[Prevalence and age-related changes of corneal astigmatism in patients before cataract surgery]

Refractive Astigmatism Outcomes of Femtosecond Laser-Assisted Arcuate Keratotomies Combined with Femtosecond Laser-Assisted Cataract Surgery: Two-Year Results

PURPOSE

To evaluate the effectiveness and stability of refractive astigmatism reduction after penetrating femtosecond laser-assisted arcuate keratotomy performed at the time of femtosecond laser-assisted cataract surgery.

METHODS

Non-randomized retrospective data analysis of all patients that underwent femtosecond laser-assisted cataract surgery with femtosecond laser-assisted arcuate keratotomy over a 4-year period with a non-toric monofocal intraocular lens (2017-2021) at a tertiary care academic center. Postoperative visual acuity, manifest refraction, and predicted residual refractive error were also recorded at 1 month, 3-6 months, 12-18 months, and 2 years postoperatively. Preoperative keratometric astigmatism was compared to postoperative refractive astigmatism using vector calculations and the ASCRS double-angle plot tool.

RESULTS

This study comprised 266 eyes (179 patients) that met inclusion criteria. The mean preoperative keratometric astigmatism magnitude was 0.99 ± 0.53 D. At 1 month, 3-6 months, 12-18 months, and 2 years postoperatively, the mean refractive cylinder was 0.49 ± 0.45 D, 0.49 ± 0.45 D, 0.55 ± 0.54 D, and 0.52 ± 0.46 D, respectively. Horizontal against-the-rule astigmatism showed a higher tendency toward undercorrection than vertical with-the-rule astigmatism, which had a slightly higher tendency toward overcorrection. With-the-rule astigmatism had smaller difference vectors between target-induced astigmatism and surgically induced astigmatism.

CONCLUSIONS

Femtosecond laser-assisted arcuate keratotomy performed at the time of femtosecond laser-assisted cataract surgery was an effective option for correcting low-to-moderate corneal astigmatism for up to 2 years.

Comparison of different methods of correcting astigmatism in cataract surgery

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.

The Influence of Angle Alpha, Angle Kappa, and Optical Aberrations on Visual Outcomes after the Implantation of a High-Addition Trifocal IOL

The aim of our investigation was to examine the possible correlations between optical aberrations, angle kappa, angle alpha, and visual outcomes following cataract surgery. In total, 56 eyes of 28 patients were implanted with the Liberty 677MY trifocal intraocular lens (IOL). Pre- and postoperative higher-order aberrations, coma, astigmatism, angle alpha, and angle kappa were registered, along with uncorrected and corrected visual acuities at multiple distances. Visual acuity and contrast sensitivity defocus curves were plotted, and the areas under the curve were calculated 1 and 3 months postoperatively. Excellent visual outcomes were found at all distances. Patients reported low levels of dysphotopsia, and 96.4% of patients achieved complete spectacle independence. While angle kappa significantly decreased during cataract surgery (p = 0.0007), angle alpha remained unchanged (p = 0.5158). Angle alpha correlated with postoperative HOAs and had a negative impact on near vision (p = 0.0543). Preoperative corneal HOA and coma had a strong adverse effect on future intermediate and near vision. Residual astigmatism significantly affected postoperative intermediate vision (p = 0.0091). Our results suggest that angle kappa is not an optimal predictive factor for future visual outcomes, while angle alpha and the preoperative screening of optical aberrations might help patient selection prior to multifocal IOL implantation.

Toric intraocular lenses: Expanding indications and preoperative and surgical considerations to improve outcomes

Since the introduction of the first toric intraocular lens (IOLs) in the early 1990s, these lenses have become the preferred choice for surgeons across the globe to correct corneal astigmatism during cataract surgery. These lenses allow patients to enjoy distortion-free distance vision with excellent outcomes. They also have their own set of challenges. Inappropriate keratometry measurement, underestimating the posterior corneal astigmatism, intraoperative IOL misalignment, postoperative rotation of these lenses, and IOL decentration after YAG-laser capsulotomy may result in residual cylindrical errors and poor uncorrected visual acuity resulting in patient dissatisfaction. This review provides a broad overview of a few important considerations, which include appropriate patient selection, precise biometry, understanding the design and science behind these lenses, knowledge of intraoperative surgical technique with emphasis on how to achieve proper alignment manually and with image-recognition devices, and successful management of postoperative complications.

