Changes In Corneal Astigmatism Research Articles

Changes in corneal curvature and astigmatism in senile cataract patients after phacoemulsification.

Analysis of changes in corneal curvature and astigmatism after phacoemulsification for senile cataracts. Retrospective collection of clinical data from patients who underwent uncomplicated phacoemulsification at the First Affiliated Hospital of Soochow University. The changes in total corneal curvature, anterior surface curvature, posterior surface curvature, and astigmatism were measured by the Sirius system. The axial length was measured by Lenstar 900. The total corneal curvature and anterior surface curvature at 3 months were all larger than those before phacoemulsification, and the difference was statistically significant (p < 0.05). Compared with preoperative results, there was no significant change in corneal posterior surface curvature and astigmatism 3 months after surgery (p > 0.05). Changes in corneal curvature and astigmatism were not significantly correlated with age at 3 months after surgery (p > 0.05). Postoperative astigmatism was increased with the growth of axial length, while corneal curvature was decreased (p < 0.05). Phacoemulsification can lead to increased postoperative corneal curvature in elderly cataract patients, and with the growth of the axial length, the corneal astigmatism was increased.

Change in Axial Length and Astigmatism after Scleral Buckling in Patients of Rhegmatogenous Retinal Detachment

Purpose: To determine changes in axial length and corneal astigmatism caused by scleral buckling in patients of uncomplicated retinal detachment undergoing scleral buckling procedure. Study Design: Quasi-experimental design. Place and Duration of Study: Peshawar Medical College and Allied hospitals, Pakistan from December, 2020 to May, 2021. Methods: This study included60 patients of uncomplicated rhegmatogenous retinal detachment, recruited through consecutive sampling technique and managed with primary scleral buckling. After a detailed history and complete examination including A-scan and Keratometric readings, patients underwent scleral buckling procedure. Changes in axial length and corneal curvatureswere measured at 6 months follow up. Quantitative analysis was done using paired T test. Results: Mean age of the sample was 41.95±13.67 years. The sample consisted of 42 males and 18 females. Encircling Band was used in 46 patients, segmental circumferential tire was used in 58 patients in one or more quadrants depending on the extent of the retinal detachment. Two patients underwent additional surgeries. The pre-operative mean axial length (AL) was 23.44±1.51 mm and post-operative AL at 6 months was 24.25±1.61mm (p &lt; 0.05). The pre-operative and post-operative astigmatism were 1.08±0.43 and 1.75 ± 0.33 diopter respectively (p &lt; 0.05). Conclusion: Scleral buckling led to a significant increase in axial length and astigmatism over a 6-month period. These changes suggest that scleral buckling can alter the optical properties of the eye, potentially affecting visual acuity and requiring careful consideration of these factors in post-operative management.

Corneal changes after large (9mm) lateral rectus muscle recession measured with Pentacam®

ABSTRACT Introduction: The aim of this study was to evaluate alterations in corneal astigmatism, axial anterior corneal curvature, anterior chamber depth, and central corneal thickness (CCT) two months after the unilateral recession of lateral rectus muscle in children. Methods: This prospective study included 37 children with intermittent exotropia who would undergo unilateral lateral rectus muscle recession. All measurements were performed using Pentacam®. Comparisons were made between the operated and fellow unoperated eyes, pre- and post-operatively. The assessment was made for changes in the radius of axial curvature on major meridians at 3 and 3.5 mm from the optical corneal center in the mid-peripheral zone. Astigmatism changes of the anterior and posterior corneal surface were calculated using vector analysis software (astigMATIC®). The interaction between age or CCT and postoperative changes in anterior and posterior surface corneal astigmatism were examined with ANOVA model. Results: In the intervention group, changes in anterior and posterior corneal surface astigmatism were statistically significant, with a mean increase of 0.56Dx90 and 0.08Dx87, respectively. In the mid-peripheral corneal zone, an increase was observed in the radius of anterior corneal axial curvature, more evident temporal 3 and 3.5 mm from the corneal center on the horizontal meridian, with corresponding decrease superiorly and inferiorly at 3 and 3.5 mm from the corneal center on the vertical meridian. Discussion: The changes in total astigmatism of the operated eyes are mainly attributed to the anterior corneal surface. These changes are associated with flattening in the 180 meridian of the cornea, leading to a shift to “with-the-rule” astigmatism.

