Eyeworld

EW INTERNATIONAL 128 February 2018 Vision Behaviour Monitor (VBM, Vivior, Zurich, Switzerland), which is a device that would help individ- ualize patients' vision needs. It has been tested in study, but is not yet available commercially. Individual lifestyles lead to indi- vidual vision needs, Dr. Cummings said. Today, the ophthalmic industry only provides compromises in some disease states. He said it's important to shift the paradigm from asking questions and trying to find the right direction to getting more objective data concerning visual behavior. This VBM features a sensor that can be worn on the patient's prescription or clear glasses, and measurements are monitored and recorded on a paired smartphone (with activities being entered on the smartphone). It measures distance, ambient light, and orientation and motion. It can also recognize activi- ty, and automatic recognition is pos- sible with most common activities. Dr. Cummings said this technology would help show at what distance the patient prefers to work and what that equates to in refractive terms. The activity recognition allows the physician to connect patient activi- ties to visual requirements. Dr. Cummings said there is high patient compliance in tests for the device, and he's hopeful that mea- surements from it will allow doctors and patients to identify and charac- terize individual activities and derive a personal vision profile. EW Editors' note: Drs. Cummings, O'Brart, Reinstein, Roberts, and Spiru have financial interests related to their pre- sentations. Drs. Brar, Goggin, LaHood, Mursch-Edlmayr, Parreira, Pimenta, Srivannaboon, Vasquez Perez, Ya- mazaki, and Zilfyan have no financial interests related to their presentations. Contact information Brar: brar_sheetal@yahoo.co.in Cummings: abc@wellingtoneyeclinic.com Goggin: michael.goggin@flinders.edu.au LaHood: benlahood@gmail.com Mursch-Edlmayr: Anna-Sophie.Mursch-Edl- mayr@kepleruniklinikum.at O'Brart: davidobrart@aol.com Parreira: soniaparreira20@hotmail.com Pimenta: afrpimenta@gmail.com Reinstein: dzr@londonvisionclinic.com Roberts: harry.roberts@nhs.net Spiru: spiru.bogdan@gmail.com Srivannaboon: sabong@gmail.com Vasquez Perez: alest99@gmail.com Yamazaki: karamawari@msn.com Femto laser-assisted cataract surgery (FLACS) II paper session Kenichiro Yamazaki, MD, Saitama, Japan, presented on using FLACS for atopic cataracts. Dr. Yamazaki started by discussing the atopic cataract. The prevalence of atopic dermatitis (AD) is 12% in Japan, 6% in the U.S., and 10–15% in Germany. Atopic cataract progression can necessitate cataract surgery in patients under 50. Variations can occur in atopic cataract like intumescent white cata- racts (IWC) and anterior subcapsular fibrosis. These could pose a problem when attempting to complete a continuous curvilinear capsulorhexis (CCC), Dr. Yamazaki said. Addition- ally, most young cataract patients opt for multifocal IOL surgery, so it is important to achieve a successful capsulotomy to set the IOL with good centration. The purpose of Dr. Yamazaki's study was to evaluate the efficacy and safety of FLACS for atopic cata- ract, especially including IWC and anterior subcapsular fibrosis. The problem with anterior subcapsular fibrosis is that when performing a manual CCC, if fibrosis exists across the line of the capsu- lorhexis, radial tears could develop. Dr. Yamazaki added that when doing manual CCC with IWC, melted substance escapes from the nucle- us. The anterior capsule's tension becomes unstable, and this results in the capsular flap becoming uncon- trollable. This condition can create a clouded state in the anterior cham- ber, making it hard to determine the flap position. Dr. Yamazaki described the study methods, with 37 eyes of 30 cases done using the LenSx laser (Alcon, Fort Worth, Texas). Two eyes had keratoconus, and all patients were implanted with diffractive mul- tifocal IOLs (except for one eye with corneal scars due to keratoconus where a monofocal IOL was used). One eye had LASIK, and one eye had scleral buckling. Free-floating capsulotomy was achieved in 32 eyes (86%). Addi- tionally, fibrosis was observed in 13 eyes (35%), including three eyes with fibrosis extending across the line of capsulotomy and requiring manual excision with iris scissors. Dr. Yamazaki noted that nine eyes had IWC, and incomplete capsulo- tomies due to anterior capsular tags were present in four eyes in the IWC group. Radial anterior capsular tear, vitreous loss, and IOL dislocation did not occur. Dr. Yamazaki concluded that proper centration of the IOL was achieved in all cases with