuals underwent spectral domain OCT of the retinal nerve layer. In OCT, a localized RNFLD was defined as a dipping of the retinal nerve fiber layer thickness curve into the red-colored band of the graph, measured at a peripapillary circle with a diameter of 3.46 mm.
In the 48 eyes of the study group, 63 localized RNFLDs were seen on the fundus photographs. On the OCTs, 58 of these 63 localized RNFLDs were detected, whereas 5 defects were not detected. Two localized RNFLDs seen on the OCTs were not found on the corresponding fundus photographs. The resulting sensitivity and specificity of OCT for detecting localized RNFLDs were 92% and 96%, respectively. The overall agreement rate between both methods was 94% (90/96), and the κ value was 0.90 (P<0.001). The results of both techniques correlated with each other for the determination of the location (Pearson correlation coefficient (r)=0.99; P<0.001) and the width of the localized RNFLDs (201 ± 123 degrees vs. 207 ± 115 degrees; r=0.93; P<0.001) «Wu XS, Xu L, Jonas JB ym. Agreement between spectr...»4.
Study 5
Four selected glaucoma eyes with visual field defects and retinal nerve fibre layer (RNFL) defects in photography were compared to Stratus optical coherence tomography (OCT) images. The RNFL defects were not picked up by the OCT algorytm or pseudo-colour images. However, defects seemed to be present in OCT grey-scale and raw data images in all four eyes «Hougaard JL, Heijl A, Bengtsson B. Glaucomatous re...»5.
Study 6 «Karvonen E, Stoor K, Luodonpää M ym. Prevalence of...»6
Earlier references supporting the evidence R7-R27