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

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.

Accurate, automatic determination of astigmatism and phase with Ctfplotter in IMOD

Ctfplotter in the IMOD software package is a flexible program for determination of CTF parameters in tilt series images. It uses a novel approach to find astigmatism by measuring defocus in one-dimensional power spectra rotationally averaged over a series of restricted angular ranges. Comparisons with Ctffind, Gctf, and Warp show that Ctfplotter's estimated astigmatism is generally more reliable than that found by these programs that fit CTF parameters to two-dimensional power spectra, especially at higher tilt angles. In addition to that intrinsic advantage, Ctfplotter can reduce the variability in astigmatism estimates further by summing results over multiple tilt angles (typically 5), while still finding defocus for each individual image. Its fitting strategy also produces better phase estimates. The program now includes features for tuning the sampling of the power spectrum so that it is well-represented for analysis, and for determining an appropriate fitting range that can vary with tilt angle. It can thus be used automatically in a variety of situations, not just for fitting tilt series, and has been integrated into the SerialEM acquisition software for real-time determination of focus and astigmatism.

Comparison of clinical outcome after implantation of two toric intraocular lenses with different haptic type: a prospective randomized controlled trial

OBJECTIVE

To study the effect of astigmatism correction, rotational stability, and related factors of two different haptic type toric intraocular lenses.

METHODS

A prospective, randomized, controlled trial. Cataract patients with preoperative corneal astigmatism of > 1 D were randomly implanted with C-loop haptic toric IOL (AcrySof-toric IOL) (group A) or plate-haptic toric IOL (AT TORBI 709 M IOL) (group B). The residual astigmatism, intraocular lens rotation, and visual quality were determined and compared between the two groups at 3 months after surgery.

RESULTS

Seventy-nine eyes were included in this study, including 40 eyes in the group A and 39 eyes in the group B. No significant difference in preoperative visual acuity, intraocular pressure, and ophthalmic biological parameters was found between the two groups. There was no significant difference in residual astigmatism between the two groups at 3 months after surgery (P > 0.05). The rotation degree in the group A was 3.85 ± 2.92°, the rotation degree in the group B was 2.33 ± 2.31°, and a significant difference in intraocular lens rotation was identified between the two groups (P < 0.05). Upon exploring the rotation-related factors of the two different haptic type toric intraocular lenses, the rotation after implanting C-loop haptic toric IOL was positively correlated with axial length (Pearson r = 0.522, P = 0.01) and corneal white-to-white distance (Pearson correlation analysis r = 0.356, P = 0.024).

CONCLUSIONS

The two different haptic type toric intraocular lenses effectively corrected regular corneal astigmatism and provided a good rotational stability after surgery. But the stability of plate-haptic toric IOL was better than that of C-loop haptic toric IOL. The rotational stability of C-loop haptic toric IOL was often related to axial length and corneal white-to-white distance.

Refractive error and vision related quality of life

BACKGROUND

To investigate and compare the vision-related quality of life (QOL) in different types of refractive error (RE).

METHODS

This cross-sectional study was performed on 200 subjects, categorized into four groups of 50 each, consisting of subjects with myopia, hyperopia, astigmatism, and emmetropia, the latter being the control group. The mean age of the participants was 23.88 ± 5.87 (range, 15 to 38: 110 females and 90 males). RE was defined as myopia, spherical equivalent (SE) < -0.25 diopters (D), hyperopia, SE > + 0.25 D, astigmatism, cylinder < -0.25 D, and emmetropia (-0.25 ≤ SE(D) ≤ + 0.25, cylinder ≥ -0.25). Groups are subdivided into very low magnitudes of RE (0.50 and 0.75) and significant RE (1.00 ≤). Vision-related QOL was assessed using the Persian version of the 25-item National Eye Institute Visual Functioning Questionnaire (NEI-VFQ-25). The NEI-VFQ was scored as visual function and socioemotional scales using Rasch analysis.

RESULTS

Corrected myopia, astigmatism, uncorrected myopia, and hyperopia had a lower vision-related QOL than emmetropes. (P < 0.001). Vision-related QOL in myopic subjects was lower than that in astigmatic participants. Very low myopes, who often do not use correction, had a significantly lower QOL than other groups.

CONCLUSION

Individuals with refractive errors experience a lower QOL score than those without. Notably, the adverse impact on QOL score is significantly greater in myopic cases, particularly very low myopia, compared to other refractive errors. Therefore, it is strongly recommended not to neglect managing very low myopia since it may improve participants' QOL.

Subjective versus objective refraction in healthy young adults

PURPOSE

To evaluate objective and subjective refraction differences in healthy young adults.

