Treatment Of High Astigmatism Research Articles

Treatment of High Astigmatism after Penetrating Keratoplasty in Patients with Keratoconus with 800 µm Base Intrastromal Corneal Ring Segments: A Retrospective Study

Treatment of High Astigmatism after Penetrating Keratoplasty in Patients with Keratoconus with 800 µm Base Intrastromal Corneal Ring Segments: A Retrospective Study

Comparison of refractive and visual outcomes between image-guided system-assisted small-incision lenticule extraction and wavefront-optimized FS-LASIK in treatment of high astigmatism.

To compare the refractive and visual results of image-guided system-assisted small-incision lenticule extraction (IGA-SMILE) and wavefront-optimized femtosecond laser in situ keratomileusis (FS-LASIK) in the treatment of high astigmatism. Osmangazi Aritmi Hospital, Bursa, Turkey. Retrospective. This retrospective case-matched study included 64 eyes that had undergone IGA-SMILE and 64 eyes that had undergone wavefront-optimized FS-LASIK. The mean preoperative myopia and astigmatism were -4.05 ± 1.98 diopter (D) and 3.11 ± 1.06 D in the IGA-SMILE group and -4.21 ± 2.23 D and -3.15 ± 0.62 D in the FS-LASIK group, respectively. One year later, visual and refractive results were compared in the groups. Vector analysis based on Alpins method was performed to evaluate astigmatic treatment. 128 eyes of 128 patients were included in this study. At 1 year, the residual astigmatism was -0.21 ± 0.25 D in the IGA-SMILE group and -0.21 ± 0.24 D in the FS-LASIK group ( P = .305). In the IGA-SMILE group, 57 eyes (89.1%) achieved uncorrected distance visual acuity of 20/20 or better, as did 56 eyes (85.9%) in the FS-LASIK group. Vector analysis results demonstrated that the difference vectors were 0.22 ± 0.24 D and 0.21 ± 0.22 D ( P = .230), the correction indexes were 0.95 ± 0.08 and 0.95 ± 0.08 ( P = .239), and the indices of success were 0.08 ± 0.09 and 0.08 ± 0.09 ( P = .248) in the IGA-SMILE and the FS-LASIK groups, respectively. The combination of an image-guided system with SMILE resulted in high efficacy and safety indices that were comparable with FS-LASIK surgery.

Two-year outcomes after full-thickness astigmatic keratotomy combined with small-incision lenticule extraction for high astigmatism

BackgroundTo evaluate clinical outcomes after full-thickness astigmatic keratotomy (FTAK) combined with small-incision lenticule extraction (SMILE) in eyes with high astigmatism.MethodsThis study comprised 75 eyes of 43 patients with over 4.0 diopters (D) of astigmatism who were treated with SMILE after FTAK. Visual acuities and refractive measurements were evaluated at 1 month after FTAK, and 1, 6, 12, and 24 months after SMILE. Vector analysis of the astigmatic changes was performed using the Alpins method.ResultsTwenty-four months after the combined procedure, the average spherical equivalent was reduced from − 6.56 ± 2.38 D to − 0.36 ± 0.42 D (p < 0.001). The uncorrected and corrected distance visual acuities improved from 1.54 ± 5.53 to − 0.02 ± 0.09 and from − 0.03 ± 0.07 D to − 0.07 ± 0.08 D (both p < 0.001), respectively. The preoperative mean astigmatism was − 5.48 ± 1.17 D, which was reduced to − 2.27 ± 0.97 D and − 0.34 ± 0.26 D at 1 month after FTAK and 24 months after SMILE, respectively (p < 0.001). The surgically-induced astigmatism after FTAK, SMILE, and FTAK and SMILE combined was 3.38 ± 1.18 D, 2.22 ± 0.84 D, and 5.39 ± 1.20 D, respectively. Furthermore, the correction index of FTAK, SMILE, and FTAK and SMILE combined was 0.63 ± 0.17, 0.90 ± 0.40, and 0.98 ± 0.06, respectively. There were no intraoperative or postoperative complications.ConclusionOur surgical procedure combining FTAK and SMILE showed good and stable clinical outcomes during two-year follow-up for the treatment of high astigmatism.