Comparison of Preoperative Measurements with Intraoperative Aberrometry in Predicting Need for Correction in Eyes with Low Astigmatism Undergoing Cataract Surgery

Purpose

To determine whether intraoperative aberrometry during cataract surgery measures higher levels of absolute astigmatism than preoperative biometry readings and which method yields a lower, final level of astigmatism if the two do not agree.

Patients and Methods

Retrospective record review of all patients who underwent uncomplicated cataract surgery from February 2015 to May 2019 with planned intraoperative aberrometry. Data analysis included preoperative keratometry, total astigmatism as measured by intraoperative aberrometry, intraocular lens model and power used, and postoperative manifest refraction ≥1 month after surgery. The primary outcome measure was the proportion of patients requiring astigmatism correction (≥0.5 D) when measured by preoperative keratometry vs intraoperative aberrometry. Secondary outcomes included postoperative residual astigmatism, where adjusted preoperative astigmatism fell below the 0.5 D threshold for treatment but the intraoperative measurement was ≥0.5 D or ≥1.0 D.

Results

A total of 451 patient records were evaluated. Intraoperative aberrometry measured statistically higher levels of mean astigmatism than keratometry (0.86 D vs 0.79 D, respectively; P < 0.0001) and significantly greater astigmatism among patients with 0.5–1.5 D of adjusted preoperative astigmatism (P < 0.0001). Significantly more patients qualified for with-the-rule astigmatism correction when measured by intraoperative aberrometry (n=339; 75%) than by preoperative keratometry alone (n=314; 70%); P < 0.03. This difference did not hold for against-the-rule or oblique astigmatism. For patients whose preoperative biometry astigmatism differed from intraoperative biometry, final postoperative astigmatism was lower when corrected if the adjusted preoperative and intraoperative measurements had a vector difference of <0.5 D, but there was no additional benefit in final astigmatism reduction when the vector difference was ≥0.5 D.

Conclusion

Using intraoperative biometry readings can produce lower postoperative astigmatism than using preoperative biometry readings, but caution should be used when interpreting intraoperative readings that disagree with preoperative measurements with a vector magnitude of >0.5 D.

Prevalence and Age-Related Changes of Corneal Astigmatism in Patients Undergoing Cataract Surgery in Northern China

Purpose

To examine the magnitude, orientation, and age-related changes of corneal astigmatism of the eyes before cataract surgery. Setting. Hebei Eye Hospital, Hebei, China.

Design

A clinical-based retrospective study.

Results

The study consisted of 5662 eyes of 5662 consecutive cataract surgery patients with a mean age of 68.26 ± 10.39 (mean ± standard deviation (SD)) years (range 40 to 97 years), and 59.86% of the patients were women. Mean corneal astigmatism was 0.98 ± 0.76 diopter (D) (range 0.00-9.61 D). Corneal astigmatism of 0.50-0.99 D was the most common range of values (30.08%), followed by 1.00-1.49 D (22.15%), ≤0.50 D (21.21%), and 1.50-1.99 D (10.28%). There was a strong U-shaped relation between corneal astigmatism and age (p for nonlinearity <.01). With the increase of age, the astigmatism axis gradually changes from with-the-rule (WTR) to against-the-rule (ATR). Moreover, in young patients with age below 65 years, WTR astigmatism was negatively correlated with age, while ATR was positively correlated with age (r = -0.11, p=.001; r = 0.10, p=.010, respectively). However, in the old patients with age above and equal to 65 years, all types of astigmatism were positively correlated with age.

Conclusion

This study may provide valuable and practical information to surgeons when selecting the appropriate surgical method and toric intraocular lens (IOLs).

Impact of Thermal Pulsation Treatment on Astigmatism Management and Outcomes in Meibomian Gland Dysfunction Patients Undergoing Cataract Surgery

Purpose

This study aimed to assess the effects of thermal pulsation system (TPS) treatment on astigmatism management in meibomian gland dysfunction (MGD) patients undergoing cataract surgery.

Patients and Methods

This single-center pilot study included 25 eyes of 23 patients who had visually significant cataract and concomitant MGD-associated dry eye in at least 1 eye and were willing to undergo TPS treatment and wait for at least 6 weeks for tear film stabilization prior to cataract surgery. Post-TPS keratometric readings were used for presurgical planning, and the actual postoperative residual refractive astigmatism (RRA) was recorded. Pre-TPS keratometry was used to mathematically simulate the RRA that would have been obtained from the lens choice and astigmatism management without TPS treatment.

