Preoperative Refractive Error Research Articles

Comparison of early visual outcomes after SMILE using VISUMAX 800 and VISUMAX 500 for myopia: a retrospective matched case–control study

VISUMAX 800 was introduced to improve the patient experience and clinical outcomes of small incision lenticule extraction (SMILE). This was a retrospective, matched, and case–control study (1:2) controlled for preoperative central corneal thickness and refractive error that compared early refractive and visual outcomes after SMILE using VISUMAX 800 and VISUMAX 500 to treat myopia. We included 50 eyes that underwent the VISUMAX 800 SMILE and 100 eyes that underwent the VISUMAX 500 SMILE. SMILE using VISUMAX 800 was performed using the CentraLign aid for vertex centration. Cyclotorsion was controlled by an OcuLign assistant in the VISUMAX 800 group after corneal marking. Corneal higher-order aberrations (HOAs) were evaluated using a Pentacam 1 month after surgery. No differences were observed in the pre- and post-operative refractive and visual outcomes at 1 day, 1 month, and 6 months after surgery. VISUMAX 800 induced less total HOAs than VISUMAX 500 (P = 0.036). No statistically significant differences were observed in the amounts of induced spherical aberrations or vertical and horizontal comas. No differences were observed in the 1 month and 6 months refractive and visual outcomes between two SMILE procedures, except for VISUMAX 800, which resulted in lower postoperative total HOAs than VISUMAX 500.

Intraoperative Assessment of the Stromal Ablation in Photorefractive Keratectomy.

Purpose: To evaluate the difference between planned and measured central ablation depth (CAD) and compare the first and second operated eye in simultaneous bilateral myopic alcohol-assisted PRK. Methods: A retrospective review of patients was performed. Demographic and preoperative data was abstracted. Intraoperative assessment included environmental data, laser-planned algorithm of ablation (L-CAD), and optical coherence pachymetry (OCP) measurements. The true stromal ablation depth (O-CAD) was calculated by subtracting the immediate post-ablation OCP measurement from the OCP measurement before laser ablation. Deviation in pachymetry (DP) between O-CAD and L-CAD was also assessed. Results: The study comprised 140 eyes from 70 consecutive patients. The mean age was 26.91 ± 6.52 years, and 57.1% were females. O-CAD was significantly correlated to preoperative refractive errors and intraoperative laser settings. DP was not correlated to any of the pre- or intraoperative parameters. L-CAD showed a significant underestimation as compared to O-CAD (67.87 ± 25.42 µm and 77.05 ± 30.79 µm, respectively, p < 0.001), which was shown in 74.3% of the cases. A moderate agreement between the two methods was noted, with a mean deviation of 17%. This difference was maintained for each eye individually (p < 0.001). In addition, DP was significantly higher in the first operated eye as compared to the second operated eye (11.97 ± 16.3 µm and 6.38 ± 19.3 µm respectively, p = 0.04). Conclusion: The intraoperative assessment of stromal ablation showed significantly higher central ablation depth values compared to the laser-planned ablation algorithm. The deviation in pachymetry was higher in the first, compared to the second, operated eye. Awareness is warranted as to the discrepancy between preoperative planning and intraoperative assessment.

Postoperative outcome and influencing factors of strabismus surgery in infants aged 1-6years.

To evaluate the postoperative outcome of strabismus surgery performed in children aged 1-6 years by investigating the change of the preoperative angle of deviation (AOD), elevation in adduction, best-corrected visual acuity (BCVA) and refractive error. Retrospective chart review of 62 children who received strabismus surgery between January 2018 and December 2021 at the Department of Ophthalmology and Optometry of the Medical University of Vienna. Age, sex, type of strabismus, AOD, BCVA, refractive error and visual acuity were evaluated with respect to the postoperative outcome. Mean follow-up was 13.55 ± 11.38 months with a mean age of 3.94 ± 1.97 years (range: 1.0-6.0) at time of surgery. 74.19% of patients (n = 46) had isolated or combined esotropia, 12.90% (n = 8) had isolated or combined exotropia and 12.90% (n = 8) had isolated strabismus sursoadductorius. Mean preoperative AOD of 15.69 ± 16.91°/15.02 ± 14.88° (near/distance) decreased to 4.00 ± 9.18°/4.83 ± 7.32° (near/distance) at final follow-up (p < 0.001). BCVA improved from 0.26 ± 0.26/0.25 ± 0.23 (left/right) to 0.21 ± 0.25/0.20 ± 0.23 (left/right) (p = 0.038). There was no significant change regarding refractive error (p = 0.109) or elevation in adduction (p = 0.212). Success rate which was defined as a residual AOD of less than 10° was 74.19% (n = 46). In 3.23% (n = 2) retreatment was necessary. Strabismus surgery in infants was shown to have a satisfactory outcome with a low retreatment rate. Surgical success rate was not linked to age, sex, type of strabismus or the preoperative parameters AOD, refractive error and visual acuity in this study.

