角膜塑型術中近視度數與眼球軸長關係之初探
中華民國眼科學會學術討論會論文摘要
Academic and Annual Meeting of the Ophthalmological Society of Taiwan (R.O.C)
第五屆國際眼科專題演講會暨第四十二次學術演講會(九十年十二月八日~九日)
ABSTRACT FORM
角膜塑型術中近視度數與眼球軸長關係之初探
張朝凱、陳德照＊、戴文瑛＊＊、林煥昇＊＊
台北博仁醫院、德照眼科診所＊、長虹診所＊＊、
Purpose：Myopia can be reduced by Orthokeratologiy procedure. But the amount of myopia reduced varied between patients. It is our interests to investigate the impacts of the axial length with the myopic reduction.
Method：A total of 20 (10 patients between 12y/o to 15y/o ) non diseased eyes with myopia over than –5.0D were studied. All subjects wore advance accelerated ortho-k contact lenses (Orthofocus B, Metro Optics, USA) overnight for six months. The lenses were replaced if needed during the treatment Subjective refraction and UCVA were measured periodically and recorded. The axial length of the eyes were measured pre and post the study with the A-scan ocular biometry..
Results：Regarding to the reviewed materials ,it is found that axial length grows 0.25mm to 0.3 mm every six months for adolescence whose age are between 12 to 15 years old. In this study , we found axial length growth has direct relationship with myopia progression. At the end of 6 months follow up, a full reduction of greater than 5.0D of myopia was found in patients with less axial length growth(<0.23mm±0.02mm), while limited reduction of myopia was found for those patients with greater axial length growth (>0.29mm±0.09mm) over six months..The amount of myopia redution was expected more satisfactory and efficient for shorter axial length (<23.27mm±1.12mm) or low myopia patients(<5.0D myopia )
Conclusion:This study suggests that the elongation rate of axial length could be one of the predictive factors influencing the result of ortho-k. However ,there are other factors could influence myopic reduction in ortho-k, such as cornel eccentricity ,corneal curvature, corneal elasiticity, IOP , tear film quality and quantity .etc which need further investigated.