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Indian Journal of Ophthalmology Apr 2023Dry eye disease is the most common complication and a frequent cause of patient dissatisfaction after corneal laser refractive surgery, which includes laser-assisted in... (Review)
Review
Dry eye disease is the most common complication and a frequent cause of patient dissatisfaction after corneal laser refractive surgery, which includes laser-assisted in situ keratomileusis (LASIK), small-incision lenticule extraction (SMILE), and photorefractive keratectomy (PRK). It has a complex, multifactorial etiology and is characterized by a highly variable clinical presentation. A detailed preoperative screening and optimization of the ocular surface prior to refractive surgery are the key to minimizing the incidence and severity of postoperative dry eye. Diagnosis of postrefractive surgery dry eye remains a challenge as no single symptom or clinical parameter is confirmative of the condition, and the symptoms and signs may not correlate well in many cases. A thorough understanding of the pathomechanism of the disease and its manifestations is essential to facilitate a treatment approach that is individualized for each patient. This article reviews various aspects of postrefractive surgery dry eye including its epidemiology, etiopathogenesis, risk factors, diagnosis, and management.
Topics: Humans; Lasers, Excimer; Myopia; Photorefractive Keratectomy; Keratomileusis, Laser In Situ; Dry Eye Syndromes
PubMed: 37026241
DOI: 10.4103/IJO.IJO_3406_22 -
Biology of keratorefractive surgery- PRK, PTK, LASIK, SMILE, inlays and other refractive procedures.Experimental Eye Research Sep 2020The outcomes of refractive surgical procedures to improve uncorrected vision in patients-including photorefractive keratectomy (PRK), laser in-situ keratomileusis... (Review)
Review
The outcomes of refractive surgical procedures to improve uncorrected vision in patients-including photorefractive keratectomy (PRK), laser in-situ keratomileusis (LASIK), Small Incision Lenticule Extraction (SMILE) and corneal inlay procedures-is in large part determined by the corneal wound healing response after surgery. The wound healing response varies depending on the type of surgery, the level of intended correction of refractive error, the post-operative inflammatory response, generation of opacity producing myofibroblasts and likely poorly understood genetic factors. This article details what is known about these specific wound healing responses that include apoptosis of keratocytes and myofibroblasts, mitosis of corneal fibroblasts and myofibroblast precursors, the development of myofibroblasts from keratocyte-derived corneal fibroblasts and bone marrow-derived fibrocytes, deposition of disordered extracellular matrix by corneal fibroblasts and myofibroblasts, healing of the epithelial injury, and regeneration of the epithelial basement membrane. Problems with epithelial and stromal cellular viability and function that are altered by corneal inlays are also discussed. A better understanding of the wound healing response in refractive surgical procedures is likely to lead to better treatments to improve outcomes, limit complications of keratorefractive surgical procedures, and improve the safety and efficiency of refractive surgical procedures.
Topics: Corneal Surgery, Laser; Humans; Keratomileusis, Laser In Situ; Keratoplasty, Penetrating; Lasers, Excimer; Myopia; Photorefractive Keratectomy; Refraction, Ocular
PubMed: 32653492
DOI: 10.1016/j.exer.2020.108136 -
American Journal of Ophthalmology Jun 2017To compare the postoperative efficacy, predictability, safety, and visual quality of all major forms of laser corneal refractive surgeries for correcting myopia. (Meta-Analysis)
Meta-Analysis Review
PURPOSE
To compare the postoperative efficacy, predictability, safety, and visual quality of all major forms of laser corneal refractive surgeries for correcting myopia.
DESIGN
Systematic review and network meta-analysis.
METHODS
Search of MEDLINE, EMBASE, Cochrane Library, and the US trial registry was conducted up to November 2015. Randomized controlled trials (RCT) reporting in accordance with the eligibility criteria were included in this review. We performed a Bayesian random-effects network meta-analysis.