METHODS

Data concerning candidates for the Israeli Air Force Flight Academy, as well as active air force pilots in all stages of service who underwent a routine health checkup between the years 2018 and 2019 were retrospectively analyzed. Objective refraction measured using a single autorefractometer was compared with subjective refraction measured by an experienced military optometrist during the same visit. The results were converted to power vectors (spherical equivalent [SE], J0, and J45). To interpret astigmatism using power vector values, the cylinder power (Cp) was determined.

RESULTS

This study included 1,395 young adult participants. The average age was 22.17 years (range, 17-39, 84.8% males). The average SE was - 0.65 ± 1.19 diopter (D) compared with - 0.71 ± 0.91D in the auto- and subjective refraction, respectively (p = 0.001). Cp was 0.91 ± 0.52D and 0.67 ± 0.40D, respectively (p < 0.001). This difference was more common in older participants (p < 0.001). J0 and J45 value differences were not significant. The absolute SE value of subjective refraction was lower in the myopic (p < 0.001) and hyperopic (p < 0.001) patients.

CONCLUSIONS

Young hyperopic participants tended to prefer "less plus" in subjective refraction compared with autorefraction. Young myopic participants tended to prefer "less minus" in subjective refraction compared with autorefraction. All participants, but mainly older participants, preferred slightly "less Cp" than that measured using autorefraction; The astigmatic axis did not differ significantly between the methods.

Rotational stability of monofocal and diffractive multifocal toric intraocular lens with identical design and material: a propensity score based prospective comparative study

PURPOSE

To compare the rotational stability of a monofocal and a diffractive multifocal toric intraocular lens(IOLs) with identical design and material.

METHODS

This prospective study enrolled patients who underwent plate-haptic toric IOL (AT TORBI 709 M and AT LISA 909 M) implantation. Propensity score matching (PSM) was performed to balance baseline factors. Follow-up examinations were conducted at 1 h, 1 day, 3 days, 1 week, 2 weeks, 1 month, and 3 months postoperatively. A linear mixed model of repeated measures was used to investigate the changes in IOL rotation over time. A 2-week timeframe was utilized to assess differences in IOL rotation between the two groups.

RESULT

After PSM, a total of 126 eyes were selected from each group for further analysis. Postoperatively, the time course of IOL rotation change in the two groups remained consistent, with the greatest rotation occurring between 1 h and 1 day postoperatively. At the 2-week postoperative mark, the monofocal toric IOL exhibited a higher degree of rotation compared to the multifocal toric IOL (5.40 ± 7.77° vs. 3.53 ± 3.54°, P = 0.015). In lens thickness(LT) ≥ 4.5 mm and white-to-white distance(WTW) ≥ 11.6 mm subgroups, the monofocal toric IOL rotated greater than the multifocal toric IOL (P = 0.026 and P = 0.011, respectively).

CONCLUSION

The diffractive multifocal toric IOL exhibits superior rotational stability compared to the monofocal toric IOL, especially in subgroups LT ≥ 4.5 mm and WTW ≥ 11.6 mm. Moreover, the time course of IOL rotation change is consistent for both, with the maximum rotation occurring between 1 h and 1 day postoperatively.

Topographic and surgical risk factors for high postoperative residual astigmatism after small incision lenticule extraction in patients with different degrees of myopia: a retrospective cohort study

BACKGROUND

To evaluate the possible topographic and surgical risk factors for high postoperative residual astigmatism in patients who undergo small-incision lenticule extraction (SMILE) surgery and have different myopia degrees.

METHODS

A retrospective cohort study was conducted, and patients who underwent SMILE surgery were enrolled. A total of 80 and 150 eyes from 40 to 75 individuals, respectively, were selected as the low myopia and high myopia groups. The demographic data, visual acuity, refraction, topographic parameters and surgical settings were recorded. Multiple linear regression with interaction tests were performed to survey the risk factors for high postoperative residual astigmatism in each group.

RESULTS

Five (6.25%) and 9 (6.00%) eyes presented with high postoperative residual astigmatism in the low myopia and high myopia groups, respectively, but these differences were not significant (P = 0.569). A steep corneal curvature was correlated with a greater risk of high postoperative residual astigmatism in the low myopia group (P = 0.015), while a higher degree of cycloplegic cylinder power, steeper corneal curvature, greater topographic cylinder power, smaller optic zone and longer incision length were associated with a high rate of postoperative residual astigmatism in the high myopia group (all P < 0.05). In addition, the interaction effects of cycloplegic and topographic cylinder power and longer incision length on the incidence of high postoperative residual astigmatism development were more evident in the high myopia group than in the low myopia group (all P < 0.05).

