Sensitivity and specificity of nonmydriatic digital imaging in screening diabetic retinopathy in Indian eyes

• Main Authors: Vishali Gupta, Reema Bansal, Amod Gupta, Anil Bhansali
• Format: Article
• Language: English
• Published: Wolters Kluwer Medknow Publications 2014-01-01
• Series: Indian Journal of Ophthalmology
• Subjects: Acromegaly; central corneal thickness; intraocular pressure; optic disc topography; retinal nerve fiber layer thickness; Best-corrected visual acuity; inner segment/outer segment junction; outer retinal corrugation; rhegmatogenous retinal detachment; Diabetic retinopathy; Indian eyes; nonmydriatic imaging; screening
• Online Access: http://www.ijo.in/article.asp?issn=0301-4738;year=2014;volume=62;issue=8;spage=851;epage=856;aulast=Gupta
• ISSN: 0301-4738; 1998-3689

Background: Nonmydriatic digital imaging (NMDI) is ideal for screening diabetic retinopathy (DR), but its use in Indian eyes has not been evaluated. Aim: The aim was to evaluate the sensitivity and specificity of NMDI as a screening tool in detecting DR in Indian eyes. Design: A prospective, nonrandomized, noncomparative, noninterventional study. Materials and Methods: A total of 500 diabetic patients visiting the endocrinology clinic (September 2008-June 2010) underwent NMDI (Zeiss Procam), followed by routine dilated fundus photography (FP; Zeiss Visupac 450+) of 345° retinal fields (1) optic disc and macula, (2) superotemporal, and (3) nasal to optic disc. Two-masked retina specialists graded the images for quality and severity of DR, and compared between NMDI and dilated FP. Statistical Analysis: SPSS Windows 17 for version. Results: Mean age was 52.97 ± 13.46 years (306 males: 194 females). The rate of ungradable images was 30.6% and 31% by the two observers. By observer 1, the sensitivity and specificity of detecting any DR was 58.8% and 69.1%, respectively, (κ = 0.608) and sight-threatening DR (STDR) was 63.1% and 68.9%, respectively, (κ = 0.641). By observer 2, the sensitivity and specificity was 57.3% and 68.3%, respectively, for any DR (κ = 0.593) and 62.8% and 68.3%, respectively, for STDR (κ = 0.637). The level of agreement between two observers was high (κ = 0.96). Conclusion: A high rate of poor quality photographs and low sensitivity limited the use of NMDI as a perfect screening system, particularly in dark iris population with diabetes as seen in Indian eyes.