Impact of Total Corneal Astigmatism Estimated With the Abulafia-Koch Formula Versus Measured With a SS-OCT Biometer on the Refractive Outcomes of a Toric Intraocular Lens in Cataract Surgery.

PURPOSE: To compare the impact of total corneal astigmatism (TCA) estimated with the Abulafia-Koch formula (TCAABU) versus measured by Total Keratometry (TK), swept-source optical coherence tomography (OCT) coupled with telecentric keratometry (TCATK) on the refractive outcomes after cataract surgery with toric intraocular lens (IOL) implantation. METHODS: Two hundred one eyes of 146 patients who underwent cataract surgery with toric IOL implantation (XY1AT; HOYA Corporation) were included in this single-center, retrospective study. For each eye, TCAABU (estimated from the anterior keratometry values measured with the IOLMaster 700 [Carl Zeiss Meditec AG]) and TCATK (measured using TK IOLMaster 700) were entered into the HOYA Toric Calculator. Patients were operated on based on TCAABU. For each eye, centroid and mean absolute error in predicted residual astigmatism (EPA) were calculated according to TCA used (TCAABU or TCATK). The cylinder power and the axis of the posterior chamber IOL were compared. RESULTS: The mean uncorrected distance visual acuity was 0.07 ± 0.12 logMAR, the mean spherical equivalent was 0.11 ± 0.40 D, and mean residual astigmatism was 0.35 ± 0.36 D. Mean centroid EPA was 0.28 D at 132° with TCAABU and 0.35 D at 148° with TCATK (P(x) < .001; P(y) < .01). Mean absolute EPA was 0.46 ± 0.32 D with TCAABU and 0.50 ± 0.37 D with TCATK (P < .01). In the with-the-rule astigmatism subgroup, a deviation from the target of less than 0.50 D was achieved in 68% of eyes with TCAABU versus 50% of eyes with TCATK. The proposed posterior chamber IOL was different depending on the calculation methods used in 86% of cases. CONCLUSIONS: Both calculation methods showed excellent results. However, the predictability error was significantly reduced when TCAABU was used compared to TCATK measured with the IOLMaster 700 in the whole cohort. Finally, TCA was overestimated by TK in the with-the-rule astigmatism subgroup. [J Refract Surg. 2023;39(3):171-179.].

Visual Performance at Different Distances After Implantation of an Isofocal Optic Design Intraocular Lens.

PURPOSE: To evaluate refractive and visual outcomes at different distances after implantation of an isofocal optic design intraocular lens (IOL) following cataract surgery. METHODS: This multicentric, retrospective/prospective, open-label, observational study considered 183 eyes of 109 patients who were implanted with the ISOPURE 123 (PhysIOL) IOL. The main outcome measures were refractive error and monocular and binocular uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected intermediate visual acuity (UIVA), and distance-corrected intermediate visual acuity (DCIVA) at 66 and 80 cm, uncorrected near visual acuity (UNVA), and distance-corrected near visual acuity (DCNVA) at 40 cm. Binocular visual acuity at different vergences (defocus curve) was also measured. Patients were evaluated at least 120 days postoperatively. RESULTS: A total of 95.7% of the eyes were within ±1.00 diopter (D) and 73.2% of the eyes were within ±0.50 D; the mean postoperative spherical equivalent was -0.12 ± 0.42 D. There were 90.54% and 98.57% of patients presenting a cumulative binocular UDVA and CDVA value of 20/25 or better, respectively; 80.65% and 50.0% of patients presented a binocular DCIVA value of 20/25 or better at 80 and 66 cm, respectively; and 41.94% of patients presented a binocular DCNVA value of 20/40 or better. The through-focus curve showed good visual acuity at far and intermediate distances with a depth of focus value of 1.50 D. No adverse events were reported. CONCLUSIONS: The current study shows that this isofocal optic design IOL provides excellent visual performance for far vision and functional intermediate vision with an extended range of vision. This lens is an effective option for providing functional intermediate vision and correcting aphakia. [J Refract Surg. 2023;39(3):150-157.].

Temperature-controlled porcine eye holder for observing intraocular temperature during cataract surgery.

