Detection of progression of glaucomatous retinal nerve fibre layer defects using optical coherence tomography-guided...

The aim was to investigate the agreement for detection of progression of glaucomatous retinal nerve fibre layer defects (RNFLD) between optical coherence tomography-guided progression analysis (OCT GPA) and conventional red-free fundus photography.

Four hundred and fifteen glaucomatous eyes that underwent at least four serial red-free photographic and OCT examinations were included in the study. Based on the inspection of the red-free fundus photographs and GPA maps, RNFLD progression was defined as the development of a new defect, widening or deepening of a pre-existing RNFLD in red-free fundus photography (photographic progression) or 'Likely Loss' on a GPA map (GPA progression). The agreement of photographic and OCT GPA progression and the factors influencing it, including refractive error, severity of glaucoma (mean deviation of the visual field), type of RNFLD (localised versus diffuse), width of the baseline RNFLD, type of RNFLD progression (new defect, widening, deepening) and location of RNFLD progression (clock-hour sector) were assessed.

Among the 415 eyes, 82 (19.8 per cent) showed photographic or GPA progression. Among the 82 eyes with progression, progression was detected only in red-free fundus photography in nine (11.0 per cent) eyes and only in GPA in 32 (39.0 per cent) eyes. In 41 eyes (50.0 per cent), progression was detected with both methods. Detection of RNFLD progression only in GPA was associated with a higher myopia, diffuse RNFLD, deepening of the RNFLD and RNFLD progression at the 6, 9 and 12 o'clock positions (p < 0.05).

OCT GPA may be a useful supplement to conventional red-free fundus photography for detecting RNFLD progression.