EyeWorld India September 2019 Issue

64 EWAP SEPTEMBER 2019 CORNEA absolute PE, not in all the cases but especially in the cases where there was a difference in lens power that was calculated by IA compared to the preoperative, comprising about 51% of the V>ÃiÃ]» À° Àii˜ Ã>ˆ`° º/…iÃi differences in prediction error can be misleading sometimes because they look like they >Ài ÛiÀÞ Ã“> `ˆvviÀi˜Við ÕÌ they result in a big difference in the eyes that end up within a half diopter of predicted postoperative spherical equivalent,” he said. The difference in mean absolute value of the prediction error was 0.12 between intraoperative aberrometry and preoperative formula- calculated value (p<0.0001). The difference in the absolute median error was also 0.12. As far as the percentage of eyes ܈̅> «Ài`ˆV̈œ˜ iÀÀœÀ ćä°xä ] in the completed data set the IA percentage was 82.4% while the preop calculation would have resulted in 68.3%. º ˜ ̅œÃi V>Ãià ܅iÀi ̅i aberrometry recommendation was different from the preoperative plan, the differences were more pronounced,” he explained. º/…i “i>˜ >L܏ÕÌi Û>Õi œv the prediction error for cases in which the IA recommended an IOL power that differed from the preoperative IOL power calculation (n=913) showed a difference of 0.19 (p<0.0001) between intraoperative aberrometry and the preop formula calculation. The absolute median error in cases in which the IA recommendation differed from the preoperative IOL power calculation (n=913) showed a difference of 0.21 (p<0.0001),” he said. In these cases, the percentage of eye with an absolute prediction iÀÀœÀ ćä°xä Ü>à nȰǯ vœÀ IA compared to 59.6% had the preop calculated IOL power been implanted. Additional analyses are needed to determine whether the level of experience of a ÃÕÀ}iœ˜ ˆ˜yÕi˜Vià ̅i ÀiÃՏÌð À° Àii˜ ̅ˆ˜ŽÃ ̅i `ˆvviÀi˜Vià may be even more pronounced for more experienced surgeons or when using more advanced power calculation formulas, which might narrow the gap. EWAP 'FKVQTUo PQVG &T $TGGP KU *GCF /GFKECN 5EKGPEG 5WTIKECN CPF 8KUKQP %CTG 0QTVJ #OGTKEC %NKPKECN &GXGNQROGPV CPF /GFKECN #HHCKTU Alcon. References £° œ>˜` ] iÌ >° /…i ƂVÀÞ-œv /œÀˆV ˆ˜ÌÀ>œVՏ>À i˜Ã ˆ˜ ÃÕLiVÌà ܈̅V>Ì>À>VÌà and corneal astigmatism: a randomized, ÃÕLiV̇“>Îi`] «>À>i‡}ÀœÕ«] £‡Þi>À study. Ophthalmol ° Óä£äÆ££Ç\Ó£ä{q££° Ó° i…˜`ˆ} Ƃ] iÌ >° Ƃˆ“ˆ˜} vœÀ emmetropia after cataract surgery: Swedish National Cataract Register study. J Cataract Refract Surg . Óä£ÓÆÎn\££n£qÈ° ΰ 7>˜} ] iÌ >° "«Ìˆ“ˆâˆ˜} ˆ˜ÌÀ>œVՏ>À lens power calculations in eyes with axial lengths above 25.0 mm. J Cataract Refract Surg ° Ó䣣ÆÎÇ\Óä£nqÓÇ° {° 7œœ`VœVŽ ] iÌ >° ˜ÌÀ>œ«iÀ>̈Ûi aberrometry versus standard preoperative biometry and a toric IOL calculator for bilateral toric IOL implantation with a femtosecond laser: One-month results. J Cataract Refract Surg ° Óä£ÈÆ{Ó\n£ÇqÓx° 5. Ianchulev T, et al. Intraoperative refractive biometry for predicting intraocular lens power calculation after prior myopic refractive surgery. Ophthalmol ° Óä£{Æ£Ó£\xÈqÈä° I ntraoperative aberrometry (IA) has the potential to provide more accurate refractive outcomes after cataract surgery. This article Ài«œÀÌà œ˜ > ÀiÌÀœÃ«iV̈Ûi ÃÌÕ`Þ LÞ À° ˆV…>i Àii˜ œ˜ iÞià ܈̅ long