Change of ectropion surgery on astigmatic vector and ocular biometry

Aim: To evaluate corneal astigmatism change and intraocular lens (IOL) power values following ectropion surgery. Materials and Methods: This comparative prospective research included patients with involutional ectropion who were divided using the snap-back test. The severity of ectropion increased progressively to reach the highest levels in Group 4. Patients underwent lateral tarsal strip procedures, and preoperative and 3-month postoperative biometry measurements were performed. Results: While the mean flattest keratometry (K1), steepest keratometry (K2), and mean keratometry (Km) values exhibited nonsignificant increases at 3 months after surgery in Groups 1 and 2 (p&amp;gt;0.05 for all), the mean values of K1, K2, and Km were increased with statistical significance in Groups 3 and 4 at 3 months postoperatively (p&amp;lt;0.05 for all). Conclusion: According to the snap-back test, ectropion in advanced stages will affect topographic values and IOL power calculations. If surgeons are going to perform cataract or refractive surgery after ectropion repair, they may consider changing the lens power selection accordingly.

Refractive outcomes after V4c Toric collamer lens implantation over 1y of follow-up.

To evaluate refractive outcomes and corneal astigmatism changes after Toric implantable collamer lens with a central port (V4c T-ICL) implantation over 1y of follow-up. A retrospective study was performed including 50 eyes of 50 patients that underwent V4c T-ICL implantation. Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, refractive and corneal astigmatism changes and corneal coupling correction were evaluated preoperatively, 1 and 12mo postoperatively. Vector analysis was used for astigmatism changes. Coefficient of adjustment (CAdj) was calculated for corneal coupling analysis. The mean UDVA achieved was 0.03 logMAR at 1mo and remained unchanged throughout the whole follow-up (P=0.193). At the last visit, 84% of the eyes achieved a CDVA of 0.00 logMAR or better. Regarding spherical equivalent refraction (SEQ), 96% of eyes were ranges of ±1.00 D and 84% of them within ±0.50 D. Also, 94% of eyes had a remaining refractive cylinder within ±1.00 D and 78% of them within ±0.50 D. Both, SEQ and refractive cylinder, remain stable over the postoperative follow-up (P=1.000 and P=0.660, respectively). In terms of surgically induced astigmatism (SIA), no statistically significant differences were found over the follow-up (P=0.102) and under correction was found with a correction index lower than the unit at each visit. A keratometric astigmatism induced of 0.59±0.53 (vector mean: 0.26×73°) D was reached at the last visit. No significant changes in terms of corneal astigmatism orientation were reported over post-surgery visits (P=0.129 and P=0.097 at 1 and 12mo respectively). No clinical significance was found for CAdj on with-the-rule astigmatism. No postoperative complications resulting from the surgery were found. Refractive outcomes suggest that the V4c T-ICL implantation for correction of myopic astigmatism was satisfactory in terms of effectiveness, safety, and stability during 1y of follow-up. Corneal astigmatism induced by the incision around 0.5 D is achieved according to the remaining refractive cylinder found at one-year post-surgery. Corneal coupling analysis results in no unexpected spherical change.

Effectiveness of toric intraocular lens implantation for correcting irregular corneal astigmatism in cataract eyes

