Correction Of High Myopic Astigmatism Research Articles

Vector analysis of high astigmatism (\u2265\u20092.0 diopters) correction after small-incision lenticule extraction with stringent head positioning and femtosecond laser-assisted laser in situ keratomileusis with compensation of cyclotorsion

BackgroundThe purpose of this study was to compare the astigmatic correction by vector analysis in patients with high myopic astigmatism after femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) with cyclotorsion compensation or small-incision lenticule extraction (SMILE) with stringent head positioning.SettingBeijing Aier-Intech Eye Hospital, Beijing, China.DesignA retrospective case series.MethodsPatients who had correction of myopic astigmatism of 2 diopters (D) or more treated with either FS-LASIK with cyclotorsion compensation or SMILE with stringent head positioning were included. The results of vision and refraction were analyzed and compared between groups with the right eye.ResultsThe study enrolled 94 patients (41eyes in an FS-LASIK with compensation of cyclotorsion group and 53 eyes in a SMILE with stringent head positioning control group. The mean preoperative manifest cylinder was -2.65 ± 0.77D in the FS-LASIK group and 2.51 ± 0.56D in the SMILE group (P = 0.302). At 12 months, there was no significant between-group difference in uncorrected distance visual acuity (UDVA, P = 0.274) and postoperative spherical equivalent (SEQ) (P = 0.107). 46.3% and 24.5% of eyes in the FS-LASIK and SMILE groups were within 0.25 D were within 0.25D postoperative cylinder, respectively, and 78% and 66% of eyes in these two groups were within 0.5 D postoperative cylinder (P = 0.027, P = 0.202). The vector analysis showed comparable between-group target-induced astigmatism (TIA) (P = 0.114), surgically induced astigmatism (SIA) (P = 0.057), difference vector (DV, P = 0.069), and the angle of error (AE) (P = 0 .213) values. The index of success (IOS) was 0.18 in the FS-LASIK group and 0.24 in the SMILE group (P = 0.024), with a significant difference between the two groups.ConclusionFS-LASIK with compensation of cyclotorsion showed a favorable correction of high myopic astigmatism (≥ 2.0 D) compared to SMILE with stringent head positioning at 12 months.

Functional Optical Zone and Visual Quality After Small-Incision Lenticule Extraction for High Myopic Astigmatism.

IntroductionThe aim of this study was to compare the functional optical zone (FOZ) after correction of high myopic astigmatism and low myopic astigmatism by small-incision lenticule extraction (SMILE).MethodsIn this prospective study, 30 patients who received SMILE for high myopic astigmatism correction (cylinderical diopters ≤ − 2.0D) were enrolled in the high astigmatism group (HA). The control group comprised 40 patients who underwent SMILE for low myopic astigmatism correction (LA; cylinderical diopters ≥ − 0.5D). FOZ was delineated as the area outlined by a change of 0.5D relative to the power at the corneal vertex on the total corneal refractive power map. An ellipse-fitting program (MatLab) was used to calculate some parameters of the FOZ. Visual quality evaluations were also conducted, including evaluations of wavefront aberrations, optical quality, and intraocular scattering, and completion of a quality of life questionnaire. All of the right eyes were analyzed in the study.ResultsThe preoperative average treatment spherical equivalent (− 5.77 ± 1.86D vs. − 6.49 ± 1.49D; P = 0.074), lenticule thickness (120.87 ± 23.27 μm vs. 118.53 ± 21.66 μm; P = 0.666), and programmed optical zone (6.58 ± 0.17 mm vs. 6.65 ± 0.18 mm; P = 0.104) were comparable between the HA and LA groups. The long axes (6.99 ± 1.14 mm vs. 5.32 ± 0.61 mm; P < 0.001), short axes (4.66 ± 0.96 mm vs. 4.23 ± 0.64 mm; P = 0.047), and area (25.90 ± 8.03 mm2 vs. 17.92 ± 4.36 mm2; P < 0.001) of the FOZ were significantly larger in the HA group than in the LA group. The centration of the FOZ were comparable between the two groups (0.62 ± 0.25 mm vs. 0.70 ± 0.25 mm; P = 0.194). Postoperative spherical aberration was lower in the HA group than in the LA group (0.07 ± 0.05 μm vs. 0.14 ± 0.10 μm; P = 0.001). There was no significant difference in the ocular scatter index (0.80 ± 0.46 vs. 0.73 ± 0.46; P = 0.447), modulated transfer function (MTF)cutoff (37.89 ± 9.79 cpd vs. 39.78 ± 7.45 cpd; P = 0.363), and Strehl in two dimensions (Strehl2D) ratio (0.20 ± 0.04 vs. 0.20 ± 0.04; P = 0.363) between the HA group and the LA group. There were no significant differences in the scores on quality of life between the HA and LA groups (45.88 ± 2.15 vs. 45.64 ± 1.84; P = 0.423). Correlation analysis revealed that increase in the spherical aberration was significantly correlated with the long axes, short axes and area in the FOZ in both groups.ConclusionWith a comparable optical design and attempted correction in SMILE, the eyes with higher myopic astigmatism correction achieved larger FOZ than the eyes with lower myopic astigmatism correction. Consequently, less spherical aberration induction was created after higher myopic astigmatism correction. This result may be associated with less corneal volume sculpted by laser for the higher astigmatism treatment, leading to fewer biochemical responses and les change in corneal aspherity. Good retinal image quality and satisfied quality of life were achieved at a comparable level in both study groups.

