Alpins Method Research Articles

Transepithelial Versus Epithelium-off Photorefractive Keratectomy in High Compound Myopic Astigmatism: A Contralateral Eye Study.

To compare clinical outcomes of transepithelial photorefractive keratectomy (t-PRK) and conventional epithelium-off PRK (PRK) in patients with high compound myopic astigmatism. Sixty eyes of 30 myopic individuals with at least -2.50 diopters (D) of spherical equivalent and 3.00 D of cylindrical refractive error were enrolled in the study. Both eyes of each patient were randomly assigned to either the t-PRK method or epithelium-off PRK as a matched contralateral control group. Refractive outcomes were evaluated 6 months after surgery. At the 6-month visit, cylindrical refractive error magnitude was lower in the t-PRK (0.51 ± 0.29 D) compared to the PRK (0.67 ± 0.30 D) group (P = .04). The residual astigmatism was 0.50 diopters or less in 23 eyes (76%) in the t-PRK group and 15 eyes (50%) in the PRK group. In vector analysis using the Alpins method, t-PRK resulted in a significantly higher percentage of success of astigmatic surgery (84.68 ± 8.95 in t-PRK versus 79.46 ± 10.88 in PRK, P = .04). Additionally, there was a marginal advantage for the t-PRK group regarding index of success of astigmatism surgery (P = .06) and absolute (P = .08) and arithmetic (P = .07) angles of error compared to the PRK group. Both groups had an equal safety profile. T-PRK is more accurate for astigmatic correction in high astigmatism than conventional PRK. Both t-PRK and PRK are comparable respecting safety and efficacy. [J Refract Surg. 2024;40(12):e956-e965.].

Using Total Corneal Astigmatism With Femtosecond Laser Cataract Surgery and Arcuate Keratotomy(ies) to Treat Low Amounts of Astigmatism.

The aim of this study was to evaluate outcomes using total corneal astigmatism (TCA) to calculate arcuate keratotomy(ies) (AK) parameters performed with femtosecond laser-assisted cataract surgery to reduce low corneal astigmatism. Patients who had femtosecond laser-assisted cataract surgery and AK with 0.50 diopter (D) to 1.30 D of TCA were included. Exclusion criteria were intraoperative complications, preexisting corneal surgery, and comorbidities that might adversely affect outcomes. Corneal tomography (Galilei G4, Zeimer Ophthalmic Systems AG) was performed preoperatively and 1 month postoperatively. TCA was input into the Donnenfeld limbal relaxing incisions nomogram to calculate the AK parameters. Preoperative and postoperative tomographic and subjective refractive measurements were compared. The Alpins method for vector analysis evaluated results. Eighty-two eyes of 82 patients were included. Mean preoperative TCA was significantly reduced from 0.80 ± 0.19 D to 0.51 D ± 0.26 D ( P < 0.001). Preoperative posterior corneal astigmatism, -0.28 ± 0.13 D, was unchanged, postoperative posterior corneal astigmatism, -0.28 ± 0.14 D ( P = 0.653). Target-induced astigmatism arithmetic mean (0.82 ± 0.21 D) was greater than that of the surgically induced astigmatism (0.70 ± 0.40 D), resulting in an arithmetic mean difference vector of 0.51 ± 0.27 D with a summated mean at 0.16 D at 20 degrees. The correction index was 0.87, indicating undercorrection. Angle of error arithmetic mean, -1.27 ± 23.27 degrees, indicated good alignment. Inputting TCA for calculation of femtosecond laser AK parameters can reduce low amounts of preoperative corneal astigmatism, thereby improving uncorrected vision.

Symmetrical femtosecond laser arc incision in correcting corneal astigmatism in cataract patients.

To evaluate the effect of symmetrical arc incision correcting corneal astigmatism in femtosecond laser-assisted phacoemulsification (FLACS). This study enrolled patients with cataract combined with regular corneal astigmatism of >0.75 D, who underwent FLACS. Symmetrical arc incision was set at 8 mm diameter and 85% depth. The follow-up time was 3-24mo (4.92±3.49mo). Pentacam recorded the corneal astigmatism and higher-order aberration at pre-operation and post-operation. The changes in corneal astigmatism were analyzed by Alpins method. The correlation of astigmatism type, age, corneal horizontal diameter, corneal thickness, arc incision length, and correction index (CI) was analyzed, and the residual corneal astigmatism was compared with the residual whole eye astigmatism. Totally 79 patients (102 eyes) were enrolled, 10 patients had corneal epithelial injury, 1 patient occurred corneal epithelial hyperplasia. The corneal astigmatism was 1.23±0.38 D pre-operation, and decreased to 0.76±0.39 D post-operation (t=10.146, P=0.000). Corneal high-order aberration was 0.17±0.08 µm pre-operation and 0.24±0.11 µm post-operation (t=-5.186, P=0.000). The residual corneal astigmatism and residual whole eye astigmatism were no significant difference (t=-0.347, P=0.729). Using Alpin's method, the following were determined: target-induced astigmatism (TIA) =1.23±0.38 D, surgery-induced astigmatism (SIA) =0.77±0.45 D, difference vector (DV)=0.77±0.39 D, and CI=0.54±0.28. Age, astigmatism size, corneal horizontal diameter, corneal thickness, and arc incision length were not correlated with CI. The CI for against the rule astigmatism (ATR) was better than that for with the rule astigmatism (WTR; P=0.001). Femtosecond laser-assisted astigmatic keratotomy has better CI of ATR, but increase higher-order corneal aberration. CI is not ideal, it's not a perfect choice if we pursue ideal correction effect.