A retrospective cohort study was conducted to observe the correction effect of Toric intraocular lens (IOL) implantation in cataract eyes with specific types of irregular corneal astigmatism. Thirty-four eyes with either the "asymmetric bow-tie" pattern (Type I) or the "angled bow-tie" pattern (Type II) were included. Corneal topography was assessed using Pentacam HR, and changes in preoperative corneal astigmatism, visual acuity, manifest refraction, and objective visual quality were measured and compared. The average uncorrected distance visual acuity improved significantly from 0.86 ± 0.40 logMAR to 0.22 ± 0.15 logMAR (P < 0.001). Preoperative corneal astigmatism of 2.05 ± 0.90 D was corrected to a postoperative residual astigmatism of 0.78 ± 0.57 D (P < 0.001), with 32% of eyes within 0.50 D. The residual astigmatism prediction errors in Type I and Type II cases were (0.97 ± 0.68 D) and (0.66 ± 0.37 D), respectively (P = 0.100). The mean spherical equivalent prediction error in Type II cases (0.07 ± 0.36 D) was significantly smaller than that in Type I cases (− 0.29 ± 0.52 D) (P = 0.030). This study concludes that Toric IOL implantation effectively corrects specific types of irregular corneal astigmatism in cataract surgery. Eyes with the "angled bow-tie" pattern show higher accuracy in refractive predictions compared to eyes with the "asymmetric bow-tie" pattern.

Significant Changes of Corneal Astigmatism After Levator Muscle Surgery for Acquired Blepharoptosis.

To investigate the change of corneal astigmatism after the correction of blepharoptosis. This was a single-center retrospective cohort study conducted in Taiwan from 2017 to 2021. The medical records of patients with acquired blepharoptosis who had received levator muscle surgeries were collected. The differences in corneal astigmatism between the measurements before and at least 1 month after surgeries were investigated. Subgroup analysis of various severities of blepharoptosis and different types of corneal astigmatism was performed to determine their impacts on the axial changes after blepharoptosis surgeries. A total of 120 eyes of 68 patients were enrolled in this study. The mean axial change of corneal astigmatism was 17.4° after blepharoptosis surgeries, and 55 eyes (45.8%) had a change of at least 10°. In the subgroup analysis, the eyes with against-the-rule, with-the-rule, and oblique astigmatism had 42.9%, 68.4%, and 91.7% with an axial change of at least 10° after surgeries, respectively. The averaged axial change of corneal astigmatism after surgeries was 22.7° in eyes with severe blepharoptosis (margin to reflex distance1 < 1 mm), whereas it was 12.0° in eyes with mild-to-moderate blepharoptosis (margin to reflex distance1 ≥ 1 mm). A high proportion of eyes had a crucial axial change in corneal astigmatism after blepharoptosis surgeries, especially in those with oblique astigmatism and severe blepharoptosis. For blepharoptosis patients needing refractive surgeries or astigmatism correction with toric intraocular lens implantation, a surgical correction of blepharoptosis may be considered beforehand.

Repositioned versus exchanged flanged intraocular lens fixation for intraocular lens dislocation

This study aimed to compare the outcomes of flanged intraocular lens (IOL) fixation with new IOL exchange after dislocated IOL removal and repositioned dislocated IOL in patients with IOL dislocation. Eighty-nine eyes that underwent flanged IOL fixation were retrospectively included, with 51 eyes in the exchanged IOL group and 38 eyes in the repositioned IOL group. In both groups, best-corrected visual acuity (BCVA) improved at 1, 3, 6, and 12 months postoperatively and did not differ between the two groups at any of these time points. However, at 1 week postoperatively, BCVA in the repositioned IOL group improved compared with baseline, whereas that in the exchanged IOL group did not. Moreover, there were lesser changes in the corneal endothelial cell density (ECD) and corneal astigmatism in the repositioned IOL group than in the exchanged IOL group. The IOL positions, including IOL tilt and IOL decentration, were not different between the groups. Flanged IOL fixation with new IOL exchange and with repositioned dislocated IOL for patients with IOL dislocation had similar visual outcomes and IOL position. However, the latter had a smaller corneal ECD decrease and astigmatic change. This technique was effective in treating IOL dislocation while minimizing corneal injury.

RELAY INTRASCLERAL 6-0 POLYPROPYLENE-ASSISTED INTRAOCULAR LENS FIXATION: A Retrospective Comparison With Modified Yamane Technique.

