OBJECTIVES: To compare the efficacy of toric implantable collamer lens (Toric-ICL) and femtosecond laser-assisted in situ keratomileusis (FS-LASIK) for myopia correction in patients with moderate to high myopia complicated with astigmatism. METHODS: We retrospectively collected data from 64 patients (aged 18-42 years) with moderate to high myopia complicated with astigmatism (128 eyes) undergoing either Toric-ICL (28 patients/56 eyes) or FS-LASIK (36 patients/72 eyes) at our department between January, 2019 and December, 2020. The changes of uncorrected distance visual acuity (UCVA), spherical equivalent (SE), mean astigmatism correction index (CI), corneal endothelial cell density (ECD) and intraocular pressure (IOP) following the procedures were compared between the two groups. RESULTS: In FS-LASIK group, all the eyes (72/72) achieved an UCVA≥1.0, similar to the rate in Toric-ICL group (55/56 eyes; P=0.2374). The postoperative SE was also comparable between FS-LASIK and Toric-ICL groups [0.43±0.06 D (range: -1.0 to 1.50 D) vs 0.38±0.05 D (range: -0.75 to 1.00 D); P=0.56]. The mean astigmatism CI was significantly higher in FS-LASIK group than in Toric-ICL group (0.8561 vs 0.7176; P<0.0001), and 88.89% of the eyes in FS-LASIK group and 69.64% in Toric-ICL group had postoperative astigmatism ≤0.50 D. No significant changes were observed in postoperative corneal ECD in FS-LASIK group, whereas ECD decreased significantly after the procedure in Toric-ICL group (P=0.0057). The patients undergoing Toric-ICL exhibited no significant changes of postoperative IOP, but the patients receiving FS-LASIK had significantly reduced IOP after the procedure (P<0.001). CONCLUSIONS Although the patients included in Toric-ICL group had higher myopia and astigmatism, Toric-ICL still showed better predictability and efficacy for astigmatic correction in Toric-ICL group. Toric-ICL is an effective and safe equivalent of FS-LASIK for correcting moderate myopia but can be more advantageous for correcting high myopia with astigmatism.
Humans ; Astigmatism/complications* ; Myopia/complications* ; Keratomileusis, Laser In Situ/methods* ; Retrospective Studies ; Adult ; Visual Acuity ; Adolescent ; Young Adult ; Treatment Outcome ; Male ; Lens Implantation, Intraocular/methods* ; Female ; Phakic Intraocular Lenses ; Intraocular Pressure

Objective: Toric intraocular lens implantation has been used to correct corneal astigmatism during cataract surgery. The study aimed to compare the visual outcomes between manual vs markerless toric intraocular lens implantation in astigmatic correction. Methods: The medical records of patients at American Eye Center who underwent phacoemulsification by multiple surgeons with insertion of monofocal or multifocal toric lenses via manual marking and markerless method from 2010-2019 were reviewed. Results: A total of 70 patients were included in the study. Results showed no significant difference in the following characteristics between manual and markerless method at one month and two months post-cataract surgery: uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected near vision acuity (UNVA), corrected near vision acuity (CNVA), refraction spherical equivalent. The UDVA, CDVA, UNVA, CNVA and astigmatism had significantly lower median/mean-rank at one and two months postoperatively compared to preoperative values. Conclusion In conclusion, our findings indicated that both manual-based and markerless systems effectively facilitated accurate placement of the toric IOL on the desired axis. Notably, there was no significant difference observed between the two methods. Both systems are straightforward to execute. In low-resource settings like the Philippines, the manual marking method can be employed when markerless guidance equipment is unavailable.
Phacoemulsification ; Astigmatism ; Philippines

Objectives: To compare the vector analysis, visual, and refractive outcomes of femtosecond-assisted laser insitu keratomileusis (LASIK) and small incision lenticule extraction (SMILE) among myopic patients with moderate myopic astigmatism. Methods: This was a single-center, retrospective, cohort study that compared eyes that underwent femtosecond LASIK or SMILE for the correction of myopia and astigmatism of 0.75 to 3.0 diopters. Vector analysis and standard graphs for reporting visual and refractive outcomes were utilized for analysis. Results: There were 82 femtosecond LASIK-treated eyes and 80 SMILE-treated eyes with similar preoperative characteristics except for slightly higher mean preoperative sphere refraction in the SMILE group (-4.2±2.4 D vs -4.9±1.6 D, p=0.03). At 3 months, femtosecond LASIK group had better mean uncorrected distance visual acuity (UDVA) (LogMAR 0.006±0.06 vs 0.06±0.09, p=0.00) and had more eyes achieving postoperative UDVA of 20/20 or better (88% versus 56%). Although there were similar postoperative spherical equivalents, residual astigmatism was higher in the SMILE group (0.11±0.22 D vs 0.32±0.30 D, p=0.00). Vector analyses showed significantly better outcomes for femtosecond LASIK than for SMILE in terms of difference vector (DV), index of success (IOS), torque, and flattening index (FI). A trend for undercorrection for higher astigmatism was seen in both groups that was greater in the SMILE group. Both groups showed high safety with the majority of eyes showing postoperative corrected distance VA (CDVA) within 1 line of preoperative CDVA (98.8% versus 91.2%). Conclusion Although femtosecond LASIK and SMILE have similar predictability at 3 months, femtosecond LASIK has relatively better efficacy and superior astigmatic outcomes than SMILE for the correction of moderate myopic astigmatism.
Astigmatism