Comparison of different methods of correcting astigmatism in cataract surgery

ABSTRACT Clinical relevance Astigmatism causes a decrement in visual acuity, and deterioration in visual quality. Background The aim of this study is to compare clear corneal incision (CCI) in the steepest meridian, opposed clear corneal incision (OCCI) and toric intraocular lens implantation methods for the correction of astigmatism in cataract surgery. Methods Total of 93 preoperative patients with the rule corneal astigmatism (between 1.00–3.00 D)underwent uncomplicated cataract surgery are retrospectively included in this study. Whole patients are divided into three groups of equal number of patients of 31 by considering the astigmatism correcting methods that are as follows. Group 1 consists of patients underwent CCI on the steepest meridian, group 2 consists of the patients underwent paired OCCI, and group 3 consists of those with toric intraocular lens implantation. The preoperative and postoperative 3rd month uncorrected distance visual acuity, refraction and, keratometry values, and surgically induced astigmatism values calculated by Alpins method are recorded. Results The age, preoperative and postoperative 3rd month spherical, spherical equivalent refraction and keratometry values of the groups are similar (p > 0.05). The preoperative uncorrected distance visual acuity values are similar in whole groups, postoperative uncorrected distance visual acuity values are the highest in group 1, and lowest in group 3 (p = 0.85, p = 0.02, respectively). The preoperative and postoperative 3rd month mean cylinder refraction values are -1.86 D, -1.00 D in group 1, −1.77 D, -0.70 D in group 2, and −1.95 D, -0.40 D in group 3. There is a statistically significant difference among the groups (p = 0.01). The surgically induced astigmatism values are statistically different among the groups [it was 0.46 ± 0.21 in group 1, 0.91 ± 0.44 in group 2, 0.33 ± 0.18 in group 3 (p < 0.001, respectively)]. Conclusion This study indicated that; CCI, paired OCCI, and toric intraocular lens implantation should be preferred and performed for the steepest meridian in low D, middle D, and high D astigmatism patients, respectively. CCI can easily be applied for low to medium D without needing extra skills and tools. On the other hand, toric intraocular lens implantation is a better option for a high astigmatism with proper and accurate planning before the surgery.

Refractive outcomes of toric intra-ocular lens implantation in cases of high posterior corneal astigmatism.

To evaluate whether the toric intra-ocular lens (IOL) power calculation based on total corneal astigmatism (TCA) in eyes with high posterior corneal astigmatism (PCA) could result in a systematic over-correction or under-correction after operation. The present study included a mono-centric retrospective study design. The data were collected from 62 consecutive eyes during uncomplicated cataract surgery by a single surgeon with a measured PCA of 0.50 diopters (D) or higher. Toric IOL calculations were made using TCA measurements. The eyes were grouped as either "with-the-rule" (WTR) or "against-the-rule" (ATR) on the basis of the steep anterior corneal meridian. The post-operative refractive astigmatic prediction error was analyzed 1 month post-operatively using the vector analysis by the Alpins method and double-angle plots method. The correction indexes were 1.14 ± 0.29 in the ATR eyes and 1.25 ± 0.18 for the WTR eyes, indicating a tendency toward over-correction. The mean over-correction was 0.22 ± 0.52D in the ATR group and 0.65 ± 0.60D in the WTR group. The magnitude of error (ME) values were significantly different from the ideal value of zero in both groups (ATR: P = 0.03; WTR: P = 0.00). No significant difference in mean absolute error (MAE) in predicted residual astigmatism was found between ATR and WTR groups (0.61 ± 0.42 D versus 0.64 ± 0.39 D; P = 0.54). The ATR group yielded better results, with 48% <0.50D prediction error in the main analysis. The results suggested that in cases of high PCA, the toric IOL calculation, which was performed using TCA, may cause a potential over-correction in the ATR and WTR eyes. For ATR eyes, over-correction led to slight disruption of post-operative visual quality because of the "with-the-rule" residual astigmatism after operation. Therefore, we suggested using TCA for toric IOL calculation in ATR eyes.