Treatment of High Astigmatism with WaveLight Allegretto Eye-Q Excimer Laser Platform

Introduction:The WaveLight Allegretto Eye-Q is a flying-spot excimer laser, with a pulse repetition rate of 400Hz, with two galvanometric scanners for positioning laser pulses. The system has an infrared high speed camera operating at 400Hz to track the patient’s eye movements that either compensates for changes in eye position or interrupts the treatment if the eye moves outside a preset predetermined range.Aim:The purpose of this study was to investigate WaveLight Allegretto Eye-Q 400Hz laser delivery platform aimed to correct astigmatism by subjecting the pre and postoperative astigmatic values to vector analysis.Methods:Patients were divided into two groups, depending on the type of astigmatism. Astigmatism was between 2 and 7 diopters (D). A total of 188 eyes (110 patients), 127 eyes (71 patients) with myopic astigmatism and 61 eyes (39 patients) with mixed astigmatism underwent unremarkable LASIK correction on WaveLight Allegretto Eye-Q 400Hz. The preoperative and postoperative sphere, negative cylinder [C] and axis (ø) of manifest refractions were subjected to vector analysis by calculations of the standard J0 (cos [4π(ø-90)/360]xC/2) and J45 (sin[4π(ø-90)/ 360]xC/2).Results:Reporting the key results, we found that J0 significantly reduced after LASIK (p<0.001) but not J45. There was no significant association between individual pairs of pre and postoperative J0 &J45 values.Conclusion:WaveLight Allegretto 400Hz showed excellent results for treating patients with high astigmatism, regardless whether it is mixed or myopic astigmatism. The J45 did not reduce significantly possibly because of the low number of eyes with oblique astigmatism. There was no genuine difference postoperatively between groups treated on WaveLight Allegretto platform according to the vector analyses.

Wavefront-Guided Photorefractive Keratectomy in the Treatment of High Astigmatism Following Keratoplasty.

To report the outcome of wavefront-guided photorefractive keratectomy (WG-PRK) in the treatment of high astigmatism following keratoplasty. A retrospective, interventional analysis including patients with high astigmatism following either penetrating keratoplasty or deep anterior lamellar keratoplasty, who underwent WG-PRK. Thirteen eyes (7 right eyes) of 12 patients (10 male) aged 35.1 ± 5.9 years were included. Preoperative astigmatism ranged between 3.00 and 5.00 D. Average follow-up time was 14.0 ± 6.2 months. Uncorrected distance visual acuity (UDVA) improved from 0.97 ± 0.58 logarithm of the minimum angle of resolution (logMAR) (Snellen equivalent ∼20/187) preoperatively to 0.13 ± 0.15 logMAR (Snellen equivalent ∼20/27) at 6 months and 0.14 ± 0.16 logMAR (Snellen equivalent ∼20/28) at the final follow-up (P = 0.001 and P = 0.002, respectively). UDVA ≥20/40 increased from 1 eye (7.7%) preoperatively to 13 eyes (100%) at 6 months and 12 eyes (92.3%) at the final follow-up (P < 0.001 for both). UDVA ≥20/25 increased from 1 eye (7.7%) preoperatively to 6 eyes (46.2%) at 6 months and at the final follow-up (P = 0.027 for both). Mean astigmatism improved from -3.98 ± 0.75 D to -1.27 ± 0.82 D and -1.40 ± 1.04 at 6 months and at the last follow-up, respectively (P = 0.001 for both). Preoperative astigmatism was ≥3.00 D in all eyes and was reduced to ≤2.50 D in all eyes at 6 months postoperatively, with 7 eyes (63.6%) having ≤1.00 D of astigmatism at both 6 months and the final follow-up. WG-PRK was safe and effective in the treatment of high and regular postkeratoplasty astigmatism.

Vector analysis of astigmatism before and after LASIK: a comparison of two different platforms for treatment of high astigmatism

To compare the outcomes of astigmatic laser in-situ keratomileusis (LASIK) procedures between two different platforms using J0 and J45 vector analysis. Patients were divided into four groups, depending on the type of astigmatism and laser platform on which they were treated. Astigmatism was between 2 and 7 diopters (D). One hundred and thirty-five patients with myopic astigmatism (246 eyes) and 102 patients with mixed astigmatism (172 eyes) underwent unremarkable LASIK correction on Wavelight Allegretto Eye-Q 400Hz and Schwind Amaris 750S laser platform. The preoperative and postoperative sphere, negative cylinder [C] and axis (ø) of manifest refractions were subjected to vector analysis by calculations of the standard J0 (cos [4π(ø-90)/360]xC/2) and J45 (sin[4π(ø-90)/360]xC/2). Reporting the key results, we found J0 significantly reduced after LASIK in both groups (p < 0.001) but not J45. There was no significant association between individual pairs of pre and postoperative J0 & J45 values. There was no significant difference between the outcomes of the two platforms. Wavelight Allegretto 400Hz and Schwind Amaris 750S showed excellent results for treating patients with astigmatism, regardless whether it is mixed or myopic astigmatism. The J45 did not reduce significantly possibly because of the low number of eyes with oblique astigmatism. There was no genuine difference post-operatively between groups treated on two different laser platforms according to the vector analyses.