CONCLUSIONS

A steep corneal curvature correlates with a high risk of high postoperative residual astigmatism after SMILE surgery, and a higher degree of cycloplegic and topographic cylinder and longer incision are associated with high postoperative residual astigmatism in individuals with high myopia.

Revisiting Javal's rule: a fresh and improved power vector approach according to age

PURPOSE

The scientific community has established Javal's rule as a model linking refractive (RA) and keratometric (KA) astigmatism since its appearance more than 100 years ago. The aim was to improve the accuracy of this relationship according to subject's age by applying the power vector analysis. Posterior corneal curvature has also been studied.

METHODS

The IOLMaster 700 optical biometer was used to measure the corneal thickness and the radius of curvature of the anterior and posterior corneal surfaces. Refractive error was determined by a non-cycloplegic subjective refraction process with trial lenses. Linear regression analyses were applied using J0 and J45 power vector components. An evaluation was carried out according to the subject's age resulting into eight regression relationships for each astigmatic vector component for each relationship.

RESULTS

A total of 2254 right eyes from 2254 healthy subjects were evaluated. A trend towards against-the-rule astigmatism (ATR) was found with aging, both for refractive astigmatism (RA) and keratometric astigmatism (KA), with 95.2% of subjects under 20 years old having with-the-rule (WTR) KA, and only 22.8% above 79 years old. The following regression equations were found between RA and KA: [Formula: see text] = 0.73 × [Formula: see text] - 0.18 (R = 0.78) and [Formula: see text] = 0.70 × [Formula: see text] + 0.04 (R = 0.69) and between RA and total corneal astigmatism (TCA): [Formula: see text] = 0.73 × [Formula: see text] + 0.13 (R=0.78) and [Formula: see text] = 0.70 × [Formula: see text] - 0.06 (R = 0.68) for the whole sample, but with sensible differences among age groups, both in the slope and in the intercept.

CONCLUSION

Ignoring the age of the subject when using Javal's rule could lead to an error in the final cylinder calculation that would increase in high astigmatisms. Applying this new power vector approach based on subject's age could improve the accuracy of the astigmatism prediction.

Corneal refractive error and astigmatism in patients aged 6 to 18 years with a history of retinopathy of prematurity and birth weight of <1500 g

PURPOSE

To investigate corneal refractive power (CR) and astigmatism (AS) in 6- to 18-year-old children with a history of retinopathy of prematurity (ROP) and birth weight of <1500 g who either did or did not undergo retinal photocoagulation (PC).

STUDY DESIGN

Retrospective study.

METHODS

We examined 143 eyes of 77 children in 2021. The children were divided into three groups for evaluation of CR and AS: those with a birth weight of ≥2500 g (normal birth weight [NBW] group, 13 eyes) as controls, those with spontaneously resolved ROP (sr-ROP group, 27 eyes), and those who underwent PC for treatment of ROP (PC-ROP group, 103 eyes). Swept-source anterior segment optical coherence tomography was used to analyze the cornea.

RESULTS

The median CR in the NBW, sr-ROP, and PC-ROP groups was 42.2 (41.3, 42.8) diopters (D), 44.5 (43.2, 45.5) D, and 45.2 (43.8, 46.6) D, respectively. The median AS in the NBW, sr-ROP, and PC-ROP groups was 1.2 (1.0, 1.5) D, 1.1 (0.8, 1.6) D, and 2.1 (1.4, 2.7) D. In the PC-ROP group, the with-the-rule astigmatic axis was 97%. In all three groups, a strong positive correlation was found between the mean anterior and posterior CR (NBW: r=0.795, sr-ROP: r=0.842, PC-ROP: r=0.890) and AS (NBW: r=0.883, sr-ROP: r=0.841, PC-ROP: r=0.860).

CONCLUSION

CR was significantly higher in the sr-ROP (p=0.013) and PC-ROP (p<0.001) groups than in the NBW group. The PC-ROP group had significantly more AS than the sr-ROP group. There was a strong correlation between the anterior and posterior CR and AS.

Toric Intraocular Lens versus Peripheral Corneal Relaxing Incisions for Astigmatism between 0.75 and 2.5 Diopters: 5-Years Outcomes

PURPOSE

To compare 5-year outcomes of toric intraocular lens (tIOL) or peripheral corneal relaxing incision (PCRI) for correction of keratometric astigmatism (KA) between 0.75 and 2.5 diopters (D).

