Abstract
Purpose::
To evaluate whether confocal scanning laser ophthalmoscopy (Heidelberg Retina Tomograph III [HRTII], Heidelberg Engineering, Heidelberg, Germany) is a valid tool for the detection of glaucomatous optic nerve damage.
Design::
Observational, cross-sectional, nonconsecutive study in Montreal, Canada.Main Outcome Measures: Positive likelihood ratio (PLR) and negative likelihood ratio (NLR), sensitivities and specificities, positive predictive value (PPV) and negative predictive value (NPV), and coefficients of agreement of Moorfields regression analysis (MRA), and Glaucoma probability score analysis (GPS).
Methods::
Two hundred fourty four, high-risk persons were enrolled during a 6-month period. Participants underwent HRT II testing and a standard ophthalmologic examination, including gonioscopy, intraocular pressure measurement, and optic disc grading. The results obtained with the HRT II program were reprocessed with the newer version of the HRT, HRT III, when it became available.
Results::
Two hundred fourty four participants were enrolled, and were examined clinically; 21 (8,6%) were found to have glaucoma. Heidelberg Retina Tomograph III testing was performed. When MRA was compared with the clinically based diagnosis, for the right eye, MRA specificity was 82%, sensitivity 70%, PPV 47%, NPV 92%, PLR 3,81 , and NLR 0,37. For the left eye, MRA specificity was 62%, sensitivity 73%, PPV 33%, NPV 90%, PLR 2,29 , and NLR 0,52. When GPS was compared with the clinically based diagnosis, for the right eye, GPS specificity was 70%, sensitivity 78%, PPV 38%, NPV 93%, PLR 2,61 , and NLR 0,32. For the left eye, GPS specificity was 62%, sensitivity 80%, PPV 30%, NPV 94%, PLR 2,10 , and NLR 0,32. When we combined MRA and GPS results for the right eye, specificity was 83%, sensitivity 71%, PPV 49%, NPV 92%, PLR 4,12 , and NLR 0,35. For the left eye, specificity was 76%, sensitivity 71%, PPV 38%, NPV 93%, PLR 2,98 , and NLR 0,38. When MRA was compared with GPS, the Kappa coefficient of agreement was 0,314 for the right eye and 0,228 for the left eye. Normal patients had significantly low GPS score ( ANOVA, p < .05 ).
Conclusions::
The results of this study suggest that a glaucoma screening program may be effective in detecting glaucoma when targeting high-risk populations. Heidelberg Retina Tomograph III testing may prove to be a useful tool in detecting glaucomatous optic nerve damage and could be used as part of a complete glaucoma screening protocol.