Eyeworld

75 EW RESIDENTS September 2018 12-month outcomes. There has not been a published cost analysis comparing manual limbal relaxing incisions to the use of the femto- second laser, which also may have a significant influence on the proce- dure that the surgeon and patient choose. The authors plan to submit this data in the future. Lastly, the authors discussed that the manual LRI group and the FS-AK group had similar "need for spectacle correction" after surgery. Many surgeons would consider this the most important outcome when it comes to patient satisfaction. Prior studies cite that ocular symptoms manifest at 0.75 D of astigmatism. 11 We think it would be interesting to design a study measuring visual data other than distance acuity, e.g., situations with bright lights in a dim setting, to see if there is a difference in patient function due to glare or ghosting of images. One could also compare quality of life in relation to spectacle independence (as performed in a study compar- ing toric IOLs to peripheral corneal incisions). 12 This study is an important con- tribution to the literature on astig- matic correction alongside cataract surgery. We look forward to seeing the 12-month results as well as the cost analysis that Roberts et al. plan to publish. EW References 1. Hoffmann PC, Hutz WW. Analysis of biome- try and prevalence data for corneal astigma- tism in 23,239 eyes. J Cataract Refract Surg. 2010;36:1479–85. 2. Razmjoo H, et al. Toric intraocular lens for astigmatism correction in cataract patients. Adv Biomed Res. 2017;6:123. 3. Young G, et al. Prevalence of astigmatism in relation to soft contact lens fitting. Eye Contact Lens. 2011;37:20–5. 4. Muller-Jensen K, et al. Limbal relaxing incisions to correct astigmatism in clear corneal cataract surgery. J Refract Surg. 1999;15:586–9. 5. Ruckl T, et al. Femtosecond laser-assisted intrastromal arcuate keratotomy to reduce corneal astigmatism. J Cataract Refract Surg. 2013;39:528–38. 6. Day AC, et al. Nonpenetrating femtosecond laser intrastromal astigmatic keratotomy of treatment as indicated by the arithmetic mean angle of error. This means that alignment accuracy was similar between the manual Men- dez ring and the femtosecond laser, which can adjust for torsion. The authors undertook a worth- while goal of comparing manual LRIs to non-penetrating FS-AKs for astigmatism correction. This randomized study was well-pow- ered, and though there were subtle differences in the baseline groups (namely preoperative visual acuity and axial length), we do not think this detracted from the significance of the results. The inclusion and exclusion criteria were appropriate and the results are likely predictive of the general population (with the caveat of intraoperative variables, e.g., surgeon performance on man- ual steps). The authors did a good job recognizing these limitations in their discussion. An interesting finding in this study is that the alignment accuracy was similar between a manual Men- dez-style ring and the femtosecond laser. However, there is an unreliable step in both manual LRI and FS-AK, which is the initial marking of the 180-degree axis. The authors did not detail how they did so in this paper, though traditionally it is manually marked by the surgeon while the pa- tient is sitting up and fixating on a distant target. Application of digital markerless alignment systems would make this a more reliable step and possibly further improve outcomes. An important caveat in this study is that only 1 month of follow-up was recorded. It would be beneficial to compare these two entities over a longer period of time to ensure regression does not occur. The authors address this issue, but are confident in their results because prior data shows stability of both manual LRI 8 and FS-AK 9 out to 2 and 3 years postop, respectively. Our own literature review similarly did not find evidence of regression of these procedures on longer-term follow-up. 10 Nonetheless, it would be prudent to directly compare the changes between these two procedures over time. The authors of this study plan to publish their in eyes having cataract surgery. J Cataract Refract Surg. 2016;42:102–9. 7. Alpins NA. A new method of analyzing vec- tors for changes in astigmatism. J Cataract Refract Surg. 1993;19:524–33. 8. Lim R, et al. Long-term stability of keratometric astigmatism after limbal relaxing incisions. J Cataract Refract Surg. 2014;40:1676–81. 9. Chan TC, et al. Corneal astigmatism and aberrations after combined femtosecond-as- sisted phacoemulsification and arcuate ker- atotomy: two-year results. Am J Ophthalmol. 2016;170:83–90. 10. Arraes JC, et al. [Limbal relaxing incisions during cataract surgery: one-year follow-up]. Arq Bras Oftalmol. 2006;69:361–4. 11. Nichamin LD. Astigmatism control. Oph- thalmol Clin North Am. 2006;19:485–93. 12. Mingo-Botin D, et al. Comparison of toric intraocular lenses and peripheral corneal relaxing incisions to treat astigmatism during cataract surgery. J Cataract Refract Surg. 2010;36:1700–8. Contact information Pyatetsky: d-pyatetsky@northwestern.edu incision or femtosecond laser-assisted astigmatic at the time of cataract surgery" Refractive outcomes after limbal relaxing incision or femtosecond laser-assisted astigmatic keratotomy in the management of corneal astigmatism at the time of cataract surgery Harry Roberts, MSc, Vijay Wagh, MD, Daniel Sullivan, MSc, Timothy Archer, MA(Oxon), David O'Brart, MD J Cataract Refract Surg. 2018;44(8): 955–963. Purpose: To compare the results of manual limbal relaxing incisions (LRI) performed during conventional phacoemulsification surgery (CPS) to non-penetrating femtosecond laser astigmatic keratotomies (FS-AK) performed during femtosecond laser-assisted cataract surgery (FLACS) in the management of corneal astigmatism. Setting: Guy's & St Thomas' NHS Foundation Trust, London, U.K. Design: Single center prospective randomized interventional case- controlled trial Methods: This was a secondary outcome of a randomized controlled trial comparing the clinical outcomes and relative costs of 400 patients treated with CPS or FLACS. All trial patients with corneal astigmatism >0.9 D were offered treatment, either LRI or FS-AK based on the original randomization. FLACS was performed with a LenSx (Alcon, Fort Worth, Texas), and CPS was performed with an Infiniti phacoemulsification machine (Alcon). Visual acuity, postoperative refraction, and corneal topography were recorded as well as any surgical complications 4 weeks postoperatively. Vector analysis was performed using the Alpin's method. Results: 51 eyes of 51 patients received LRI and 53 eyes of 53 patients received FS-AK. The mean target induced astigmatism (TIA) was 1.5 D and 1.38 D, respectively, with 1.02 D and 1.23 D surgically induced astigmatism (SIA) (p=0.21), resulting in the FS-AK having a smaller difference vector (DV) 1.17 vs. 0.89 (p=0.02) and a greater correction index (CI) 0.48 vs. 0.73 (p=0.02). 44% of patients treated with FS-AK attained postoperative cylinder of <0.5 D compared with 20% in the LRI group (p=0.01). There were no complications in either group directly relating to the LRI/FS-AKs. Conclusions: The FS-AK group achieved a higher CI and a smaller DV. FS-AK patients showed less postoperative cylinder than LRI patients.

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