METHODS

Setting: University Hospital. Design: Randomized clinical trial. Eighty eyes (80 participants) received either tIOL or PCRI. Patients were assessed preoperatively, 1-month, 1, and 5 years. Primary outcomes were uncorrected (UDVA) and best-corrected distance logMAR visual acuity (CDVA). Secondary outcomes were a manifest refractive sphere, refractive astigmatism (Ra), spherical equivalent (SEQ), KA & mean keratometry (KM), and Quality-of-Life Impact of Refractive Correction (QIRC) scores.

RESULTS

There was no difference between the two groups in UDVA, CDVA, refractive sphere, KM, RA, and SEQ. KA reduced after 1 month in the PCRI group and remained stable until 5 years. From 1 to 5 years, the number of eyes with distance emmetropia (within ±0.13D) changed from 59% (20/34 eyes) to 32% (6/19 eyes) for tIOLs and from 43% (15/36 eyes) to 20% (4/21 eyes) for PCRIs with 32% (6/19 eyes) and 20% (4/21 eyes) showing >0.5D change in SEQ at 5-years respectively. Compared to 1-year, Ra significantly increased at 5 years in both groups with no difference between the groups. Mean overall QIRC scores were not different between the groups (tIOL: 49.88 ± 7.47; PCRI: 52.09 ± 7.02; p = .18).

CONCLUSIONS

Although there was no difference between the overall visual and vision-related quality of life outcomes between tIOLs and PCRIs, an increase in refractive astigmatism and reduction in distance emmetropia with time was noted in both groups.

Cylinder power progression associated with axial length in young children: a two-year follow-up study

PURPOSE

To describe the association of refraction development and axial length (AL) in young children and provide new insights into the progression of cylinder power.

METHODS

Children (2-3 grades) were enrolled from primary schools in Shanghai and followed up for two years. Cycloplegic refraction, AL, and corneal curvature radius were measured. Refraction parameters were compared among groups with different AL, AL1 (AL < 23.5 mm), AL2 (23.5 mm ≤ AL < 24.5 mm), and AL3 (AL ≥ 24.5 mm). Multiple regression analysis was used to explore risk factors of diopter of cylinder (DC) progression.

RESULTS

In total, out of 6891 enrolled children, 5961 participants (7-11 yrs) were included in the final analysis. Over the two-year period, the cylinder power significantly changed, and those with longer AL had more rapid DC progression over the two years (AL1, -0.09 ± 0.35 D; AL2, -0.15 ± 0.39 D; AL3, -0.29 ± 0.44 D) (P < 0.001). The change in DC was independently associated with AL at baseline (P < 0.001). The proportion of with-the-rule astigmatism increased from 91.3% to 92.1% in AL1 group, from 89.1% to 91.8% in AL2 group and from 87.1% to 92.0% in AL3 group.

CONCLUSIONS

Young children with long AL experienced rapid progression of cylinder power. Both the control of myopia progression and attention to the correction of astigmatism are necessary in the health management of children with long AL. The significantly increased AL in participants might contribute to both the extent and direction of astigmatism.

Comparison of visual outcomes in adult patients with different types of developmental cataracts after toric multifocal intraocular lenses implantation

PURPOSE

 To analyze and compare the visual performance and patient satisfaction following the implantation of toric multifocal intraocular lenses (TMIOLs) in adult patients with different types of developmental cataracts (DC) accompanied by corneal astigmatism (CA).

METHODS

 This is a prospective observational cohort study. Patients diagnosed with DC aged 18-30 years were divided into three groups according to the anatomic location of the lens opacity: cortical, nuclear, and posterior subcapsular (PSC) groups, and implanted with TMIOLs. Visual acuity (VA), postoperative refractive astigmatism (RA), intraocular lens (IOL) rotation, high-order aberrations (HOAs), modulation transfer function (MTF) curve, and Strehl ratio were compared. The functional vision and incidence of photic phenomena were surveyed using questionnaires.

RESULTS

 Fifty-five eyes of 37 patients were enrolled and completed a 1-year follow-up. The mean CA was 2.06 ± 0.79 D preoperatively, and the mean RA was 0.29 ± 0.30 D 3-month postoperatively. The IOL rotation was 2.48° ± 1.89°, with no deviation > 10°. At 12 months, mean uncorrected distance VA improved from 0.93 ± 0.41 preoperatively to 0.08 ± 0.08 logarithm of the minimum angle of resolution (logMAR), mean uncorrected near VA increased from 0.45 ± 0.30 preoperatively to 0.12 ± 0.11 logMAR, and mean uncorrected intermediate VA was 0.14 ± 0.08 logMAR. The cortical and nuclear groups displayed better improvements in uncorrected near and intermediate VA than that in the PSC group. Similar results were observed in the 3-month defocus curves, HOAs, MTF curve, halo incidence, and near vision satisfaction.