Short-Term Impact of Different Corneal Incision Positions on Postoperative Astigmatism and Visual Quality After SMILE Surgery.

This study aimed to evaluate the short-term impact of different incision positions on astigmatism and visual quality after small incision lenticule extraction (SMILE) surgery. This prospective study enrolled patients who decided to have SMILE to correct myopia. Patients were randomly allocated into three groups of different incision positions (groupA, B, and C with incision position at 90°, 120°, and 150° respectively). Preoperative and postoperative visual acuity, spherical equivalent, and high-order aberrations (HOAs) were measured and compared among groups. Astigmatism was analyzed with the ASSORT Group Analysis Calculator based on the Alpins method. A total of 148 eyes were included for analysis (48 eyes in groupA, 50 eyes in groupB, and 50 eyes in groupC). At 1month postoperatively, the mean uncorrected distance visual acuity (UDVA) logMAR in groupA, B, and C was - 0.03, - 0.03, and - 0.04, respectively. The mean corrected distance visual acuity (CDVA) logMAR in groupA, B, and C was - 0.03, - 0.04, and - 0.04, respectively (P > 0.05). The mean postoperative spherical equivalent (SE) values were - 0.01 ± 0.38, - 0.07 ± 0.39, and - 0.16 ± 0.49 (D) in groupA, B, and C, respectively (P > 0.05). There was no statistically significant difference in preoperative and postoperative magnitude of astigmatism among different groups (P > 0.05). Significant differences were found in the distribution of astigmatism axis among the three groups at 1day (P = 0.02) and 1week (P = 0.02) postoperatively. However, such differences were no longer significant at 1month after surgery (P > 0.05). No significant differences were found in HOAs among different groups 1month after surgery (P > 0.05). Different incision positions have no effect on postoperative astigmatism and visual quality 1month after SMILE surgery, though differences were found in the distribution of the astigmatism axis within 1week after the surgery.

Refractive and Visual Outcomes of SMILE for Compound Myopic Astigmatism With the VISUMAX 800

To report the first refractive and visual outcomes of small incision lenticule extraction (SMILE) using the VISUMAX 800 femtosecond laser (Carl Zeiss Meditec AG). This was a retrospective analysis of consecutive eyes treated by SMILE using the VISUMAX 800 femtosecond laser at London Vision Clinic, EuroEyes Group, London, United Kingdom. Inclusion criteria were patients aged younger than 45 years, a corrected distance visual acuity (CDVA) of 20/20 or better, and the 3-month postoperative timepoint data being available for analysis. Standard outcomes analysis and vector analysis by the Alpins method were performed. During the study period, 128 eyes of 66 consecutive patients were treated. Three-month data were available for 118 eyes (92%), and 10 eyes (8%) were lost to follow-up. The mean attempted spherical equivalent refraction (SEQ) was -4.65 ± 1.91 diopters (D) (range: -1.90 to -10.05 D) and the mean cylinder was -0.98 ± 0.78 D (range: 0.00 to -4.00 D). The mean age was 30 ± 5 years (range: 20 to 43 years), with 54% women and 46% men. Postoperative SEQ was within ±0.50 D in 86% and ±1.00 D in 100% of eyes. Uncorrected distance visual acuity was 20/20 or better in 91% of eyes. One line of CDVA was lost in 8% of eyes, and no eyes lost two or more lines. There was a small but statistically significant increase in contrast sensitivity at 3, 6, 12, and 18 cpd. Early outcomes data for SMILE with the second generation VISUMAX 800 femtosecond laser demonstrated an effective and safe option equivalent to published first generation VisuMax outcomes for the treatment myopia and astigmatism. [J Refract Surg. 2023;39(5):294-301.].

Toric intraocular lenses versus paired opposite corneal incisions in correction of low-grade astigmatism after phacoemulsification

