鑽石刀近視手術後的白內障老花眼矯正手術(手術影片5:19)
Customized Phacoemulsification for post-RK with VERION™ Image Guided System and AutoSert IOL Injector
大約52歲的許先生，本身的職業是一位郵差，因為工作的關係，長時間在外面四處送信，最近這幾個月來，開始看不清楚信封上的地址，尤其在騎樓底下或光線昏暗時更是看不清楚，因為看不清的關係，就更用力去看，反而眼睛常常感到疲備、酸澀不適，而影響送信的工作效率，許先生感到老花眼非常的困擾，經由郵局同事大力推薦新眼光眼科診所的蕭醫師，所以來到我們診所諮詢老花眼手術相關的問題！
經過蕭醫師仔細的問診及評估過後，因為許先生以前就有近視約450度，因為不喜歡戴眼鏡的關係，在二十多年前就接受過近視矯正手術，二十多年前的近視矯正手術不同於現在的近視雷射，此種手術無法精準矯正度數，是醫師依照個人經驗使用鑽石刀將角膜做放射狀的切開手術(Radial Keratotomy)，使前、後角膜皆變平以達到降低近視度數的目的，但術後視力大多不穩定，且隨著年齡增長、老花眼度數增加而視力會顯得更加模糊並影響日常生活。
我們也幫許先生做了相關檢查，視神經視網膜斷層掃描(OCT)及眼底散瞳檢查，蕭醫師評估過後認為許先生沒有其他視網膜或視神經的病變，只是單純的老花眼越來越嚴重，也有點輕微水晶體混濁的問題。於是預計在白內障老花眼手術後應有不錯的手術效果。
2016年7月13日我們幫他做右眼白內障老花眼手術，許先生選擇植入多焦點新視延「全焦段人工水晶體」，術後隔天回診時，許先生很高興，他非常滿意手術後的結果，還一直問蕭醫師甚麼時後可以開另外一眼的手術，蕭醫師笑說至少等右眼的度數穩定，因為許先生之前做過近視雷射的關係，所以在水晶體的計算上會比較複雜一些，必須參考病人之前的近視度數、角膜的狀況、病人的年齡一起做評估才行！
約二周後我們幫許先生安排做右眼白內障老花眼手術，手術後許先生說看東西變比較亮，視覺品質也跟著提高，蕭醫師請許先生測試近距離閱讀書本，許先生因為可以很輕易的閱讀出書本上的文字感到很開心，手術後不管是看遠或是看近都覺得很清晰！他非常謝謝蕭醫師幫他做了雙眼的老花眼手術，因為現在上班時，閱讀信件上的地址變的非常得輕鬆，不像之前閱讀起來非常吃力！(手術影片5:19)
參考資料：
Dr. Masket firmly believes the post-RK eye "is such a moving target, a multifocal lens should not be considered—it will fail unless we achieve absolute or near emmetropia." He noted that the refraction can change from morning until evening and there may be progressive hyperopic shift over time.
Barbara Bowers, MD, in private practice, Innovative Ophthalmology, Paducah, Ky., disagrees—she'll bring these patients in at several different times throughout a day "and if the vision is fluctuating a little bit, I'll consider a multifocal. If they're fluctuating drastically between the morning and afternoon readings, I'll tell them point-blank a multifocal lens will make them miserable." Dr. Masket uses four or five devices to find the flattest Ks, and those are the readings he'll use for IOL calculation.
Astigmatism is an essential component to evaluate in these eyes, said Barry Schechter, MD, in practice, Florida Eye Microsurgical Institute, Boynton Beach, Fla. "We've had some very nice results with toric IOLs in RK patients who have varying amounts of regular astigmatism," he said. "You want to look for wound gaping. If the wounds have healed nice and tight, you're more likely to get a very stable postop refraction after time, but if you see some gaping, you've got the potential for refractive surprises."
If there's "very irregular astigmatism," Dr. Schechter advises against a toric—"you just have to go with a plain monofocal aspheric lens. I've been surprised with the results obtained and with the range of vision possible due to the spherical equivalent."
Dr. Masket avoids toric lenses in some post-RK patients "for fear they may someday need a corneal transplant" and because it's rare to have regular astigmatism in these eyes.
In general, he advises adding "about a half diopter" of measured IOL power for a patient with four incisions, between 1-1.5 D for those with eight incisions, and 2 D for those with 12 or more incisions. While intraoperative aberrometry may be very useful in eyes having prior laser vision correction, it is less accurate in the post-RK eye, as corneal curvature changes during cataract surgery in these eyes, he added.
http://www.eyeworld.org/article-calculating-iol-power-in-post-rk-eyes