CONCLUSION

In adult patients with DC accompanied by CA, TMIOLs implantation achieved good postoperative visual outcomes and significantly reduced glasses dependency. Patients with cortical or nuclear lens opacity showed better whole-course VA and quality of vision, while patients with PSC opacity showed unsatisfactory near vision and suffered more photic phenomena.

Influence of Upper Eyelid Surgeries on Corneal Morphology Detected with Pentacam

PURPOSE

To analyze the corneal morphological parameters before and one month after the upper eyelid (UE) blepharoplasty and external levator resection (ELR) for ptosis surgery.

MATERIALS AND METHODS

Seventy eyes of 70 patients with dermatochalasis (50 eyes) and acquired aponeurotic ptosis (AAP) (20 eyes) included in this prospective study. Detailed ophthalmologic examination was performed including the best corrected visual acuity (BCVA), slit lamp examination and dilated fundoscopy. Measurements were made before and one month after the surgeries using Pentacam. Central corneal thickness (CCT), pupil center pachymetry (PCP) and thinnest pachymetry (TP), cornea front astigmatism (AST), flat keratometry (K1), steep keratometry (K2) and mean keratometry (Km) values were evaluated.

RESULTS

Higher postoperative Km measurements were observed in dermatochalasis (p = 0.038) patients. Postoperative AST values were significantly lower in both dermatochalasis and ptosis cases (p = 0.034, p = 0.003, respectively). Increased PCP and TP were found in the AAP patients (p = 0.014, p = 0.015, respectively).

DISCUSSION

UE blepharoplasty and ELR surgeries both lead to some significant changes on corneal structure post-operatively.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Simple Technique for Stabilizing Toric Intraocular Lens during Removal of Ophthalmic Viscosurgical Device

INTRODUCTION

The aim of this study was to describe a simple technique for the implantation of toric intraocular lenses (IOLs) with increased stability during ophthalmic viscosurgical device (OVD) removal.

METHODS

The technique was performed on 20 eyes with 20 patients (mean age: 77.9 ± 9.21 years). The patients had cataract surgery with implantation of a single-piece, acrylic IOL (AcrySof Toric IOL, SN6A; Alcon Laboratories, Inc.). The intraoperative IOL rotation during OVD removal, rotational error of toric IOL axis at 30 min and 24 h after surgery, and mean preoperative and postoperative IOP were evaluated. Images were captured before and after removal of OVD from surgical video, and used to evaluate intraoperative IOL rotation.

RESULTS

The mean amount of IOL rotation during OVD removal with the current technique was 0.88 ± 0.93°, which was less than the 10.25 ± 5.50° previously reported for the conventional technique. The rotational error of toric IOL axis at 30 min and 24 h were 3.90 ± 3.71 and 3.05 ± 3.22°, respectively. The mean preoperative IOP and postoperative IOP were 13.84 ± 2.39 and 14.15 ± 4.68 mm Hg, respectively.

CONCLUSIONS

With the current technique, the toric IOL is stable during OVD removal and repositioning of the IOL during surgery is less likely to be required.

Refractive and corneal astigmatism in Chinese 4-15 years old children: prevalence and risk factors

BACKGROUND

To investigate the prevalence and risk factors of refractive astigmatism (RA) and corneal astigmatism (CA) in preschool children and school-aged children in Shanghai, China.

METHODS

In this school-based, cross-sectional study, 4-15 years old children across three learning stages of kindergarten, primary school, and junior high school underwent noncycloplegic autorefraction and completed comprehensive questionnaires involving time spent on daily homework and outdoor activities. Data from the right eyes were analysed.

RESULTS

Overall, 7084 children (mean ± standard deviation (SD) of age: 8.08 ± 3.11 years) were included, and the prevalence rates of RA/CA ( ≤ - 1.0 D) in children were 15.8%/64% in kindergartens, 16.5%/65% in primary schools, and 32.8%/76.9% in junior high schools. The magnitude and prevalence of RA and CA all increased with age or with learning stage (all P < 0.001). The presence of RA was associated with more myopic spherical power (odds ratio (OR) 0.956, P = 0.021), junior high school (OR 1.973, P < 0.001), longer homework time on weekdays (OR 1.074, P = 0.029), and shorter outdoor activity time on weekends (odds ratio 0.929, P = 0.013).

CONCLUSION

In the wide age range of 4 to 15 years, the magnitude and prevalence of RA and CA increased with the learning stage, and these increases mainly began at the primary school stage. Factors, including longer homework time and shorter outdoor time were correlated with the presence of RA.

Vector analysis of astigmatism correction after PRK, FS-LASIK, and SMILE for myopic astigmatism

PURPOSE

To compare astigmatic correction among photorefractive keratectomy (PRK), femtosecond laser-assisted in situ keratomileusis (FS-LASIK), and small-incision lenticule extraction (SMILE).

