Recovery of Uncorrected Visual Acuity After Laser In Situ Keratomileusis or Photorefractive Keratectomy for Low Myopia

Cornea ◽  
2001 ◽  
Vol 20 (2) ◽  
pp. 153-155 ◽  
Author(s):  
Mark B. Walker ◽  
Steven E. Wilson
2015 ◽  
Vol 2015 ◽  
pp. 1-4
Author(s):  
Priyanka Chhadva ◽  
Florence Cabot ◽  
Anat Galor ◽  
Sonia H. Yoo

Purpose. To describe a case of 3 refractive procedures performed in one eye over 2 decades.Methods. Case report.Results. A 41-year-old patient presented for refractive surgery evaluation. His ocular history includes bilateral radial keratotomy performed 21 years ago for moderate myopia: spherical equivalence of −4.25 D bilaterally. Postoperative uncorrected visual acuity (UCVA) was 20/30; however, over time he developed a hyperopic shift and UCVA decreased to 20/40 in the right eye. Thus, laser-assisted in situ keratomileusis (LASIK) was performed at an outside institution 6.5 years later, and the patient had initial improvement of UCVA to 20/25. Due to a change in refractive error, the patient underwent uneventful astigmatic keratotomy 13 years after LASIK in the right eye, and 1.5 years after surgery best-corrected visual acuity was 20/25 with manifest refraction of −1.00+5.50×134°.  Conclusion. We report the outcomes and natural refractive progression in a patient who underwent three corneal refractive procedures over two decades. This case underlines the difficulties of long-term management of post-RK hyperopia and astigmatism.


2021 ◽  
pp. 889-893
Author(s):  
Ha Eun Sim ◽  
Min Ji Kang ◽  
Jee Hye Lee ◽  
Seung Hwa Baik ◽  
Sun Young Kim ◽  
...  

This report describes a case of Scheimpflug topography oriented adequate repositioning of a misaligned thick free flap after laser in situ keratomileusis (LASIK). A 24-year-old patient consulted for irregular astigmatism and disoriented free right eye flap. The patient previously underwent binocular LASIK at a private clinic. During the right eye surgery, the flap was repositioned after laser ablation due to the free flap. The free flap was not repositioned to its original configuration due to insufficient preoperative corneal marking. On examination, the uncorrected visual acuity was 0.4, and refractive power was +2.00 Dsph with −4.25 Dcyl axis 66 in the right eye. Scheimpflug topography revealed irregular right eye astigmatism. The sagittal curvature of topography showed a 40° counterclockwise misalignment of the steep axis of the cornea. The free flap was repositioned by 40° clockwise rotation. After this, the refractive corneal power improved to −1.00 Dsph with −1.00 Dcyl Axis 19 in the right eye. The uncorrected and best-corrected visual acuity improved to 20/30 and 20/25 (x − 0.25Dsph −1.25 Dcyl A20), respectively. This is the first report on free flap repositioning using Scheimpflug topography. As proper flap positioning was compromised because of the free LASIK flap with no preoperative corneal marking, the flap was effectively repositioned using Scheimpflug topography.


2021 ◽  
Author(s):  
Yunjie Zhang ◽  
Tiankun Li ◽  
Zhangliang Li ◽  
Mali Dai ◽  
Qinmei Wang ◽  
...  

Abstract Background To compare the quantitative and qualitative optical outcomes of single-step transepithelial photorefractive keratectomy (TPRK) and off-flap epipolis-laser in situ keratomileusis (Epi-LASIK) in moderate to high myopia. Methods In this prospective self-control study, we included patients with moderate to high myopia who were randomized to undergo TPRK in one eye and Epi-LASIK in the other eye. Twelve-month follow-up results for visual acuity, refraction, ocular high-order aberrations, contrast sensitivity, postoperative pain, epithelial healing, and haze grade were assessed. Results A total of 64 eyes (32 patients) were enrolled in the study. More eyes completed re-epithelialization in the TPRK group than in the Off-flap Epi-LASIK group 3–4 days postoperatively, while all eyes completed re-epithelialization by seven days. More eyes achieved a visual acuity (both UDVA and CDVA) of better than 20/20 in the TPRK group than in the Off-flap Epi-LASIK group. The ± 0.50 D predictability for correction of the spherical equivalent (SE) was higher in the eyes of the TPRK group (91%) than in those of the off-flap Epi-LASIK group (80%) 12 months after surgery. No significant differences in ocular aberrations, including coma, spherical, and trefoil, were found between the two groups at 12 months. There were also no significant differences in visual acuity, contrast sensitivity, pain, and haze grading between the two groups. Conclusions Both TPRK and off-flap Epi-LASIK are safe, effective, and predictable treatments for moderate to high myopia with comparable surgical outcomes. Trial registration: This study was retrospectively registered on ClinicalTrial.gov (NCT05060094, 17/09/2021).


