myopia patients who wear SCL more than 10 years before Small Incision Lenticule Extraction

myopia patients who wear SCL for 10 years or less before Small Incision Lenticule Extraction

myopia patients who have not worn SCLs before Small Incision Lenticule Extraction

It consists of 10 items related to visual symptoms, including glare, halo, radiating light, foggy vision, blurred vision, visual distortion, diplopia, visual fluctuation, difficulty in focusing and difficulty in depth perception. Each item consists of three dimensions: frequency, severity and degree of distress. Therefore, this questionnaire contains a total of 30 questions. The answers to the above three dimensions respectively include four options, namely frequency: never, occasionally, often, and frequently; Severity: None, mild, moderate, severe; Degree of distress: None, a little, some, very much. The corresponding scores for the four options are 0, 1, 2, and 3 respectively. The higher the score, the worse the visual quality

Under sufficient correction conditions, dark adaptation lasted for 10 minutes. Using the CSV-1000 contrast sensitivity tester at a distance of 3 meters, under the conditions of bright vision (85 cd/m ²), bright glare (135 lx), dark vision (3 cd/m ²), and dark glare (28 lx) respectively, Test the highest CS level that can be distinguished at 3, 6, 12 and 18 c/d spatial frequencies one by one. At each spatial frequency, the examinee needs to point out the bar grid sight in the upper and lower two circular sight targets and report the direction of the bar grid. After the result is correct, gradually reduce the bar grid contrast until the examinee can no longer recognize it. The inverse of the lowest recognizable contrast at this time is the contrast sensitivity. Record in logarithmic units according to the grade value conversion table.

In this study, the ACCMetrics V.2 software developed by the University of Manchester in the UK for the HRT confocal microscope of Heidelberg Company was used to conduct automatic quantitative analysis and data recording on three nerve fiber images at different positions selected in a single shoot. The parameters analyzed include corneal nerve fiber density (CNFD sterand/mm 2) and corneal nerve fiber length( CNFL, mm/mm 2), corneal nerve fiber area (CNFA mm2/mm 2), corneal nerve fiber width (CNFW mm ), etc. Each inspection is carried out by the same inspector to reduce subjective errors.

Including corneal fluorescein staining score and tear film break-up time examination.

Corneal fluorescein staining score The corneal fluorescein staining was observed in different regions under a cobalt blue filter and scored. The cornea was divided into three regions: upper, middle and lower. Scores were given based on the fluorescein staining of the corneal epithelium in each region. No staining was scored as 0 points, 1 point for 1 to 30 staining points, 2 points for more than 30 staining points and no fusion of the staining points, and 3 points for the presence of corneal patellar staining fusion, filamentous substances and ulcers, etc. The total score is 9 points.

Tear film break-up time Instruct the patients to look straight ahead, observe with a slit lamp and cobalt blue filter, and measure the time when dry spots first appear on the cornea after one involuntary blinking movement with a stopwatch. Each patient is measured three times, and the average of the three measurements i