Purpose To compare toric intraocular lens (IOL) implantation versus monofocal (Eyhance) IOL with paired corneal incisions for correction of low-grade astigmatism after phacoemulsification. Patients and methods A retrospective comparative study included 30 patients with low-grade astigmatism (−0.75 to −1.50 D) who underwent phacoemulsification: group 1 underwent toric IOL implantation (TECNIS toric) and group 2 underwent enhanced monofocal IOL (TECNIS Eyhance) with paired corneal incision along steep corneal meridian. Best-corrected visual acuity, astigmatism power, and axis were assessed preoperatively and 3 months postoperatively. Vector analysis of astigmatism was done using the Alpins method. Results The mean postoperative residual astigmatism was significantly lower in group 1 versus group 2 (−0.357±0.128 and −0.538±0.225 D, respectively; P=0.015). A significantly higher decrease in astigmatism was noted in group 1 (−0.93±0.18 and −0.38±0.69 D, respectively; P=0.006), with no significant difference in postoperative visual acuity. Paired comparison revealed significant decrease in astigmatism (P&lt;0.0001 in group 1 and 0.04 in group 2) and improvement in uncorrected visual acuity (P&lt;0.0001 for both groups). A significantly higher percentage of success was noted in group 1 (P=0.017), with a higher difference vector in group 2 (P=0.008). Conclusion Our results suggest that both toric IOL and paired corneal incision are efficient methods for postoperative astigmatism correction and achieving postoperative spectacle independence in patients with low-grade astigmatism. Toric IOL is superior in reducing postoperative astigmatism, reflecting more consistent results. The recommendation of IOL type and astigmatism correction should be tailored according to the patient's requirements, especially with the expanded need for good intermediate vision for everyday tasks that may benefit from enhanced IOLs.

Comparison of surgically induced astigmatic changes after cataract surgery in post-Laser in situ keratomileusis corneas versus virgin eyes.

Postoperative refraction in modern mi-croincision cataract surgery gained extra importance in patients with the previous laser-assisted in situ keratomileusis (LASIK) surgery. The surgically induced astigmatic changes in those eyes may differ not only in magnitude but also in direction compared to virgin corneas. This study aimed to compare the surgically induced astigmatic changes after microscopic cataract surgery between post-LASIK corneas and virgin eyes. Cases that underwent microincision cataract surgery in eyes with and without previous LASIK surgery were reviewed. The demographics, the axial length at cataract surgery, the central corneal thickness, spheric and cylindric values, keratometry readings, and postoperative posterior corneal astigmatism were retrospectively evaluated. A modified Alpins method was used for astigmatic vector analysis, and baseline astigmatism, surgically induced astigmatism, difference vector, flattening effect, and torque were assessed. A total of 42 eyes from 24 subjects was evaluated. Group I consisted of 14 eyes with the previous LASIK, and Group II included 28 eyes without any refractive surgery. Preoperative mean central corneal thickness in Group I was significantly thinner (p=0.012). There was no significant difference in baseline astigmatism between the groups regarding magnitude and power vectors. After microincision cataract surgery, there were no significant differences in mean spheric and cylindric values and mean keratometry readings (all p>0.05). However, surgically induced astigmatism and difference vector were significantly higher on J45 vector component in post-LASIK eyes and microincision cataract surgery steepening effect on post-LASIK corneas was significantly higher than those in virgin eyes (p=0.001, p=0.002 and p=0.018, respectively). Cataract surgery has steepened the corneas in both groups with a significantly higher steepening effect in post-LASIK eyes. Certainly, corneal topography cataract surgery is particularly helpful to provide more precise surgically induced astigmatism interpretations.

Clinical results of topography-guided laser-assisted in situ keratomileusis using the anterior corneal astigmatism axis and manifest refractive astigmatism axis.

To evaluate the clinical results of primary topography-guided femtosecond laser-assisted in situ keratomileusis (TG-FS-LASIK) using the Pentacam-measured anterior corneal astigmatism axis (ACA) or manifest refractive astigmatism axis (MRA). In this prospective cohort study, all eyes were treated with primary TG-FS-LASIK using the manifest cylinder. Thirty-two right eyes were treated using ACA with axis disparity > 5° in the experimental group, and 32 right eyes were treated using MRA with axis disparity ≤ 5° in the control group. Visual, refractive outcomes, and corneal higher-order aberrations were evaluated. Vector analysis of astigmatism was performed using Alpins method with the ASSORT software. The mean logMAR UDVA in the experimental group was - 0.12 ± 0.06, - 0.05 ± 0.08, and - 0.08 ± 0.08 at 1-week, 1-month, and 3-month follow-up, whereas - 0.05 ± 0.06, - 0.12 ± 0.06, and - 0.14 ± 0.06 in the control group (p = 0.017, p < 0.001, and p = 0.003). At 3-month follow-up, 79% eyes achieved a UDVA of 20/16 or better, 9% gained one line of corrected distance visual acuity, the mean manifest cylinder was - 0.375 ± 0.254 D, 84% showed a manifest cylinder within ± 0.50 D, the mean magnitude of difference vector was 0.41 ± 0.35 D, the mean absolute angle of error (AE) was 7.36 ± 6.21°, and 41% exhibited an arithmetic AE within ± 5° in the experimental group, whereas 94%, 19%, - 0.203 ± 0.148 D, 100%, 0.21 ± 0.15 D, 3.39 ± 3.68°, and 69% in the control group (all p < 0.05). The postoperative and preoperative corneal spherical aberrations were comparable in both groups (p > 0.05). Primary topography-guided FS-LASIK using Pentacam-measured anterior corneal astigmatism axis exhibited slightly inferior clinical results to that using the manifest refractive astigmatism axis. Both methods achieved comparable postoperative and preoperative corneal spherical aberrations.