To describe a new surgical technique that uses a relay suture to optimize sutureless scleral fixation of intraocular lens in eyes with capsular insufficiency and to evaluate the outcomes of this technique versus Flanged, double needle-guided, scleral fixation of intraocular lens with haptic trimming (modified Yamane approach). Relay intrascleral 6-0 polypropylene sutures with flanges generated at the intraocular ends were used to fixate and securely hold a rigid intraocular lens with haptic eyelets against the inner scleral wall. The results were analyzed at 3-, 6-, and 12-month follow-up. This retrospective cohort study found that compared with the control group (n = 27), the relay-sutured group (n = 26) had greater mean changes in corneal astigmatism (0.44 vs. -0.52 diopters [D]) and fewer mean degrees of intraocular lens astigmatism (0.62 vs. 1.1 D). The mean intraocular lens decentration was comparable between both the groups; however, in the control group, there was a significant increase in intraocular lens tilt degrees from 3 to 12 months. Moreover, significantly higher proportions of patients with persistent macular edema and iris-optic capture were seen in the control group. The relay-sutured technique may be an alternative to flapless scleral fixation of intraocular lens and provides a stable intraocular lens position with acceptable complication rates.

Change in Corneal Astigmatism After Phacoemulsification with Rigid Intraocular Lens Implantation

Phacoemulsification with lens implant is the preferred method of cataract extraction nowadays. In resource-deficient settings, rigid polymethyl methacrylate (PMMA) lenses are implanted which require enlargement of corneal incision to 5.5mm. Objectives: We conducted this study to evaluate the effect of corneal incisions secured with a single suture on corneal astigmatism after routine cataract surgery. Methods: It was a quasi-experimental study conducted at tertiary care hospitals. Sixty patients were studied and preoperative visual acuity and keratometry readings were noted. After standard phacoemulsification, a 5.5mm rigid PMMA lens was implanted in the bag, and the corneal incision was sutured using a single central 10/0 nylon suture. Visual acuity and keratometry readings were noted on 1st postoperative day, 1-week postoperatively, and 6-weeks postoperatively and compared with pre-operative values. Results: The mean age was 59.27 ± 10.72 (range: 46 – 78) years. There were 32 (53.3%) males and 28(46.7%) females in the study. The mean preoperative keratometry reading was 0.89 ± 0.70 D, and the mean first-day postoperative cylinder was 1.94 ± 0.98 D (p &lt; 0.05). The mean astigmatism at the 6th week postoperatively was 0.96 ± 0.65 D, and its comparison with the pre-operative astigmatism was statistically not significant (p &gt; 0.05). Surgically induced astigmatism was found to be 0.07 diopters. Almost 60% of the patients achieved uncorrected 6/7.5 or better visual acuity, and more than one-third of patients achieved 6/6 best corrected visual acuity six weeks after the cataract surgery using the described technique. Conclusions: Phacoemulsification with 5.5mm PMMA IOL with a central single suture is an effective procedure for postoperative astigmatism and visual outcome.

Corneal tomography changes following major (6 mm) medial rectus muscle recession: a prospective cohort study using Pentacam®

ABSTRACT Introduction The aim of this study is to evaluate changes in corneal astigmatism, axial anterior corneal curvature, as well as changes in the anterior chamber depth and central corneal thickness, 2 months following the unilateral recession of medial rectus muscle in children. Methods Thirty-three children with esotropia were prospectively evaluated following unilateral medial rectus muscle recession, using Pentacam®. Comparisons were made between the operated and fellow unoperated eyes, pre, and postoperatively. The assessment was made for changes in the radius of axial curvature on major meridians at 3 and 3.5 mm from the optical corneal center in the mid-peripheral zone. Astigmatism changes of the anterior and posterior corneal surface were calculated using vector analysis software (astigMATIC®). ANOVA model was used to examine the interaction between age or central corneal thickness and postoperative changes in anterior and posterior surface corneal astigmatism. Results In the intervention group, changes in anterior and posterior corneal surface astigmatism were statistically significant, with a mean increase of 0.59Dx92 and 0.08Dx91, respectively. In the mid-peripheral corneal zone, there is an increase in the radius of anterior corneal axial curvature more evident nasally 3.5 mm from the corneal center on the horizontal meridian, with corresponding decrease superiorly and inferiorly at 3 and 3.5 mm from the corneal center on the vertical meridian. Discussion The changes in total astigmatism of the operated eyes are mainly attributed to the anterior corneal surface. These changes are associated with flattening in the 180 meridian of the cornea, leading to a shift to “with-the-rule” astigmatism.

