Abstract
Purpose: :
To determine the spatial relationship in optic disc topographic parameter values obtained with confocal scanning laser ophthalmoscopy between right and left eyes in patients with early glaucoma.
Methods: :
Three–hundred–and thirty–four eyes of 167 patients (ocular hypertensives, glaucoma suspects, or glaucoma patients) were recruited from DIGS. All patients underwent HRT II imaging in both eyes. Eyes with one reliable visual field test in both eyes on standard automated perimetry using the 24–2 program closest to the imaging date were included. The amount of overlap in abnormal neuroretinal rim areas as classified by the Moorfields regression analysis (MRA, software version 3.0) between eyes was calculated as the ratio of overlapping abnormal rim sectors to the total number of abnormal rim sectors. Inter eye concordance ratio was calculated using the six neuroretinal rim sectors derived from MRA.
Results: :
Average mean deviation (MD) for right eyes was –1.79 ± 2.76 dB and –2.19 ± 4.07 dB for left eyes. Of the right (left) eyes, 39 (39) eyes were classified "borderline" by MRA, 62 (65) eyes were "within normal limits" and 66 (63) eyes "outside normal limits". 78 patients had a normal overall MRA result in both eyes (when considering "borderline" as "normal"). Of the 89 patients with a defect in at least 1 sector, mean inter–eye concordance was 0.27 ± 0.37 when considering "borderline" as a normal MRA result. When considering "borderline" as abnormal, concordance rate increased to 0.43 ± 0.38. The lowest overlap of neuroretinal rim abnormality was found in the temporal inferior sector with 20.9% (9 of 43 eyes, Kappa ± SE = 0.23 ± 0.09; "borderline" = normal) overlapping. The highest overlap was found in the nasal–inferior sector with 35.1% (13 of 37 eyes, Kappa ± SE = 0.44 ± 0.09, "borderline" = normal) overlapping.
Conclusions: :
In early glaucoma, there is a moderate to good spatial relationship in abnormal neuroretinal rim areas between eyes. Longitudinal studies may provide insight about the change of this relationship when the disease is advancing.
Keywords: imaging/image analysis: clinical • optic disc