During cataract surgery, the intraocular temperature changes when irrigating low-temperature fluid and ophthalmic viscosurgical devices (OVDs) are inserted in the anterior chamber, and such a temperature variation affects the unfolding of the intraocular lens (IOL). A porcine eye holder was developed for simulating temperature conditions in clinical surgery by maintaining the ocular temperature close to the body temperature. An aluminum holder was designed to fit porcine eyes and maintain the ocular temperature at approximately 36 °C, while surgery was performed at a room temperature of 20 °C. Intraocular temperature was monitored using a thermocouple sensor placed close to the posterior capsule in the vitreous cavity. Temperatures and microscopic image of the anterior chamber were simultaneously recorded. With the use of the eye holder system, the intraocular temperature unstable during surgery was observed, and there were significant reductions during hydrodissection, irrigation and aspiration, OVD insertion in the capsule, and OVD removal after IOL implantation.

[Hereditary ectopia lentis: diagnosis and surgical treatment]. / Nasledstvenno obuslovlennye varianty ektopii khrustalika: diagnostika i khirurgicheskoe lechenie.

This review describes hereditary diseases in which ectopia lentis may be present as one of the symptoms, considers the basic diagnostic concepts of lens disposition, and analyzes the options in surgical treatment of ectopia lentis and optical correction of aphakia.

[Emphasizing the standard application of toric intraocular lenses].

In the era of refractive cataract surgery, corneal astigmatism is a crucial factor that affects visual quality after cataract surgery. Toric intraocular lenses (IOLs) have a wide correction range, good surgical predictability, minimal damage to the ocular surface, and stable long-term effects, which can significantly improve postoperative visual quality and patient satisfaction. However, there are still several challenges in the clinical application of toric IOLs, including the awareness of astigmatism correction, the accuracy of preoperative biometry, the widespread adoption of the concept of total corneal astigmatism, the management of surgical planning and details, and the control of postoperative residual astigmatism. This article aims to address these issues to further standardize the clinical application of toric IOLs and help improve the overall level of refractive cataract surgery in China.

[Effects of three methods for correction of low-degree against-the-rule corneal astigmatism during cataract surgery].

Objective: To compare the clinical effects of and visual quality after correction of low-degree against-the-rule (ATR) corneal astigmatism by implantation of an astigmatism-corrected intraocular lens (IOL), femtosecond laser release and manual release in cataract surgery. Methods: It was a prospective cohort study. A total of 120 patients (120 eyes) with cataract combined with low-degree ATR corneal astigmatism diagnosed in Chongqing Aier Mega Eye Hospital from December 2017 to October 2020 were included and divided into 3 groups, each with 40 patients, according to their own selections of astigmatism correction methods during cataract surgery. In the astigmatism-corrected IOL group, phacoemulsification for cataract extraction combined with toric IOL implantation was performed. In the femtosecond laser release group, astigmatic keratotomy using a femtosecond laser was combined. In the manual release group, a limbal relaxing incision was made. Uncorrected distance visual acuity (UDVA) and corneal astigmatism were measured before surgery. At 3 months and 1 year after surgery, UDVA and best-corrected distance visual acuity were examined, as well as whole eye residual astigmatism by ARK-1, corneal astigmatism by the IOLMaster 500, whole eye high order aberration (HOA) and modulation transfer function (MTF) by the iTrace visual function analyzer. Analysis of variance was used for the comparison of data in a normal distribution. Repeated measures were used for the comparison within groups. The rank sum test was used for the comparison of data that were not normally distributed. Results: Of the 120 patients, 100 patients (100 eyes), including 44 males and 56 females, with an age of (66.48±6.20) years, completed the follow-up. Among the three groups, the differences were not statistically significant in terms of gender distribution, age, preoperative corneal astigmatism, UDVA and spherical equivalent of the IOL (all P>0.05). At 3 months and 1 year after surgery, the UDVA was significantly better than that before surgery in each group (Z=5.18, 5.04, 4.98, 4.99, 4.90, 4.89; all P<0.001). At the two time points, the differences in the whole eye residual astigmatism among the three groups were statistically significant (H=30.69, 31.23; both P<0.001). At 3 months, the whole eye residual astigmatism in the astigmatism-corrected IOL group was lower than that in the other two groups. At 1 year, the residual astigmatism in the astigmatism-corrected IOL group [0.25(0.00, 0.50) D] was also lower compared to that in the femtosecond laser release group [0.50(0.50, 0.75) D] and the manual release group [0.75(0.50, 0.75) D] (Z=-3.71, -5.18, -3.94, -5.15; all P<0.001). The differences in the HOA at 3 months and 1 year among the three groups were statistically significant (H=36.30, 34.38; both P<0.001). The HOA in the astigmatism-corrected IOL group was significantly higher than that in the other two groups at the two time points (Z=5.01, 4.73, 5.31, 5.27; all P<0.001). At 3 months and 1 year, the differences in the MTF value among the three groups were also statistically significant (H=30.02, 29.92; both P<0.001), and the MTF value in the femtosecond laser release group was significantly higher than that in the other two groups (Z=4.61, 4.67, 4.66, 4.69; all P<0.001). Conclusions: All the three astigmatism correction methods used at the time of cataract surgery can effectively correct low-degree ATR corneal astigmatism. The residual astigmatism in the whole eye after astigmatism-corrected IOL implantation is small and stable, while the HOA after release using the femtosecond laser is low with good visual quality.

