EyeWorld Asia-Pacific September 2019 Issue

2XWFRPHV RI WKH 1HZ &RPELQHG 7UHDWPHQWV IRU .HUDWRFRQXV Dr. Aanchal Gupta 7KH WULSOH SURFHGXUH KDV VKRZQ SURPLVLQJ results in patients with keratoconus. $OWKRXJK FURVV OLQNLQJ LV H[FHOOHQW LQ WHUPV RI halting progression, there are un-answered TXHVWLRQV RQ KRZPXFK FURVV OLQNLQJ LV VXɝFLHQW DQG ZKHWKHU FRPELQHG PRGDOLWLHV DUH VDIH DQG H΍HFWLYH RYHU ORQJHU GXUDWLRQ RI WLPH $ ORQJ WHUP IROORZ XS RI D ODUJHU population study is required to validate the FXUUHQW ȴQGLQJV 6 7RSRJUDSK\ *XLGHG 7UHDWPHQW IRU ΖUUHJXODU &RUQHDV Dr. Arthur Cheng 7232*5$3+< *8Ζ'(' 75($70(17 )25 'Ζ))Ζ&8/7 &$6(6 7RSRJUDSK\ JXLGHG 35. LV EHFRPLQJ LQFUHDVLQJ SRSXODU LQ WKH WUHDWPHQW RI LUUHJXODU FRUQHDV ΖW KDV VKRZQ LPSURYHPHQW LQ EHWWHU DVWLJPDWLF FRUUHFWLRQ EHVW FRUUHFWHG YLVXDO DFXLW\ %&9$ DQG HQKDQFHPHQW RI TXDOLW\ RI YLVLRQ Table 3 : Procedure of Topography guided 35. IROORZHG E\ &;/ 6WHS 37. WR UHPRYH XQHYHQ HSLWKHOLXP RQ corneal surface 6WHS • 7RSRJUDSK\ JXLGHG 35. WR UHGXFH irregularities of the corneal surface • Asphericity adjustment • Myopic compensation • Astigmatic compensation • Limited ablation depth to aim for VWURPDO WKLFNQHVV RI ! ƉP Step 3 &URVVOLQNLQJ 6WHS $SSOLFDWLRQ RI PLWRP\FLQ & WR SUHYHQW scarring and reduce haze Corneal ectasia, keratoconus, scarring, trauma and previous surgical procedures are some common FDXVHV RI LUUHJXODU FRUQHD OHDGLQJ WR VLJQLȴFDQW visual disabilities. “Topography-guided treatment that combines myopic and hyperopic ablations has demonstrated successful outcomes in patients with irregular corneas,” said Dr. Arthur Cheng. Keratoconus is commonly seen in the clinics. The treatment options for keratoconus include corneal collagen crosslinking (CXL), intraocular stromal ring and topography guided PRK plus crosslinking. 7KRXJK FRUQHDO FROODJHQ FURVVOLQNLQJ LV H΍HFWLYH LQ KDOWLQJ GLVHDVH SURJUHVVLRQ LW LV QRW H΍HFWLYH in correcting abnormal shape. Intraocular stromal ring has an unpredictable outcome and is not applicable to central cone. On the other hand, topography guided PRK followed by CXL has shown promising results, and better outcomes. The steps involved in performing Topography-guided PRK IROORZHG E\ &;/ LV H[SODLQHG LQ 7DEOH “The idea of topography guided PRK is to reverse the disease progression in patients with irregular corneas; that is to reverse the myopia, reverse astigmatic change and reverse coning.” added Dr Cheng. Another important consideration in topography guided trans-epithelial PRK is the need for appropriateadjustmentof spherical equivalentafter correction of astigmatism. Spherical compensation FDQ UHGXFH WKH FRQH FXUYDWXUH DQG ȵDWWHQ WKH central cornea. “The extent of compensation depends on the steepest area and the underlying refractive error,” explained Dr. Cheng. Young patients with progressive keratoconus, who DUH QRW VDWLVȴHG ZLWK ULJLG FRQWDFW OHQVHV DQG D KLJK degree of refractive error, are common in everyday practice. These cases are often complicated with very poor uncorrected and best-corrected visual acuity. Dr. Aanchal Gupta’s approach in these patients is keraring implantation followed by a topography- JXLGHG 35. 7* 35. DIWHU PRQWKV Ȋ7KH ZDLWLQJ WLPH RI PRQWKV LV HVVHQWLDO EHFDXVH WKHUH LV D KXJH amount of regularization needed for such severe corneas,” explained Dr. Gupta. “If the best-corrected visual acuity post keraring implantation is poor, then an ICL will not be suitable because patient still has a very irregular cornea.” Dr. Gupta’s unpublished data on triple procedure including TG PRK with CXL post keraring implantation in keratoconus patients has been encouraging. The TG PRK was done using the topography-guided