To evaluate and confirm the performance of an artificial neural network (ANN) trained to recognize glaucomatous visual field defects, and compare its diagnostic accuracy with that of other algorithms proposed for the detection of visual field loss.
SITA Standard 30-2 visual fields, from 100 glaucoma patients and 116 healthy participants, formed the data set. Our ANN was a previously described fully trained network using scored pattern deviation probability maps as input data. Its diagnostic accuracy was compared to that of the Glaucoma Hemifield Test, the Pattern Standard Deviation index at the P<5% and <1%, and also to a technique based on the recognizing clusters of significantly depressed test points.
The included tests had early to moderate visual field loss (median MD=−6.16 dB). ANN achieved a sensitivity of 93% at a specificity level of 94% with an area under the receiver operating characteristic curve of 0.984. Glaucoma Hemifield Test attained a sensitivity of 92% at 91% specificity. Pattern Standard Deviation, with a cut off level at P<5% had a sensitivity of 89% with a specificity of 93%, whereas at P<1% the sensitivity and specificity was 72% and 97%, respectively. The cluster algorithm yielded a sensitivity of 95% and a specificity of 82%.
The high diagnostic performance of our ANN based on refined input visual field data was confirmed in this independent sample. Its diagnostic accuracy was slightly to considerably better than that of the compared algorithms. The results indicate the large potential for ANN as an important clinical glaucoma diagnostic tool.
Department of Clinical Sciences, Ophthalmology, Malmö University Hospital, Lund University, SE-205 02 Malmö, Sweden
Supported by grants K2005-74X-1426-13A and K2005-74BI-15375-01A from the Swedish research council [vetenskapsrådet], by the foundation of Crown Princess Margareta for visually handicapped [Stiftelsen Kronprincessan Margaretas arbetsnämd för synskadade (KMA)], and by the Järnhardt foundation (Järnhardts stiftelse).
Reprints: Dimitrios Bizios, MD, Department of Clinical Sciences, Ophthalmology, Malmö University Hospital, Lund University, SE-205 02 Malmö, Sweden (e-mail: email@example.com).
Received for publication March 6, 2006; accepted October 10, 2006