IntraLase-Enabled Astigmatic Keratotomy for Correction of Astigmatism After Descemet Stripping Automated Endothelial Keratoplasty: A Case Report

The purpose of this study was to report on the treatment of high astigmatism after Descemet stripping automated endothelial keratoplasty with IntraLase (IntraLase, Inc., Irvine, CA) -enabled astigmatic keratotomy (IEAK). A 85-year-old patient with pseudophakic bullous keratopathy underwent an intraocular lens exchange and Descemet stripping automated endothelial keratoplasty surgery on his left eye. Four months after surgery, high astigmatism was treated with IEAK. Preoperative uncorrected visual acuity was 20/300 and best spectacle-corrected visual acuity was 20/100 with a refraction of -4.00 + 5.75 x 150. Seven months post-IEAK, uncorrected visual acuity was improved to 20/60 and best spectacle-corrected visual acuity 20/40-2 with a refraction of -1.50 + 2.75 x 100. IEAK, as presented here, can be used for the correction of high post-Descemet stripping automated endothelial keratoplasty astigmatism.

Corneal Wedge Excision in the Treatment of High Astigmatism After Penetrating Keratoplasty

To report 5 cases of high astigmatism after penetrating keratoplasty (PK) treated with corneal wedge excisions. We report our experience of 5 patients treated with corneal wedge excisions for high astigmatism after PK. A thin sliver of cornea measuring between 0.1 and 0.2 mm in thickness was excised from just inside the graft-recipient interface. The length of the incision centered at the axis of the flatter meridian of the cornea and was extended over a range of 60-90 degrees. The wound was closed with interrupted 10-0 nylon sutures placed every 15 degrees. We also report, for the first time, both pre- and postoperative corneal topography in 3 of our patients who underwent wedge excisions. The mean preoperative astigmatism was 15.2 D (range, 8.5-29.1 D). Postoperatively, after wedge excision, the mean astigmatism was reduced to 2.3 D (range, 1.9-3.7 D). The mean reduction in astigmatism was 12.9 D (range, 6.3-25.4 D). Corneal wedge resection is an effective treatment for high astigmatism after PK. It may prove particularly useful in cases of high astigmatism or where other treatments are not appropriate. We believe that there is still a role for wedge resection as one of many tools to be used in the treatment of high post-PK astigmatism.

Correction of high astigmatism with astigmatic keratotomy combined with laser in situ keratomileusis

Purpose To evaluate the efficacy, predictability, and stability of a combined procedure, arcuate keratotomy and laser in situ keratomileusis (LASIK), for the correction of high astigmatism. Setting Instituto de Microcirugı́a Ocular (IMO), Barcelona, Spain. Methods Fifteen eyes of 11 patients with naturally occurring astigmatism (NOA) (86.66%) or surgically induced astigmatism (SIA) (13.34%) between −3.00 and −8.00 diopters (D) who had astigmatic keratotomy were studied. The patients had a secondary procedure, LASIK, to correct the residual refractive error. Results Mean baseline spherical equivalent refraction was −2.47 D ± 3.69 (SD) and mean refractive cylinder, −4.59 ± 1.66 D. Twelve months after LASIK, mean spherical equivalent was −0.09 ± 1.50 D and the mean refractive cylinder, −1.21 ± 1.07 D. The mean cylindrical correction attempted in the NOA group was −4.05 ± 1.19 D and in the SIA group, −7.00 ± 1.41 D. Postoperatively, the values were −1.50 ± 1.17 D and −1.62 ± 0.17 D, respectively. Twelve months after LASIK, the uncorrected visual acuity (UCVA) was 0.5 ± 0.1. The UCVA in the NOA group (0.50 ± 0.08) was better than in the SIA group (0.32 ± 0.10). The efficacy index was 0.96 overall. Best corrected visual acuity deteriorated by 1 Snellen line in 1 case (6.6%) but improved by 1 and 2 Snellen lines in 4 cases (26.6%) and 2 cases (13.3%), respectively. All procedures were completed without adverse reactions intraoperatively or postoperatively. Conclusions This combined technique was effective in the treatment of high astigmatism, with excellent results compared with the results of each procedure alone. Because of its high predictability, we strongly recommend the technique in cases with astigmatism higher than 3.0 D, particularly in those with astigmatism higher than 5.0 D.