[Long term results of central hole type posterior chamber intraocular lens in the correction of moderate to high myopia].

Objective: To evaluate the long-term safety,effectiveness,predictability and stability of ICL V4c implantation for moderate to high myopia. Methods: In this retrospective case series study, 95 eyes from 50 patients with moderate to severe myopia who were treated in 2015 underwent central hole type posterior chamber intraocular lens (ICL V4c) implantation at Eye & ENT Hospital of Fudan University. The patients were followed up for a period of five years, during which we assessed various parameters including uncorrected visual acuity (UDVA), corrected visual acuity (CDVA), refractive error, axial length, intraocular pressure, endothelial cell density (ECD), vault, and complications. We used the paired t-test and repeated measures one-way ANOVA in SPSS statistical software to analyze the data. Results: The mean spherical equivalent refraction (SE) decreased significantly from (-12.16±3.04) D preoperatively to (-0.19±0.55) D at one month and (-1.14±0.84) D at five years postoperatively. The safety indices (postoperative CDVA/preoperative CDVA) were 1.24±0.27 and 1.13±0.27, respectively, and the efficacy indices (postoperative UDVA/preoperative CDVA) were 1.14±0.25 and 0.87±0.26 at one month and five years postoperatively. At one month after surgery, 80.00% of the eyes were within ±0.50 D of the expected correction, and 96.84% were within ±1.00 D. There was no significant difference in IOP between preoperative and postoperative measurements. The rate of ECD was 3.87%, and the vault decreased by 106.32 µm at five years postoperatively. Conclusion: ICL V4c implantation is safe and effective with good predictability and stability for long term.

[Outcomes of surgical treatment of congenital cataract with microphthalmia in infancy].

Objective: To examine the outcomes of surgical treatment for infants with congenital cataract and microphthalmia (CATM). Methods: It was a retrospective case series study. Data of 28 (55 eyes) CATM children who underwent cataract surgery at the Qingdao Eye Hospital of Shandong First Medical University and were followed up for more than 5 years between January 2010 and December 2014 under the age of 6 months. There were 15 male and 13 female children. The age at the time of surgery was (3.2±1.3) months, and the follow-up time was (8.2±1.7) years. The data included the basic information of the children, the ocular biological parameters before and after surgery and intraocular lens (IOL) implantation, and the occurrence of complications. Paired t-tests or Wilcoxon signed rank tests were used to compare groups, and logistic regression analysis was used to identify factors related to IOL implantation, secondary glaucoma, and visual axis opacification (VAO). Results: The mean preoperative axial length was (16.6±1.0) mm, and the mean horizontal corneal diameter was (9.5±0.9) mm. The axial growth rate within 2 years after the first stage of surgery was (1.4±0.8) mm/year. None of the children had an IOL implanted before the age of 2. Sixty percent of the eyes (33/55) received IOL implantation within 2 to 4 years after the first stage of surgery, while the remaining 40% (22/55) did not receive IOL implantation at the last follow-up. The axial growth rate was (0.9±0.7) mm/year within two years after the second stage of surgery. Postoperative secondary glaucoma occurred in 7 eyes (12.7%), and VAO occurred in 15 eyes (27.3%). IOL implantation was associated with preoperative axial length (OR=0.072, P<0.001) and age at the first stage of surgery (OR=7.270, P<0.001), but not with preoperative corneal diameter (P=0.735). The incidence of VAO was associated with preoperative corneal diameter (OR=4.124, P=0.011), but not with age at the first stage of surgery (P=0.489) or preoperative axial length (P=0.489). No factors related to the occurrence of secondary glaucoma were found. The best corrected visual acuity at the last follow-up after IOL implantation was (0.37±0.28) logMAR, which was better than that of children without IOL implantation (0.67±0.19) logMAR (U=49.50, P=0.003). Conclusions: Children with CATM can obtain the opportunity for IOL implantation through early surgery and ultimately achieve good visual outcomes. Properly selecting the timing for implanting IOL can keep the incidence of secondary glaucoma at an acceptable level.