RESULTS
Forty-eight RCTs were identified. For efficacy (uncorrected visual acuity [UCVA]), there were no statistically significant differences between any pair of treatments analyzed. The SUCRA (surface under the cumulative ranking curve) ranking (from best to worst) was femtosecond-based laser in situ keratomileusis (FS-LASIK), LASIK, small-incision lenticule extraction, femtosecond lenticule extraction (FLEx), photorefractive keratectomy (PRK), laser epithelial keratomileusis (LASEK), epipolis (Epi)-LASIK, transepithelial PRK (T-PRK). For predictability (refractive spherical equivalent [SE]), a statistically significant difference was found when FS-LASIK was compared with LASIK (odds ratio [OR] 2.29, 95% credible interval [CrI] 1.20-4.14), PRK (OR 2.16, 95% CrI 1.15-4.03), LASEK (OR 2.09, 95% CrI 1.08-4.55), and Epi-LASIK (OR 2.74, 95% CrI 1.11-6.20). The SUCRA ranking (from best to worst) was FS-LASIK, T-PRK, LASEK, PRK, LASIK, Epi-LASIK. There were no statistically significant differences in the safety (best spectacle-corrected visual acuity) comparisons. For both postoperative higher-order aberrations (HOAs) and contrast sensitivity (CS), there were no statistically significant differences between any pair of treatments analyzed. The SUCRA ranking results show that some corneal surface ablation techniques (PRK and LASEK) rank highest.
CONCLUSIONS
This network meta-analysis shows that there were no statistically significant differences in either visual outcomes (efficacy and safety) or visual quality (HOAs and CS). FS-LASIK behaved better in predictability than any other type of surgeries.
Topics: Cornea; Humans; Lasers, Excimer; Myopia; Network Meta-Analysis; Photorefractive Keratectomy; Postoperative Period; Refraction, Ocular; Visual Acuity
PubMed: 28336402
DOI: 10.1016/j.ajo.2017.03.013 -
Vision (Basel, Switzerland) Mar 2024The type and nature of refractive surgery procedures has greatly increased over the past few decades, allowing for almost all patient populations to be treated to... (Review)
Review
The type and nature of refractive surgery procedures has greatly increased over the past few decades, allowing for almost all patient populations to be treated to extremely high satisfaction. Conventional photorefractive keratectomy involves the removal of the corneal epithelium through mechanical debridement or dilute alcohol instillation. An improvement to this method utilises laser epithelial removal in a single-step process termed transepithelial photorefractive keratectomy (transPRK). We explore the history of transPRK from its early adoption as a two-step process, identify different transPRK platforms from major manufacturers, and describe the role of transPRK in the refractive surgery armamentarium. This is a narrative review of the literature. This review finds that TransPRK is a safe and effective procedure that works across a variety of patient populations. Though often not seen as a primary treatment option when compared to other corneal-based procedures that offer a faster and more comfortable recovery, there are many scenarios in which these procedures are not possible. These include, but are not limited to, cases of corneal instability, previous refractive surgery, or transplant where higher-order aberrations can impair vision in a manner not amenable to spectacle or contact lens correction. We discuss refinements to the procedure that would help improve outcomes, including optimising patient discomfort after surgery as well as reducing corneal haze and refractive regression.
PubMed: 38535765
DOI: 10.3390/vision8010016 -
Journal of Ophthalmology 2022This meta-analysis review compares the primary and secondary outcomes of transepithelial photorefractive keratectomy (TPRK) to the conventional photorefractive... (Review)
Review
This meta-analysis review compares the primary and secondary outcomes of transepithelial photorefractive keratectomy (TPRK) to the conventional photorefractive keratectomy (PRK), in terms of efficacy, predictability, safety, and patient perspectives. A total of 1711 eyes with PRK (811 eyes) and TPRK (900 eyes) from 12 studies were included through bibliographic searches. The main outcomes were efficacy, predictability, and safety parameters, and the secondary outcomes included visual and patient-reported parameters. The effect measures were weighted mean differences with 95% confidence intervals (CI) which were derived from the random-effects model of the meta-analysis to account for possible heterogeneity. TPRK procedure presents a comparable status in the main outcome and a very dominant significance in all the secondary outcomes in this meta-analysis. This study updates the evidence of the accuracy of TPRK procedure for surgical correction of all refractive errors and was deemed safer with less surgical time required and an early healing time.
