EyeWorld Asia-Pacific September 2019 Issue

&RPSDULVRQ RI :DYHIURQW RSWLPL]HG YV 7RSRJUDSK\ JXLGHG YV 705 /$6Ζ. Prof Tae-Young Chung 3URI &KHQ <XHJXR Chairman, Department of Ophthalmology Peking University Third Hospital, China 3URI 7DH <RXQJ &KXQJ Associate Professor, Department of Ophthalmology Samsung Medical Centre, South Korea 'U $UWKXU &KHQJ Consultant ophthal- mologist and refractive surgeon Hong Kong Sanatorium Hospital 3URI =KDL &KDQJELQ Tongren Eye Center, Beijing Tongren Hospital, China 3 :KHQ SHUIRUPLQJ WRSRJUDSK\ JXLGHG /$6Ζ. LI &$ 05$ WUHDWLQJ &$ ZLWK 705 7* LV D SUHIHUUHG FKRLFH ΖI WKH &$ ! 05$ WUHDWLQJ 05$ ZLWK )'$ 7* VHHPV WR EH D PRUH VXLWDEOH RSWLRQ 8VLQJ PRGLȴHG 705 WUHDWLQJ PLGSRLQW EHWZHHQ 05$ DQG &$ ZKHQ &$ ! 05$ PD\ DOVR UHVXOW LQ DVWLJPDWLF RYHU FRUUHFWLRQ $ FRPSUHKHQVLYH SUH RSHUDWLYH evaluation, excellent topography, appropriate patient selection, high TXDOLW\ LPDJHV ZLWK 7RSRO\]HU 9$5Ζ2 DQG XQGHUVWDQGLQJ ELRPHFKDQLFDO SURSHUWLHV of the cornea are crucial for successful WUHDWPHQW ZLWK &RQWRXUD TM Vision. Capturing high-quality images with Topolyzer VARIO is another crucial determinant of treatment success. It is recommended to have at least 4-8 images before the day of surgery. “Sometimes, the VARIO images do not work well when the cyclotorsion fails to register, in which case a manual marking or manual alignment (with the red cross-line projector under the EX500) of astigmatism is needed,” added Dr. Ryu. Another consideration for topography- guided Contoura TM Vision is to understand the biomechanical properties of the cornea. Patients with Tomographic/Biomechanical Index (TBI) > 1 should be excluded from laser refractive surgery. 7%Ζ FXW R΍ YDOXH RI SURYLGHV VHQVLWLYLW\ IRU GHWHFWLQJ FOLQLFDO HFWDVLD ZLWK VSHFLȴFLW\ 2 Adding accelerated cross-linking inborderlinepatients and converting to phaco surgery is the surgeon’s personal preference, noted Dr. Ryu. An active customer relationship management, ensuring patient satisfaction and results is another reason for selecting Contoura TM Vision. Dr. Ryu continued “My aim is to convert LASIK and PRK to customized ablation to provide accuracy and satisfaction to the patients”. “The challenge with wavefront-optimized ablation is that the human wavefront aberration is dynamic and constantly changes with accommodation (leading to aspherical ablation), whereas topography-guided ablation aims to target the aberration at the anterior surface of the cornea, which is relatively constant regardless of accommodation. This is why we should treat corneal aberration rather than ocular aberration,” said Prof. Tae-Young Chung. However, since treatment of corneal HOA has DQ H΍HFW RQ UHIUDFWLYH RXWFRPH LW LV EHOLHYHG that treating refractive astigmatism and corneal HOA would result in over-correction or under- correction of refractive astigmatism depending on WKH D[LV GL΍HUHQFH 7KHUHIRUH WKH FRQFHSW RI WRSRJUDSK\ PRGLȴHG refraction (TMR) was introduced, which involves treating corneal HOA and topography-based corneal astigmatism instead of treating corneal HOA and the manifest refraction (FDA-TG). In addition, in sub-group analysis of TMR-TG, astigmatic over-correction was more when corneal astigmatism (CA) was greater than manifest refractive astigmatism (MRA). Astigmatic over-correction was associated with SUH RSHUDWLYH PDJQLWXGH GL΍HUHQFH EHWZHHQ &$ DQG 5$ ZKLFK LV TXDQWLȴHG E\ RFXODU UHVLGXDO astigmatism (ORA). “Since a higher ORA is associated with poor visual outcome it needs to be detected early to avoid suboptimal visual outcome,” highlighted Prof. Chung.