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.

Age-Related Changes in Total Corneal Astigmatism in Eyes With High Myopia.

The purpose of this study was to compare age-related changes in corneal astigmatism in eyes with and without high myopia. Eight-hundred eyes with high myopia (axial length ≥26.0 mm) and 800 eyes without high myopia (200 eyes each from patients in their 40s, 50s, 60s, and ≥70s) underwent videokeratographic examination. The amounts of vertical/horizontal (Rx) and oblique astigmatism (Ry) components, irregular astigmatism, and corneal shape were compared between eyes with and without high myopia and among age categories. In both groups, the mean Rx significantly changed to more positive with age ( P < 0.001), whereas the Ry did not change significantly. The Rx was significantly more negative in the high myopia group than in the control group in all age categories ( P ≤ 0.003), whereas the Ry did not differ significantly. The mean changes in the Rx and Ry during each 2 consecutive decades did not differ significantly between groups. The asymmetry and higher-order irregularity components increased with age ( P ≤ 0.001) but did not differ significantly between groups, except for the higher-order irregularity in patients in their 60s ( P = 0.018). In the averaged map, the corneal shape changed from with-the-rule to against-the-rule astigmatism with age in both groups, but the changes occurred later in the high myopia group. Age-related changes from with-the-rule to against-the-rule astigmatism occurred later in eyes with high myopia compared with eyes without high myopia in middle or older aged patients, but this change in each age decade was comparable between eyes with and without high myopia.

Clinical Outcomes of Femtosecond Laser-assisted Implantation of 325-Degree Versus 340-Degree Arc Length Intracorneal Ring Segments in Naive Keratoconic Eyes.

To evaluate and compare clinical outcomes after femtosecond laser-assisted implantation of 325-degree versus 340-degree arc length intracorneal ring segments (ICRS) in eyes with keratoconus (KCN). In this prospective non-randomized interventional case series, 23 eyes of 21 patients diagnosed with KCN, underwent femtosecond laser-assisted implantation of two types of ICRS, which included a 325-degree ICRS (Group 325) and a 340-degree ICRS (Group 340). The primary outcome measures were uncorrected distance visual acuity (UDVA), and the secondary outcome measures included corrected distance visual acuity (CDVA), sphere, cylinder, mean refractive spherical equivalent (MRSE), keratometry, vectorial change in corneal astigmatism, and the location of maximum keratometry relative to the corneal apex. The study groups were compared using the primary and secondary outcome measures obtained at postoperative months six and 12. Groups 325 and 340 consisted of 10 and 13 eyes, respectively. The two groups were comparable in terms of parameters measured preoperatively. On comparison to the baseline values, both study groups exhibited a significant increase in UDVA and CDVA measured at postoperative month six (Ps 0.05) and a significant decrease in the sphere, cylinder, spherical equivalent refraction, and keratometry readings measured at postoperative months six and 12 (Ps 0.05). No significant differences were observed between the two groups in terms of visual, refractive, and keratometric outcomes at any time point. No intraoperative or postoperative complications were observed in any of the study groups. Both the 325-degree ICRS and the 340-degree ICRS effectively and equally improved visual, refractive, and keratometric outcomes in keratoconic eyes.