Comparison of refractive and visual outcomes between image-guided system-assisted small-incision lenticule extraction and wavefront-optimized FS-LASIK in treatment of high astigmatism.

To compare the refractive and visual results of image-guided system-assisted small-incision lenticule extraction (IGA-SMILE) and wavefront-optimized femtosecond laser in situ keratomileusis (FS-LASIK) in the treatment of high astigmatism. Osmangazi Aritmi Hospital, Bursa, Turkey. Retrospective. This retrospective case-matched study included 64 eyes that had undergone IGA-SMILE and 64 eyes that had undergone wavefront-optimized FS-LASIK. The mean preoperative myopia and astigmatism were -4.05 ± 1.98 diopter (D) and 3.11 ± 1.06 D in the IGA-SMILE group and -4.21 ± 2.23 D and -3.15 ± 0.62 D in the FS-LASIK group, respectively. One year later, visual and refractive results were compared in the groups. Vector analysis based on Alpins method was performed to evaluate astigmatic treatment. 128 eyes of 128 patients were included in this study. At 1 year, the residual astigmatism was -0.21 ± 0.25 D in the IGA-SMILE group and -0.21 ± 0.24 D in the FS-LASIK group ( P = .305). In the IGA-SMILE group, 57 eyes (89.1%) achieved uncorrected distance visual acuity of 20/20 or better, as did 56 eyes (85.9%) in the FS-LASIK group. Vector analysis results demonstrated that the difference vectors were 0.22 ± 0.24 D and 0.21 ± 0.22 D ( P = .230), the correction indexes were 0.95 ± 0.08 and 0.95 ± 0.08 ( P = .239), and the indices of success were 0.08 ± 0.09 and 0.08 ± 0.09 ( P = .248) in the IGA-SMILE and the FS-LASIK groups, respectively. The combination of an image-guided system with SMILE resulted in high efficacy and safety indices that were comparable with FS-LASIK surgery.

Efficacy and Safety After Toric Posterior Chamber Implantable Collamer Lens and Toric Iris-Fixated Foldable Phakic Intraocular Lens for Myopic Astigmatism.

To compare visual, refractive, and safety outcomes of toric posterior chamber Implantable Collamer Lens (T-ICL) (STAAR Surgical) and toric iris-fixated foldable phakic intraocular lens (IOL) (T-Artiflex; Ophtec BV) implantation for the correction of myopic astigmatism. This retrospective cohort study included 312 eyes of 312 patients who had phakic IOL implantation for myopic astigmatism. Two groups were defined: 205 eyes that underwent T-ICL implantation and 107 eyes that underwent T-Artiflex implantation. Safety, efficacy, and predictability outcomes were evaluated preoperatively and at 12 months postoperatively. Refractive and corneal astigmatic vector analysis were performed using the Alpins method. One year postoperatively, uncorrected distance visual acuity was 0.05 ± 0.18 (T-ICL) and 0.10 ± 0.16 (T-Artiflex) logMAR, with efficacy indexes of 1.16 ± 0.27 and 1.05 ± 0.31, respectively (P < .001). Safety indexes were 1.28 ± 0.30 and 1.21 ± 0.31, respectively (P = .04). Spherical equivalent was within ±0.50 diopters (D) of emmetropia in 165 (80.5%) and 88 (82.2%) eyes, respectively. Refractive astigmatic analysis showed an index of success of 0.28 ± 0.33 (T-ICL) and 0.31 ± 0.26 (T-Artiflex) (P = .07). Surgically induced corneal astigmatism was 0.48 ± 0.74 and 0.81 ± 0.61 D, respectively (P < .001). Mean endothelial loss was 1.11% and 2.05%, respectively (P = .42). Six (2.9%) eyes in the T-ICL group and 1 (0.9%) eye in the T-Artiflex group had phakic IOL repositioning due to significant misalignment. No vision-threatening complications occurred. Both the T-ICL and T-Artiflex groups showed high visual and refractive efficacy with a good safety profile for the correction of myopic astigmatism. T-ICL implantation demonstrated significantly better efficacy and safety indexes after 12 months. Vector analysis showed similar refractive astigmatic correction in both groups, but T-Artiflex implantation revealed higher surgically induced corneal astigmatism. [J Refract Surg. 2022;38(6):339-347.].