OBJECTIVE

Toric intraocular lens implantation has been used to correct corneal astigmatism during cataract surgery. The study aimed to compare the visual outcomes between manual vs markerless toric intraocular lens implantation in astigmatic correction.

The medical records of patients at American Eye Center who underwent phacoemulsification by multiple surgeons with insertion of monofocal or multifocal toric lenses via manual marking and markerless method from 2010-2019 were reviewed.

A total of 70 patients were included in the study. Results showed no significant difference in the following characteristics between manual and markerless method at one month and two months post-cataract surgery: uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected near vision acuity (UNVA), corrected near vision acuity (CNVA), refraction spherical equivalent. The UDVA, CDVA, UNVA, CNVA and astigmatism had significantly lower median/mean-rank at one and two months postoperatively compared to preoperative values.

In conclusion, our findings indicated that both manual-based and markerless systems effectively facilitated accurate placement of the toric IOL on the desired axis. Notably, there was no significant difference observed between the two methods. Both systems are straightforward to execute. In low-resource settings like the Philippines, the manual marking method can be employed when markerless guidance equipment is unavailable.

Humans ; Nephritis, Hereditary/genetics* ; Astigmatism ; Mutation ; Collagen Type IV/genetics*

astigmatism vector versus surgically induced astigmatism vector exhibited slopes and coefficients (R²) of 0.9618 and 0.9748, respectively (y = 0.9618x + 0.0006, R² = 0.9748). While total corneal root mean square higher order aberrations, coma and trefoil showed statistically significant increase, spherical aberration did not show statistically significant change after SMILE.CONCLUSIONS: SMILE has proven to be effective and safe for correcting myopia and astigmatism. We showed that SMILE did not induce spherical aberrations. A small increase in postoperative corneal higher order aberration may be associated with increase in coma and trefoil.]]>
Astigmatism ; Coma ; Corneal Topography ; Corneal Wavefront Aberration ; Humans ; Linear Models ; Lotus ; Myopia ; Refractive Surgical Procedures ; Retrospective Studies ; Visual Acuity

Objectives: Refractive changes have been studied after muscle surgery in literature but most results are inconsistent. It has been postulated that changes in corneal tension after muscle surgery may cause a change in corneal curvature resulting in the change in refraction postoperatively. This study investigated changes in corneal topography and clinical refraction after horizontal rectus muscle surgery. Methods: Twenty-one eyes of 13 patients underwent horizontal rectus muscle surgery via limbal approach. Manifest refraction, cycloplegic refraction, and corneal topography were measured preoperatively, and postoperatively at day 1 and weeks 1, 2, 4 and 8. The proportion of subjects with at least 0.5 D change from preoperative measurements and the proportion of subjects that needed new prescription postoperative were also computed. Analysis of the results were done using the Friedman test to identify significant differences among measurements at different time periods with post-hoc analysis utilized to identify specific time periods with significant changes from preoperative measurements. Results: Mean corneal keratometry, horizontal, vertical, and oblique astigmatism, obtained topographically showed no significant difference from preoperative measurements. The statistically significant difference in corneal astigmatism in the recession group at day 1, week 4 and week 8 postoperatively was not confirmed when converted to power vectors in both vertical/horizontal (J0) and oblique (J45) astigmatism. Clinical refraction showed a transient myopic shift in spherical equivalent, statistically significant only on postoperative day 1 in the recession group. There was no statistically significant difference in clinical astigmatism. There was ≥ 0.5 D change in spherical equivalent in 60% in both study groups by the end of follow-up. The shift in J0 was more than 10% in the recession group. More than fifty percent (52.4%) needed new prescription for glasses. Conclusion No statistically significant change in corneal topography and clinical refraction following horizontal rectus muscle surgery were found. Patients should still be refracted at least 2 weeks postoperatively to check if there is a need for change in prescription glasses to improve alignment and/or improve vision.
Astigmatism ; Oculomotor Muscles ; Ophthalmologic Surgical Procedures ; Vision Tests ; Strabismus