Effect of Chalazion on Corneal Astigmatism

A common eyelid disease chalazion causes eye morbidity due to inflammation and cosmetic disfigurement. Important factors in corneal refractive surgery, intraocular lens power calculations for cataract surgery and visual acuity assessments are corneal topographic changes. For better outcome of ocular surgery corneal astigmatism should be corrected earlier. The aim of this study is to evaluate changes in corneal astigmatism according to chalazion size and location. Methods: This cross-sectional study was conducted in saveetha medical college and hospitals, Thandalam , Department of Ophthalmology Outpatient department. A total of 44 eyes from 33 patients were included in the chalazion group and 70 eyes from 46 patients comprised the control group. Chalazia were classified according to location and size. An autokeratorefractometer and a dual-Scheimpflug analyzer were utilized to evaluate corneal changes. Result: Oblique astigmatism was greater in the chalazion group compared with the control group (p &lt; 0.05). Astigmatism by simulated keratometry (simK), steep K by simK, total root mean square, second order aberration, oblique astigmatism, and vertical astigmatism were significantly greater in the upper eyelid group (p &lt; 0.05). Astigmatism by simK, second order aberration, oblique astigmatism, and vertical astigmatism were significantly greater in the large-sized chalazion group (p &lt; 0.05). Corneal wavefront aberration was the greatest in the upper eyelid chalazion group, whole area group, and large-sized chalazion group (p &lt; 0.05). Conclusions: Large-sized chalazion in the upper eyelid should be treated in the early phase as great changes in corneal topography were noticed. Corneal topography should be performed preoperatively before chalazion is treated.

Evaluation of long-term clinical outcomes after Toric Implantable Collamer Lens implantation.

To evaluate the long-term (8-10 years) outcomes of Toric Implantable Collamer Lens (TICL) surgery. Nagoya Eye Clinic, Nagoya, Aichi, Japan. Retrospective observational study. We enrolled patients who underwent TICL surgery from 2005-2009 to correct myopia and myopic astigmatism. The safety, efficacy, predictability, astigmatism correction efficacy, and complications were evaluated using preoperative, 1-year postoperative, and final examination data. We included 133 eyes of 77 patients. At the final visit, the mean uncorrected and corrected visual acuity were -0.01±0.2 and -0.17±0.05, respectively. The mean safety and efficacy indices were 0.91±0.26 and 0.68±0.21, respectively. The manifest astigmatism was -0.45±0.43 D. The mean corneal astigmatism change from 1 year post-surgery to the final visit was 0.40±0.26 D. Of the 38 eyes with a change in corneal astigmatism ≥0.5 D, 30 eyes (78.9%) changed to against-the-rule (ATR) astigmatism, one (2.6%) changed to oblique astigmatism, and seven changed (18.4%) to with-the-rule (WTR) astigmatism. The mean manifest astigmatism change from 1 year post-surgery to the final visit was 0.43±0.52 D. Of the 60 eyes with a change in manifest astigmatism ≥0.5 D, 25 (41.7%) changed to ATR astigmatism, 18 (30.0%) changed to oblique astigmatism, and 17 (28.3%) changed to WTR astigmatism. During follow-up, eight of 133 eyes (6.0%) developed anterior subcapsular cataracts, among which four (3.0%) underwent TICL removal and phacoemulsification and aspiration. No vision-threatening complications occurred. TICL surgery showed good long-term astigmatism-correcting effects, although the long-term uncorrected visual acuity decreased. The procedure was effective in correcting myopia and astigmatism.

Comparative Study of Pre - Operative and Post Operative Changes in Corneal Astigmatism in Pterygium Patient Operated with Conjunctival Autograft

Comparative Study of Pre - Operative and Post Operative Changes in Corneal Astigmatism in Pterygium Patient Operated with Conjunctival Autograft

SS-OCT-based ocular biometry in an adult Korean population with cataract.

To evaluate the characteristics of ocular biometric parameters in adult Korean patients with cataract. Department of Ophthalmology, Seoul National University Hospital, Seoul, South Korea. Retrospective case series. Ocular biometric values of 5273 eyes of 5273 Korean patients undergoing cataract surgery measured with the IOLMaster 700 at the Seoul National University Hospital between November 2019 and December 2021 were reviewed. A total of 5273 eyes of 5273 Korean patients were analyzed. The mean ± SD age was 66.1 ± 12.8 years, and 62% were female. Overall, age and ocular biometric parameters were correlated with each other. Particularly, age showed a negative correlation with anterior chamber depth (ACD; r = -0.357), axial length (AL; r = -0.344), and posterior keratometry (PK; r = -0.054) and a positive correlation with lens thickness (LT; r = 0.484), angle α ( r = 0.194), total keratometry (TK; r = 0.137), anterior keratometry (AK; r = 0.129), and angle κ ( r = 0.071). AL showed a positive correlation with ACD ( r = 0.503) and PK ( r = 0.339) and a negative correlation with AK ( r = -0.342), TK ( r = -0.334), LT ( r = -0.288), angle α ( r = -0.220), and angle κ ( r = -0.040). With age, anterior and total corneal astigmatism changed from with-the-rule (WTR) to against-the-rule (ATR) astigmatism. Posterior corneal astigmatism was ATR regardless of age; however, the magnitude decreased with age. Age showed a significant correlation in the order of LT, ACD, and AL. With age, angle α and κ increased, and total corneal astigmatism changes from WTR to ATR, which is mainly affected by changes in anterior corneal astigmatism. AL showed a significant correlation in the order of ACD, AK, PK, and TK. These data are pertinent for improving the result after cataract surgery, especially when using premium intraocular lenses.