METHODS

This prospective study enrolled 157 eyes that underwent three procedures (59 PRK, 47 FS-LASIK, and 51 SMILE) for the treatment of myopia with low to high astigmatism (- 0.25 to - 4.50 D). Ocular residual astigmatism (ORA) was calculated by vector analysis using refractive (RA) and corneal astigmatism. Vector analysis results were compared in different procedures in the two RA groups (low ≤ 1.00 D and high > 1.00 D) at 3 and 12 months postoperatively.

RESULTS

There were no significant between-group differences in postoperative safety and efficacy outcomes (all P > 0.05). No significant differences were found in postoperative cylinders between all surgical groups (all p > 0.05), except for 3 months postoperative ORA in FS-LASIK (P = 0.004). At 12 months, 77%, 59.2%, and 50% of eyes attain emmetropia in the FS-LASIK, SMILE, and PRK groups, respectively. Vector analysis showed comparable values for surgical induced astigmatism, target induced astigmatism, mean error, and angle of error between groups at 12 months. Significant differences were observed only in the correction index and difference vector parameters in the astigmatic > 1.00 D group at 3 months (P < 0.001), and FS-LASIK was preferable.

CONCLUSIONS

One-year outcomes revealed that PRK, FS-LASIK, and SMILE were all equally effective in correcting myopic astigmatism. However, FS-LASIK demonstrated more favorable astigmatism correction in eyes with astigmatism > 1.00D in early postoperatively.

Epithelial Inoculation After Small-Incision Lenticule Extraction (SMILE): A Case Report

Epithelial ingrowth is a rare condition that is generally seen after laser in situ keratomileusis (LASIK) and has been reported in the literature in a small number of cases after small-incision lenticule extraction (SMILE) surgery. "Epithelial inoculation" should also be considered in patients presenting with decreased vision and an appearance similar to epithelial ingrowth in the early period after SMILE surgery. A 23-year-old woman presented to our clinic with a request for refractive surgery. Her manifest refractions were -7.50 -1.00 x 180° in the right eye and -7.25 -1.00 x 150° in the left eye, and best corrected distance visual acuity was 10/10 in both eyes. The SMILE procedure was performed with the Visumax femtosecond laser (Carl Zeiss Meditec AG). Slit-lamp examination at postoperative 1 week revealed a small grayish-white intrastromal opacity resembling epithelial ingrowth in the central optic axis of the right eye. Irrigation of the interface was performed with balanced salt solution using an irrigation cannula and the epithelial cluster was removed. The patient remained clinically stable 6 months after surgery and has experienced no recurrence. When epithelial inoculation is observed early after SMILE surgery, immediate irrigation of the interface appears to be an effective and safe treatment.

Estimating the Genetic Contribution to Astigmatism and Myopia in the Mexican Population

Astigmatism and myopia are two common ocular refractive errors that can impact daily life, including learning and productivity. Current knowledge suggests that the etiology of these conditions is the result of a complex interplay between genetic and environmental factors. Studies in populations of European ancestry have demonstrated a higher concordance of refractive errors in monozygotic (MZ) twins compared to dizygotic (DZ) twins. However, there is a lack of studies on genetically informative samples of multi-ethnic ancestry. This study aimed to estimate the genetic contribution to astigmatism and myopia in the Mexican population. A sample of 1399 families, including 243 twin pairs and 1156 single twins, completed a medical questionnaire about their own and their co-twin's diagnosis of astigmatism and myopia. Concordance rates for astigmatism and myopia were estimated, and heritability and genetic correlations were determined using a bivariate ACE Cholesky decomposition method, decomposed into A (additive genetic), C (shared environmental) and E (unique environmental) components. The results showed a higher concordance rate for astigmatism and myopia for MZ twins (.74 and .74, respectively) than for DZ twins (.50 and .55). The AE model, instead of the ACE model, best fitted the data. Based on this, heritability estimates were .81 for astigmatism and .81 for myopia, with a cross-trait genetic correlation of rA = .80, nonshared environmental correlation rE = .89, and a phenotypic correlation of rP = .80. These results are consistent with previous findings in other populations, providing evidence for a similar genetic architecture of these conditions in the multi-ethnic Mexican population.

The Prevalence of Astigmatism and Spectacle Wear in Polish Schoolchildren

INTRODUCTION

Unilateral or asymmetric astigmatism is considered a principal refractive error leading to amblyopia and regular eye examinations should be carried out during childhood to prevent visual impairment. The aim of this study was to evaluate the prevalence of astigmatism and spectacle wear among Polish schoolchildren.

