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Clinical Ophthalmology (Auckland, N.Z.) 2023Transepithelial photorefractive keratectomy (Trans PRK) is a relatively new technology for refractive surgery and has shown promising results in myopia correction. The... (Review)
Review
Transepithelial photorefractive keratectomy (Trans PRK) is a relatively new technology for refractive surgery and has shown promising results in myopia correction. The data on hyperopia correction by this method are limited. In this review, we have attempted to understand the outcomes of this technology on hyperopic eyes. There are comparable results with conventional PRK and laser in situ keratomileusis (LASIK) as far as refractive stability, regression rate, predictability, and post-operative complications are concerned. The best results have been obtained in lower hyperopic corrections. In moderate to higher hyperopia, the limited data available show higher regression, unstable visual outcomes, and increased stromal haze. There is a need to evaluate the technology further to understand its success for hyperopic refractive surgery.
PubMed: 37273504
DOI: 10.2147/OPTH.S415636 -
Arquivos Brasileiros de Oftalmologia 2021To compare postoperative pain and discomfort between mechanical and transepithelial photorefractive keratectomies.
PURPOSE
To compare postoperative pain and discomfort between mechanical and transepithelial photorefractive keratectomies.
METHODS
This prospective comparative study included 190 eyes of 95 patients with hyperopia (up to +4.00 D), astigmatism (up to -5.00 D), and myopia (up to -8.00 D) who underwent mechanical photorefractive keratectomy in one eye and transepithelial photorefractive keratectomy in the contralateral eye using Wavelight Allegretto EX500 excimer laser. The patients were unaware of the side treated with each technique. The interval between operations in the same patient was 15-30 days. Both eyes had similar refraction before surgery, with a maximum of 15-µm difference in ablation. Postoperative questionnaires were administered on days 1 and 7 to assess the patients' level of discomfort (0=no discomfort to 5=extreme discomfort) with the following symptoms: pain, burning sensation, itchiness, tearing, photophobia, eye redness, foreign body sensation, and eyelid swelling. Patients were also asked about which method they preferred.
RESULTS
The sample consisted of 61 women (64.21%) and 34 men (35.79%). The mean (SD) patient age was 31.66 (6.69) years (range, 22-54 years). On postoperative day 1, the patients reported significantly less discomfort in terms of pain (1.9 ± 1.74 vs 2.5 ± 1.83; p=0.017), burning sensation (1.8 ± 1.56 vs 2.5 ± 1.68; p=0.004), tearing (2.3 ± 1.71 vs 3.1 ± 1.69; p=0.001), and foreign body sensation (1.9 ± 1.77 vs 2.5 ± 1.86; p=0.024) in the eye that received mechanical photorefractive keratectomy than in the eye that received transepithelial photorefractive keratectomy. No significant differences were found between the mechanical and transepithelial photorefractive keratectomies on postoperative day 7. Fifty-nine patients (62.10%) preferred mechanical photorefractive keratectomy, while 32 (33.68%) preferred transepithelial photorefractive keratectomy. Four patients (4.22%) expressed no preference.
CONCLUSIONS
Our results showed that pain scores were significantly lower in the mechanical photorefractive keratectomy-treated eyes than in the transepithelial photorefractive keratectomy-treated eyes on postoperative day 1, which may have provided greater patient comfort after surgery and led patients to prefer the mechanical photorefractive keratectomy technique.
Topics: Adult; Female; Foreign Bodies; Humans; Lasers, Excimer; Male; Middle Aged; Pain, Postoperative; Photorefractive Keratectomy; Prospective Studies; Refraction, Ocular; Young Adult
PubMed: 34431901
DOI: 10.5935/0004-2749.20220026 -
International Journal of Ophthalmology 2022To compare the visual results of non-topography-guided and topography-guided photorefractive keratectomy (PRK) applying sequential and simultaneous corneal cross-linking...
AIM
To compare the visual results of non-topography-guided and topography-guided photorefractive keratectomy (PRK) applying sequential and simultaneous corneal cross-linking (CXL) treatment for keratoconus.
METHODS
Interventional and comparative prospective study. Sixty-nine eyes (36 patients) suffering from keratoconus (stages 1 Amsler-Krumeich classification) were divided into four groups: sequential topography-guided photorefractive keratectomy with CXL, simultaneous topography-guided photorefractive keratectomy with CXL, simultaneous non-topography guided photorefractive keratectomy with CXL, and sequential non-topography guided photorefractive keratectomy with CXL. The main outcome measures were pre- and postoperative uncorrected distance visual acuity (UDVA), best corrected distance visual acuity (CDVA), manifest refraction, contrast sensitivity, and keratometry.
RESULTS
All analyzed visual, contrast sensitivity, and refractive parameters showed a significant improvement in the four groups (all <0.05). A noticeable improvement was seen in keratometry in all the groups, and a remarkable difference was observed between topography-guided groups in comparison to non-topography-guided groups (<0.05). Interestingly, the improvement in all parameters showed a degree of stability to the end of the follow-up.
CONCLUSION
The treatment priorities in all four groups are safety, efficacy, and predictability in the correction of the sphero-cylindrical errors in mild and moderate keratoconus. No significant differences among groups in the recorded objective outcomes were found.
