EyeWorld Asia-Pacific September 2019 Issue

(DUO\ FOLQLFDO H[SHULHQFH ZLWK 6WUHDPOLJKW Dr. Rick Wolfe 6WUHDP/LJKW TM transepithelial PRK results in quicker surgery, faster healing and better patient satisfaction. 6WUHDP/LJKW TM should be used where ZDYHIURQW RSWLPL]HG 35. SURȴOHV DUH SODQQHG 6SHFLDO FDUH RI SRVW VXUJLFDO H\HV ZLWK WKLFN DQG LUUHJXODU HSLWKHOLXP is essential. 6WUHDP/LJKW TM (; WUDQV35. LV WKH latest, no-touch, one-step technology XVHG WR SHUIRUP 7UDQV (SL SKRWRUHIUDFWLYH NHUDWHFWRP\ 35. LQ SDWLHQWV ZKR FDQQRW KDYH D /$6Ζ. ȵDS (SLWKHOLDO PDSSLQJ VKRXOG EH XVHG WR GHWHUPLQH FRUQHDO DEQRUPDOLWLHV EHIRUH SHUIRUPLQJ WUDQVHSLWKHOLDO 35. &XVWRP 4 IRU 3UHVE\RSHV Prof Zhang Fengju 11 Figure 6: Reduction in recurrent corneal erosions with T PRK Early clinical experience with StreamLight TM , the latest no-touch, one-step technology used to perform trans-epithelial photorefractive keratectomy (Trans-Epi PRK) has been promising. Potential advantages of StreamLight TM include faster surgery (2sec/D), better patient acceptance due to its no-touch mechanism, and quicker treatment with one-step technique. In addition, it has been shown to be associated with faster healing and less pain, with better or equivalent results compared to conventional PRK. Reduction in incidenceof complications, particularly recurrent corneal erosion syndrome (RCES) (Figure 6) is an a software designed to assist in calculations for Contoura LASIK treatments. “Phorcides has the potential to make Trans-epi PTK very predictable for irregular corneas by assessing the refractive H΍HFW RI D 37. RI JLYHQ GHSWK RQ D SDUWLFXODU epithelial layer. It has the potential to regularize the cornea and achieve refractive predictability simultaneously”, added Dr. Cummings. additional advantage, 5 stated Dr. Rick Wolfe. A point to be noted during Trans-Epi PRK is the increase in local corneal temperature due to higher energy load. The normal corneal surface WHPSHUDWXUH LV DURXQG WR r& DQG WHPSHUDWXUH DERYH r& PD\ GHQDWXUL]H FROODJHQ proteins resulting in tissue damage and reduced refractive outcomes. “This is an important issue and should bemanaged H΍HFWLYHO\ ȋ DGGHG 'U :ROIH $ VWXG\ RI 7UDQV (SL 35. XVLQJ +] H[FLPHU ODVHU V\VWHP VKRZHG that the maximum temperature reached was up WR | ZLWK WKH XVH RI VSHFLDO VRIWZDUH WKDW reduced the thermal load. 6 Presbyopia is a loss of accommodative amplitude that occurs with age. Presbyopia can be treated by static methods (e.g. monovision, corneal inlays) that increase the depth of focus or by dynamic methods (e.g. scleral implants and accommodative IOLs), which try to restore accommodation. Normal cornea is aspheric in shape (prolate shape) that gradually reduces its refractive power towards periphery, merging all rays of light to a single focus and reducing the spherical aberration. On the other hand, the combination of monovision (central rays are focused in front of the retina) and a hyperprolate cornea (peripheral rays are focused behind the FHQWUDO UD\V FUHDWHV D ODUJHU GHSWK RI ȴHOG LQGXFLQJ a negative spherical aberration, by an adjusting the corneal asphericity factor (Q factor). This type of treatment is called the CustomQ, stated Prof. Zhang. Though Custom Q allows the surgeon to customize target refraction and corneal asphericity, certain pre-requisites for Custom Q need to be followed to HQVXUH VXFFHVVIXO RXWFRPH 7DEOH “Besides theconventional pre-operativeexamination, the most important test before starting Custom Q is the tolerance test for monovision procedure. It is essential to counsel the patient, lower his expectation and inform about the possibility of enhancement.” cautioned Prof Zhang.