METHODS

A cross sectional study was carried out in children aged 6 to 14 years old from 50 schools in Poland. The presence of astigmatism was assessed by non-cycloplegic autorefraction, and defined as a cylinder equal or greater than 0.75 D. Children were classified as living in urban or rural areas according to the school location. Spectacle wear was defined as having spectacles at school.

RESULTS

The study included 1041 children and 52.3% were girls (n = 544). The mean age was 8.62 ± 2.04 years. The prevalence of astigmatism was 7.3% (95% confidence interval [CI]: 5.8-9.1%). Only 21.7% of children with astigmatism wore spectacles at school. Astigmatism was diagnosed in 8.2% of boys (95% CI: 6.0-11.0%) and 6.4% of girls (95% CI: 4.5-8.8%; p = .13); cylindrical anisometropia was present in 19/76 (25.0%) of children with astigmatism (95% CI: 15.8%-36.3%). Against-the-rule astigmatism was the most common; it was observed in 48.7% of children with astigmatism, followed by with-the-rule astigmatism (44.7%) and oblique astigmatism (6.6%). The prevalence of astigmatism was not linearly correlated with age (r = 0.24; p = .53). Gender, age and place of living were not significantly associated with the presence of astigmatism.

CONCLUSIONS

This study reports a low prevalence of astigmatism in Polish school children. However, the majority of children with astigmatism were uncorrected. Further longitudinal studies are warranted.

Congenital ptosis repair in children: comparison of frontalis muscle suspension surgery and levator muscle surgery

PURPOSE

Comparing the surgical and refractive outcomes of congenital ptosis repair by different surgical techniques.

METHODS

This longitudinal cohort study reviewed medical records of 101 patients who underwent congenital ptosis repair, from 2006 to 2022 in a single center. Analysis was performed for demographic background, co-morbidities, pre-operative and post-operative ocular examinations and refraction, complications, reoperations, and success rates.

RESULTS

Following exclusion criteria, we remained with 80 patients (103 eyes) who underwent either frontalis muscle suspension surgery (FMS) (55 eyes) or levator muscle surgery (LM) (48 eyes). Patients in the FMS group were younger (mean age of 3.1 vs. 6.0 years, p < 0.001) and had worse pre-operative ocular assessments including prevalence of visual axis involvement, chin-up head position, ptosis severity, and levator muscle function (LF) (p < 0.001). Both groups had a 25% rate of reoperation, however while in the LM group reoperation was required solely due to undercorrection, in the FMS group various indications prompted reoperation. Success rate was higher in the FMS group (87.3% vs. 60.4%, p = 0.002). While pre-operative astigmatism was higher in the LM group (p = 0.019), no significant differences were observed post-operatively. Spherical and spherical equivalent changes over time were significant only in the FMS group (p = 0.010 and p = 0.004, respectively).

CONCLUSIONS

Within our cohort, a higher success rate of congenital ptosis repair was observed among patients who underwent FMS compared to LM, despite similar reoperation rates. In cases of severe ptosis and moderate LF, LM demonstrated a lower-than-anticipated success rate. Astigmatic changes following ptosis repair were not consistent in either group.

Effect of femtosecond laser-assisted arcuate keratotomy versus toric intraocular lens implantation on correction of astigmatism in cataract surgery: a systematic review and meta-analysis

PURPOSE

To compare the efficacy of femtosecond laser-assisted arcuate keratotomy (FSAK) combined with non-toric intraocular lens (IOL) implantation versus Toric IOL (TIOL) implantation in correcting corneal astigmatism in cataract patients.

METHODS

Relevant literature was searched in databases including PubMed, Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL), and SinoMed. Data from the included studies were extracted. A meta-analysis was conducted to compare the correction performance of FSAK combined with non-toric IOL implantation and TIOL implantation using postoperative refractive astigmatism, correction index, and uncorrected distance visual acuity (UDVA) outcomes. Publication bias assessment and sensitivity analysis were also performed.

RESULTS

Five comparative studies were ultimately included in the meta-analysis. The TIOL group had smaller postoperative refractive astigmatism and a greater correction index compared to the FSAK group. The mean differences in postoperative refractive astigmatism and correction index between the two groups were - 0.19D (95% CI = 0.12 to 0.26, P < 0.01, I2 = 7%) and - 0.09 (95% CI =  - 0.18 to 0.00, P = 0.04, I2 = 0%), respectively. We found no statistically significant difference in UDVA between the two groups (95% CI =  - 0.01 to 0.11, P = 0.09, I2 = 70%).

