Diagnostic Accuracy of Disc Damage Likelihood Scale and Cup-To-Disc Ratio for Diagnosis of Glaucoma

Purpose:  To find the diagnostic accuracy of Disc Damage Likelihood Scale (DDLS) and cup-to-disc ratio (CDR) for diagnosis of glaucoma taking CCT adjusted IOP and characteristic visual filed defects with corresponding OCT-ONH changes as standard. Study Design:  Comparative, cross-sectional. Place and Duration of Study:  Department of Ophthalmology, Mayo Hospital, Lahore, from August 2020 to February 2021. Methods:  Three hundred and nine patients were enrolled after taking informed consent. Demographic data was obtained, and patients underwent complete ocular exam including DDLS and CDR, Slit-lamp biomicroscopy, gonioscopy and Intraocular pressure (IOP). Central corneal thickness, visual fields and OCT ONH was done. The patient was said to have glaucoma if his CCT adjusted IOP was greater than 21 mmHg, visual field defects and OCT changes. It was compared with CDR and DDLS, which was taken as suggestive of glaucoma with scores greater than 5. Results:  Mean age of patients was 54.82 ± 9.29 years, 108 (34.95%) were males. The sensitivity, specificity and diagnostic accuracy of DDLS for detection of glaucoma was 78.57%, 84.97% and 80.91% and the sensitivity, specificity and diagnostic accuracy of CDR for detection of glaucoma was 82.14%, 49.56% & 70.23% taking CCT adjusted IOP and characteristic visual field defects with corresponding OCT changes as standard. Conclusion:  Disk Damage likelihood scale is useful, cost effective and has higher accuracy to detect glaucomatous damage as compared to cup-to-disc ratio for diagnosis of glaucoma taking CCT adjusted IOP and characteristic visual field defects with corresponding OCT changes as standard.