2003 ◽  
Vol 46 (1) ◽  
pp. 15-18 ◽  
Author(s):  
Hana Langrová ◽  
Matthias Derse ◽  
Dagmar Hejcmanová ◽  
Alena Feuermannová ◽  
Pavel Rozsíval ◽  
...  

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.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Jing Wang ◽  
Weiqian Cao ◽  
Liming Tao

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.


2020 ◽  
Author(s):  
Zhongxiu Zhao ◽  
Miaomiao Zhu ◽  
Qian Jian ◽  
Xialu Liu ◽  
Pingting Ma ◽  
...  

Abstract Background The individualized ablation is not only able to correct corneal low-order aberrations but also improve the corneal high-order aberrations in corneal asymmetry patients. In this study, we compared the effect of patients with mid-to-high astigmatism asymmetric corneas (1-4D) after three different surgical methods: Selective coma guidance femtosecond Laser in-situ keratomileusis (CWFG-FS-LASIK),Aberration-Free femtosecond Laser in-situ keratomileusis (AF-FS-LASIK) and Small incision lenticule (SMILE).Methods One hundred and fourteen eyes from 58 patients were enrolled in the retrospective study. We measured and compared the best corrected visual acuity (BCVA), uncorrected visual acuity (UCVA), residual astigmatism, total coma, vertical coma (Z3-1), horizontal coma (Z31), Modulation Transfer Function (MTF) and Point Spread Function (PSF) at preoperation and postoperation after three months.Results Visual acuity of patients in three groups was increased after surgeries, but the improvements of visual acuity and residual astigmatism among them were no significant differences. However, the improvements of 4mm and 6mm total coma, Z3-1 and Z31 in CWFG-FS-LASIK were superior than in AF-FS-LASIK and SMILE. Consistent with this, the improvements of MTF and PSF (3mm and 5mm) in CWFG-FS-LASIK were better than in AF-FS-LASIK and SMILE.Conclusions In surgeries for treating patients with mid-to-high astigmatism in asymmetric corneas, the selective coma-guided mode was able to decrease the coma of original cornea, improve visual acuity and optimize the visual quality of patients.


2017 ◽  
Vol 46 (2) ◽  
pp. 901-907
Author(s):  
Yulin Lei ◽  
Jie Hou ◽  
Xiuyun Zheng

Objective Decentered flaps are rarely reported after femtosecond laser-assisted in situ keratomileusis flap procedures. We present a patient with a decentered flap after preparation of a corneal flap using the Femto LDV technique. Methods The 22-year-old man required a redo operation because of a decentered corneal flap. It was performed the same day at the patient's insistence and with his consent. The new corneal flap for the redo surgery was prepared using the femtosecond laser technique and IntraLase. Results Uncorrected visual acuity for each eye was 1.2 during the 12-month follow-up. The results of the Femtosecond laser technique showed good predictability and repeatability regarding the preparation of corneal flaps, but it still may cause some intraoperative complications. Conclusion Once redo surgery is needed, the size and depth of the initially prepared flap should be determined using anterior segment optical coherence tomography to pre-set the parameters for preparation of the redo flap.


2021 ◽  
pp. 112067212110334
Author(s):  
Olga Reitblat ◽  
Assaf Gershoni ◽  
Michael Mimouni ◽  
Eitan Livny ◽  
Yoav Nahum ◽  
...  

Purpose: To examine the clinical outcomes, efficacy, safety, and predictability of transepithelial photorefractive keratectomy (Trans-PRK) operations performed on the day of the first screening visit in comparison with operations scheduled at a following appointment. Methods: Data of consecutive patients with myopia of various degrees, who underwent Trans-PRK, were retrospectively analyzed. Findings were compared between patients who underwent Trans-PRK on the same day of first consultation to patients that underwent surgery at subsequent visits, following initial consultation on a different day. Results: The study included 599 eyes treated on the initial visit day and 1936 eyes treated on a subsequent visit. Mean final spherical equivalent was close to emmetropia in both groups ( p = 0.183). Efficacy indices were 0.928 ± 0.192 in the initial-visit group and 0.945 ± 0.163 in the second-visit group ( p = 0.152). Safety indices were 0.954 ± 0.156 and 0.955 ± 0.151 ( p = 0.707), respectively. No differences between the groups were seen in uncorrected visual acuity (UDVA) of ⩾20/20, ⩾20/25, and ⩾20/32. Only the sub-analysis of patients reaching UDVA of 20/40 or better was slightly lower in the first-visit (95.5%) compared with the second-visit group (97.9%, p = 0.001). Results of attempted correction within ±0.50 D were: 63.3% and 69.0%, respectively ( p = 0.009). Complications profiles in the two groups were comparable. Conclusions: Trans-PRK completed on the day of the first screening appointment demonstrated a similar safety outcome compared with subsequent-visits procedures, and slightly lower, yet comparable, results regarding efficacy and predictability.