CONCLUSIONS

FSAK combined with non-toric IOL implantation was found to be less effective than TIOL implantation in correcting preoperative corneal astigmatism in cataract patients. The difference in the effectiveness of astigmatism correction between the two surgical methods seems to diminish, as the degree of preoperative corneal astigmatism decreases.

[Influence of tropical endemic limboconjunctivitis on the distribution of astigmatism in a black pediatric population: A hospital-based case-control study]

PURPOSE

To study the influence of tropical endemic limboconjunctivitis (TELC) on the distribution of astigmatism in a population of black children.

PATIENTS AND METHODS

We matched two groups of 36 children between the ages of 3 and 15 by age and sex. Group 1 consisted of children with TELC, and group 2 was made up of controls. All underwent cycloplegic refraction. The studied variables were age, sex, type and stage of TELC, spherical equivalent, absolute cylinder value and clinical type of astigmatism. The odds ratio was used to quantify the link between TELC and astigmatism. We used the Chi2 test for the comparison of qualitative variables and the Student T test for the comparison of the means of quantitative variables. The threshold of significance of the differences was set at 0.05.

RESULTS

Astigmatism was more common in children with TELC (61.97% vs. 37.5%), (OR=1.53; 95% CI 1.08-2.15; P=0.012). The history of TELC was associated with an increased risk of with-the-rule astigmatism (OR 1.91; 95%CI (1.23-2.97).

CONCLUSION

Pediatric TELC is frequently associated with the with-the-rule astigmatism in our practice setting.

Supplemental Toric Intraocular Lenses in the Ciliary Sulcus for Correction of Residual Refractive Astigmatism: A Review

PURPOSE

This study conducted a critical review of the peer-reviewed literature on the use of supplemental toric intraocular lenses (STIOL) in the ciliary sulcus to correct residual refractive astigmatism.

METHODS

This review used PubMed as a database from 1 January 2010 to 13 March 2023. According to the inclusion and exclusion criteria defined, 14 articles were selected for the current review.

RESULTS

The data of 155 eyes were analyzed. Most of the studies reviewed had a short follow-up and poor or limited design, including case reports, case series, and retrospective cohorts. The follow-up period ranged from 43 days to 4.5 years. STIOL rotation was the most frequently described complication in the literature, with a mean rotation of 30.48 ± 19.90°. These patients required repositioning in 50 of 155 eyes (32.25%). Moreover, four eyes (2.58%) required scleral fixation sutures and two eyes (1.29%) iris fixation. Other complications were high intraocular pressure (3 eyes, 1.93%), transient corneal edema (2 eyes, 1.29%), corneal decompensation (2 eyes, 1.29%), and pigment dispersion (1 eye, 0.64%). From the total, 57.41% of eyes (89 eyes from 155) achieved within ± 0.50D of target refractive astigmatism. It is important to highlight that at least 52 eyes out of the 155 (33.54%) had an abnormal cornea with irregular astigmatism.

CONCLUSION

STIOL seem to offer good visual and refractive outcomes. However, STIOL showed variable rotational stability, especially in some platforms. Further studies with a more robust design, methodology, and standardized analysis methods are needed to confirm these trends.

Corneal topographic changes in patients with thyroid eye disease: A retrospective cross-sectional study

PURPOSE

This study aimed to evaluate corneal topographic findings in patients with thyroid eye disease (TED) using a Galilei camera and compare their corneal topographic parameters with those of control patients.

METHODS

This retrospective cross-sectional study included 52 eyes of 26 patients with TED (study group) and 40 eyes of 20 controls treated at a tertiary medical center in Taiwan between January and December 2021. All participants underwent basic ophthalmological examinations, corneal topography examination using a Galilei dual Scheimpflug camera, thyroid function examination, and orbital computed tomography. The corneal topographic parameters and cross-sectional area of the extraocular muscles were compared between the TED and control groups.

RESULTS

Several corneal topographic parameters, including the Inferior-Superior Index, Keratoconus Prediction Index, Surface Asymmetry Index, Surface Regularity Index, simulated keratometry astigmatism, and anterior instantaneous astigmatism axis, differed significantly between the groups (P ≤ 0.05). The anterior instantaneous astigmatism axis was more oblique in the TED group than in the control group. A scatter plot revealed a more scattered distribution in the anterior instantaneous astigmatism axis in the TED group than in the control group. However, the corneal topographic parameters did not differ significantly among the different thyroid dysfunction groups.

CONCLUSIONS

The corneas of patients with TED are suspicious and keratoconus-like, and TED can increase anterior corneal astigmatism in the oblique axis, albeit with large variations in the extent of change. These TED-related corneal changes may aid in the early diagnosis of TED, especially "silent" TED.