The Effect of Astigmatism Axis on Visual Acuity

2016 ◽  
Vol 27 (3) ◽  
pp. 308-311 ◽  
Author(s):  
Michael Mimouni ◽  
Achia Nemet ◽  
Russell Pokroy ◽  
Tzahi Sela ◽  
Gur Munzer ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Refractive Surgery ◽  
Laser In Situ Keratomileusis ◽  
Stepwise Multiple Regression ◽  
Spherical Equivalent ◽  
Tel Aviv ◽  
Uncorrected Distance Visual Acuity ◽  
Laser Refractive Surgery ◽  
Better Than

Purpose To evaluate the effect of astigmatism axis on uncorrected distance visual acuity (UDVA) in emmetropic eyes that underwent laser refractive surgery. Methods This retrospective study included patients who underwent laser in situ keratomileusis or photorefractive keratectomy between January 2000 and December 2015 at the Care-Vision Laser Centers, Tel Aviv, Israel. Eyes with a 3-month postoperative spherical equivalent between -0.5 D and 0.5 D were included in this study. Eyes with ocular comorbidities and planned ametropia were excluded. Study eyes were divided into 3 groups according to the steep astigmatic axis: with the rule (WTR) (60-120), oblique (31-59 or 121-149), and against the rule (ATR) (0-30 or 150-180). The UDVA of these 3 groups was compared. The oblique group was divided into oblique ATR and oblique WTR, which were compared with each other. Results A total of 17,416 consecutive eyes of 8,708 patients were studied. The WTR eyes (n = 10,651) had significantly better UDVA (logMAR 0.01 ± 0.08) than the oblique (n = 3,141, logMAR 0.02 ± 0.09) and ATR eyes (n = 3,624, logMAR 0.02 ± 0.10) (p<0.001). The oblique WTR group had significantly better UDVA than the oblique ATR group (p<0.001). The UDVA of the oblique and ATR groups was similar. Stepwise multiple regression analysis showed that the group accounted for 15% of the UDVA variance (p = 0.04). Conclusions The astigmatic axis has a small but significant effect on UDVA in emmetropic eyes; WTR was better than oblique and ATR astigmatism. Therefore, when correcting astigmatism, it may be preferable to err towards WTR astigmatism.

scholarly journals Visual differences in topography-guided versus wavefront-optimized LASIK in the treatment of myopia: a Meta-analysis

2021 ◽  
Vol 14 (10) ◽  
pp. 1602-1609
Author(s):  
Peng-Cheng Hu ◽  
◽  
Xian-Hui Wu ◽  
Yan-Qing Li ◽  
Ke-Wei Li ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Web Of Science ◽  
Spherical Aberration ◽  
Meta Analysis ◽  
Laser In Situ Keratomileusis ◽  
Wavefront Aberration ◽  
Spherical Equivalent ◽  
Uncorrected Distance Visual Acuity ◽  
Manifest Refraction

AIM: To investigate the potential differences between topography-guided (TG) and wavefront-optimized (WFO) laser in situ keratomileusis (LASIK) for the treatment of myopia. METHODS: A systematic literature search was performed to determine relevant trials comparing LASIK with TG and WFO from the time of library construction to August 2020, and The PubMed, Cochrane, Web of Science, EMBASE and Chinese databases (i.e. CNKI, CBM, WAN FANG and VIP) were accessed. The data on visual acuity, refractive status and wavefront aberration were retrieved and evaluated from three to six months after surgery. STATA (version 14.0) software was used for statistical analysis. A cumulative Meta-analysis was simultaneously performed. RESULTS: Eleven studies with a total of 1425 eyes were incorporated. No statistically significant differences were evident between TG and WFO ablation in the proportion of eyes achieving an uncorrected distance visual acuity (UCVA) of 20/20 or better (P=0.377), gaining one line or more (P=0.05), postoperative cylinder (P=0.40), vertical coma (P=0.593) and horizontal coma (P=0.957). After TG ablation, the proportion of the patients’ eyes of which postoperative refraction is within ±0.5 diopter of the target refraction was significantly higher than that undergoes WFO (P=0.003). As opposed to the WFO group, manifest refraction spherical equivalent (MRSE; P=0.000) was lower, and UCVA (P=0.005) was better in the TG group. The higher-order aberrations (HOAs; P=0.000), spherical aberration (P=0.000) and coma (P=0.000) were significantly lower in TG group. The cumulative Meta-analysis illustrated that the proportion of eyes achieving UCVA of 20/20 or better, postoperative refraction within ±0.5 diopter, and MRSE has steady between the two groups. CONCLUSION: Both TG-LASIK and WFO-LASIK are safe, effective, and predictable for correcting myopia. TG-LASIK may produce fewer aberration and is more precise than WFO-LASIK.

