SPS-214 Astigmatism Management, Toric IOL Alignment | ASCRS
2020 ASCRS Virtual Annual Meeting

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Papers in this Session
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In-the-Bag Implantation of a Supplementary Intraocular Pinhole Device
Authors
Bruno C. Trindade, MD, PhD
Claudio C. Trindade, MD, PhD
Fernando C. Trindade, MD, PhD
Liliana Werner, MD, PhD

Methods
60 eyes of 58 patients who had the intraocular pinhole implanted in the capsular bag together with the primary IOL to treat irregular corneal astigmatism secondary to multiple causes were enrolled. Mean follow-up was 16 months (range 7 to 48). Patients were assessed in their scheduled follow-up visits. Uncorrected and best-corrected visual acuity were recorded at each visit. An infrared slit-lamp photography was captured and analyzed to verify the presence of interlenticular membrane formation.

Results
Mean uncorrected and best-corrected visual acuity improved from LogMAR 1.34 ± 0.338 and 0.57 ± 0.145 preoperatively to 0.14 ± 0.012 (p<0.001) and 0.12 ± 0.008 (p=0.001) postoperatively respectively one year after surgery. Mild pinhole decentration was noted in 5 eyes (8.3%). Interlenticular opacification (ILO) was not noted in any patient.

Conclusion
Implantation of the XtraFocus intraocular pinhole inside the capsular bag is safe. Improvement in both uncorrected and best-corrected visual acuity was significant and sustained overtime. ILO does not occur when this implant is positioned in the capsular bag together with a primary IOL.
Astigmatism Correction with Intrastromal Limbal Relaxing Incisions during Femtosecond Laser Assisted Cataract Surgery
Authors
Albert Hu, BEng
Carter W. Lim
Sohel Somani, MD, FRCSC
Hannah H. Chiu, MD, FRCSC
Eric S. Tam, MD, FRCSC

Methods
This is a retrospective study of cataract surgeries performed by 3 experienced surgeons. Limbal relaxing incisions of double LRI arcs of 40º, 50º and 60º, and single LRI arcs of 50º and 60º were made on the Catalys femtosecond laser platform with default settings, at 60% stromal depth at steep axis and 10mm diameter, centered at the corneal center. All patients with complete data (~200 eyes) during the period of June 1st 2019 to Aug 30th 2019 were included. IOL Master 700 was used in measuring keratometric astigmatism and axes preoperatively, postoperatively at 1-week, 1-month, and 3-months. Vector analyses were performed using the Alpins vector method with VectrAK and ASSORT software.

Results
For LRI arc lengths of single 50º and 60º, double 40º, 50º and 60º, mean preop astigmatism±SD were 0.71±0.30D, 0.93±0.28D, 1.36±0.28D, 1.41±0.38D and 2.62±0.76D, respectively. Double 60º arcs had the most significantly reductions in mean astigmatism±SD at post-op month 3/POM3 (1.71±1.18D, P=0.007), followed by double 50º arcs (1.05 ± 0.43D, P=0.01). Double 40º and single 60º had small but still significantly reduction at POM3(1.14 ± 0.55D and 0.75±0.40D, P=0.03 and P=0.046 respectively). Arcs smaller than 60º showed no statistical significant reduction in astigmatism. Vector analyses of double 60º, 50º, 40º and single 60º arcs showed correction indices of 0.42, 0.43, 0.56, 0.45 respectively.

Conclusion
Larger LRI incisions are associated with greater reductions in astigmatism and have greater flattening effects. LRIs less than 60º offers no significant reduction in astigmatism. Cataract surgeons should have a lower threshold for using larger LRI incisions.
Trends of Under and over Correction of Astigmatism with Toric IOLs According to a Toric Back Calculator.
Authors
Brent A. Kramer, MD
John P. Berdahl, MD
David R. Hardten, MD

Methods
Retrospective review of entries to the astigmatismfix.com website since its launch in 2012 through December, 31 2019. Analysis will include the rate of under and overcorrection of astigmatism stratified by the meridian of astigmatism (i.e. ATR, WTR, oblique). Data will be trended over time. The effect intraoperative aberrometry has on under/correction will also be evaluated.