Analyse vectorielle de la correction de l’astigmatisme par incisions arciformes au laser femtoseconde dans les astigmatismes géants post-kératoplastie transfixiante

To study the results of femtosecond laser-assisted arcuate keratotomy in extreme astigmatism after penetrating keratoplasty, using a Ziemer LDVZ6 with a modified Lindstrom nomogram. Case series, retrospective study. Consecutive eyes that underwent femtosecond laser-assisted arcuate keratotomy between 2014 and 2019 in the Nantes University Hospital for extreme astigmatism after penetrating keratoplasty were included. Twenty-four eyes of 24 patients were included. The mean age was 53.3±12.2 years at the time of the arcuate keratotomies. Indications for penetrating keratoplasty were keratoconus in 66.7% of cases, herpes keratitis in 16.7% of cases, and corneal dystrophy in 16.7% of cases. The mean initial best corrected visual acuity was 0.36±0.23 logMar versus 0.26±0.15 logMar at the 3-month postoperative visit (P=0.04). At the postoperative visit, 54% (13/24) of eyes had improved best corrected visual acuity (BCVA), and 25% had no change in BCVA, with a mean cylinder reduction of 3.3 diopters. The mean preoperative topographic cylinder was 9.5±3.2 diopters versus 6.2±2.8 diopters postoperatively (absolute values; P<0.001), i.e. a 34.7% reduction in astigmatism. At the 3-month postoperative visit, 20.8% of eyes (5/24) had topographic astigmatism less than 3 diopters with a mean astigmatism reduction of 97±55% (range: 17; 201) using the Alpins method. No suppurative keratitis or endophthalmitis were observed. Twenty-one percent of patients underwent a second arcuate keratotomy after 3 to 6 months due to insufficient refractive results. Development of new nomograms designed for extreme astigmatism after penetrating keratoplasty would enhance the precision and reproducibility of femtosecond laser-assisted arcuate keratotomy in these cases.

Comparison of clinical outcomes of astigmatic correction using toric intraocular lens

AIM: To compare the clinical effects of two brands of Toric intraocular lens used in surgical correction of cataract with corneal astigmatism. METHODS: Totally 35 patients (50 eyes) with corneal astigmatism who underwent ophthalmic surgery from April 2019 to July 2019 were retrospectively analyzed. Among them, 25 eyes of 20 patients were implanted with Rayner 623T, while 25 eyes of 15 patients with Alcon AcrySof Toric intraocular lens (IOL). Three months after surgery, the uncorrected distance visual acuity (UCDVA), best corrected distance visual acuity (BCDVA), residual astigmatism, rotational degree of intraocular lens, contrast sensitivity, objective visual quality and the National Eye Institute 25-Item Visual Function Questionnaire (NEI VFQ-25) scale score were compared. Vector analysis was performed using the Alpins method. RESULTS: The mean postoperative UCDVA and BCDVA (logMAR) in the Rayner group were 0.17±0.20 and 0.08±0.15, respectively (P&gt;0.05), while those in the Alcon group were 0.21±0.16 and 0.10±0.11, respectively (P&gt;0.05). The mean residual astigmatism in the Rayner group was -0.57±0.24 D while that in the Alcon group was -0.50±0.28 D (P&gt;0.05). There was no statistically significant difference between the two groups in IOL rotational stability, vector analysis parameters, contrast sensitivity and objective visual quality (P&gt;0.05). The NEI VFQ-25 scale score was 85.16±5.91 in the Rayner group while it was 82.08±6.16 in the Alcon group (P&gt;0.05). CONCLUSION: The two brands of toric intraocular lens-Rayner 623T and Alcon AcrySof toric show no significant difference in their clinical outcomes.

Comparison of clinical outcomes between Wavelight Allegretto Eye-Q and Schwind Amaris 1050RS in high myopic astigmatism

Purposes: To compare clinical outcomes between Wavelight Allegretto Eye-Q 400Hz and Schwind Amaris 1050RS in high myopic astigmatism. Methods: non-randomized, controlled, interventional study of 90 eyes with at least 1.5diopter astigmatism, assigned into two groups depends to the L machine and followed up three months post-op. Primary outcomes include uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), subjective refraction spherical equivalent (SRSE), cylinder, safety and efficacy indices, refractive predictability and stability; and optical aberration and contrast sensitivity changes after surgery. Besides, Alpins method about residual astigmatism is also analyzed and compared between groups. Results: Safety index of Schwind Amaris and Allegretto group is 1.011 ± 0.169 and 1.007 ± 0.055 (p = 0.510); effective index is 1 ± 0.032 and 0.991 ± 0.077 (p = 0.567; stability index is 0.003 and 0.1 (p = 0.134); predictability index within [±0.5D] after three-month postop is 91.1% and 95.6% (p = 0.398), respectively. Post-op residual astigmatism in Schwind Amaris and Allegretto group is -0.139 ± 0.22 and -0.183 ± 0.27 (p = 0.396). Regarding Alpins method in astigmatic analysis of Schwind Amaris and Allegretto groups: SIA (surgically induced astigmatism) is 1.792 ± 0.534 and 1.920 ± 0.588 (p = 0.284); AE (angle of error) is 1.04 ± 2.881 and -0.08 ± 3.790 (p = 0.119); CI (correction index) is 0.98 ± 0.107 and 1.02 ± 0.142 (p = 0.165); SAS (Success of Astigmatism Surgery) is 92.01 ± 12.77 and 89.78 ± 16.32 (p = 0.472), respectively. Contrast sensitivity and higher optical aberration changes after surgery between two groups are insignificant differences (p &gt; 0.05). Conclusions: Clinical outcomes of both lasers machine are good. There is no significant differences in residual astigmatism and high-order aberrations or contrast sensitivity changes after surgery between two groups.