Objective: To determine the effect of corneal collagen cross-linking on the corneal curvature of eyes with keratoconus measured using an Oculus Pentacam® at 2 years and annually thereafter. Methods: This was a descriptive, retrospective study involving patients with keratoconus who had undergone uncomplicated collagen cross-linking using the Dresden protocol from January 2012 to March 2016. Baseline measurements of best-corrected visual acuity (BCVA), maximum K value (Kmax), corneal astigmatism, anterior and posterior elevation map changes were recorded and compared with data taken at 2 and 3 years Results: This study included 32 patients (48 eyes) with a mean follow-up of 28.88 ± 6.23 months. Only 4 patients (6 eyes) had 3-year follow-up data with a mean follow-up of 42.83 ± 4.58 months. When all eyes were considered, significant changes were noted in Kmax, BCVA, and anterior and posterior elevation maps between baseline and 2-year follow-up. Specifically, there were significant decreases in Kmax (p<0.0001) and anterior elevation (p<0.05), and significant improvement in BCVA (p<0.01) while posterior elevation (p<0.0001) was found to have increased significantly at 2nd year follow-up compared to baseline. When only eyes with 3-year follow-up data was analyzed, only BCVA showed significant change (p<0.05). Corneal astigmatism remained stable during the study period. Conclusion Two to 3 years after collagen cross-linking for keratoconus, corneal curvature parameters and BCVA showed improved and stable outcomes when compared to baseline.
Keratoconus ; Astigmatism

PURPOSE: To determine the efficacy of 4-haptic bitoric intraocular lens (IOL) implantation in Asian patients with cataract and astigmatism. METHODS: A total of 19 eyes with ≤25.0 mm axial length and ≥0.75 diopters (D) corneal astigmatism were included in this prospective non-comparative study. All subjects underwent phacoemulsification with implantation of an AT Torbi 709M IOL. Visual and refractive outcomes as well as toric IOL axis were evaluated during a 3-month follow-up. Errors in predicted residual spherical equivalent were calculated by subtracting predicted residual spherical equivalent from postoperative refraction. RESULTS: Uncorrected and corrected distance visual acuity improved significantly 3 months after surgery, from 0.43 to 0.05 and from 0.24 to −0.05, respectively. Mean refractive cylinders also decreased significantly, from −1.91 preoperatively to −0.54 D 3 months after surgery. Mean J0 and J45 decreased 3 months postoperatively, from 0.26 to 0.03 D and from 0.24 to −0.06 D, respectively. After 3 months, mean absolute IOL rotation was 1.81°. Errors in predicted residual spherical equivalent showed a hyperopic shift of 0.35 D. CONCLUSIONS: Implantation of 4-haptic bitoric IOL proved to be effective for correcting astigmatism in Asian eyes during cataract surgery.
Asian Continental Ancestry Group ; Astigmatism ; Cataract ; Follow-Up Studies ; Humans ; Lens Implantation, Intraocular ; Lenses, Intraocular ; Phacoemulsification ; Prospective Studies ; Visual Acuity

BACKGROUND: To objectively investigate accommodative response to various refractive stimuli in subjects with normal accommodation. METHODS: This prospective, non-randomized clinical trial included 64 eyes of 32 subjects with a mean spherical equivalent −1.4 diopters (D). We evaluated changes in accommodative power, pupil diameter, astigmatic value, and axis when visual stimuli were applied to binocular, monocular (dominant eye, non-dominant eye, ipsilateral, and contralateral), and pinhole conditions. Visual stimuli were given at 0.25 D (4 m), 2 D (50 cm), 3 D (33 cm), and 4 D (25 cm) and accommodative response was evaluated using open view binocular autorefractor/keratometer. RESULTS: The accommodative response to binocular stimulus was 90.9% of the actual refractive stimulus, while that of the monocular stimulus was 84.6%. The binocular stimulus induced a smaller pupil diameter than did the monocular stimulus. There was no difference in accommodative response between the dominant eye and non-dominant eye or between ipsilateral and contralateral stimuli. As the refractive stimuli became stronger, the absolute astigmatic value increased and the direction of the astigmatism axis became more horizontal. Pinhole glasses required 10%–15% less accommodative power compared with the monocular condition. CONCLUSION: Binocular stimuli enable more precise and effective accommodation than do monocular stimuli. Accommodative response is composed of 90% true accommodation and 10% pseudo-accommodation, and the refractive stimulus in one eye affects the contralateral eye to the same extent. This should be taken into account when developing guidelines for wearing smart glasses while driving, as visual stimulation is applied to only one eye, but far distance attention is constantly needed. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03557346
Astigmatism ; Eyeglasses ; Glass ; Non-Randomized Controlled Trials as Topic ; Photic Stimulation ; Prospective Studies ; Pupil ; Telescopes*