Formula constant optimisation techniques including variation of keratometer or corneal refractive index and consideration for classical and modern IOL formulae.

BACKGROUND: To investigate whether variation of the keratometer/corneal refractive index nK/nC improves the performance (prediction error PE) of classical and a modern intraocular lens (IOL) power calculation formula and further, to establish whether any trend error of PE for corneal radius R could be eliminated using formula constant and nK/nC optimisation. METHODS: Based on 2 large datasets (1: N = 888 Hoya Vivinex aberration-correcting and 2: N = 822 Alcon SA60AT spherical lens) a classical formula constant optimisation has been performed for the Hoffer Q, Holladay 1, Haigis and Castrop formulae, to minimise the root mean squared (rms) PE (situation A). In two further optimisations, the formula constants and the formula specific nK/nC value were optimised to minimise the rms PE (situation B) or rms PE and trend error of PE for R (situation C). Nonlinear iterative optimisation strategy was applied according to Levenberg-Marquardt. RESULTS: Optimising for rms PE and trend error (C) mainly improved the performance of the Holladay 1. The Haigis formula also showed a slight improvement compared to (A). The Hoffer Q formula shows no relevant trend error of PE for R. In contrast, the Holladay shows a positive and the Haigis (and the Castrop a slight) negative trend error of PE for R. The trend error could be fully eliminated by optimising formula constants and nK/nC in (B), but this was at the cost of overall performance in the case of the Holladay 1 formula. CONCLUSION: Classical IOL calculation concepts should be critically examined for potential improvement of formula performance by variation of the empirical nK/nC value defined in the formula. With additional degrees of freedom additional optimisation terms such as trend errors might be considered in new intelligent optimisation strategies.

[Safety and efficacy of toric intraocular lens implantation for more than 5 years].

Objective: To evaluate the clinical safety and efficacy of toric intraocular lens (IOL) implantation for more than 5 years. Methods: This study was a prospective cohort study in which subjects were continuously observed over a two-year period (May 2014 to May 2016) in nine hospitals. The study randomly assigned subjects to two groups using a central dynamic randomization system: the study group, which received Proming® IQ toric IOL implants, and the control group, which received AcrySof® IQ toric IOL implants. The subjects completed a one-year follow-up, during which various measures were taken and evaluated, including visual acuity, IOL rotation, postoperative complications, intraocular pressure, and subjective evaluation (preoperatively and at 1 day, 6 months, 1 year, and 5 years post-surgery). The main statistical analysis methods include the Mann-Whitney U test, independent sample t-test, Wilcoxon signed rank test, paired sample t-test, chi-square test, and Fisher's exact test. Results: A total of 45 eyes (26 in the study group and 19 in the control group) completed the five-year continuous observation period. The mean age of the subjects was (72.07±10.67) years and the mean interval from surgery to the last visit was (5.39±0.47) years. After five years, there were no significant differences in uncorrected distance visual acuity (0.20±0.26 vs. 0.16±0.13, t=0.17,P=0.752), best corrected distance visual acuity[0.00(0.00, 0.20) vs. 0.05±0.10, U=188.00, P=0.880], uncorrected near visual acuity[0.50 (0.20, 0.60) vs. 0.42±0.20, t=0.35, P=0.857], and best corrected near visual acuity (0.13±0.16 vs. 0.17±0.23, U=161.00, P=0.884) between the two groups. However, all measures improved significantly from baseline levels in both groups (all P<0.05). Five years after surgery, no matter objective refraction [(-0.67±0.85) D vs. (-0.73±1.08)D] or subjective refraction[-0.50 (-1.00, 0.00)D vs. (0.69±0.87)D], the degree of cylindrical degree is significantly lower than preoperative corneal astigmatism [(1.27±0.49) D vs. (1.34±0.82) D, all P<0.001]. In addition, there were no significant differences in intraocular pressure, subjective evaluation of visual adverse symptoms, distance vision spectacle independence, or overall satisfaction evaluation between the two groups (all P>0.05). The IOL rotation was 3.0°(1.0°, 6.0°) in the study group and 4.0°(2.0°, 6.0°)in the control group (U=185.50,P=0.574), indicating no significant difference between the groups in terms of rotational stability. Five years after surgery, there were 7 cases of posterior capsular opacification in the study group and 4 cases in the control group. There were no cases of IOL glistening in the study group, but 5 cases (26.32%) were observed in the control group. Conclusions: The long-term effects of Proming® toric IOL implantation in correcting cataracts with regular corneal astigmatism are clear after five years, with few complications and stable results.