Photorefractive keratectomy in flat, normal, and steep corneas.

To compare photorefractive keratectomy (PRK) outcomes in patients with different corneal steepness. Care-Vision Laser Center, Tel-Aviv, Israel. Retrospective comparative chart review. Patients included in this study underwent wavefront optimized myopic PRK between January 2013 and December 2019. Patients were divided into 3 groups based on the steepness of the cornea (steep keratometry) (flat: <42 diopters [D], normal: 42 to 46 D and steep: >46 D). One to one matching was performed to verify that baseline parameters (age, preoperative visual acuity and refractive error) were similar between groups. Primary outcome measures were: postoperative corrected/uncorrected distance visual acuity (CDVA/UDVA), efficacy index (postoperative UDVA/preoperative CDVA), safety index (postoperative CDVA/preoperative CDVA), spherical equivalence (SEQ) and cylinder. After matching, 650 eyes were included in each group, which were similar in baseline parameters. There were no significant postoperative differences between flat, normal, and steep corneas in terms of safety index (1.02 vs 1.03 vs 1.03, P = .28), efficacy index (1.01 vs 1.01 vs 1.02, P = .57), logMAR CDVA (0.01 vs 0.02 vs 0.01, P = .76), logMAR UDVA (0.02 vs 0.03 vs 0.02, P = .68), %SEQ within 0.50 D (73.9% vs 74.2% vs 74.6%, P = .95) or 1.00 D of target (91.9% vs 92.5% vs 92.2%, P = .92), %cylinder within 0.50 D (82.8% vs 82.2% vs 81.4%, P = .81) or 1.00 D of target (96.9% vs 97.1% vs 97.2%, P = .95). No significant differences were found between flat, normal and steep corneas following wavefront-optimized myopic PRK. Thus, this procedure may be safely and effectively performed in both flat and steep corneas.

Comparison of errors in ablation depth calculation after myopic femtosecond laser in situ keratomileusis in patients with different degrees of myopia: a prospective study

BackgroundTo investigate the difference between the predicted preoperative corneal ablation depth and the measured ablation depth for femtosecond laser in situ keratomileusis (FS-LASIK) in patients with different degrees of myopia, and to analyze the source of the difference.MethodsA total of 55 patients (109 eyes) were included in this study. Multiple logistics regression was applied to analyze the sources affecting postoperative refractive outcomes. The difference between the preoperative predicted corneal ablation depth and the 1-day postoperative ablation depth in patients with different degrees of myopia was explored using linear regression. Corneal biomechanical parameters influencing error in ablation depth calculation were examined using multiple linear regression.ResultsOne hundred and nine eyes were divided into low to moderate myopia (55 eyes, myopia of 6 D or less), high myopia (45 eyes, myopia ranging from 6 D to a maximum of 9 D), and very high myopia group (9 eyes, myopia greater than 9 D) based on preoperative refractive error (spherical equivalent). Postoperative visual outcomes were comparable among the three groups of patients, with no significant difference in uncorrected visual acuity (UCVA). We did find notable disparities in spherical equivalent (SE) and central corneal thickness (CCT) in patients with different degrees of myopia at 1 day postoperatively (all p < 0.001). Logistic regression analysis showed that error in ablation depth calculation was an independent risk factor for refractive outcomes one day after surgery (OR = 1.689, 95% CI: 1.366 – 2.089). There was a substantial discrepancy in error in ablation depth calculation at 1 day postoperatively between the three groups. The measured ablation depth of the laser platform was lower than the predicted ablation depth in the low to moderate myopia and very high myopia groups, but the opposite was true in the high myopia group. Pre-operative SE (p < 0.001) and corneal front minimum radius of curvature (Front Rmin) (p = 0.007) obviously influenced the error in ablation depth calculation.ConclusionsError in ablation depth calculation values vary significantly between patients with different degrees of myopia and correlate highly with preoperative SE and Front Rmin. At the same time, the available evidence suggests that error in ablation depth calculation is an influential factor in postoperative refractive status, so it is imperative to control error in ablation depth calculation.