Effect of Upper Lid Blepharoplasty Surgery on Corneal Topography and Corneal High-Order Aberrations.

The objective of this study was to prospectively investigate the effect of upper eyelid blepharoplasty surgery for dermatochalasis on corneal topographic data and high-order aberrations (HOAs). Fifty eyelids of 50 patients with dermatochalasis who underwent upper lid blepharoplasty surgery were prospectively studied. A Pentacam (Scheimpflug camera, Oculus) device was used to measure corneal topographic values, astigmatism degree, and HOAs before and at 2 months after upper eyelid blepharoplasty. The mean age of the patients included in the study was 55.96 ± 12.4 years, 40 (80%) were female and 10 (20%) were male. We found no statistically significant difference in the pre-and postoperative values of corneal topographic parameters (p > 0.05 for all). In addition, we observed no significant postoperative change in the root mean square values of low, high, and total aberration values. In HOAs, we detected no significant change in spherical aberration, horizontal and vertical coma, and vertical trefoil; we only found a statistically significant increase in horizontal trefoil values after surgery (p < 0.05). In our study, we found that upper eyelid blepharoplasty did not cause significant changes in corneal topography, astigmatism, and ocular HOAs. However, studies are reporting different results in the literature. For this reason, it is important for patients considering upper eyelid surgery to be warned about visual changes that may occur after surgery.

Refractive Outcome After Corneal Lenticule Implantation Ex Vivo Non-Human Study

Purpose To evaluate changes in corneal refractive parameters after implantation of a stromal lenticule of different thickness. We assume that the refractive outcome depends on the optical power of the used lenticule. Methods We conducted an ex-vivo non-human study on 33 normotonic porcine eyeballs divided into two groups, for 4D and 8D human lenticule implantation. Corneal stromal lenticules were obtained as a by-product from a laser procedure ReLEx SMILE. We evaluated corneal refractive parameters measured on Oculus Pentacam© device before and immediately after the intrastromal lenticule implantation. Results There was no statistically significant difference in corneal refractive parameters between the eyeball groups before lenticule implantation. In both groups, the intrastromal implantation in the depth of 300um led to a significant increase of central corneal pachymetry and corneal anterior steepening. In the 4D group the average central corneal pachymetry increased from 903 ± 124.59 to 1230 ± 148.99 (p = 0.0022) and in 8D group from 733.35 ± 69.60 to 1109 ± 161.64 (p = 0.0008). Induced changes in other studied parameters were not statistically significant, Kmax changed from 45.57 ± 2.78 to 72.07 ± 16.83 (p = 0.0094) and Km front from 40.72 ± 1.60 to 48.87 ± 5.83 (p = 0.0037) in 4D group and in the 8D group average Kmax increased from 42.22 ± 1.54 to 62.95 ± 12.67 (p = 0.0001) and K2 front 40.46 ± 1.64 to 51.51 ± 9.63 (p = 0.0037). There were no significant differences in refractive changes between the 4D and 8D groups after lenticule implantation. Conclusion Intrastromal corneal lenticule implantation induces changes in corneal refractive parameters. In both groups, the implantation induced a significant increase of an anterior corneal steepening without any significant influence on posterior corneal flattening. Corneal lenticule implantation did not lead to any significant change of corneal astigmatism. However, in order to have more precise data for future clinical applications we need to continue with the experiments and verify the results on human corneas.