Results
From 2013 through 2019, 28,791 entries which were thought to represent real patients were made in astigmatismfix.com. Overall, the rate of overcorrection for WTR, ATR, and oblique astigmatism was found to be 50%, 38% and 41%. In 2019, the rate of over-correction was 41% , 42%, and 41%, and there was no statistical difference between the groups. Intraoperative aberrometry did not have a significant effect on the frequency of axis-flip when consider all IOLs. However, it did decrease the absolute amount of astigmatism over/under-correction from 0.80D to 0.71D (p<0.05).

Conclusion
Regarding astigmatism over-correction (i.e. axis flip) with toric IOLs, there was no difference between WTR, ATR, and oblique astigmatism in 2019, as was seen in prior years. While intraoperative aberrometry did not have a significant effect on the rate of astigmatism over/under-correction, it did decrease the magnitude of under/over-correction.
Corneal Spherical Aberration in an Elderly Population with High Astigmatism
Authors
Grzegorz Labuz, PhD
Ramin Khoramnia, MD
Gerd U. Auffarth, MD, PhD

Methods
A retrospective analysis of corneal topography data obtained using a Pentacam Scheimpflug camera was performed. The data were routinely collected from Nov 2009 to Jun 2019 at the Heidelberg University Eye Clinic. Total corneal spherical aberration (i.e., from the anterior and posterior corneal surface) was obtained for a 6-mm pupil. We included only patients who were 60 years of age or older at the time of examination. Other inclusion criteria were an excellent quality score, the total deviation index (BAD D) < 1.60, and the thinnest pachymetry of 480 µm or greater. One eye per subject was chosen randomly. A total of 1,5557 eyes were selected for the statistical analysis.

Results
A high-astigmatic group comprised of 326 subjects with corneal astigmatism greater or equal to 1.5 D, the remaining 1,231 had no or low astigmatism. The former group had the median (range) astigmatism of 2.0D (from 1.5 to 6.4D), and the latter had 0.7D (from 0 to 1.4D). Corneal spherical aberration in patients with high astigmatism was higher than that of the controls by 0.02, which was statistically significant (Mann-Whitney U-test, P = .03). The Z[4,0] aberration gradually increased with the cylinder power with a slope of 0.013 (P < .01), though the correlation was weak (R-squared = 0.01).

Conclusion
We showed that the amount of spherical aberration is minimally (albeit statistically significant) greater in elderly subjects with high corneal astigmatic. Spherical aberration increases with the cylinder power showing a tendency that those patients may benefit more from intraocular lenses that feature higher spherical-aberration correction.
Prospective Evaluation of Iris Registration-Guided Femtosecond Laser-Assisted Capsular Marks for Toric IOL Alignment during Cataract Surgery
Authors
Denise M. Visco, MD, MBA, ABO
Warren E. Hill, MD, FACS
Yuri McKee, MD

Methods
This prospective, multicenter study enrolled 36 patients aged ≥18 years (mean age: 65.3±9.1 years), stable regular keratometric cylinder ≥0.50 D, vector difference ≤0.50 D in anterior corneal astigmatism as measured by Cassini Corneal Analyzer (Cassini Technologies) compared with Zeiss IOLMaster 700 (Carl Zeiss Meditec) or Lenstar 900 (Haag-Streit), and predicted residual refractive astigmatism (RRA) ≤0.50. All eyes underwent FLACS and toric IOL implantation guided by LENSAR IntelliAxis-RC system that creates a pair of capsular marks (CMs) on the capsular rim during standard capsulotomy procedure. These CMs facilitate toric IOL alignment to its intended axis of implantation.

Results
Preliminary data of 36 eyes were evaluated. Astigmatism reduced statistically significantly from mean keratometric astigmatism of 2.07 ±0.79 D to mean RRA of -0.12 ± 0.19 D compared (p<0.001) at postoperative 6 weeks. All eyes (100%) were within refractive astigmatism ≤ 0.50 D postoperatively. Assessment of toric IOL rotation from its intended axis of implantation with reference to CMs showed no IOL misalignment in any of the eyes. No adverse events were reported. More data are being collected.