scholarly journals Comparison of Intraocular Pressure before and after Laser In Situ Keratomileusis Refractive Surgery Measured with Perkins Tonometry, Noncontact Tonometry, and Transpalpebral Tonometry

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Isabel Cacho ◽  
Juan Sanchez-Naves ◽  
Laura Batres ◽  
Jesús Pintor ◽  
Gonzalo Carracedo
Keyword(s):  
Intraocular Pressure ◽  
Refractive Surgery ◽  
Corneal Thickness ◽  
Laser In Situ Keratomileusis ◽  
Spherical Equivalent ◽  
Transpalpebral Tonometry ◽  
Spherical Equivalent Refraction ◽  
Before And After ◽  
Noncontact Tonometry

Purpose. To compare the intraocular pressure (IOP) before and after Laser In Situ Keratomileusis (LASIK), measured by Diaton, Perkins, and noncontact air pulse tonometers.Methods. Fifty-seven patients with a mean age of 34.88 were scheduled for myopia LASIK treatment. Spherical equivalent refraction (SER), corneal curvature (K), and central corneal thickness (CCT) and superior corneal thickness (SCT) were obtained before and after LASIK surgery. IOP values before and after surgery were measured using Diaton, Perkins, and noncontact air pulse tonometers.Results. The IOP values before and after LASIK surgery using Perkins tonometer and air tonometers were statistically significant (p<0.05). However, no significant differences were found (p>0.05) for IOP values measured with Diaton tonometer. CCT decreases significantly after surgery (p<0.05) but no statistical differences were found in SCT (p=0.08). Correlations between pre- and postsurgery were found for all tonometers used, withp=0.001andr=0.434for the air pulse tonometer,p=0.008andr=0.355for Perkins, andp<0.001andr=0.637for Diaton.Conclusion. Transpalpebral tonometry may be useful for measuring postsurgery IOP after myopic LASIK ablation because this technique is not influenced by the treatment.

scholarly journals Comparison of outcomes after topography-modified refraction versus wavefront-optimized versus manifest topography-guided LASIK

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Jaeryung Kim ◽  
Sung-Ho Choi ◽  
Dong Hui Lim ◽  
Gil-Joong Yoon ◽  
Tae-Young Chung
Keyword(s):  
Visual Acuity ◽  
Vector Analysis ◽  
Laser In Situ Keratomileusis ◽  
Distance Visual Acuity ◽  
Postoperative Astigmatism ◽  
Uncorrected Distance Visual Acuity ◽  
Manifest Refraction ◽  
Corrected Distance Visual Acuity ◽  
Myopic Astigmatism

Abstract Background To compare the outcomes of myopia and myopic astigmatism corrected with topography-modified refraction laser in situ keratomileusis (TMR-LASIK), wavefront-optimized (WFO) LASIK, and topography-guided (TG) LASIK with a correction target based on the manifest refraction (manifest TG-LASIK). Methods This observational, retrospective cohort study included patients who underwent LASIK using the WaveLight® EX500 excimer laser to correct myopia and myopic astigmatism between August 2016 and July 2017. Patients who underwent TMR-LASIK (85 patients), WFO-LASIK (70 patients), or manifest TG-LASIK (40 patients) were enrolled, and only one eye from each patient was analyzed. All participants underwent measurement of the uncorrected distance visual acuity (UDVA), best-corrected distance visual acuity (BCVA), manifest refraction, vector analysis of astigmatic change, corneal topography, and corneal wavefront analysis at baseline and at every posttreatment visit. Results Three months postoperatively, a UDVA of 0.0 logMAR or better and manifest refraction spherical equivalent (MRSE) within ±0.5 diopters (D) did not differ across the TMR-, WFO-, and manifest TG-LASIK groups. However, the residual cylinder in the TMR group was significantly larger than that in the WFO and manifest TG groups. The magnitude of error in the TMR group measured using astigmatism vector analysis was significantly higher than that in the WFO and manifest TG groups. Conclusions Although these three LASIK platforms achieved the predicted surgical outcomes, TMR-LASIK overcorrected astigmatism and showed a higher residual postoperative astigmatism compared with WFO- and manifest TG-LASIK.