Influencing factors of visual prognosis in patients with persistent submacular fluid after successful scleral buckle surgery for macula-off retinal detachment

Objective: To investigate the factors influencing visual outcomes in patients with rhegmatogenous retinal detachment (RRD) who developed persistent submacular fluid (PSF) after scleral buckling surgery. Methods: A retrospective case series analysis was conducted. Clinical data were collected from patients who underwent successful scleral buckling surgery for RRD at Beijing Tongren Hospital from June 2020 to December 2022 and were followed up. Patients with RRD involving the macular area preoperatively and graded as C1 or below in proliferative vitreoretinopathy (PVR) were included. Surgical procedures followed a minimally invasive scleral buckling approach. PSF was defined as subretinal fluid persisting for more than 1 month postoperatively. Regular follow-up visits were scheduled at postoperative days 1, 3, 7, 2 weeks, and 1 month, followed by monthly visits until complete PSF absorption. Best-corrected visual acuity (BCVA), intraocular pressure, refractive error, slit-lamp biomicroscopy, binocular indirect ophthalmoscopy, and optical coherence tomography (OCT) were performed at each follow-up time point. Eyes were divided into two groups based on whether the final follow-up BCVA was≥0.5 and whether the absorption time of PSF was>6 months, and statistical analysis was performed using the Wilcoxon signed-rank test, chi-squared test, and Mann-Whitney U test. Results: A total of 46 patients (46 eyes) were included in this study, comprising 25 males and 21 females, with a median age of 32.5 (21.0, 57.3) years. The preoperative equivalent spherical refractive error was (-5.27±4.05) D, and the preoperative duration of illness was 30 (14, 92) days. The preoperative BCVA (logarithm of the minimum angle of resolution,logMAR) was 2.00 (1.00, 2.50). Scleral buckle surgery was performed in 28 eyes (60.9%), and 18 eyes (39.1%) underwent scleral buckle surgery combined with encircling. External drainage was performed in 15 eyes (32.6%), while 31 eyes (67.4%) had no external drainage. BCVA (logMAR) at 1 month, 3 months, and the final follow-up postoperatively was 0.60 (0.50, 1.00), 0.40 (0.28, 0.53), and 0.15 (0.00, 0.50), respectively. In the final follow-up, 31 eyes (67.4%) achieved BCVA≥0.5, and 26 eyes (56.5%) had continuous ellipsoid zone on OCT. The differences in BCVA (logMAR) between preoperative, 1 month, 3 months, and the final follow-up were statistically significant (Z=-5.85, -5.63, -4.73;all P<0.001). The absorption time of PSF postoperatively was 6.50 (3.00, 9.00) months, ranging from 2 to 19 months. The eyes with PSF duration<3 months, 3-6 months, and>6 months were 12 eyes (26.1%), 11 eyes (23.9%), and 23 eyes (50.0%), respectively. There were statistically significant differences between the two groups in preoperative BCVA≥0.05, preoperative duration of illness within 1 month, PVR grading, surgical method, and continuous ellipsoid zone on OCT (all P<0.05), while there were no statistically significant differences between the two groups in PSF absorption time, different types of PSF, and intraoperative drainage (all P>0.05). The PSF absorption time in the two groups was 7 (3, 10) months and 6 (4, 8) months, with no statistically significant difference (P>0.05). Conclusions: Preoperative visual acuity, duration of illness, and PVR grading are factors influencing visual outcomes in patients with RRD who have undergone scleral buckling surgery and develop PSF. In contrast, intraoperative drainage, PSF absorption time, and different PSF types are not factors affecting visual prognosis. Although PSF may persist for a long time after scleral buckling surgery, it does not significantly impact long-term visual outcomes.

Non-invasive assessment of the tear film after LASIK.

The aim of the study was to compare the assessment of the ocular surface using classic methods with the newly developed keratoscopy-based MYAH (Topcon EU, Visia Imaging, Japan) device after femtosecond laser-assisted in situ keratomileusis (LASIK). This cross-sectional and observational study analyzed 80 eyes of 40 patients. Tear film and ocular surface evaluation were performed at baseline, postoperative week 1, and month 1. Measurements obtained using the Schirmer I test and invasive tear-film breakup time (I-TBT) were compared with non-invasive evaluation of the tear break-up time (NI-TBT), tear meniscus height (TMH) and blink analysis obtained using the MYAH device. Findings were correlated with the Ocular Surface Disease Index (OSDI) questionnaire in all subjects. The study included 80 eyes of 40 consecutive patients (21 males and 19 females) with a mean age of 26.6 ± 5.9 years (18-40 years) and a mean spherical equivalent value of -3.64 D (-9.63 to -0.25 D). There was a significant decrease in Schirmer I test (19.21 ± 8.4 vs. 16.61 ± 9.1 vs. 14.69 ± 9.86, p= 0.02, respectively) and I-TBT values (8.59 ± 3.4 vs. 7.4 ± 3.25 vs. 6.17 ± 3.01, p=0.03 respectively). OSDI values showed a significant increase after LASIK (11.56 ± 6.3 vs. 17.24 ± 7.5 vs. 14.71 ± 9.6, p=0.03, respectively). 5% level NI-TBT was significantly lower at 1 week 6.75 and 1 month 7.45 than baseline 13.2 at follow-up (p=0.037). Ocular protection index (6.6 vs. 2.3 vs. 2.6, p=0.009, respectively) and blink/minutes (18 vs. 17 vs. 15, p=0.002, respectively) values showed a statistically significant decrease. Our data detected a weak correlation between I-TBT and noninvasive first TBT, 5% level TBT parameters at month 1 follow-up. This study also found no correlation between contact lens use, older age, female gender, and pre-operative refractive error with the noninvasive MYAH dry eye parameters. This study demonstrated the ability of the new keratoscopy-based MYAH device to detect changes in the short term after LASIK surgery.