Results

Following TPS treatment, the magnitude of astigmatism increased in 52% of eyes, decreased in 24%, and remained unchanged in 24%. Correspondingly, astigmatism treatment modality changed in 68% of eyes after tear film stabilization with TPS treatment. The type of astigmatism management increased (ie, shifted from no treatment to LRI or LRI to toric IOL) in 25% of eyes and decreased in 8%. Actual RRA ≤0.5 D was achieved in 76% of eyes, compared to simulated RRA ≤0.5 D in 40% of eyes (p=0.004).

Conclusion

Stabilization of the tear film with TPS treatment resulted in less RRA than if pre-TPS keratometric readings had been used to determine the astigmatism management method and toric IOL power and axis.

Outcomes of Femtosecond Laser Arcuate Incisions in the Treatment of Low Corneal Astigmatism

Purpose

To evaluate real-world outcomes of astigmatism management with femtosecond laser arcuate incisions in patients with low corneal astigmatism (<1.0 D) using a novel formula for arcuate incision calculation compared to outcomes after conventional cataract surgery without surgical management of astigmatism.

Patients and Methods

The Wörtz-Gupta™ Formula (available at www.lricalc.com) was used to calculate femtosecond laser arcuate parameters for 224 patients with <1 D of corneal astigmatism who underwent cataract surgery; lens power was determined with the Barrett Universal II formula. Uncorrected distance visual acuity (UCDVA) and refractive astigmatism measurements were obtained, with an average follow-up of 4 weeks.

Results

The average preoperative cylinder was similar (0.61 D in the femtosecond group [n=124] and 0.57 D in the conventional group [n=100] (P>0.05)). More patients had ≤0.5 D of postoperative corneal astigmatism in the femtosecond group (n=110/124, 89%) than in the conventional group (n=71/100, 71%), respectively (P=0.001). The mean absolute postoperative refractive astigmatism was higher in the conventional surgery group than in the femtosecond group (0.43 ± 0.4 D vs 0.26 ± 0.28 D); these differences were statistically significant (P<0.001). The percentage of patients with UCDVA of 20/20 or better vision was higher in the femtosecond group (62%) than the conventional group (48%) (P=0.025).

Conclusion

Using the femtosecond laser for arcuate incisions in combination with a novel nomogram can provide excellent anatomic and refractive outcomes in patients with lower levels of preoperative astigmatism at the time of cataract surgery.

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Clinical outcomes of Ankoris toric intraocular lens implantation using a computer-assisted marker system

PURPOSE

To report the clinical outcomes of patients who underwent cataract surgery with implantation of Ankoris monofocal toric intraocular lens (IOL) (PhysIOL SA, Liège, Belgium) using the Zeiss Callisto Eye (Carl Zeiss AG, Dublin, CA).

METHODS

We conducted a retrospective case series of patients who underwent routine cataract extraction and implantation of Ankoris toric IOL using the Zeiss Callisto eye between January 2018 and December 2018 by four senior surgeons. Patients' medical records were reviewed, and clinical outcomes including postoperative refraction, visual acuity outcomes, IOL position and deviation from planned axis were collected.

RESULTS

Fifty-six eyes of 56 patients were included, 48% were female, and the mean age was 70 ± 8 years. Patients with pseudoexfoliation syndrome, glaucoma or keratoconus were excluded from the study. Pre-operative mean corneal astigmatism was 2.38 ± 0.78 diopters (D), and mean implanted IOL cylindrical power was 3.06 ± 1.07 D. IOL rotation 30 days postoperatively was within 5° in 82% of eyes and between 6° and 10° in 10.8% of eyes. Mean postoperative refractive astigmatism 30 days postoperatively was 0.22 ± 0.36 D; in 84% of eyes the postoperative refractive astigmatism was ≤ 0.50 D. IOL rotation significantly increased between day 1 to day 7 postoperatively (1.91 ± 3.15° to 3.18 ± 3.3°, P = 0.001). However, no significant rotation had occurred between day 7 and day 30 postoperatively (P = 0.093).

CONCLUSION

Cataract surgery with implantation of Ankoris monofocal toric IOL using the Zeiss Callisto Eye marking system is predictable and effective in reducing refractive astigmatism.

