Machine learning based strategy surpasses the traditional method for selecting the first trial Lens parameters for corneal refractive therapy in Chinese adolescents with myopia.

PURPOSE: Return zone depth (RZD) and landing zone angle (LZA) are important parameters of corneal refractive therapy (CRT) lenses. A new machine learning algorithm is proposed for prescribing CRT lens parameters in Chinese adolescents with myopia. METHODS: This is a retrospective study. In total, 1037 Chinese adolescents with myopia (1037 right eyes) were enrolled. A calculation model based on corneal elevation maps was constructed to calculate RZD and LZA for the four quadrants. Furthermore, multiple linear regression and optimized machine learning models were established to predict RZD and LZA values for different combinations of age, sex, and ocular parameters. The four methods (sliding card, linear regression, calculation and optimized machine learning) were then compared to the parameters of the final ordered lens. RESULTS: The optimized machine learning pipeline achieved the best performance. Age, sex, horizontal visible iris diameter (HVID), spherical equivalent refraction degree (SER), eccentricity (e), keratometric (K) readings, corneal astigmatism (CA), axial length (AL), AL/corneal curvature ratio (AL/MK), and anterior chamber depth (ACD) were significant to the machine learning model. The R values for the nasal, temporal, superior and inferior LZA based on machine learning were 0.843, 0.693, 0.866 and 0.762, respectively, and those for the RZD were 0.970, 0.964, 0.975 and 0.964, respectively. CONCLUSIONS: The feasibility and efficiency of an optimized machine learning method to predict LZA and RZD parameters has been demonstrated. The advantage of the proposed method is that it is more accurate, easier to use and faster to implement than the traditional sliding card method.

Local injection of M-CH combined with i.p. hyperthermic hypo-osmolar infusion is an effective therapy in advanced gastric cancer.

Treatment failure of surgically treated gastric cancer is attributed to the spread of gastric cancer cells into the abdominal cavity and lymphatic or hematogenic canals. In the present study, local injection of mitomycin C bound to activated carbon (M-CH) combined with i.p. hyperthermic hypo-osmolar infusion (IPHHOI) was intraoperatively administered to prevent lymph node recurrence and peritoneal recurrence of gastric cancer. Between April 1998 and August 1999, 79 patients with advanced gastric cancer were allocated randomly to two groups. Forty patients underwent M-CH plus IPHHOI combined with surgery (M-CH1+IPHHOI group) and the remaining 39 underwent surgery alone (control group). Lymph node and peritoneal recurrence were significantly decreased in the M-CH1+IPHHOI group compared to that in the control group (p<0.05). The 1- and 2-year survival rates for the M-CH1+IPHHOI group were 91.2 and 72.1%, and those for the control group were 78.9 and 45.5%. The M-CH1IPHHOI group reaped a significant survival benefit (p=0.0352) compared to the control group. Although this study was conducted randomly for a small number of patients and short time, compared with the control group, the M-CH1+IPHHOI group had a beneficial effect in preventing lymph node recurrence and peritoneal recurrence after curative gastrectomy for advanced gastric cancer.