A New-type Labeling Application Assisted By Smart Phone For Targeted Axial Position In IOL Implantation

Objective:To evaluate the convenience and accuracy of a new-type of "arbitrary point two-step method" assisted by smart phone for finding the target axis in the cataract phacoemulsification and intraocular lens implantation.Methods: A prospective and observational study,which included 62 cases(62 eyes)of age-related cataracts who were admitted to Shenyang He’s Eye Hospital for surgery from October 2021 to April 2022.All patients underwent toric intraocular lens implantation under simulation,and the axial position was placed with the steep corneal axis as the target.All patients underwent detailed examination before surgery and were randomly divided into two groups: control group and experimental group.The "traditional two-step method" of marking under slit lamp was adopted in the control group,and the steps are as follows.Step 1,the horizontal light band under the slit lamp was used to guide the horizontal axis marking at 3 o’clock and 9 o’clock positions of the corneal limbus before surgical mydriasis.Step 2,the radial line was located at the steep axis(i.e.,the target axis position),which was marked with the horizontal axis mark point as the reference during the surgery using a scale mark ring.In the experimental group,the "two-step method with any point" assisted by smart phone was used.Step 1,a point was marked at any position of the limbus under the direct vision of the naked eye before surgery,and the actual angle value of the marked point was photographed and measured by using the smart selfdeveloped APP mobile phone.Step 2,the target axis position was marked by using a scale mark ring with the marked point of the known angle value as the reference during surgery.Biometric measurement and anterior segment image acquisition were utilized for all patients using IOLmaster700 preoperatively.During the operation,CALLISTO eye operation navigation system was used as the standard reference to measure and calculate the deviation value(deviation-1)of reference mark points in the first step,the deviation value(deviation-total)of target axial mark points in the second step and the deviation value(deviation-2)of the angle between reference mark points and target axial mark points in all patients,and they were compared between the two groups.The preoperative marking process for all patients were timed and compared between two groups.Results: For the deviation-1 value comparison,the value in experimental group was1.06± 1.39°,which was lower than 2.48± 2.23 °in control group,and the difference was statistically significant(P < 0.05).For deviation-2 value comparison,the experimental group was 1.35± 1.40 ° and the control group 1.48±1.79 °,the difference was not statistically significant(P >0.05).Deviation–total comparison,the experimental group was 1.77± 1.54°,lower than control group 2.81± 1.58°,and the difference was statistically significant(P < 0.05);The duration of preoperative marking process in experimental group was shorter than that in control group,and the difference was statistically significant(P < 0.05).The difference in the number of cases of zero deviation-1 of mark points between two groups was statistically significant(P < 0.05).The error within deviation-1 of the two groups was ≤ 3° and the difference was statistically significant(P < 0.05)。Conclusion: Compared with the traditional two-step method,the new-type method with random point assisted by smart phone is more convenient,time-saving and accurate for finding the target axis in the cataract phacoemulsification combined with intraocular lens implantation,which is worth well spreading.