The toric implantable collamer lens for the correction of high compound myopic astigmatism

Objective To study the safety and efficacy of toric implantable collamer lens (TICL) for the correction of high compound myopic astigmatism. Methods Thirty eyes of 15 patients with high myopic astigmatism were retrospectively analyzed.They were treated with TICL implantation via corneal incision under surface anesthesia.The range of preoperative myopia diopters was -8.00~-21.00D with average (-12.42±3.86) D. Astigmatism ranged from -1.50 to -6.50D with average (-2.56±1.32) D. and the equivalent spherical diopters was (-14.56±0.32)D; All patients were followed up for 12 months. Results The range of myopia diopters 12 months after operation was-0.25D to+ 0.25D with average (-0.16±0.17) D and the range of postoperative astigmatism was 0~0.50D with average (-0.15±0.16) D UCVA in 20 eyes (66.67%) was improved by one line after operation compared with BCVA before operation. UCVA in 6 eyes (20.00%) was improved by two lines.Preoperative intraocular pressure of patients was (15.49±1.07) mmHg, and the intraocular pressure 1 day after operation was(15.75±1.32)mmHg.The difference of intraocular pressure was not statistically significant between preoperation and one day after operation(t=0.42, p=0.67); The intraocular pressure 12 months after surgery was (15.40±1.04) mmHg (1 mmHg=0.133 kPa), and compared with the preoperative intraocular pressure, the difference was not statiatically significant(t=0.33, P=0.74). The mean preoperative endothelial cell counting was (2840.75±83.04)/mm2, and 12 months after operation, the average endothelial cell counting was (2837.75±82.95) /mm2. The difference was not statistically significant between preoperation and postoperation(t=0.518, P=0.776); The vision decreased in one eye 12 months after operation, and the imbalance of TICL arch height in right eye was found under mydriasis. The astigmatism was corrected by adjusting the TICL position, and the visual acuity was recovered. Conclusion The keys of TICL implantation for the correction of high myopic astigmatism are accurate preoperative parameters measurement, appropriate TICL selection, complete aspiration of sodium hyaluronate and stable postoperative intraocular pressure. Key words: Myopia, very high; Astigmatism; Lens, intraocular, toric, implantable, collamer

Three-year follow-up of posterior chamber toric phakic intraocular lens implantation for the correction of high myopic astigmatism in eyes with keratoconus

AimTo assess the clinical outcomes following the use of toric implantable collamer lenses (toric ICL, STAAR Surgical) for the correction of high myopic astigmatism with keratoconus.MethodsThis retrospective study evaluated 21...

Very High Fluence Collagen Cross-linking as a Refractive Enhancement of a Regressed Previous Astigmatic Keratotomy

To report a novel application of collagen cross-linking (CXL) in refractive astigmatic enhancement of previously performed astigmatic keratotomy. A 28-year-old woman with prior history of bioptics correction of high myopic astigmatism with femtosecond laser-assisted astigmatic keratotomy followed by topography-guided LASIK showed long-term regression of the astigmatism 4 years later. A novel CXL application was employed in an attempt to reverse the regression of the astigmatic keratotomy. The high fluence CXL intervention resulted in correction of 2 diopters of topographic and refractive cylinder. Uncorrected distance visual acuity changed from 20/50 to 20/20 and refraction from -0.50 -2.00 @ 90 to +0.25 -0.25 @ 90 at the 7-month follow-up. A possible novel application of high fluence CXL with refractive cornea effect is introduced. It may offer rapid and simple rehabilitation and its effect may be tapered.

Clinical outcomes of posterior chamber toric phakic intraocular lens implantation for the correction of high myopic astigmatism in eyes with keratoconus: 6-month follow-up

To assess the early clinical outcomes of toric implantable collamer lenses (toric ICL™, STAAR Surgical) for the correction of high myopic astigmatism with keratoconus. This study evaluated 27eyes of 14 patients with spherical equivalents of -10.11 ± 2.46 D (mean ± standard deviation) and astigmatism of -3.03 ± 1.58 D who underwent toric ICL implantation for mild keratoconus. Before, and 1, 3 and 6months after surgery, we assessed the safety, efficacy, predictability, stability, and adverse events of the surgery. LogMAR uncorrected visual acuity (UCVA) and LogMAR best spectacle-corrected visual acuity (BSCVA) were -0.09 ± 0.16 and -0.15 ± 0.09 respectively, 6months after surgery. The safety and efficacy indices were 1.12 ± 0.18 and 1.01 ± 0.25. At 6months, 85% and 96% of the eyes were within ±0.5 and ±1.0 D respectively of the targeted correction. Manifest refraction changes of 0.00 ± 0.35 D occurred from 1week to 6months. No vision-threatening complications occurred during the observation period. Toric ICL implantation was good in all measures of safety, efficacy, predictability, and stability for the correction of spherical and cylindrical errors in eyes with early keratoconus throughout the 6-month follow-up period, suggesting its viability as a surgical option for the treatment of such eyes.