FLACS for atopic cataract, despite the presence of anterior subcapsular fibrosis or IWC. "In cases of IWC, we should be careful of capsular tag," he said, stressing that FLACS can be per- formed safely with atopic cataract. Pseudophakic IOLs: Toric paper session Michael Goggin, MD, Adelaide, Australia, presented his paper, "As- sessing the likely effect of posterior corneal curvature on toric intraocu- lar lens calculation for IOLs of 2.5 D cylinder power or more." Dr. Goggin began by discussing the impact of posterior corneal astig- matism and the consequences of ig- noring it. Although posterior corneal astigmatism cannot be measured well, the error can be improved by incorporating information about the posterior corneal astigmatism into IOL calculations. His study aimed to establish if overcorrection of with-the-rule (WTR) corneas or undercorrection of against-the-rule (ATR) corneas occurs if toric IOLs are calculated on the ba- sis of anterior corneal measurements in eyes requiring toric IOL cylinder power of 2.5 D or greater. The study examined 113 consecutive eyes with anterior corneal keratometric astig- matism requiring IOL cylinder pow- er of 2.5 D or greater. IOL cylinder powers were calculated using anteri- or corneal curvature data alone and inserted. The patients were grouped as either WTR or ATR on the basis of the steep anterior corneal meridian. Targeted and achieved astigmatic outcomes were compared at 6 to 8 weeks. Results found that in eyes requiring toric IOLs of cylinder power 2.5 D or greater, there was an overcorrection in anterior WTR eyes and undercorrection in anterior ATR eyes. Dr. Goggin noted that this is probably a posterior corneal astig- matism effect but was not clinically significant. IOL cylinder powers are sufficiently accurately calculated using unadjusted anterior keratom- etry values in these eyes. Adjust- ment in these eyes will likely lead to increased postoperative refractive astigmatism, and adjustment is advocated by the Barrett Toric and Baylor nomogram. Ben LaHood, MD, Adelaide, Australia, presented on "Posterior corneal astigmatism calculated in eyes requiring a range of toric IOL powers." "We are currently relying on population estimates to guide our choice of toric IOL for individual patients," he said, and calculating posterior corneal astigmatism can help refine nomograms that phy- sicians use and can provide device validation. Dr. LaHood noted that total oc- ular astigmatism consists of anterior and posterior astigmatism and toric IOL cylinder power. Vector subtrac- tion of anterior corneal and toric IOL cylinder power from total ocular astigmatism at the corneal plane is performed, and that leaves behind posterior corneal astigmatism. He described his study of 367 consecutive toric IOL implants (with nine exclusions for previous LASIK). Refraction and keratometry were measured at 6 weeks postop, and vector calculations were done using measured AC depth and toric IOL axis. The steep posterior corneal axis orientation was determined: 13.96% horizontal, 21.79% oblique, and 64.25% vertical. Dr. LaHood said that the vertical rate was found to be generally lower than previous studies, noting that a highly quoted study from Douglas Koch, MD, in 2012 found it to be 86%. He went on to discuss the rel- evance of the axis orientation. The current assumption is that the vast majority of patients have steep ver- tical axis orientation of the posterior cornea, but there could potentially be fewer patients with steep verti- cal, based on the study. This means that there may be some over- and undercorrections happening. Dr. LaHood stressed the importance of measuring individuals accurately in the future instead of using popula- tion data. Dr. LaHood highlighted the magnitude found in the study, which had a mean of 0.87 D and median of 0.78 D, which he said is higher than in other studies. This could be due to study population differences, as the study consisted of all toric IOLs, with higher anterior corneal astigmatism. These are the patients we need to know about, he said. In conclusion, Dr. LaHood said that posterior corneal astigmatism may be greater in a toric IOL requir- ing population. Hopefully, accurate measurement of the posterior cornea is coming soon. "The steep axis being vertical may be less common than we think," he added. LASIK and imaging paper session Arthur Cummings, MD, Dublin, Ireland, presented "Objective eval- uation of patients' visual behaviour for cataract surgery planning." His presentation focused mainly on the International continued from page 127

• Blank Page
• Blank Page (1)