scholarly journals Photorefractive keratectomy for correction of myopia: Our one-year experience

2012 ◽  
Vol 69 (10) ◽  
pp. 852-857
Author(s):  
Mirko Resan ◽  
Miroslav Vukosavljevic ◽  
Milorad Milivojevic
Keyword(s):  
Visual Acuity ◽  
Postoperative Complications ◽  
Intraoperative Complications ◽  
Mean Value ◽  
Ablation Depth ◽  
Laser In Situ Keratomileusis ◽  
Photorefractive Keratectomy ◽  
Corneal Tissue ◽  
Surgical Method ◽  
A Prospective Study

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.

scholarly journals Laser in situ keratomyleusis (LASIK) for correction of myopia and hypermetropia: Our one year experience

2009 ◽  
Vol 66 (12) ◽  
pp. 979-984
Author(s):  
Miroslav Vukosavljevic ◽  
Milorad Milivojevic ◽  
Mirko Resan ◽  
Vesna Cerovic
Keyword(s):  
Visual Acuity ◽  
Postoperative Complications ◽  
Intraoperative Complications ◽  
Mean Value ◽  
Spherical Equivalent ◽  
Surgical Method ◽  
The Third ◽  
Epithelial Ingrowth ◽  
A Prospective Study

Background/Aim. Laser in situ keratamileusis (LASIK) is the most commonly used refractive surgical method worldwide. The aim of this study was to examine the effectiveness and safety of LASIK in the correction of myopia and hyperopia. Methods. The study included myopic and hyperopic eyes with preoperative best corrected visual acuity (BCVA) = 1 (20/20), of the total number of 322 divided into 2 groups - 1) myopic eyes (n = 241) which were divided into 4 subgroups according to the myopia strength: a) ? -1.75 D (n = 23), b) from -2 to -3.75 D (n = 81), c) from -4 to -6.75 D (n = 113), d) ? -7 D (n = 24); 2) hyperopic eyes (n = 81) which were divided into 3 subgroups according to the hyperopia strength: a) ? +1.75D (n = 10), b) from +2 to +3.75 D (n = 46), c) ? +4 D (n = 25). Myopic and hyperopic eyes with preoperative BCVA ? 0.9 (eyes with ambliopia) were excluded from the study, as well as eyes with astigmatism > 1.5 D. To assess the effectiveness of LASIK we examined the percentage of eyes in the mentioned subgroups, which derived uncorrected visual acuity (UCVA) 6 month after the intervention to the following: a) UCVA = 1 (20/20) and b) UCVA ? 0.5 (20/40). To assess the safety of LASIK we examined the frequency of intraoperative and postoperative complications. A prospective study was performed in a 6-months follow-up period. Results. Refractive spherical equivalent (RSE) of myopic eyes was in the range from -0.75 D to -12 D. In the first subgroup preoperative mean value of RSE with standard deviation (mean RSE ? SD) was -1.39 ? 0.36 D, and 6 months after the LASIK 100% of the eyes had UCVA = 20/20. In the second subgroup preoperative mean RSE ? SD was -2.85 ? 0.50 D, and 6 months after LASIK 93% of the eyes had UCVA = 20/20, but 100% of the eyes had UCVA ? 20/40. In the third subgroup preoperative mean RSE ? SD was -5.03 ? 0.75 D, and 6 months after the LASIK 90% of the eyes had UCVA = 20/20, but 100% of the eyes had UCVA ? 20/40. In the fourth subgroup preoperative mean RSE ? SD was -7.68 ? 1.03 D, and 6 months after the LASIK 96% of the eyes had UCVA = 20/20, but 100% of eyes had UCVA ? 20/40. Refractive spherical equivalent of hyperopic eyes was in the range from +1 D to +6 D. In the first subgroup preoperative mean RSE ? SD was +1.50 ? 0.30 D, and 6 months after the LASIK 90% of the eyes had UCVA = 20/20, but 100% of the eyes had UCVA ? 20/40. In the second subgroup preoperative mean RSE ? SD was +2.65 ? 0.46 D, and 6 months after the LASIK 87% of the eyes had UCVA = 20/20, but 96% of the eyes had UCVA ? 20/40. In the third subgroup preoperative mean RSE ? SD was +4.62 ? 0.68 D, and 6 months after the LASIK 64% of the eyes had UCVA = 20/20, but 100% of the eyes had UCVA ? 20/40. In our study intraoperative complications appeared in 6 eyes (1.86%): thin flap in 2 eyes (0.62%) and epithelial defects in 4 eyes (1.24%), yet postoperative complications appeared in 10 eyes (3.10%): flap folds in 2 eyes (0.62%), epithelial ingrowth in 4 eyes (1.24%) and regression in 4 eyes (1.24%). Conclusion. LASIK is effective and safe refractive surgical method for correcting myopia up to -12 D and hyperopia up to +6 D.