Effect of Keratoconus Stage and Classification Parameters on Deep Anterior Lamellar Keratoplasty Outcomes.

The aim of this study was to investigate the effect of the keratoconus (KC) stage according to the Amsler-Krumeich classification system and the parameters used in this classification on deep anterior lamellar keratoplasty outcomes. The preoperative KC stage was determined, and the presence of corneal scarring was noted. The preoperative and postoperative best-corrected visual acuity (BCVA), refractive error, mean central keratometry (K mean ) readings, topographic astigmatism, and minimum corneal thickness (CT) values were recorded. Intraoperative and postoperative complications were also noted. One hundred thirty-seven eyes (54 eyes in stage 3-83 eyes in stage 4) were included in the study. The mean follow-up period was 42.20 ± 24.36 months. There was no statistically significant difference between stage 3 and 4 KC groups for postoperative BCVA, K mean , CT, spherical equivalent, and topographic astigmatism values (each P value >0.05). The effect of preoperative BCVA, K mean , CT, and refractive error values on postoperative BCVA could not be demonstrated ( P = 0.264). In addition, no statistically significant correlation was found between postoperative and preoperative values (each P value > 0.05). Although intraoperative Descemet membrane perforation and postoperative early suture loosening were observed more frequently in stage 4 KC than in stage 3 KC, the 2 groups were statistically similar for these and other complications (each P value >0.05). The preoperative KC stage and the parameters used in classification are not useful in predicting postoperative deep anterior lamellar keratoplasty outcomes. The timing of the surgery should be planned with the awareness that the progression of the disease will not have a negative effect on outcomes.

Flapless and Conjunctiva-Sparing Technique for Transscleral Fixation of Intraocular Lens to Correct Refractive Errors in Eyes without Adequate Capsular Support.

To evaluate refractive outcomes, intraocular lens (IOL) power calculation, and IOL position following a novel conjunctiva-sparing transscleral fixation technique. Forty-one eyes of 40 patients managed with a flapless transscleral-sutured technique were included. Preoperative and postoperative refractive errors (spherical equivalents, SE) were compared. IOL position was assessed on the Scheimpflug images. IOL power was calculated by SRK/T, Holladay 1, and Hoffer Q formulas. The mean age was 57.39 ± 14.83 years (range: 26 to 79 years), and the mean follow-up was 7.46 ± 6.42 months (range: 1 to 24 months). Surgical indications were aphakia (n = 14), subluxated lenses (n = 3), and IOL dislocation (n = 24). The SE was 4.50 ± 6.38 diopter (D) (range: -3.75 to 13.75 D) preoperatively and -1.68 ± 1.57 D (range: -5.50 to 1.13 D) postoperatively (P < 0.001). The mean tilt angle and decentration were 2.90° ± 1.93° (range: 0.39° to 9.10°) and 0.23 ± 0.19 mm (range: 0.02 to 0.94 mm) vertically, and 1.75° ± 1.41° (range: 0.24° to 7.65°) and 0.18 ± 0.19 mm (range: 0.02 to 1.06 mm) horizontally, which were clinically insignificant. All three IOL formulas produced myopic errors (range: -0.29 to -0.50 D). The SRK/T had the lowest median absolute error (0.55 D), followed by the Holladay 1 (0.70 D) and the Hoffer Q (0.74 D). The three formulas had the same percentage of prediction errors (PEs) within ±0.5 D (43.48%), while the Hoffer Q had the highest percentage of PEs within ±1.0 D (82.61%). The present technique can serve as an alternative approach for transscleral IOL fixation and refractive correction in eyes with compromised capsular support, ensuring the stability of IOLs and reasonable IOL power calculation accuracy.