scholarly journals Corneal Refractive Surgery in Patients with History of Optic Neuritis

2019 ◽  
Author(s):  
Majid Moshirfar ◽  
William D. Wagner ◽  
Steven H. Linn ◽  
Tanner W. Brown ◽  
Jackson L. Goldberg ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Optic Neuritis ◽  
Refractive Surgery ◽  
Retrospective Chart Review ◽  
Uncorrected Distance Visual Acuity ◽  
Tertiary Center ◽  
Before And After ◽  
History Of ◽  
Corneal Refractive Surgery

Purpose: The purpose of this study was to evaluate the risk of recurrence of optic neuritis after corneal refractive surgery in patients with a history of optic neuritis and to examine the safety and efficacy of the procedure in this population. Methods: This was a retrospective chart review of patients with a history of optic neuritis who underwent laser-assisted in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK) at a single tertiary center from June 1996 to December 2014. Fifteen eyes of 14 patients were included in this study. Visual acuity before and after the surgery was recorded. Patients were followed-up for over five years postoperatively for the recurrence of optic neuritis. Results: The average LogMAR best corrected visual acuity (BCVA) preoperatively was 0.12 ± 0.19 (–0.10 to 0.60) and postoperatively was 0.06 ± 0.10 (–0.10 to 0.30). No eyes lost lines of BCVA. The average LogMAR uncorrected distance visual acuity (UDVA) after surgery was 0.12 ± 0.13 (0.00 to 0.48). Twenty-eight percent of patients reached a UDVA of 20/20 or better after refractive surgery. Optic neuritis recurred in 3/15 (20%) eyes and 3/14 patients (21%). Conclusion: While corneal refractive procedures appear safe in patients with a history of optic neuritis, our data suggest that their efficacy may be reduced.

scholarly journals Accommodation Amplitude Before and After Laser In Situ Keratomiletus (LASIK) In Myopic Patients

2020 ◽  
Vol 3 (1) ◽  
pp. 1-18
Author(s):  
Bonita Asyigah ◽  
Ani Ismail
Keyword(s):  
Visual Acuity ◽  
Intraocular Pressure ◽  
Refractive Surgery ◽  
Laser In Situ Keratomileusis ◽  
Adaptation Mechanism ◽  
Near Vision ◽  
Before And After ◽  
Center Hospital

ABSTRACT Introductions: Laser in situ Keratomileusis (LASIK) is the most common refractive surgery to treat myopia. One of the most common complain after this procedure is blurry near- vision. Objectives: To evaluate the role of accommodation amplitude (AA) in myopic patients before and after LASIK and its effect to blurry near-vision in myopic patients after LASIK Methods: Patients with myopia who underwent LASIK procedure in Sriwijaya Eye Center Hospital from January to February 2018 studied prospectively. AA was assessed before and after LASIK with 1 day, 1 week and 1 month. Myopia degree, intraocular pressure (IOP), age, gender, ablation and corneal profile were also assessed. Results: A total 52 eyes from 32 patients were included. Visual acuity (VA) of all sample were significantly improve in 1 day after LASIK (p 0,001). Mean AA in myopic patients before LASIK 9,25 D and AA 1 day after LASIK were all significantly decrease into 9,00D (p 0,012) which can cause in blurry near- vision after LASIK. In 1 month followed-up, mean AA is significantly improved into 11,00 D (p 0,000) with no complain. Other factor that affect the changing AA were corneal cell density (CD), IOP and AA before LASIK. Conclusions: There is significant AA difference in myopic patients before and after LASIK. Blurry near-vision after LASIK is caused by AA adaptation mechanism after LASIK.

scholarly journals Outcomes of Refractive Surgery Consultations at an Academic Center: Characteristics Associated with Proceeding (or Not Proceeding) with Surgery

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Irene C. Kuo ◽  
Benjamin Lee ◽  
Jiangxia Wang
Keyword(s):  
Refractive Surgery ◽  
Laser In Situ Keratomileusis ◽  
Spherical Equivalent ◽  
Implantable Collamer Lens ◽  
High Patient Satisfaction ◽  
Academic Center ◽  
Johns Hopkins University ◽  
Technological Limitations

