Telemedicine Screening Program for Glaucoma Using Tonometry, Scanning Laser Opthalmoscopy (HRT) and Scanning Laser Polarimetry (GDX)

Abstract

Purpose: : Assessment of a Telemedicine Screening Program for glaucoma using imaging devices.

Methods: : Cross-sectional study in a population based sample. 414 subjects were examined with HRT-3, GDX-VCC, rebound tonometry (Icare) and pachymetry. All subjects with at least 2 of the 3 following criteria were considered suspects and referred to a glaucoma consultation: global Moorfields Regression Analysis borderline (BL) or outside normal limits (ONL), NFI value of GDX ≥30, and tonometry ≥ 21mmHg. Only good quality images were considered (see below). Examination at the Primary Care Centre was performed by 4 technicians and the results were sent to the reading centre where they were checked for quality and final diagnosis. Glaucoma consultation included tonometry with Goldman applanation tonometry, Humphrey perimetry, optic disc photographs, gonioscopy and ophthalmic examination at the Hospital. Subjects were diagnosed of glaucoma if both optic nerve and visual field were considered as glaucomatous.

Results: : The screening program detected 51 patients as glaucoma suspects. Five subjects (10%) did not accept attending the glaucoma consultation and 46 completed the study. Of those 46, 88% (81 eyes) had good quality HRT images (SD < 30 and at least acceptable HRT Quality Control and resulted pathologic (BL or ONL) in 53 eyes (58%). GDX had good quality (Q > 6) in 73 eyes (76%) and resulted abnormal in 34 eyes (42%). At glaucoma consultation the final diagnosis was: 13 glaucomas, 2 ocular hypertensives, 21 glaucoma suspects and 10 normals.

Conclusions: : The TELEMEDICINE SCREENING PROGRAM detected 12% glaucoma suspects with a specificity of 78%.

Keywords: imaging/image analysis: clinical • clinical (human) or epidemiologic studies: outcomes/complications • detection