The Recurrence of Ptosis after Correction Surgery Is Associated with Refractive Error

Background and objectives: Previous studies on ptosis recurrence after correction surgery have tended to focus on postoperative complications, surgical methods and suspension materials, few have mentioned refractive error. This research is to investigate the potential relation between refractive error and recurrence after correction surgery in pediatric patients with simple congenital ptosis. Materials and Methods: We conducted a retrospective analysis of data from patients with simple congenital ptosis who were treated at Zhongshan Ophthalmic Center (ZOC) between 2017 and 2020. In total, 111 eyelids of 85 patients without surgery-related complications who underwent frontalis muscle flap suspension (FMFS) for simple congenital ptosis were included. Postoperative changes in eyelid height were assessed. Cycloplegic refraction was assessed before surgery and during the follow-up period (every 3 months after surgery). Recurrence in the postoperative period was defined as a marginal reflex distance 1 (MRD1) of <1 mm. Results: There were 16 recurrence and 69 non-recurrence cases, with no statistically significant differences, in terms of patient age at the time of surgery, patient sex, or preoperative MRD1, between the recurrence and non-recurrence groups. The postoperative cylindrical diopter (adjusted odds ratio [OR] = 0.432, p = 0.005), laterality (adjusted OR = 0.202, p = 0.006), and preoperative MRD1 (adjusted OR = 0.617, p = 0.019) were associated with ptosis recurrence after surgery. Differences between the recurrence and non-recurrence groups in spherical diopter and spherical equivalent (SE) before and after surgery were not statistically significant. In addition, preoperative refractive error and postoperative spherical diopter were not significantly associated with ptosis recurrence after correction surgery. Conclusions: Ptosis recurrence after FMFS in pediatric cases of congenital ptosis is associated with refractive error. Timely refractive correction and amblyopia treatment may help to reduce ptosis recurrence.

Wavefront-guided PRK treatment of myopia using a refractive aberrometer.

To evaluate the safety, effectiveness, and patient-reported outcomes of wavefront-guided photorefractive keratectomy (PRK) for the correction of myopic refractive errors with and without astigmatism. U.S. multicenter study. Prospective, nonrandomized clinical investigation. 334 eyes (167 patients) underwent wavefront-guided PRK with the STAR S4 IR Excimer Laser System. Patients had preoperative myopic refractive errors with sphere up to -8.00 diopters (D) and cylinder up to -4.00 D with a maximum spherical equivalent (SE) of -10.00 D. All eyes were targeted for emmetropia, and treatment plans were derived from the iDESIGN system wavefront measurements. At 6 months, the point of refractive stability, 99.4% of eyes achieved 20/20 or better uncorrected distance visual acuity (UDVA), 92% of eyes achieved 20/16 or better UDVA, 85.5% of eyes achieved manifest refraction SE (MRSE) within 0.50 D of target, mean SE was -0.06, and less than 1% of eyes lost more than 2 lines of corrected distance visual acuity. Glare and halos occurred with similar or lower frequencies at 6 months vs preoperative. Results from the National Eye Institute Refractive Error Quality of life questionnaire showed statistically significant improvements at 6 months vs preoperative across most measures of vision-related functioning and well-being. Approximately 98% of patients reported high satisfaction with their overall vision at 6 months. Wavefront-guided PRK with the iDESIGN aberrometer was safe, effective, and predictable for the correction of low to moderate myopia with and without astigmatism and led to high patient satisfaction.

Refractive changes after strabismus surgery in patients with intermittent exotropia.

To evaluate the long-term refractive changes after horizontal muscle surgery in patients with intermittent exotropia and investigate the correlation between changes in the postoperative refractive error and clinical factors. We retrospectively reviewed the clinical data of patients aged < 15 years who underwent unilateral strabismus surgery (lateral rectus recession and medial rectus resection [RR, n = 47], lateral rectus recession and medial rectus plication [RP, n = 81], or lateral rectus recession [LRc, n = 68]). Preoperative and postoperative refractive errors up to four years after surgery were recorded. A mixed model was applied to compare the refractive error between the operated and fellow eyes and identify the factors associated with postoperative refractive changes. The mean age at surgery was 7.5±2.4years, and girls accounted for 56.1% of the study population. There was no significant difference in the change in the spherical equivalent of refractive error between both eyes throughout the postoperative period. In contrast, the operated eyes consistently and significantly showed higher cylindrical power in with-the-rule astigmatism by 0.25D than in fellow eyes. Age, sex, and preoperative refractive error were not correlated with changes in postoperative astigmatism. Meanwhile, the type of surgery showed a significant interaction with the astigmatism changes. RP had less effect on the changes in astigmatism than RR and LRc (p = 0.001 and p = 0.022, respectively). Horizontal muscle surgery has no long-term effect on the change in the spherical equivalent. However, mild with-the-rule astigmatism is induced and sustained after surgery, and the type of surgery affects the postoperative change of astigmatism.

Transient change in the binocular visual function after femtosecond laser-assisted in situ keratomileusis for myopia patients.