Objective. Refractive surgery volume has not rebounded despite economic recovery and literature describing safety, efficacy, and high patient satisfaction. We sought to examine characteristics of consultation seekers and status after consultation. Methods. Charts of patients seeking refractive surgery at Johns Hopkins University from 2013 through 2016 were retrospectively reviewed for age, gender, refractive characteristics, and outcome: surgery (photorefractive keratectomy, laser in-situ keratomileusis, implantable collamer lens, or refractive lens exchange); no surgery—“lost candidate” (good candidates who were lost after consultation); noncandidates based on technological limitations or contraindications; or no surgery—possessing expectations that surgery would not meet. Associations between characteristics and status after consultation were examined. Results. Twenty percent (142/712) of all patients were “lost candidates”; 57% (408/712) completed surgery. More women (56% or 401/712) sought consultation, but a greater percentage (63% or 195/311) of men completed surgery than women did (53% or 213/401) p=0.02. Of consultation seekers, 60% were low myopes, 29% were high myopes (>6 diopters of myopic spherical equivalent), and 11% were hyperopes. Surgical patients’ mean age was 34.2 ± 10.2 (standard deviation) years; for each additional year of age, patients were less likely to have surgery p<0.001. Hyperopes were ≥3 times more likely than myopes to have expectations not met by surgery or to be noncandidates than to have surgery p<0.005. Conclusions. Most patients seeking refractive surgery had 6 diopters or less of myopia. About 20% of patients were lost after consultation; better counseling and follow-up of candidates may be warranted. Expectations and technology limit eligibility for many, especially hyperopes. Low surgery volume may affect training of future refractive surgeons.

scholarly journals Effect of Photorefractive Keratectomy and Laser in situ Keratomileusis in High Myopia on logMAR Visual Acuity and Contrast Sensitivity

2003 ◽  
Vol 46 (1) ◽  
pp. 15-18 ◽  
Author(s):  
Hana Langrová ◽  
Matthias Derse ◽  
Dagmar Hejcmanová ◽  
Alena Feuermannová ◽  
Pavel Rozsíval ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Contrast Sensitivity ◽  
High Myopia ◽  
Laser In Situ Keratomileusis ◽  
Photorefractive Keratectomy ◽  
Spherical Equivalent ◽  
Spatial Frequencies ◽  
Quality Of Vision

Purpose: To compare effect of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) on contrast sensitivity (CS) and best corrected visual acuity (BCVA) in high myopia. Methods: 38 myopes (PRK) and 31 patients (LASIK) were examined before and 1, 3, 6, and 12 months postoperatively. Mean preoperative spherical equivalent was -8.0 ± 1.7D (PRK) and -9.2 ± 2.1D (LASIK). CS was tested on a computerized system of the Contrast Sensitivity 8010 Type at 6 spatial frequencies (0.74 and 29.55 c/deg), BCVA was measured on logMAR charts. Results: At 12 months postoperatively, mean spherical equivalent was -0.6 ± 1.0D (PRK) and -1.0 ± 0.8D (LASIK). Postoperative values of CS were significantly higher in the PRK group, except for spatial frequencies of 3.69 and 7.39 c/deg up to 3 months postoperatively. The initial significant decrease of BCVA lasted up to 6 months after PRK. In the LASIK group BCVA was not significantly different from its preoperative level at the 3-months follow-up. Conclusions: The significant improvement of CS after PRK suggest that PRK can improve quality of vision in eyes with high myopia. Although recovery of BCVA after LASIK was faster than after PRK, there may be a persistent decrease in CS.

scholarly journals Effect of Transepithelial Photorefractive Keratectomy without Mitomycin C in the Treatment of Femtosecond Laser In Situ Keratomileusis Corneal Flap Complications

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Jing Wang ◽  
Weiqian Cao ◽  
Liming Tao
Keyword(s):  
Visual Acuity ◽  
Femtosecond Laser ◽  
Mitomycin C ◽  
Laser In Situ Keratomileusis ◽  
Photorefractive Keratectomy ◽  
Distance Visual Acuity ◽  
Uncorrected Distance Visual Acuity ◽  
Haze Formation

Purpose. To assess the efficacy and safety of transepithelial photorefractive keratectomy (TPRK) without mitomycin C as treatment for femtosecond laser in situ keratomileusis (FS-LASIK) corneal flap complications. Methods. Eight patients with corneal flap complications that occurred after FS-LASIK (five with eccentric flaps, two with buttonhole flaps, and one with a thick flap) were included in the study. Patients were treated with TPRK without mitomycin C between two weeks and twelve months after surgery. The postoperative manifest refraction, uncorrected distance visual acuity, and haze formation were assessed during six months of follow-up. Results. The mean manifest refractive spherical and cylinder refraction was 0.16 ± 0.26 and −0.44 ± 0.33 diopters, respectively, at six months postoperatively. The uncorrected distance visual acuity was above 20/25 in all patients after six months of follow-up. No haze formation was detected. Conclusions. TPRK without mitomycin C appears to be a safe and effective treatment for FS-LASIK corneal flap complications.