PubMed: 36051276
DOI: 10.1155/2022/3022672 -
Indian Journal of Ophthalmology Jan 2022To compare visual outcomes and vision-related quality of life (VRQoL) between subjects before and after photorefractive keratotomy (PRK) and controls. In addition, VRQoL...
PURPOSE
To compare visual outcomes and vision-related quality of life (VRQoL) between subjects before and after photorefractive keratotomy (PRK) and controls. In addition, VRQoL was compared between subjects at different periods of PRK surgery.
METHODS
This was a cross-sectional study that included subjects with refractive errors aged 19-40 years and age-matched controls. Subjects were divided into three groups: pre-, post-PRK, and control. Subjects in the post-PRK group were divided into three subgroups (1-week, <6-month, and >6-month follow-up visits). Measurements including uncorrected distance visual acuity (UCVA), corrected distance visual acuity (CDVA), spherical equivalent (SE) of manifest refraction, and corneal topography were obtained for all participants. The Quality of Life Impact of Refractive Correction (QIRC) questionnaire was administered to compare VRQOL between groups and between post-refractive surgery subgroups.
RESULTS
A total of 145 participants were included in this study. The mean age ± standard deviation (SD) of all participants was 26.29 ± 5.1 years. There was a significant difference (P < 0.001) in total QIRC scores between groups. The total QIRC score was better in the post-PRK group than in the pre-PRK and control groups. The scores of items included in the convenience, well-being, and health concern domains were significantly higher in the post-PRK group than in the pre-PRK and control groups. Within the post-PRK group, significant differences (P < 0.001) were found in UCVA and SE between the post-PRK subgroups. Uncorrected VA and SE were better in the post-PRK groups who were followed up in the < 6 and > 6 months subgroups than in the 1-week follow-up subgroup (P < 0.0001).
CONCLUSION
A significant improvement in visual outcomes and VRQoL occurred after PRK surgery. Subjects enjoyed their VRQoL after refractive surgery.
Topics: Cross-Sectional Studies; Follow-Up Studies; Humans; Lasers, Excimer; Myopia; Photorefractive Keratectomy; Quality of Life; Refraction, Ocular; Treatment Outcome
PubMed: 34937209
DOI: 10.4103/ijo.IJO_16_21 -
Cornea Oct 2023Customized photorefractive keratectomy with minimal tissue ablation combined with corneal cross-linking seems to be a long-term safe and effective strategy for...
Customized photorefractive keratectomy with minimal tissue ablation combined with corneal cross-linking seems to be a long-term safe and effective strategy for anatomical and visual management of keratoconus, postsurgical ectasia, and other ectasia management. Multiple published studies, many with long-term follow-up, have supported the Athens Protocol and its various forms as a means to manage corneal ectatic disorders, which not only stabilize corneal shapes but also improve functional vision.