The goal of this study was to compare the difference in binocular visual function for high and low-moderate myopes before and after femtosecond laser-assisted in situ keratomileusis (FS-LASIK). Thirty-three subjects (17 males and 16 females) were divided into two groups according to their preoperative refractive errors in spherical equivalent (SE): low-moderate myopia group (SE ≥-6.00 D) and high myopia group (SE <-6.00 D). The binocular visual function including accommodative amplitude (AA), accommodative facility (AF), positive and negative relative accommodation (PRA and NRA, respectively), horizontal phoria measurement, positive and negative fusion vergence, accommodative-convergence over accommodation (AC/A) ratio, and stereopsis were assessed with the best-corrected vision before patients received FS-LASIK and 7 and 30 days after the surgery. Repeated measures analysis of variance (ANOVA) was applied to study the change in binocular visual function. The AF values in both groups were significantly reduced after 7 days of FS-LASIK (baseline vs. day 7 (mean): high myopia group: 7.85 vs. 5.62 cpm, repeated ANOVA, P = 0.01; low-moderate myopia group: 5.95 vs. 4.40 cpm, repeated ANOVA, P = 0.04). This change returned to the baseline level 30 days after the operation. In addition, the horizontal phoria values in both groups were significantly reduced for both distant (P = 0.019 and P = 0.001, respectively) and near (P = 0.003 and P = 0.049, respectively) 7 days after the operation, but they rebound to preoperative state after 30 days. A transient change in binocular visual function was noticed after 7 days of FS-LASIK operation, which could cause symptoms of asthenopia. Our data showed all the binocular visual functions returned to baseline level after 30 days of operation.

Simple method of measuring ocular rotation in supine position during small incision lenticule extraction.

To introduce a novel measurement method of static cyclotorsion in small incision lenticule extraction (SMILE) and to investigate the effect of preoperative parameters on cyclotorsion and the effect of cyclotorsion on postoperative outcomes. The medical records of 242 patients and 484 eyes who underwent SMILE surgery were retrospectively reviewed. Preoperative intraocular pressure, refractive error, and corneal thickness were investigated. Refractive values and visual acuity were measured at 1d, 1, 3, and 6mo. Ocular cyclotorsion in the supine position was measured by calculating the location and angle of the incision site of the cornea in the anterior slit photograph taken after surgery. Of the total 484 eyes in 242 patients, preoperative mean spherical equivalent (SE) was -4.10±1.64 D, and the mean astigmatism was -0.82±0.74 D. Uncorrected distance visual acuity (UCVA) and SE improved significantly after the surgery. Moreover, 219 (45.2%) eyes had excyclotorsion, 235 (48.6%) eyes had incyclotorsion, and 30 (6.2%) eyes had no torsion. The right eyes tended to be excyclotorted, and the left eyes tended to be incyclotorted (P<0.01). The mean cyclotorsion was 1.18°±3.69°, and the mean absolute value of cyclotorsion was 3.14°±2.26°. The range of cyclotorsion was 0.5°-11.4°. It was found that the smaller the preoperative sphere, the higher the amount of cyclotorsion (r=0.11, P=0.016). There was no significant association between the amount of cyclotorsion and preoperative astigmatism. There was no correlation between sex, preoperative corneal thickness, preoperative intraocular pressure, amount of cyclotorsion, and direction of cyclotorsion. The ratio of right eye excyclotorsion and left eye incyclotorsion on 1d was higher than that at 1, 3, and 6mo (all P<0.01). There was no difference between the 1, 3, and 6mo results in the right and left eyes (P=0.15, P=0.16, respectively). The newly devised ocular cyclotorsion measurement method can be used to evaluate ocular cyclotorsion after SMILE. Preoperative SE is associated with the amount of cyclotorsion, however, cyclotorsion doesn't have a significant effect on the results of SMILE surgery.

Comment on: Safety of phakic intraocular collamer lens implantation in 95 highly myopic special-needs children

