Assessment of the Heidelberg Retina Tomograph in the detection of sight-threatening diabetic maculopathy

• Published in: Eye (London) Vol. 13; no. 2; pp. 136 - 144
• Main Authors: ZAMBARAKJI, H. J, BUTLER, T. K. H, VERNON, S. A
• Format: Journal Article
• Language: English
• Published: Basingstoke Nature Publishing Group 01.04.1999
• Subjects: Adult; Aged; Aged, 80 and over; Biological and medical sciences; Diabetic Retinopathy - diagnosis; Diabetic Retinopathy - surgery; Female; Humans; Investigative techniques of ocular function and vision; Investigative techniques, diagnostic techniques (general aspects); Laser Coagulation; Macular Degeneration - diagnosis; Macular Degeneration - surgery; Male; Medical sciences; Microscopy, Confocal; Middle Aged; Ophthalmoscopes; Predictive Value of Tests; Reproducibility of Results; Sensitivity and Specificity; Tomography - instrumentation; Vision Screening - instrumentation; Visual Acuity; Endocrinopathy; Human; Evaluation; Macula; Edema; Eye disease; Diabetes mellitus; Tomograph; Maculopathy; Technique; Medical screening
• ISSN: 0950-222X; 1476-5454
• DOI: 10.1038/eye.1999.40

To assess the potential role of the Heidelberg Retina Tomograph (HRT) in screening for sight-threatening macular oedema in diabetes. One hundred and thirty-one eyes of 81 consecutive diabetic patients who fitted the inclusion criteria were included in the study. On HRT, the volume above the reference plane bound within a 2 mm diameter circle centred at the fovea was measured. The volumetric indices were compared with the mean measurement index in a group of 20 age-matched controls (mean score = 1, mean +2 SD score = 1.8). We also assessed the sensitivity of the subjective analysis of the intensity image and the addition of the three-dimensional map to the intensity image for detecting macular oedema and clinically significant macular oedema (CSMO). One hundred and twelve eyes of 71 patients had a corrected Snellen visual acuity of 6/9 or better. When considering eyes with 6/9 or better vision only, the system's sensitivity for detecting CSMO was 58.33% 'per eye' examined, and 81.82% 'per patient' examined using a cut-off volumetric index of 1.8. In our study eyes with 6/9 or better vision, we found a 21% prevalence of CSMO. The predictive values of a positive test were 38.89% and 45% (cut-off score 1.8, 'per eye' and 'per patient' respectively) for CSMO. The predictive values of a negative test were 86.84% and 90.48% (cut-off score 1.8, 'per eye' and 'per patient' respectively) for CSMO. The volumetric assessment of diabetic maculopathy by HRT is a potentially useful method for screening eyes at risk. A larger group of patients with a greater number of eyes with minimal or no maculopathy is required to establish the specificity of this technique.