AN EXPERT-SYSTEM FOR THE DIAGNOSIS OF TRO UBLES OF INTRAOCULAR-PRESSURE

Purpose This expert system (ES) is designed to avoid the four types of diagnosis errors: by omission or by confusion both of which may occur when collecting signs and symptoms and when analyzed data. This ES us es a thesaurus containing 42 classical and objective signs and a compr ehensive library. For a given case report, it provides the practitione r with a positive diagnosis, and if possible, one or several etiologie s taking into account all the data known about intraocular disorders. Methods This ES is run on a PC-compatible computer with 640 KB RAM and without hard drive. The 90 KB program is written in compiled Basic. A fter checking the case report to rule out nonsenses, the logic conside rs every likelihood. The syndromic diagnosis is set by identification. Comparisons of prevalence interfere, when needed, in a second, phase, within the framework of etiological diagnosis. Results When tested on a set of 180 cases records combined with 115 cases extracted from the literature corresponding to more than 1,900 diagnoses, this ES yielde d 100% correct positive and differential diagnoses, thus validating th e logical hypotheses. Probability of error by omission was less than a 3% and probability of error by confusion was well below 0.1%. Besides , the logical analysis shelds light on the intellectual mechanisms of diagnosis. Conclusions This ES is user-friendly, easy to update and ca n answer clinical problems the ophthalmologist has to cope with in dia gnosis and therapy of intraocular pressure disorders.