Agreement between IOLMaster® 500 and Pentacam® HR for keratometry assessment in type 2 diabetic and non-diabetic patients

AIM

To evaluate inter-device agreement of anterior keratometry obtained by the IOLMaster^® 500 and Pentacam^® HR in type 2 diabetic and non-diabetic patients.

METHODS

Corneal measurements were sequentially performed in 60 diabetes mellitus (DM) and 48 age and sex-matched controls undergoing cataract surgery. Variables recorded included flat and steep keratometry, mean keratometry (K_m), astigmatism magnitude, axis location, J0 and J45 components. Bland-Altman plots and intraclass correlation coefficients were used for examination of agreement. Subgroup analyses were performed for astigmatism magnitude, diabetes duration, hemoglobin A1c (HbA1c) levels and diabetic retinopathy (DR) stage.

RESULTS

Agreement for K_m and astigmatism magnitude were considered good and moderate, with 95% limits of agreement (LoA) of -1.09 to 1.23 diopters (D) and -0.83 to 0.86 D in DM group, respectively; and -0.59 to 0.72 D and -0.98 to 0.75 D in non-DM group, respectively. In contrast, the 95% LoA for corneal axis exceeded the clinically relevant margins in both groups. In the total sample, only 41 eyes (38%) had a smaller than 5-degree difference. Diabetes duration, HbA1c levels and DR stage were not found to significantly affect agreement. Logistic regression showed that higher corneal power (P=0.021) and astigmatism magnitude (P=0.011) were associated with a decreased risk of having a difference in axis location greater than 10-degrees.

CONCLUSION

In both groups, IOLMaster and Pentacam agree well for corneal power and moderately for astigmatism. However, axis location disagreement is frequent in eyes with flatter corneas and small amounts of astigmatism.

Consensus on the management of astigmatism in cataract surgery

This project was aimed at achieving consensus on the management of astigmatism during cataract surgery by ophthalmologists from Latin America using modified Delphi technique. Relevant peer-reviewed literature was identified, and 21 clinical research questions associated with the definition, classification, measurement, and treatment of astigmatism during cataract surgery were formulated. Twenty participants were divided into seven groups, and each group was assigned three questions to which they had to respond in written form, after thoroughly reviewing the literature. The assigned questions with corresponding responses by each group were discussed with other participants in round 4 – presentation of findings. The consensus was achieved if approval was obtained from at least 80% of participants. The present paper provides several agreements and recommendations for management of astigmatism during cataract surgery, which could potentially minimize the variability in practice patterns and help ophthalmologists adopt optimal practices for cataract patients with astigmatism and improve patient satisfaction.

Corneal astigmatism in cataract surgery patients from Bosnia and Herzegovina

PURPOSE

To determine corneal astigmatism prevalence, its correlations with age and symmetry pattern in fellow eyes of patients undergoing cataract surgery.

METHODS

This is a clinical-based retrospective cross-sectional study. Keratometry measurements of patients undergoing cataract surgery assigned to University Clinical Center Tuzla, Bosnia and Herzegovina, between January 2011 and June 2012 were recorded and analyzed retrospectively.

RESULTS

The study consisted of 4080 eyes of 2205 consecutive cataract surgery patients with a mean age of 68.24 years ± 9.25 (SD) (range 32-84 years), and 54.0% of the patients were women. Mean corneal astigmatism was 0.72 ± 0.61 D (range 0-6.5 D). The prevalence of corneal astigmatism 1.0 D or more was in 1291 eyes (31.64%), 1.5 D or more in 736 eyes (18.03%), 2.0 D or more in 396 eyes (9.71%) and 3.0 D or more in 108 eyes (2.65%). There was no significant difference in the magnitude of astigmatism between age groups (p = 0.10), male and female (p = 0.29) or right and left (p = 0.75) eyes. The prevalence and amount of astigmatism increased with age (p < 0.05). Gradual shift from with-the-rule astigmatism toward against-the-rule astigmatism was observed (p = 0.03). Patients with higher amount of astigmatism in one eye are more likely to have significant astigmatism in fellow eye (p < 0.01). Symmetry in pairs of eyes is present in eyes with astigmatism greater than 2.5 D (p < 0.01).

CONCLUSION

This study provides useful reference data for cataract surgeons and patients from Bosnia and Herzegovina.