Toric Intraocular Lenses for the Management of Corneal Astigmatism at the Time of Cataract Surgery

Methods This audit was conducted in a UK ophthalmology department and included 48 eyes of 42 patients. Surgery was performed during 2019 in patients with 2.50 diopters (D) or more corneal astigmatism. Anterior keratometry readings were used to determine the toric IOL power. Vector analysis using the Alpins method was used to assess changes in astigmatism pre to postoperatively. Results There were 18 right and 26 left eyes included. In terms of gender, 61% of patients were female and 39% were male. The mean (±standard deviation (SD)) age was 70 (±11) years. The mean (±SD) axial length, K1, K2, and delta K was 23.55 (±1.4) mm, 42.71 (±1.39) D, 45.78 (±1.60) D, and 3.01 (±0.89) D, respectively. Postoperatively, the median spherical, cylinder, and spherical equivalent refraction was 0.00 D, −1.00 D, and 0.00 D, respectively. Postoperatively, 41% of the eyes had ≤0.50 D of spectacle astigmatism and 80% had ≤1.00 D. No patient required a secondary procedure to reposition the IOL from rotation. In vector analysis with the use of polar diagrams, there was a tendency for overcorrection of with-the-rule astigmatism and undercorrection of against-the-rule astigmatism. Conclusions Significant reductions in astigmatism can be achieved with the use of toric IOLs in patients undergoing cataract surgery. Further improvements may be possible with surgeon-specific determination of their surgically induced astigmatism and flattening effect from the main corneal incision. Furthermore, the use of an optical biometer that directly measures the posterior corneal curvature and permits automatic toric IOL power determination with modern formulas avoiding the need for manual data entry may reduce the risk of human error and improve visual and refractive outcomes.

Clinical Outcomes of a New Type of Continuous Intrastromal Corneal Ring for Treatment of Keratoconus.

The purpose of this study was to evaluate the efficacy and safety of implantation of a new continuous corneal ring in keratoconic corneas of an Iranian population. This study was conducted on 95 contact lens-intolerant keratoconic eyes with clear central corneas. A continuous corneal ring, annular intrastromal corneal inlay (AICI), was inserted using femtosecond laser in all cases. Patients were followed up for 1, 3, and 12 months postsurgery. Visual and subjective refractive outcomes were evaluated in each examination. Besides, keratometry and aberrometric values were recorded before and 12 months after surgery. Finally, vector analysis of refractive astigmatism was performed using the Alpins method. The uncorrected and corrected distance visual acuities improved significantly 12 months after surgery from 0.91 ± 0.39 to 0.38 ± 0.22 (P < 0 0.001) and 0.33 ± 0.21 to 0.13 ± 0.11 logMAR (P < 0.001), respectively. Moreover, spherical and cylindrical refractive components reduced from -2.52 ± 2.62 to -0.76 ± 1.78 D (P < 0.001) and -4.14 ± 1.64 to -1.91 ± 1.18 D (P < 0.001), respectively. The mean anterior keratometry had a significant reduction 12 months after AICI insertion (P< 0.001). Primary coma and spherical aberration values showed a significant increase (both, P < 0.05). Our results showed 100% safety (safety index: 1.8) and 45% efficacy (efficacy index: 1). AICI implantation seemed to be a safe and effective procedure for improving visual acuity and refractive outcomes in subjects with keratoconus.