We discussed the study by Reynolds et al. during the ESCRS journal club on July 7, 2021.1 In this retrospective case series, the investigators presented perioperative and longer-term adverse event data from 95 special-needs children or adults with myopia who could not comply with spectacles and/or contact lenses and underwent implantation of an intraocular collamer lens (ICL). Although this study addressed an important clinical question in a challenging patient group, we would like to highlight some points of discussion that are of relevance to the interpretation of the study. The definition of adverse events as minor or major seemed somewhat controversial. For example, in this study, wound leak requiring repair was designated as major since it necessitated a return to the theater, whereas endothelial cell loss was classed as minor. Although this nomenclature may be understandable in the context of a short-term clinical study after intervention, these definitions may not lend appropriate weight to possible serious longer-term safety concerns. The endothelial cell count was only measured in 31 of 160 eyes (ie, less than 19% of the cohort). Consequently, firm conclusions about the long-term safety of ICL implantation in this patient group cannot be made. Furthermore, these eyes are likely to be unrepresentative of the cohort since they are presumably from the most cooperative individuals. A greater yield may have been possible through specular microscopy in the lateral decubitus position undertaken under general anesthesia, although we appreciate that repeated anesthesia may have an overall detrimental effect on special-needs children. In this highly heterogeneous patient group, a more detailed presentation of the data might have allowed the reader to appreciate the relationships between clinical parameters (ie age and refraction) and adverse events. For example, the mean preoperative spherical equivalent refractive error was −11 D (range: −4 to −22) and mean age was 9.3 years (range: 1.8 to 25) with some nonpediatric patients. Illustration of distribution of refractive error and age as individual datapoints would have allowed the reader to determine, for example, whether there is a relationship between preoperative refractive error or age and postoperative endothelial cell loss? Moreover, could these parameters predict the development of postoperative pupil block? Furthermore, the details of adverse events by group (age, refraction, and underlying disorder) would have been helpful. Although the authors reported that there were 95 children and 160 implanted eyes, the article states that 35 unilateral and 60 bilateral surgeries were performed, which adds up to only 155 eyes. Previous studies on the subject have shown that ICL implantation is safe in children with a low rate of adverse events.2 Many of these studies were conducted by the same study group.3,4 Nevertheless, randomized controlled studies are needed in a larger number of pediatric patients to argue that the benefits outweigh the risks as stated by the researchers in their conclusion. Specifically, the measurement of postoperative endothelial cell counts in most individuals in such cohorts are required to make meaningful statements about long-term safety.

Morphological change of the posterior pole following the horizontal strabismus surgery with swept source optical coherence tomography

Extraocular muscle movement during strabismus surgery causes changes in eyeball shape. Because extraocular muscle insertion is in front of the equator, it is thought that changes due to strabismus surgery mainly occur in the anterior segment. However, changes in the posterior segment of eye may also occur, which may also result in changes in refractive error after strabismus surgery. Using a 3-dimensional reconstruction technique (en face imaging) of the swept source optical coherence tomography, we determined and quantitatively measured the posterior polar change. The deepest interface between Bruch’s membrane and the choroid could be identified as the deepest point of the eyeball (DPE), and the location of the DPE relative to the optic disc and the fovea was measured. After lateral rectus muscle recession, the DPE moved away from the fovea, but after medial rectus muscle recession, the DPE moved toward the fovea. The amount of DPE movement differed by age and preoperative refractive error. Our findings suggest that the positional shift of the rectus muscle in horizontal strabismus surgery causes a structural change in the posterior segment of the eye, and the postoperative refractive changes may be related to this shift.

Safety of phakic intraocular collamer lens implantation in 95 highly myopic special-needs children.

To assess the safety of intraocular collamer lens (ICL) implantation in children with high ametropia by reporting rates and case specifics of perioperative and longer-term adverse events (AEs). . St. Louis Children's Hospital at Washington University Medical Center, St. Louis, Missouri. Retrospective case series. Clinical data were collated retrospectively for 95 special-needs children (160 eyes) implanted with a Visian ICL over the past 5 years. All surgeries were performed at St Louis Children's Hospital under brief general anesthesia. The mean follow-up period was 2.0 ± 1.4 years (range, 0.5 to 5.2). The mean age at implantation was 9.3 ± 5.2 years (range, 1.8 to 25) and mean preoperative spherical equivalent refractive error was -11.20 ± 3.90 diopters (range, 4 to 22). 62 children (62/95, 65%) had a neurodevelopmental disorder. 3 eyes (3/160, 2%) reported minor AE, consisting of steroid-response ocular hypertension, which resolved with cessation of topical steroid drops. Endothelial cell loss averaged 8.1% over 2 years, comparable with that reported in ICL-implanted adults. The most common major AE (7 eyes [7/160, 4%]) was postoperative pupillary block, requiring revision of the peripheral iridotomy. 1 child (1 eye [1/160, 0.6%]) with self-injurious behavior required repair of a wound leak. 1 child (1 eye [1/160, 0.6%]) with Down syndrome developed a cataract 2.8 years after ICL surgery, and 1 child (1 eye [1/160, 0.6%]) with severe autism spectrum disorder experienced traumatic retinal detachment 1.2 years after implantation. The most common major AE among the cohort with Visian ICL was pupillary block due to closure of the iridotomy. Overall, the AE rate was low in this higher risk, difficult-to-manage population of special-needs children.

Patient-Reported Quality of Life and Satisfaction After Refractive Lens Extraction Using a Diffractive Trifocal IOL: A Multicenter Retrospective Cohort Study.

