# Optical and Electronic Expert System for Diagnosing Eye Pathology in Glaucoma
## 7 Evaluation of Metrological Indicators  
For most medical and biological studies, the degree of probability of an error-free forecast equal to 95% is considered sufficient, and the number of cases of the general population in which deviations from the patterns established during a sample study may be observed should not exceed 5%. In a number of studies related, for example, to the use of highly toxic substances, vaccines, and surgical treatments, as a result of which serious diseases, complications, and fatal consequences are possible, the degree of probability \(p=99.1\%\) is used, i.e., in no more than in 1% of cases of the general population, deviations from the regularities established in the sample population are possible. The given degree of probability (\(p\)) of an error-free forecast corresponds to a certain value of the criterion t substituted into the formula, which also depends on the number of observations. When n > 30, the degree of probability of an error-free forecast (\(p=99.1\%\)) corresponds to the value of t = 3, and when \(p=97.2\%\), this corresponds to a value of t = 2. When n < 30, the value of t at the appropriate degree of probability of an error-free forecast is determined according to a special table ([PERSON]). We determined the error of representativeness (mp) and the confidence limits of the relative indicator of the general population (R\({}_{\text{gen}}\)) in relation to the table of results obtained through diagnosis by an ophthalmologist and with the help of an expert database (See Table 2). A group of glaucoma patients consisting of 126 people aged 50-65 years but with different stages was used. The representativeness error of the relative indicators was determined according to the diagnoses of an ophthalmologist. \[m_{\text{1B}}=\sqrt{\frac{43\times(100-43)}{42}}=7.64\%\]  
\[m_{\text{2B}}=\sqrt{\frac{14\times(100-14)}{42}}=5.35\%\]  
\[m_{\text{3B}}=\sqrt{\frac{43\times(100-43)}{42}}=7.64\%\]  
The error of representativeness of the relative indicators was determined according to the diagnoses obtained with the help of the expert database. \[m_{\text{1c}}=\sqrt{\frac{40\times(100-40)}{42}}=7.56\%\]  
\[m_{\text{2c}}=\sqrt{\frac{12\times(100-12)}{42}}=5.01\%\]  
\[m_{\text{3c}}=\sqrt{\frac{48\times(100-48)}{42}}=7.71\%\] \begin{table}
\begin{tabular}{c c c c c c} \hline \multicolumn{2}{c}{**Diagnosis by an Ophthalmologist**} & \multicolumn{2}{c}{**The Diagnosis was Obtained with the Help of an Expert Base**} \\ \hline \multicolumn{2}{c}{**The Number of**} & \multirow{2}{*}{\begin{tabular}{c} **Stages of** \\ **Glaucoma** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Percentage of the** \\ **Total Quantity, \%** \\ \end{tabular} } & \multicolumn{2}{c}{**The Number of**} & \multirow{2}{*}{\
\begin{tabular}{c} **Stages of** \\ **Patients with a** \\ **Certain Stage** \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} **Percentage of the** \\ **Total Quantity, \%** \\ \end{tabular} } \\ \hline
54 & I & 43 & 51 & I & 40 \\ \hline
18 & II & 14 & 15 & II & 12 \\ \hline
54 & III & 43 & 60 & III & 48 \\ \hline \end{tabular}
\end{table} 
Table 2: Comparison of the diagnoses obtained using different methods (\(p<0.05\)). The confidence limits of the average values of the general population (R\({}_{\text{gen}}\)) were calculated as follows:  
* It was necessary to set the degree of probability of an error-free forecast (\(p\) = 95%). * At a given degree of probability and with a number of observations of more than 30, the value of the criterion t was equal to 2 (t = 2). * Then, P\({}_{\text{1B}}\) = P\({}_{\text{choice}}\)\(\pm\) tm = 43% \(\pm\) 2 \(\times\) 7.64 = 43% \(\pm\) 15.28%. * Then, P\({}_{\text{2B}}\) = P\({}_{\text{choice}}\)\(\pm\) tm = 14% \(\pm\) 2 \(\times\) 5.35 = 14% \(\pm\) 10.70%. * Then, P\({}_{\text{3B}}\) = P\({}_{\text{choice}}\)\(\pm\) tm = 43% \(\pm\) 2 \(\times\) 7.64 = 43% \(\pm\) 15.28%. * Then, P\({}_{\text{1c}}\) = P\({}_{\text{choice}}\)\(\pm\) tm = 40% \(\pm\) 2 \(\times\) 7.56 = 40% \(\pm\) 15.12%.