scholarly journals Functional optical zone after wavefront-optimized versus wavefront-guided laser in situ keratomileusis

2021 ◽  
Vol 10 (3) ◽  
pp. 129-137
Author(s):  
Mariam A Elshawarby ◽  
Ali Saad ◽  
Thanaa Helmy ◽  
Mouamen M. Seleet ◽  
Tamer Elraggal
Keyword(s):  
Visual Acuity ◽  
Refractive Error ◽  
Ablation Depth ◽  
Laser In Situ Keratomileusis ◽  
Treatment Modalities ◽  
Significant Difference ◽  
Corneal Asphericity ◽  
Optical Zone ◽  
The Mean

Background: Many studies have used functional optical zone (FOZ) as a measure to compare different refractive laser treatment modalities. However, to our knowledge, no study has compared wavefrontoptimized (WFO) and wavefront-guided (WFG) laser in situ keratomileusis (LASIK) using FOZ. We compared the FOZ after WFO versus WFG LASIK in patients with myopia and myopic astigmatism.Methods: In this prospective comparative study, we included 100 myopic eyes of 50 patients with or without astigmatism. They were divided into two groups according to the platform used: WFO or WFG femtosecond LASIK. Using Holladay’s equivalent keratometry reading (EKR) report of Pentacam HR, FOZ was defined as a zone centered on the pupil center with a standard deviation (SD) of 0.5 D, around the mean EKR. The differences in FOZ between the two platforms were analyzed at 3 months postoperatively. Visual acuity, refractive error, corneal asphericity (Q-value), and root mean square of higher-order aberrations (RMS for HOAs) were evaluated and compared.Results: The mean ± SD of patient age was 26.64 ± 5.67 years. The preoperative characteristics of the two groups were comparable (all P > 0.05). The intended optical zone (IOZ) was 6 mm in both groups. The mean laser ablation depth was significantly greater in the WFG group (18 ?m per D) than in the WFO group (16 ?m per D) (P = 0.035). At 3 months postoperatively, the mean ± SD of FOZ diameter was 4.32 ± 0.94 mm (71.99 ± 15.68% of intended optical zone) in the WFO group and 4.16 ± 1.13 mm (69.33 ± 18.78% of intended optical zone) in the WFG group, with no significant difference between the two groups (P = 0.622). The change in corneal asphericity was greater in the WFG group than in the WFO group (P = 0.034). Postoperative mean corrected and uncorrected distance visual acuity, manifest refraction, and RMS for HOAs showed no significant difference between the two groups (all P > 0.05).Conclusions: We found that WFG LASIK resulted in greater ablation depth and change in corneal asphericity than WFO LASIK at 3 months postoperatively. However, there was no significant difference in FOZ diameter, refractive error, and RMS for HOAs between the two groups. Further research is needed to confirm these findings.

Two-year successful results of femto-LASIK in steep and opacified corneas

2020 ◽  
Vol 1 (1) ◽  
pp. 37-43
Author(s):  
Amr Mounir ◽  
Emad Latif Matthias ◽  
Islam Awny
Keyword(s):  
Visual Acuity ◽  
Femtosecond Laser ◽  
Intraoperative Complications ◽  
Anterior Segment ◽  
Laser In Situ Keratomileusis ◽  
Distance Visual Acuity ◽  
Uncorrected Distance Visual Acuity ◽  
Refractive Correction ◽  
Corneal Opacities ◽  
The Right

  Background: Flap creation is the most critical step of laser in situ keratomileusis (LASIK). The introduction of the femtosecond laser with its uniform flaps, which enhance the accuracy of LASIK, has decreased the risk of flap-related complications like buttonholes and incomplete flaps. We recommended femtosecond laser-assisted LASIK (FS-LASIK) in the presence of superficial corneal opacities. Case Presentation: We report a case of a 31-year-old female who reported to the Cornea clinic of the Sohag Center for LASIK and Corneal Surgeries, Sohag, Egypt, complaining of bilateral decreased vision due to refractive error. The uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) were 0.01 and 0.7 with a refractive correction of -3.50Ds/ –3.00Dc x 172° in the right eye and 0.01 and 0.6 with a refractive correction of -1.75 Ds/-6.00Dc x164° in the left eye, respectively. Slit-lamp examination of the anterior segment showed bilateral superior vascularized corneal scars and a linear superior conjunctival scar suggestive of old trachoma. Corneal tomographic imaging with a Scheimpflug based tomography device (Oculus Inc., Wetzlar, Germany) revealed a symmetrical bow tie with a very steep cornea without other ectatic changes. The patient underwent bilateral FS-LASIK with an excimer laser. No intraoperative complications occurred. She was followed up for two years with serial corneal topographies and stable post-LASIK results and visual outcomes. Conclusions: FS-LASIK, in the presence of superficial corneal opacities, was safe and effective and induced no complications with special precautions. However, these findings are yet to be confirmed using well‐designed clinical studies with larger samples and longer follow-ups.