axial lengths (>26.5 mm) undergoing cataract surgery with ˆ˜ÌÀ>œ«iÀ>̈Ûi “i>ÃÕÀi“i˜Ìà ÕȘ} ̅i ",Ƃ ÃÞÃÌi“° À° Àii˜ ˆÃ >˜ optometric scientist working at Alcon and co-author with Dr. Robert Cionni on a previously published study including over 30,000 data sets from a variety of surgeons providing preoperative, intraoperative, and postoperative data. 1 The results from this study suggest that ORA provides increased predictability (lower absolute prediction error) for eyes with long axial i˜}̅° *œÃÈLÞ œv “œÀi È}˜ˆwV>˜Vi Ü>à ̅i ÃÕLÃiÌ ˆ˜ ܅ˆV…Ì…i Ƃ measurements differed from the preoperative assessment where 86.7% vs 59.6% (p<0.0001) had an absolute prediction error less than 0.5 D. There are a number of potential drawbacks in this study. It is retrospective and it is unclear which preoperative formulae and measurement systems were used or what was the respective level of surgeon experience. Nevertheless, it could be argued that the sample «œ«Õ>̈œ˜ Ài«ÀiÃi˜Ìà > ºÀi> ܜÀ`» ÃVi˜>Àˆœ° The evidence for the use of IA in refractive predictability after cataract surgery in the peer-reviewed literature is varied. A recent publication by Davison et al. did not show any difference between spherical outcomes comparing IA and modern IOL formulae such as ̅i >ÀÀiÌÌ vœÀ“Տ>° 2 œÜiÛiÀ] ̅iÀi Ü>à > ÃÕ}}iÃ̈œ˜ ̅>Ì >Ã̈}“>̈V results were improved in their more recent comparative study. 3 Sudhakar and co-authors showed no improvement in refractive outcomes with the use of IA in short eyes (<22.1 mm) when using “œ`iÀ˜ " vœÀ“Տ>i ÃÕV…>à ̅i >ÀÀiÌÌ 1˜ˆÛiÀÃ> œÀ ˆ‡, ° 4 ÕÀ̅iÀ] <…>˜} iÌ >° VœÕ` >Ãœ ˜œÌ `i“œ˜ÃÌÀ>Ìi >˜Þ `ˆvviÀi˜Vi ˆv ̅i modern formulae were used. 5 The use of IA does involve increased cost and longer operating time. Issues such as corneal wound edema represent uncontrolled variables and contribute to the noise in the system. œÜiÛiÀ] Ƃ Õ«Ì>Ži ˆÃ ˆ˜VÀi>Ș} >à ̅i ÌiV…˜œœ}Þ Vœ˜Ìˆ˜Õià ̜ iۜÛi° ÕÀ̅iÀ ÃÌÕ`ˆià >Ài ÀiµÕˆÀi` ̜ «ÀœÛi > ÃÕvwVˆi˜Ì >˜` Vœ˜ÃˆÃÌi˜Ì >`Û>˜Ì>}i œÛiÀ VÕÀÀi˜Ì “i̅œ`à ̜ ÕÃ̈vÞ Üˆ`iëÀi>` Õ«Ì>Ži° References 1. Cionni RJ, et al. A large retrospective database analysis comparing outcomes of intraoperative aberrometry with conventional preoperative planning. J Cataract Refract Surg ° Óä£nÆ{{£ä®\£ÓÎäq£ÓÎx° 2. Davison JA, et al. Clinically relevant differences in the selection of toric intraocular lens power in normal eyes: preoperative measurement vs intraoperative aberrometry. Clin Ophthalmol ° Ó䣙 >Þ ÎäÆ£Î\™£Îq™Óä° 3. Davison JA, Potvin R. Preoperative measurement vs. intraoperative aberrometry for the selection of intraocular lens sphere power in normal eyes. Clin Ophthalmol ° Óä£Ç >Þ £ÇÆ££\™ÓÎq™Ó™° 4. Sudhakar S, et al. Intraoperative aberrometry versus preoperative biometry for intraocular lens power selection in short eyes. J Cataract Refract Surg . Ó䣙Æ{xÈ®\Ç£™qÇÓ{° x° <…>˜} <] iÌ >° ,ivÀ>V̈Ûi œÕÌVœ“ià œv ˆ˜ÌÀ>œ«iÀ>̈Ûi Ü>ÛivÀœ˜Ì >LiÀÀœ“iÌÀÞ versus optical biometry alone for intraocular lens power calculation. Indian J Ophthalmol ° Óä£ÇÆÈx™®\n£Îqn£Ç° 'FKVQTUo PQVG &T 5WVVQP FGENCTGF PQ TGNGXCPV ƂPCPEKCN KPVGTGUVU Gerard Sutton, MBBS, MMed, FRANZCO, FRACS …>ÌÃܜœ` iÜ -œÕ̅7>iÃ] ƂÕÃÌÀ>ˆ> Level 3 270 Victoria Avenue gerard.sutton@vei.com.au ASIA-PACIFIC PERSPECTIVES