Optimal Timing of Repositioning Surgery for a Plate-Haptic Toric Intraocular Lens: A Multicenter Retrospective Study.

PURPOSE: To evaluate risk factors for significant rotation and determine optimal timing for repositioning surgery following a plate-haptic toric intraocular lens (IOL) implantation. METHODS: This retrospective study enrolled patients who underwent the plate-haptic toric IOL implantation at seven hospitals in Shanghai. IOL rotation and residual astigmatism were compared before and after repositioning surgery. Risk factors for significant IOL rotation after cataract surgery were identified by stepwise multiple linear regression analysis. Spearman's and linear regression analyses were performed to identify factors associated with IOL rotation after repositioning. The receiver operator characteristic (ROC) curve was used to analyze the optimal timing for repositioning surgery. RESULTS: Among 2,745 eyes implanted with the toric IOL, 46 eyes (1.68%) of 45 patients underwent repositioning surgery. Axial length and lens thickness were significantly associated with IOL rotation before repositioning. After repositioning surgery, IOL rotation and residual astigmatism were significantly reduced (all P < .001). IOL rotation after repositioning was negatively associated with the timing of repositioning surgery (all P < .001). The ROC curve showed that the optimal cut-off for the timing of repositioning surgery was 15 days or greater. CONCLUSIONS: The prevalence of repositioning surgery after the plate-haptic toric IOL implantation was 1.68%, and the optimal timing for repositioning surgery was recommended to be 2 to 3 weeks after cataract surgery. [J Refract Surg. 2023;39(2):120-126.].

Late-onset toxic anterior segment syndrome after ICL implantation: two case reports.

BACKGROUND: Toxic anterior segment syndrome (TASS) is a non-infectious inflammation that can occur after any anterior segment procedure. This case report presents two relatively rare late-onset TASS cases after V4c implantable collamer lens (ICL) operation. CASE PRESENTATION: One 25-year-old woman and one 31-year-old woman suddenly had vision loss in monocular for 1 week after biocular V4c ICL operations and with no subjective complaints. They both presented fibrin formation in the anterior chamber such as keratic precipitates and white pus on the surface of the ICL. Fundus examination was normal. After 4 to 5 weeks of topical and oral steroid treatment, visual acuity and fibrin formation in the anterior chamber improved during the follow-up. CONCLUSIONS: TASS should be suspected in any patient during the late period following ICL surgery; Once TASS is diagnosed, adequate treatment with intensive steroid therapy can be implemented.

Experimental analysis of recommended corneal incision sizes in cataract surgery using 13 intraocular lens injector systems.