2012 ◽  
Vol 69 (10) ◽  
pp. 852-857
Author(s):  
Mirko Resan ◽  
Miroslav Vukosavljevic ◽  
Milorad Milivojevic

Background/Aim. Photorefractive keratectomy (PRK), after laser in situ keratomileusis (LASIK), is commonly performed refractive surgical method worldwide. The aim of this study was to examine the effectiveness and safety of PRK in correction of various strengths of myopia and to assess how much corneal tissue is being removed with one diopter sphere (Dsph) correction by using different optical zones (OZ). Methods. A prospective study with a follow-up period of 6 months included 55 patients of which 100 myopic eyes were treated by PRK method (one eye was included in 10 patients). Myopic eyes with a preoperative best corrected visual acuity (BCVA) = 1.0 (20/20) were analysed. In order to assess the effectiveness of PRK operated myopic eyes were divided into four groups according to the dioptric power: 1)? -1.75 Dsph (n = 26); 2) from -2 to -3.75 Dsph (n = 44); 3) from -4 to -6.75 Dsph (n = 23), and 4) ? -7 Dsph (n = 7). Myopic eyes with preoperative BCVA ? 0.9 (amblyopic eyes) were excluded from the study, as well as eyes with astigmatism > -1.5 Dcyl. To assess the effectiveness of PRK we examined the percentage of eyes in the mentioned groups, which derived uncorrected visual acuity (UCVA) 6 months after the intervention to the following: a) UCVA = 1.0 (20/20) and b) UCVA ? 0.5 (20/40). To assess the safety of PRK we examined the frequency of intraoperative and postoperative complications. To estimate how much corneal tissue was removed with one Dsph correction by using different OZ, we used preoperative and postoperative (after 6 months) central pachymetry values expressed in ?m and volume of cornea (central 7 mm) expressed in mm?. In that sense, we used only the myopic eyes with clear preoperative spherical refraction. The total number of these eyes was 27, of which 16 eyes were treated using a 6.5 mm OZ and 11 eyes using a 7 mm OZ. Results. Refractive spherical equivalent (RSE) for all eyes was in the range from -0.75 to -8.75 Dsph, and preoperative mean value of RSE with standard deviation (mean RSE ? SD) was -3.32 ? 1.83 Dsph. Six months after PRK, 91% of eyes had UCVA = 20/20, and 99% of eyes had UCVA ? 20/40. In the first group (? -1.75 Dsph) preoperative mean RSE ? SD was -1.34 ? 0.32 Dsph, six months after PRK, 96% of eyes had UCVA = 20/20, and 100% of eyes had UCVA ? 20/40. In the second group (from -2 to -3.75 Dsph) preoperative mean RSE ? SD was - 2.95 ? 0.57 Dsph, six months after PRK, 89% of eyes had UCVA = 20/20, and 100% of eyes had UCVA ? 20/40. In the third group (from -4 to -6.75 Dsph) preoperative mean RSE ? SD was - 4.93 ? 0.70 Dsph, six months after PRK, 100% of eyes had UCVA = 20/20. In the fourth group (? - 7 Dsph) preoperative mean RSE ? SD was -7.71 ? 0.67 Dsph, six months after PRK, 57% of eyes had UCVA = 20/20, and 86% of eyes had UCVA ? 20/40. There were no intraoperative complications while postoperative complications occurred in 2 patients - in both cases in one eye (2%). In that cases, epithelial defects were detected. In the group of eyes that were treated by 6.5 mm OZ mean RSE ? SD was -2.45 ? 0.99 Dsph, the ablation depth per 1 Dsph was 17.54 ? 5.58 ?m and ablated volume of central 7 mm cornea by 1 Dsph was 0.43 ? 0.18 mm?. In the group of eyes that were treated by 7 mm OZ mean RSE ? SD was -3.32 ? 2.26 Dsph, the ablation depth per 1 Dsph was 23.73 ? 6.91 ?m and ablated volume of central 7 mm cornea by 1 Dsph was 0.61 ? 0.31 mm?. Conclusion. PRK is effective and safe refractive surgical method for correcting myopia up to -8 .75 Dsph. OZ size is the main factor determining the depth of the excimer laser ablation of the corneal tissue volume consumed by 1 Dsph. Higher OZ value determines higher consumption of cornea tissue.


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