Conclusion
Iris registration-guided, femtosecond laser-assisted capsular marking with LENSAR IntelliAxis Refractive Capsulorhexis was safe and effective in guiding toric IOL alignment to its intended axis of implantation, thereby reducing astigmatism. All eyes had RRA ≤ 0.50 D at postoperative week 6 and no toric IOL misalignment was observed.
A Novel Approach to Toric IOL Alignment Using Femtosecond Laser Capsulotomy Marks and Iris Registration in Cataract Refractive Surgery
Authors
Maria L. Adams, DO
Vasilios F. Diakonis, PhD, MD
Robert J. Weinstock, MD

Methods
This study included 44 eyes that had undergone astigmatism correction with toric IOL implantation for pre-existing astigmatism ranging from 1.18 to 3.19 D during FLACS. Iris registration based cyclorotation correction was used to create a refractive capsulotomy with toric IOL alignment marks placed on the desired axis of implantation. Maximum extensibility and tensile strength of capsulotomy with capsular marks has previously been found to be equivalent to standard capsulotomy. Absence of parallax error facilitated accurate alignment of toric IOL. Visual and refractive outcomes were studied. Patients were assessed at 1 day, 1 week and 1 month.

Results
Astigmatism improved significantly (p value <0.001) from 1.84±0.51D preoperatively to 0.35±0.42D postoperatively. Post-operatively, 77.3% eyes had refractive astigmatism of ≤0.5D. UDVA of ≥20/25 was achieved in 97.7% eyes. More data is being collected. More robust analysis including vector analysis will be presented.

Conclusion
FSL assisted capsular marks are safe and effective for guiding toric IOL implantation.
Using Small Aperture Optics to Treat Corneal Astigmatism
Author
John A. Vukich, MD

Methods
Prospective, multicenter, non-randomized, interventional study of 114 subjects implanted monocularly with an IC-8 IOL. The IC-8 IOL combines an aspheric monofocal IOL, without toricity, with an embedded opaque mini-ring. Subjects were separated into three groups based on pre-operative corneal astigmatism: group 1 (< 0.75 D, n=114), group 2 (0.76 – 1.50 D, n=25) and group 3 (> 1.50 D, n=6). Monocular uncorrected distance, intermediate and near visual acuity in the IC-8 IOL eye were combined across 1, 3 and 6 month exams and compared between groups. Results are reported in logMAR + standard deviation.

Results
Mean UCDVA was 0.01 + 0.13 for Group 1, 0.06 + 0.13 for Group 2 and 0.28 + 0.17 for Group 3. Achieved UCIVA for Groups 1, 2 and 3 were 0.09 + 0.12, 0.09 + 0.10 and 0.32 + 0.24, respectively. For UCNVA, subjects achieved 0.22 + 0.12 in Group 1, 0.23 + 0.10 in Group 2 and 0.37 + 0.27 in Group 3. Statistical analysis showed for all measured distances, Groups 1 and 2 were the same. Group 3 was statistically significantly worse than Group 1 at far (p=0.0006), intermediate (p=0.0212) and near (p=0.2164).

Conclusion
A small-aperture IOL can be used to effectively treat up to 1.50 D of pre-operative corneal astigmatism without degradation of visual acuity at any focal distance.
Refractive and Keratometric Outcomes of Resident-Performed Manual Limbal Relaxing Incisions: 1 Year Results
Authors
Kamran M. Riaz, MD
Blake Williams, MD
Li Wang, MD, PhD
Asim V Farooq, MD

Methods
Retrospective study of 118 eyes that received manual LRIs using a fixed depth 550 micron diamond blade at the time of resident-performed cataract surgery. Length, location and number of LRIs were determined using an online calculator. Outcomes studied were preoperative keratometry and postoperative UCVA, BCVA, refraction and keratometry at POD1, POW1, POM1, POM3-6 and POM12-18 timepoints. The double-angle astigmatism plot tool and analysis of WTW-ATW (with-the-wound and against-the-wound) changes were used to assess the effect of the astigmatism correction at 1-month, 3-6month and 12-18month postoperative visits.