scholarly journals Flap Sliding Technique for Managing Flap Striae following Laser In Situ Keratomileusis

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Khaled Abdelazeem ◽  
Mohamed A. Nassr ◽  
Hazem Abdelmotaal ◽  
Ehab Wasfi ◽  
Dalia Mohamed El-Sebaity
Keyword(s):  
Visual Acuity ◽  
Laser In Situ Keratomileusis ◽  
Distance Visual Acuity ◽  
Uncorrected Distance Visual Acuity ◽  
Corrected Distance Visual Acuity ◽  
Safe Technique ◽  
Optical Zone ◽  
Sliding Technique ◽  
Flap Elevation

Purpose. To assess the efficacy and safety of a simple, noninvasive, “flap-sliding” technique for managing flap striae following laser in situ keratomileusis (LASIK). Methods. This prospective, interventional study included eyes with post-LASIK flap striae. All eyes underwent flap sliding 1-2 days after surgery. Following flap edge epithelialisation, a cellulose sponge was used to gently slide the flap perpendicular to the striae direction. This technique allows for flap striae treatment without flap lifting, avoiding any associated lifting complications. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and refractive error were monitored one day after the flap-sliding procedure. Results. Fifteen eyes (15 patients) with post-LASIK flap striae were managed using the flap-sliding technique. The procedure did not successfully relocate the flap striae in 1 eye, and flap elevation and floating (using a balanced salt solution) were required. Therefore, 14 eyes were included in post-flap-sliding analyses. The UDVA improved in all patients the first day after the flap-sliding procedure was performed, with 11 of 14 eyes (78.57%) reaching an UDVA of 20/25 or better. Complications following flap sliding occurred in 2 eyes (14.29%). One eye had intraoperative epithelial abrasion, and 1 eye had residual postoperative striae outside of the optical zone. Conclusion. The flap-sliding technique is a simple, noninvasive, efficient, and safe technique for managing post-LASIK flap striae that develop after epithelial healing in the early post-LASIK period. This trial is registered with NCT04055337.

scholarly journals Femtosecond Laser-Assisted In Situ Keratomileusis Treatment of Residual Refractive Error following Femtosecond Laser-Enabled Keratoplasty

2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Elizabeth Shen ◽  
Lester Tsai ◽  
Hannah Muniz Castro ◽  
Matthew Wade ◽  
Marjan Farid
Keyword(s):  
Visual Acuity ◽  
Femtosecond Laser ◽  
Spherical Equivalent ◽  
Case Review ◽  
Retrospective Case ◽  
Distance Visual Acuity ◽  
Uncorrected Distance Visual Acuity ◽  
Corrected Distance Visual Acuity ◽  
The University

Purpose. To evaluate the safety and effectiveness of femtosecond laser-assisted in situ keratomileusis (LASIK) in the treatment of residual myopia and astigmatism following femtosecond laser-enabled keratoplasty (FLEK). Design. Retrospective case review. Methods. Chart review of all patients with prior FLEK who subsequently underwent femto-LASIK surgery after full suture removal was performed at the Gavin Herbert Eye Institute at the University of California, Irvine. A total of 14 eyes in 13 patients met this criterion, and their comprehensive examinations performed at standard intervals were reviewed. Main outcome measures include uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) expressed as the logarithm of the minimum angle of resolution (logMAR), manifest refractive astigmatism, and spherical equivalent. Results. From the preoperative visit to the 3 month visit, all 14 eyes significantly improved in UDVA (logMAR, 0.93 ± 0.23 to 0.44 ± 0.32, P=0.002) with no loss of CDVA (logMAR, 0.26 ± 0.19 to 0.18 ± 0.23, P=0.50). All 14 eyes showed significant improvement in manifest refractive astigmatism (4.71 ± 1.77 to 2.18 ± 1.45 diopters (D), P=0.003) and spherical equivalent (−2.57 ± 2.45 to −0.48 ± 0.83 D, P=0.0007). There were no flap or graft complications as a result of femto-LASIK. Conclusions. Our findings suggest that femto-LASIK on eyes with prior FLEK is safe and effective in improving visual acuity and reducing residual astigmatism.

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