Topics: Humans; Keratoconus; Photorefractive Keratectomy; Corneal Cross-Linking; Dilatation, Pathologic
PubMed: 37669421
DOI: 10.1097/ICO.0000000000003320 -
Indian Journal of Ophthalmology 2012Phototherapeutic keratectomy (PTK) is done regularly for anterior corneal diseases such as corneal dystrophies, corneal degenerations, scars, and band-shaped... (Review)
Review
Phototherapeutic keratectomy (PTK) is done regularly for anterior corneal diseases such as corneal dystrophies, corneal degenerations, scars, and band-shaped keratopathy. The various indications include both therapeutic and visual. The aim of this article is to discuss the therapeutic indications for PTK, the specific technique pertaining to a specific etiology, the various other procedures like amniotic membrane graft combined with PTK or PTK being done for recurrences in the grafts, and PTK done before cataract surgery when the anterior corneal pathology coexists with the cataract. Post PTK management such as healing of an epithelial defect, use of steroids in the post PTK period, recurrences of primary disease pathology, and infections, will be discussed. Methods of literature search: A Medline search was carried out for articles in the English language, with the keywords, phototherapeutic keratectomy, band-shaped keratopathy, spheroidal degeneration, scars, bullous keratopathy, and corneal dystrophy. The relevant references are mentioned here.
Topics: Corneal Diseases; Humans; Photorefractive Keratectomy; Treatment Outcome
PubMed: 22218239
DOI: 10.4103/0301-4738.91335 -
Indian Journal of Ophthalmology Dec 2020Photorefractive keratectomy (PRK) eye surgery is widely used for patients at risk for corneal ectasia to maintain an aspheric corneal shape. Wavefront-guided (WFG)... (Meta-Analysis)
Meta-Analysis Review
Photorefractive keratectomy (PRK) eye surgery is widely used for patients at risk for corneal ectasia to maintain an aspheric corneal shape. Wavefront-guided (WFG) ablation profile was designed to reduce pre-existing higher-order aberrations (HOA). We aimed to compare the corneal aberrations and visual outcomes between WFG and Wavefront Optimized (WFO) PRK in patients with myopia. Eight randomized clinical trials were included. We searched PubMed, Scopus, Web of Science and CENTRAL at March 2020, and updated the search in September 2020 using relevant keywords, The data were extracted and pooled as Mean Difference (MD) with a 95% Confidence Interval (CI), using Review Manager software (version 5.4). Pooled results showed no significance between Uncorrected Distance Visual Acuity (UDVA) and Corrected Distance Visual Acuity (CDVA) between both groups underwent WFG and WFO PPR after three months follow up (MD = -0.03; 95% CI: [-0.06, 0.00]; P = 0.07), (MD = -0.02; 95% CI: [-0.04, 0.01]; P = 0.22) respectively. Although, no significant difference between mean manifest cylinder after three and 12 months follow up, but the total MD for mean manifest cylinder difference was significantly lower with the WFG treatment method (MD = -0.12, (95% CI: [0.23:-0.01], P = 0.03). This shows a slight advantage of the WFG over the WFO method. The visual performance showed similarity and excellent refractive outcomes in both WFO and WFG PRK. No significant statistical differences between the two approaches. On further comparison, there was a slight advantage of the WFG over the WFO method.
Topics: Corneal Wavefront Aberration; Humans; Lasers, Excimer; Photorefractive Keratectomy; Prospective Studies; Refraction, Ocular; Treatment Outcome
PubMed: 33229644
DOI: 10.4103/ijo.IJO_2921_20 -
Indian Journal of Ophthalmology Dec 2020Over the past two decades, excimer laser-based refractive surgery procedures have been successfully established for their safety and satisfactory visual outcomes.... (Review)
Review
Over the past two decades, excimer laser-based refractive surgery procedures have been successfully established for their safety and satisfactory visual outcomes. Surface ablation procedures or photorefractive keratectomy (PRK) are practised commonly for the correction of refractive errors including myopia, astigmatism and hyperopia. Satisfactory visual outcomes are achieved in majority of cases, although a very small percentage have issues related to corneal haze, regression, and its associated visual disturbances. To ensure optimal outcomes and to minimize complications, certain keys to success have been designed on the basis of the current review of literature on surface ablation procedures.
Topics: Astigmatism; Cornea; Humans; Lasers, Excimer; Myopia; Photorefractive Keratectomy; Refraction, Ocular; Treatment Outcome; Visual Acuity
PubMed: 33229660
DOI: 10.4103/ijo.IJO_2178_20