Results
Corneal astigmatism magnitude values were significantly decreased at all postoperative visits (P<0.001). WTW-ATW changes were significantly different from zero at all postop visits (all P<0.001). WTW-ATW changes at 3-6 months and 12-18 months are significantly smaller than that at 1 month (P<0.05), but there was no difference between 3-6 months and 12-18 months (P>0.05). Compared to preop corneal astigmatism, higher % of eyes have refractive astigmatism <=0.25 D, <=0.50 D, <=0.75 D, and <=1.0 D at 1 month and 12 months (all P<0.05). Regression of effect after 1 month was approximately 0.11D. Double-angle plots show decrease in centroid values (P<0.05) at 1-month and 12-18 month visits.

Conclusion
LRIs performed by novice surgeons can achieve effective and sustained reduction of keratometric and refractive astigmatism for patients with mild-moderate preoperative astigmatism. Non clinically significant regression may occur after three months. Surgical educators may be encouraged by these results to teach this technique to their trainees.
Accuracy of Intra-Stromal Corneal Toric IOL Alignment Marks in PMMA Spheres with a Femtosecond Laser System
Authors
Wendell Scott, MD
Tim Schultz, MD
Niksa Valim, PhD
David Dewey, MSc
H. Burkhard Dick, MD, PhD

Methods
The accuracy of the alignment mark was tested on both synthetic and patient eyes. 16 PMMA hemisphere samples were used for alignment mark incisions with the laser system (CATALYS®; J&J). The actual incisions were disposed in the synthetic eyes at 0 and 180 degrees, with a length of 1.5mm. The alignment marks were compared with digital analysis of video microscopy by toggling the incision overlay on and off before and after laser delivery. The performance of alignment marks was also tested on 10 eyes of 10 patients (5 women and 5 men). The preoperative corneal astigmatism in all patient eyes was more than 1.0 D and the preoperative corrected distance visual acuity was 0.63 or worse.

Results
16 enface measurement of synthetic eyes were evaluated. Based on the alignment mark parameters in PMMA spheres, the alignment error of 0 to 1.3 degrees was observed. The average alignment error in synthetic eyes was 0.58 ± 0.43 degrees. In addition to the alignment error, the errors in intended optical zone, intended length, and intended axis were measured 0.69% ± 0.89%, 3.45% ± 1.38%, and 0.013 ± 0.01 degrees, respectively. In eyes that underwent laser alignment marks, the marks were clearly visible under the operating microscope. The image analysis of the mark on patient eyes showed parallel incisions with a misalignment of less than 1 degree.

Conclusion
The toric IOL alignment mark procedure with the used laser system led to a mean error of 0.58 degrees in PMMA spheres and misalignment of less than 1 degree in 10 patient eyes. Laser assisted marking showed significant improvement compared with manual marking.
Efficacy of Combined Femtosecond Laser Assisted Cataract Surgery with Astigmatism Management & Descemet’S Membrane Endothelial Keratoplasty
Author
Yuri McKee, MD

Methods
Eight eyes of 8 patients with corneal endothelial dystrophies and age related cataract and corneal astigmatism between 0.45 D to 1.95 D underwent combined triple procedure of femtosecond laser assisted arcuate keratotomy and cataract extraction with monofocal IOL implantation and DMEK procedure. Trabelular micro-bypass shunt (istent) implantation was also performed in 2 eyes. The main outcome measures were uncorrected and corrected distance visual acuity (UDVA, CDVA), manifest refraction spherical equivalent (MRSE), refractive astigmatism, and endothelial cell density. Patient results were reported at 3 months after surgery.

Results
At postoperative 3 months, astigmatism reduced significantly from a mean preoperative corneal astigmatism of 0.90 D to a mean refractive astigmatism of 0.34 D postoperatively (p=0.001). Postoperative residual refractive astigmatism (RRA) was ≤0.5 D in 75% eyes and all eyes (100%) were within RRA of 1.0 D. UDVA of 20/32 or better was achieved in 75% eyes. All eyes had CDVA of 20/32 or better postoperatively. Nearly 75% eyes were within ±0.5 D of the intended MRSE.

Conclusion
Combined triple procedure of arcuate keratotomy, cataract extraction, IOL implantation and DMEK seems to be safe and effective in improving visual and refractive outcomes in astigmatic and cataractous eyes of patients with corneal endothelial dystrophies. No intra or postoperative complications were observed

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