Comparison of penetrating femtosecond laser-assisted astigmatic keratotomy and toric intraocular lens implantation for correction of astigmatism in cataract surgery

This study tried to compare the clinical outcomes of femtosecond laser-assisted astigmatic keratotomy (FSAK) and toric intraocular lens (IOL) implantation for astigmatism correction and identify factors affecting the efficacy of FSAK and toric IOL implantation in astigmatism correction. This retrospective case series comprised patients with corneal astigmatism ranging between 0.5 D and 4.5 D. Patients underwent FSAK or toric IOL implantation for cataract treatment and correction of astigmatism at the Samsung Medical Center, a tertiary surgical center, between April 2016 and December 2018. All patients underwent examination before and at three months after the surgery for comparative evaluation of refractive astigmatism, corneal high order aberrations and irregularity index. The astigmatism correction was analyzed by the Alpins method. Subgroup analysis of preoperative factors was based on the extent of target-induced astigmatism (TIA), the degree of astigmatism, and astigmatism classification based on topography. Thirty-one eyes underwent toric IOL implantation and 35 eyes underwent FSAK. The refractive astigmatism was significantly decreased in both toric IOL (P = 0.000) and FSAK group (P = 0.003). The correction index (CI) of refractive astigmatism was 0.84 ± 0.39 in the toric IOL and 0.71 ± 0.60 in the FSAK group. There was no difference between the two groups (P = 0.337). The CI of the FSAK group was significantly lower than in the toric IOL group when TIA was more than 1.5 D (P = 0.006), when correcting against-the-rule (P = 0.017), and limbus-to-limbus astigmatism (P = 0.008). In conclusion, toric IOL implantation is an effective and safe procedure for correcting preoperative astigmatism in cataract surgery in the short-term observation.

Efficacy comparison between toric intraocular lens and aspheric intraocular lens plus steep-axis incision in cataract patients with low corneal astigmatism.

The present study aimed to evaluate and compare the efficacy of toric intraocular lens (IOL) implantation and aspheric IOL implantation with steep-axis incision for correcting mild to moderate corneal astigmatism in cataract patients. A prospective, single-center, open label, randomized, two-arm study was designed. Cataract patients with corneal astigmatism of 1.0-2.0D were enrolled and divided into test and control groups. The test group had the AcrySof® IQ Toric IOL implanted and the control group had the AcrySof® IQ IOL implanted with a steep-axis corneal incision. All patients underwent examinations of uncorrected distance visual acuity (UCDVA), corrected distance visual acuity (CDVA), subjective refraction, and corneal astigmatism before surgery and at the 1-day, 1-month, and 3-month follow-ups. Vector astigmatism analysis was evaluated using the Alpins method. We enrolled 26 eyes of 20 patients in the study, with 13 eyes in each group. The test group had better vision than the control group at the 3-month follow-up and had more cases with a UCDVA of 20/20 (10/13 vs. 4/13). The surgically induced astigmatism (SIA) vector of the test group was higher than that of the control group (1.22±0.64 vs. 0.84±0.45). The correction index of the test group was closer to 1 compared to that of the control group (0.7 vs. 0.46). Approximately 85% of patients in the test group had an angle of error within -15° to 15°. However, only 23% of patients in the control group were within that range. Though steep-axis corneal incision was cost-saving and easy-to perform, its astigmatismcorrecting efficacy was not as good as the Toric IOL implantation for cataract patients with low to moderate corneal astigmatism.

Evaluation of Astigmatism-Correcting Efficiency and Rotational Stability after Cataract Surgery with a Double-Loop Haptic Toric Intraocular Lens: A 1-Year Follow-Up

Objectives: The aim of this study was to assess the clinical outcomes, predictability of results, efficiency of astigmatism correction, and rotational stability of the Bi-Flex 677TAY (Medicontur Medical Engineering Ltd., Zsámbék, Hungary) monofocal toric intraocular lens (IOL) designed for cataract patients with astigmatism. Methods: The IOLs were implanted either mono- or binocularly, following routine cataract surgery. Visual and refractive outcomes, as well as off-axis rotation were assessed throughout a 1-year follow-up period. All clinical data for this work were collected retrospectively. Vector analysis based on the Alpins method was performed to assess the efficiency of astigmatism correction. Results: No complications or adverse events occurred during surgery or the follow-up period. IOL implantation brought 88% of eyes into the ±0.50 D, and 100% into the ± 1.00 D range compared to the target spherical equivalent refraction, emmetropia. Astigmatism correction brought similar results: 94% of eyes had a residual cylindrical error of not higher than ±0.50 D, and 97% were within ±1.00 D. Vector analysis resulted in a correction index of 0.96 and a difference vector of 0.17. Both refractive and visual outcomes showed long-term stability. During the 12-month follow-up period, no eyes had a rotation of >5°. Absolute rotation after 1 year was 1.42 ± 1.89° (median = 0°), while signed rotation was 1.06 ± 2.12° (median = 0°). Conclusion: The Bi-Flex 677TAY monofocal toric IOL, designed by Medicontur Medical Engineering Ltd., represents an efficient and safe solution for cataract patients with astigmatism. Clinical and refractive outcomes are predictable, and rotational stability ensures long-term visual comfort.