To assess patient satisfaction and quality of life after refractive lens exchange with a trifocal intraocular lens (IOL). Consecutive patients who underwent refractive lens exchange with the AT LISA tri or AT LISA tri toric IOL (Carl Zeiss Meditec AG) at one of five surgical centers were surveyed for their quality of life and satisfaction after surgery using a standardized questionnaire. Patient responses were compared to patient characteristics such as age, sex, axial lengths, and preoperative refraction. A total of 102 patients with 204 treated eyes were included in the analysis. The mean age was 54.6 ± 5.2 years. A total of 172 eyes were hypermetropic, 3 were emmetropic, and 25 were myopic, with a mean preoperative refractive error of 0.93 ± 2.17 diopters. Reported postoperative satisfaction was as follows: 81.4% stated that their expectations were completely met and 17.6% stated that they were partially met. Self-reported refractive error quality of life improved significantly in all queried areas of life. Most frequently reported postoperative limitations were driving at night and driving in bad weather conditions. Halos were reported by 91 (90.1%) patients. Patient satisfaction and self-reported quality of life after refractive lens exchange with the AT LISA tri or AT LISA tri toric IOL was high. Glare and halos remain the only significant drawback of the procedure, leading to 40% of patients experiencing difficulties in night driving. Preoperative communication of these drawbacks is obligatory to avoid postoperative disappointment. [J Refract Surg. 2021;37(11):768-774.].

Accuracy of Total Corneal Power Calculation for Multifocal Toric Intraocular Lens Implantation: Swept-Source OCT-Based Biometer vs Scheimpflug Tomographer.

To evaluate the accuracy of total corneal power calculation from a swept-source optical coherence tomography-based biometer and a rotating Scheimpflug tomographer for the Acrysof IQ Panoptix toric TFNT intraocular lens (IOL) (Alcon Labroatories, Inc). A retrospective study was undertaken on 145 eyes implanted with the TFNT IOL. The accuracy of total corneal power calculation from a SS-OCT-based biometer (IOLMaster 700; Carl Zeiss Meditec AG; total keratometry [TK]) and a rotating Scheimpflug tomographer (Oculus Optikgeräte GmbH; total corneal refractive power at 3 mm [TCRP3] and at 4 mm [TCRP4]) were compared. The surgically induced astigmatism vector, difference vector, angle of vector, correction index, index of success, coefficient of adjustment, and flattening index were analyzed using the VectrAK analysis program (ASSORT). The index of success showed a significant difference between the three methods (P = .035, analysis of variance test). The mean ± standard deviation of the index of success was the best in TK (0.43 ± 0.20), followed by TCRP4 (0.47 ± 0.24, P = .400, Bonferroni HSD test) and TCRP3 (0.50 ± 0.22, P = .030, Bonferroni HSD test). The preoperative refractive astigmatism prediction error was within ±0.50 diopters (D) in 62 eyes (42.8%) when using TCRP4 and in 66 eyes (45.5%) when using TK. These study results suggest that the refractive accuracy of TFNT implantation using total corneal power from TCRP4 and TK was favorable. [J Refract Surg. 2021;37(10):686-692.].

Changes in corneal asphericity and spherical aberration after femtosecond laser in situ keratomileusis

Purpose The aim of this study was to evaluate the changes in corneal asphericity (Q value) and spherical aberration after femtosecond laser in situ keratomileusis using Scheimpflug imaging.Patients and methods This is a prospective nonrandomized study that included 170 myopic eyes and 30 hyperopic eyes. All patients had wave front-optimized femtosecond laser in situ keratomileusis using the EX-500 and FS200 machines (WaveLight, Alcon). Patients within ±0.50 diopter (D) of plano-refraction and with an uncorrected distance visual acuity of at least 20/20 were evaluated. The Q values and corneal spherical aberration Zernike values were obtained using Scheimpflug imaging (Oculyzer II) preoperatively and 1–3 months postoperatively.Results The mean preoperative Q value was −0.28±0.11 and −0.22±0.15 in myopic and hyperopic eyes, respectively, and became +0.35±0.44 and −0.64±0.31, respectively, postoperatively. The asphericity change was highly correlated with the preoperative spherical equivalent (r2=0.81, P≤0.001). The mean preoperative corneal spherical aberration was +0.21±0.08 µm in the myopic eyes, and +0.36±0.11 µm in the hyperopic eyes and became +0.36±0.17 and 0.00±0.29 µm, respectively, postoperatively. The corneal spherical aberration changes were correlated with the amount of preoperative refractive error (r2=0.34, P<0.001). There was a tendency for the Q values and spherical aberrations to become more positive after myopic ablation and more negative after hyperopic ablation.Conclusions Myopic and hyperopic corrections induced changes in the Q value and spherical aberrations in opposite directions (i.e. positive in myopic and negative in hyperopic eyes). The changes depend on the magnitude of the refractive correction.