Posterior chamber toric phakic intraocular lens implantation for high myopic astigmatism in eyes with pellucid marginal degeneration

We report a case in which toric intraocular Collamer lenses (ICLs) effectively corrected the refractive errors of pellucid marginal degeneration (PMD). Preoperatively, in the patient's right eye, the manifest refraction was -10.5 -3.5 x 55, the uncorrected distance visual acuity (UDVA) was 20/1000, and the corrected distance visual acuity (CDVA) was 20/16; in the left eye, the manifest refraction was -11.0 - 6.5 x 130 and the UDVA and CDVA were 20/1000 and 20/20, respectively. After bilateral implantation of a toric ICL, in the right eye, the manifest refraction was +1.50 - 0.75 x 10, the UDVA was 20/16, and the CDVA was 20/12.5; in the left eye, the manifest refraction was +2.5 -3.25 x 125 and the UDVA and CDVA were 20/40 and 20/16, respectively. No sign of progressive disease and no vision-threatening complication were observed during the 6-month follow-up. Toric ICL implantation may be a viable surgical option for the correction of high myopic astigmatism in eyes with PMD. No author has a financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes.

Toric Implantable Collamer Lens for High Myopic Astigmatic Asian Eyes

To evaluate early visual outcomes, refractive outcomes, and complications of the Toric Implantable Collamer Lens (TICL) for the correction of high myopic astigmatism in Asian eyes. Prospective, nonrandomized clinical study. Forty-four eyes of 29 patients with myopia (spherical equivalent) between 6 and 18.25 diopters (D), and 1 and 4.5 D of astigmatism. Implantation of TICL. Uncorrected visual acuity (UCVA), manifest refraction, best spectacle-corrected visual acuity (BSCVA), and postoperative complications. At 6 months postoperatively, 70.59% of eyes had 20/20 or better UCVA and 68.57% had postoperative UCVA better than or equal to preoperative BSCVA. At baseline, no eyes had refractive cylinder <1 D; however, postoperatively 77.14% of eyes had <1.00 D of refractive cylinder. The mean refractive cylinder changed from 2.64 D (+/-0.91) preoperatively to 0.59 D (+/-0.51) postoperatively. Sixty percent of eyes were within 0.50 D and 85.71% of eyes were within 1.00 D of the targeted cylinder correction. Baseline manifest refraction spherical equivalent (MRSE) changed from -13.18 D (+/-2.41) to 0.00 D (+/-0.42) postoperatively. The number of eyes within 0.50 D and 1.00 D of the predicted MRSE were 82.86% and 97.14%, respectively. A BSCVA of 20/15 occurred in 45.71% of eyes postoperatively compared with 22.86% of eyes preoperatively. A BSCVA of 20/20 or better occurred in 94.29% postoperatively compared with 77.14% preoperatively. Postoperatively, 1 eye (2.86%) lost 1 line of BSCVA and none lost >1 line of BSCVA. Thirty-one percent of eyes gained 1 line of BSCVA and 8.57% gained 2 lines of BSCVA postoperatively. Misalignment of TICL axis occurred in 2 eyes of 2 patients. The visual outcomes, refractive outcomes, and predictability are comparable with the United States Food and Drug Administration data on TICLs in non-Asian eyes. Safety concerns were not identified.

Phakic Toric Implantable Collamer Lens Implantation for the Correction of High Myopic Astigmatism in Eyes With Keratoconus

To present two patients in whom phakic toric Implantable Collamer Lenses (toric ICL, STAAR Surgical) have been effective for the correction of high myopic astigmatism with stable keratoconus. Both patients had a history of contact lens intolerance, and refraction and corneal topography were stable for 3 to 4 years. Preoperatively, the manifest refraction was -10.00 -6.00 x 100 in case 1 and -8.00 -2.75 x 100 in case 2. Postoperatively, the manifest refraction was +0.50 -1.00 x 90 in case 1 and -0.25 -1.25 x 100 in case 2. Uncorrected visual acuity and best spectacle-corrected visual acuity were markedly improved after implantation in both patients. No progressive sign of keratoconus was seen during 1-year follow-up. Phakic toric ICL implantation may be an alternative for the correction of high myopic astigmatism in eyes with stable keratoconus.