Smaller corneal incisions in cataract surgery are linked with a better visual outcome and less frequent postoperative endophthalmitis. The insertion of intraocular lens (IOL) injector systems into the anterior chamber of the eye to implant an IOL is associated with incision enlargement (IE) impeding these positive effects. The aim of this study was to compare manufacturers' recommended incision sizes (IS) of 13 different intraocular lens injector systems in regard of intraoperative IE and postoperative IS. In total, 499 corneal incisions in ex vivo porcine eyes were analyzed. The preoperative ISs depended on the recommended IS of the examined injector system. The IS was measured right before and after IOL injector insertion with an incision gauge set. There was intraoperative IE in 87% of the incisions with a mean IE of 0.26 ± 0.18 mm. IE was often significantly larger in small IS compared to larger IS concerning an injector system (P < 0.05). Five injector systems needed to have a significantly larger IS than the manufacturers' recommended IS with an average difference of 0.3 mm when applying study criteria (P < 0.05). Thus, the present study shows that IS recommendations require to be critically analyzed by ophthalmic surgeons to enable evidence-based practice.

Ten-year refractive and visual outcomes of intraocular lens implantation in infants with congenital cataract.

INTRODUCTION: There is no consensus regarding optimal target refraction after intraocular lens implantation in infants. This study aimed to clarify relationships of initial postoperative refraction with long-term refractive and visual outcomes. METHODS: This retrospective review included 14 infants (22 eyes) who underwent unilateral or bilateral cataract extraction and primary intraocular lens implantation before the age of 1 year. All infants had ≥10 years of follow-up. RESULTS: All eyes exhibited myopic shift over a mean follow-up period of 15.9 ± 2.8 years. The greatest myopic shift occurred in the first postoperative year (mean=-5.39 ± +3.50 dioptres [D]), but smaller amounts continued beyond the tenth year (mean=-2.64 ± +2.02 D between 10 years postoperatively and last follow-up). Total myopic shift at 10 years ranged from -21.88 to -3.75 D (mean=-11.62 ± +5.14 D). Younger age at operation was correlated with larger myopic shifts at 1 year (P=0.025) and 10 years (P=0.006) postoperatively. Immediate postoperative refraction was a predictor of spherical equivalent refraction at 1 year (P=0.015) but not at 10 years (P=0.116). Immediate postoperative refraction was negatively correlated with final best-corrected visual acuity (BCVA) (P=0.018). Immediate postoperative refraction of ≥+7.00 D was correlated with worse final BCVA (P=0.029). CONCLUSION: Considerable variation in myopic shift hinders the prediction of long-term refractive outcomes in individual patients. When selecting target refraction in infants, low to moderate hyperopia (<+7.00 D) should be considered to balance the avoidance of high myopia in adulthood with the risk of worse long-term visual acuity related to high postoperative hyperopia.

Development of an implantable collamer lens sizing model: a retrospective study using ANTERION swept-source optical coherence tomography and a literature review.

BACKGROUND: Optimal sizing for phakic intraocular lens (EVO-ICL with KS-AquaPort) implantation plays an important role in preventing postoperative complications. We aimed to formulate optimal lens sizing using ocular biometric parameters measured with a Heidelberg anterior segment optical coherence tomography (AS-OCT) device. METHODS: We retrospectively analyzed 892 eyes of 471 healthy subjects treated with an intraocular collamer lens (ICL) and assigned them to either the development (80%) or validation (20%) set. We built vault prediction models using the development set via classic linear regression methods as well as partial least squares and least absolute shrinkage and selection operator (LASSO) regression techniques. We evaluated prediction abilities based on the Bayesian information criterion (BIC) to select the best prediction model. The performance was measured using Pearson's correlation coefficient and the mean squared error (MAE) between the achieved and predicted results. RESULTS: Measurements of aqueous depth (AQD), anterior chamber volume, anterior chamber angle (ACA) distance, spur-to-spur distance, crystalline lens thickness (LT), and white-to-white distance from ANTERION were highly associated with the ICL vault. The LASSO model using the AQD, ACA distance, and LT showed the best BIC results for postoperative ICL vault prediction. In the validation dataset, the LASSO model showed the strongest correlation (r = 0.582, P < 0.001) and the lowest MAE (104.7 µm). CONCLUSION: This is the first study to develop a postoperative ICL vault prediction and lens-sizing model based on the ANTERION. As the measurements from ANTERION and other AS-OCT devices are not interchangeable, ANTERION may be used for optimal ICL sizing using our formula. Because our model was developed based on the East Asian population, further studies are needed to explore the role of this prediction model in different populations.