scholarly journals Clinical Outcomes of Single-Step Transepithelial Photorefractive Keratectomy and Off-Flap Epipolis-Laser in Situ Keratomileusis in Moderate to High Myopia: 12-Month Follow-Up

2021 ◽  
Author(s):  
Yunjie Zhang ◽  
Tiankun Li ◽  
Zhangliang Li ◽  
Mali Dai ◽  
Qinmei Wang ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Contrast Sensitivity ◽  
High Myopia ◽  
Single Step ◽  
Self Control ◽  
Laser In Situ Keratomileusis ◽  
Photorefractive Keratectomy ◽  
Group 3

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).

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 Redo surgery using IntraLase femtosecond laser for treating a decentered laser in situ keratomileusis flap

2017 ◽  
Vol 46 (2) ◽  
pp. 901-907
Author(s):  
Yulin Lei ◽  
Jie Hou ◽  
Xiuyun Zheng
Keyword(s):  
Visual Acuity ◽  
Femtosecond Laser ◽  
Intraoperative Complications ◽  
Anterior Segment ◽  
Laser In Situ Keratomileusis ◽  
Redo Surgery ◽  
Laser Technique ◽  
Uncorrected Visual Acuity

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.

scholarly journals EVALUATION OF COMPLICATIONS OF PHACOEMULSIFICATION WITH PCIOL IMPLANTATION SURGERY

2019 ◽  
Vol 3 (10) ◽  
Author(s):  
Angli Manhas ◽  
Rameshwar S Manhas ◽  
Gaurav S Manhas ◽  
Dinesh Gupta
Keyword(s):  
Visual Acuity ◽  
Postoperative Complications ◽  
Intraocular Lens ◽  
Intraoperative Complications ◽  
Operating Time ◽  
Visual Outcome ◽  
Posterior Chamber ◽  
Extracapsular Cataract Extraction ◽  
Age Group ◽  
Posterior Chamber Intraocular Lens

Background: Phacoemulsification is a state of the art surgery for cata­ract removal. From the simple procedure of couching practiced by sushruta to latest method of phaco emulsification of Charles kelman, cataract surgery had undergone a tremendous metamorphosis. Phacoemulsification is one of the most successful surgical procedures performed, and its popularity is due to decreased operating time and a shorter postoperative healing period. The objective of the study was to evaluate intraoperative and postoperative complications of phacoemulsification with PCIOL implantation surgery. Materials & Methods: The present prospective study was conducted over a period of 6 months on patients having visually significant cataract that presented to or were referred to ophthalmology Department, GMCH, Jammu and after getting admission underwent planned extracapsular cataract extraction by phacoemulsification with posterior chamber intraocular lens ( PCIOL) implantation. After meeting inclusion & exclusion crieteria all the patients underwent complete examination as history, ocular examination, systemic examination and laboratory tests like haemoglobin etc. Results: Out of 200, maximum numbers of patients were in age group of 41-50 i.e. 90 followed by 82 patients in 51-60yrs age group. Males were 112.Total of 148 patients were from urban area. Best corrected preoperative visual acuity of ≤6/36 was seen in 102 patients whereas 6th week postoperatively only 7 patients had visual acuity of ≤6/36. The final 6th week postoperative best corrected visual acuity of 6/12- 6/6 was found in 171 patients. Among intraoperative complications hyphaema & constriction of pupil each were seen in 2 patients, followed by posterior capsule rent in 3 patients only while postoperatively mild uveitis was seen in 30 followed by striate keratopathy in 12 patients. Conclusion: From present study, we may conclude that phacoemulsification with posterior chamber intraocular lens implantation is a good surgical tecqinique for cataract which can be performed safely with good visual outcome, with few intraoperative and postoperative complications in expert hands. Keywords: Phacoemulsification , visual outcome, complications

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