Clinical validation of RIA-G, an automated optic nerve head analysis software

Purpose: To clinically validate a new automated glaucoma diagnosis software RIA-G. Methods: A double-blinded study was conducted where 229 valid random fundus images were evaluated independently by RIA-G and three expert ophthalmologists. Optic nerve head parameters [vertical and horizontal cup–disc ratio (CDR) and neuroretinal rim (NRR) changes] were quantified. Disc damage likelihood scale (DDLS) staging and presence of glaucoma were noted. The software output was compared with consensus values of ophthalmologists. Results: Mean difference between the vertical CDR output by RIA-G and the ophthalmologists was ? 0.004 ± 0.1. Good agreement and strong correlation existed between the two [interclass correlation coefficient (ICC) 0.79; r = 0.77, P < 0.005]. Mean difference for horizontal CDR was ? 0.07 ± 0.13 with a moderate to strong agreement and correlation (ICC 0.48; r = 0.61, P < 0.05). Experts and RIA-G found a violation of the inferior–superior NRR in 47 and 54 images, respectively (Cohen's kappa = 0.56 ± 0.07). RIA-G accurately detected DDLS in 66.2% cases, while in 93.8% cases, output was within ± 1 stage (ICC 0.51). Sensitivity and specificity of RIA-G to diagnose glaucomatous neuropathy were 82.3% and 91.8%, respectively. Overall agreement between RIA-G and experts for glaucoma diagnosis was good (Cohen's kappa = 0.62 ± 0.07). Overall accuracy of RIA-G to detect glaucomatous neuropathy was 90.3%. A detection error rate of 5% was noted. Conclusion: RIA-G showed good agreement with the experts and proved to be a reliable software for detecting glaucomatous optic neuropathy. The ability to quantify optic nerve head parameters from simple fundus photographs will prove particularly useful in glaucoma screening, where no direct patient–doctor contact is established.

Clinical value of Optic Nerve Head Parameters and Disc-damage Likelihood Scale in the diagnosis and treatment of glaucoma / 中国医师进修杂志

Glaucoma, alias'the thief of light', characterized by visual field defects that correspond to damaged areas of the optic nerve head, is a common ophthalmopathy causing irreversible blindness. Thus early diagnosis is crucial. Structural assessment can detect Glaucoma in early stage and diminish the risk of irreversible visual impairment. There are now several apparatus which can clinically measure ONH parameters and confirm DDLS (disc damage likelihood scale) precisely and reproducibly. Comprehensive estimate considering RNFLD (retina nervefiberlayer defects), offers reliable evidence as well as potent support for preclinical detecting, measurement and follow-up observations.