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Evaluation of Myopic Progression in Orthokeratologic therapy for students in Taiwan William Cheng , Cheng’s Eyes Clinic Purpose: The mainly purpose of orthokeratologic therapy is blockage of myopic progression , not to correct the myopia. Method: There are 557patients (1059eyes),from1998 Feb.14 to 2004 Feb.13, received with orthokeratologic therapy for the rapidly progression of myopia in our ophthalmic departments. They were followed up in my clinic every week in the first 3 mouths period and every mouth in later, and checked up the naked and corrected visual acuity, cornea and the external ocular surface by slit-lamp every clinic time. However, they should be checked up the lens wearing pattern about the centering, central curve , compression area , lens movement and tear content under the fluorescent stain every time. Lens Design:The design of orthokeratologic (ok)lens were according double reverse geographic theory with 4 curves as fellows: Basal Curve 6.0 mm, Fitting Curve 0.6mm, Alignment Curve 1.1mm and Peripheral Curve 0.4mm.Thediameter of lens were 10.2mm. The central thickness of ok lens were 0.2mm.The lens material is BonstonXO (KD value ,110) proved by FDA. Cleaning Method: Using daily cleaning solution and conditional solution for permeable gas hard contact lens but paying more attention to the cutting angle between basal curve and fitting curve Overnight wearing about 6~8 hours for all patients excluding the daily wearing cases, Alarm system being set up for preventing infection as fellows: (1) Stopping the ok. lens wearing if ocular pain persisting for 2 hours, (2) Visiting the eye’s clinic if the ocular pain persisting for 6 hours, (3) Wearing withdraw one day per week (weekend). Evaluation of the refractional change after stopping orthokeratologic therapy from 1to 6 mouths (average 2.4 mouths) in 20 students amount of 557 patients with orthokeratologic treatment over half year to 6.25 years(average2.63years) Result: Compare with the original myopic state of this 20 cases (average treatment for 2.63 years) , there was no any myopic progression ( 47.10 degrees below the original data) for them with orthokeratologic therapy( average stopping therapy for 2.4 mouths.) , as the table 1.and Fig 1, Discussion: Compared with the other myopic corrections, orthokeratologic myopic therapy with a better prognosis for myopic progression. Compared with cycloplegic drug therapy for the school students (from 7 to 18 years olds), We had better dates in ok therapy for the blockage of myopic progression, as the table 1.and Fig 1.Cycloplegic drug only slowing the progression of myopia but couldn’t stopped it. Although glass wearing providing the best corrected visual acuity, it couldn’t prevent the myopia progression The soft contact lens providing the functions as same as glass, but the hard contact lens also performed a role for myopia progression. The OK lens ,also a extended permeable hard lens , performing a important role for the student myopia progression during learning stage, might be a good choice for students or their parents worried their myopia progression , especially malignant myopia. Conclusion: There was no any myopic progression ( 47.10 degrees below the original data) for the students with orthokeratologic therapy ( average stopping therapy for 2.4 mouths.) , compared with the average 75 degree increase myopic change per year of the recent epidermiologic data in Taiwan.(Table 2 and Fig.2) Fig.1 Compare with the original myopic state of this 20 cases (average treatment for 2.63 years) , there was no obvious myopic progression ( average 47.10 degrees below the original data) for them with orthokeratologic therapy ( average stopping therapy for 2.4 mouths.) 接受角膜塑型片之停戴時況分佈圖 200 150 100 50 增 減 0 度 - 50 0 1 2 3 4 5 6 7 數 - 100 - 150 - 200 - 250 - 300 - 350 停戴時間( 月) Stopping ok lens therapy(mouths) 年別 72 年 75 年 79 年 84 年 89 年 92 年 國小一年級 5.8% 3.0% 6.5% 12.8% 20.4% 24.7% 國小六年級 36.7% 27.5% 35.2% 55.8% 60.5% 48.7% 國中三年級 64.2% 61.6% 74.0% 76.4% 80.7% 71.3% 高中三年級 76.8% 76.3% 75.2% 84.1% 84.2% 86.0% 72年 台灣地區學生近視盛行率統計圖 75年 100% 79年 86.0% 84年 80% 89年 盛 60% 92年 行 率 40% 20% 24.7% 0% 國小一年級 國小六年級 國中三年級 高中三年級 年別
"Evaluation of Myopic Progression in Orthokeratologic therapy for "