PubMed: 35601161
DOI: 10.18240/ijo.2022.05.05 -
Romanian Journal of Ophthalmology 2015Optical aberrations lead to defects in image-forming, the image obtained being imperfect and thereby decreasing the quality of vision. When an optic system is not... (Review)
Review
Optical aberrations lead to defects in image-forming, the image obtained being imperfect and thereby decreasing the quality of vision. When an optic system is not perfect, as happens with the eye, the rays of light that pass through the system produce optical aberrations. The purpose of this review is to describe optical aberrations and their impact on vision and how refractive surgery outcomes are influenced by them. The main optical aberrations of the eye are as follows: spherical aberration, chromatic aberration, oblique astigmatism and high order aberrations. When the patient undergoes various types of surgeries (cataract surgery, corneal refractive surgery) the properties of the eye change and the eye doctor must take into account the correction of optical aberrations to improve vision quality. LASIK (laser keratomileusis), PRK (photorefractive keratectomy), UDVA (uncorrected distance visual acuity), SA (spherical aberrations), HOA (higher-order aberrations), RMS (root mean square).
PubMed: 29450310
DOI: No ID Found -
BMC Ophthalmology Feb 2022To assess transepithelial photorefractive keratectomy (tPRK) in terms of corneal epithelial healing rate, postoperative pain, postoperative discomfort, and visual and... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
To assess transepithelial photorefractive keratectomy (tPRK) in terms of corneal epithelial healing rate, postoperative pain, postoperative discomfort, and visual and refraction outcomes compared to mechanical epithelial debridement PRK (mPRK) and alcohol-assisted PRK (aaPRK).
METHODS
In this double-masked, randomized clinical trial, thirty-nine patients underwent tPRK in one eye and mPRK in the fellow eye (arm A), and 33 patients underwent tPRK in one eye and aaPRK in the contralateral eye (arm B). All surgical procedures were done using the Schwind Amaris excimer laser. The area of corneal epithelial defect in all eyes was captured and analyzed using ImageJ software.
RESULTS
Mean epithelial healing time was respectively 3.74 ± 0.82 and 3.59 ± 0.79 days in tPRK versus mPRK (P = 0.21) in arm A, and 3.67 ± 0.92 and 3.67 ± 0.74 days in tPRK versus aaPRK (P = 1.00) in arm B. Accounting for the initial corneal epithelial defect area, the epithelial healing rate was faster in conventional PRK groups compared to tPRK (both P<0.001) in both arms. However, there was no significant difference in safety, efficacy, spherical equivalent refractive accuracy, or corneal haze development between tPRK and conventional PRK groups (all P > 0.05).
CONCLUSIONS
All three methods are effective in terms of visual and refractive outcomes. However, although time to complete re-epithelialization was similar with the three methods, the epithelial healing rate was faster in conventional PRK considering the initial corneal epithelial defect area, and the patients experienced less pain and discomfort in the first postoperative day.
TRIAL REGISTRATION
IRCT, IRCT20200317046804N1 . Retrospectively registered 5 May 2020.
Topics: Astigmatism; Epithelium, Corneal; Humans; Lasers, Excimer; Pain, Postoperative; Photorefractive Keratectomy; Refraction, Ocular; Treatment Outcome
PubMed: 35148689
DOI: 10.1186/s12886-022-02293-2 -
Indian Journal of Ophthalmology Dec 2020
Topics: Corneal Stroma; Humans; Lasers, Excimer; Photorefractive Keratectomy
PubMed: 33229633
DOI: 10.4103/ijo.IJO_2543_20 -
BMC Ophthalmology Jul 2023Recent studies have presented inflammatory features on keratoconus (KC) and many inflammatory markers are described in the tears of patients with this disease. The KC... (Observational Study)
Observational Study
BACKGROUND
Recent studies have presented inflammatory features on keratoconus (KC) and many inflammatory markers are described in the tears of patients with this disease. The KC pathogenesis is still unknown just like the correlation with inflammatory patterns. However, environmental and genetic issues may be part of the progress of KC. In addition, some systemic features, such as allergy and obesity, seem to be related to the progression of KC. Our purpose was to evaluate the neuropeptides vasoactive intestinal peptide (VIP), neuropeptide Y (NPY), chemokines ligand 2 (CCL-2) and 5 (CCL-5), and interleukins 6 (IL-6) and 8 (IL-8) on corneal epithelial cells and blood of patients with KC and in healthy controls. In addition, the neutrophil-to-lymphocyte ratio (NLR) was evaluated to predict inflammation.
METHODS
This including prospective observational study included 32 KC patients who underwent corneal crosslinking (CXL) and 32 control patients who underwent photorefractive keratectomy (PRK). Patients' corneal epithelial cells were removed surgically, and blood (buffy coat) was analyzed. Samples in triplicate were evaluated on rt-PCR for neuropeptides (VIP e NPY), interleukins (IL-6 e IL-8), and chemokines (CCL-2 and CCL-5).
RESULTS
Our study showed statistically higher CCL-5 and IL-8 on corneal epithelial cells in patients with KC. Blood cells were statistically higher in VIP and NPY in the KC group. Interleukin-8 on blood cells was statistically significant in KC'S group; for CCL-2 and CCL-5 they were statistically lower in patients with KC compared with controls. NLR showed no difference between the groups.
CONCLUSIONS
Our data support the findings of other studies that suggested altering KC status, such as inflammatory corneal disease. The presence of IL-8 in the cornea and blood samples of KC's group suggested systemic disease with a possible local or repercussion action. Further studies are warranted to elucidate KC pathogenesis and its correlation to systemic disease.
Topics: Humans; Epithelium, Corneal; Interleukin-8; Interleukin-6; Cornea; Keratoconus; Chemokines; Corneal Topography
PubMed: 37460969
DOI: 10.1186/s12886-023-03013-0 -
The Cochrane Database of Systematic... Feb 2016Myopia (near-sightedness or short-sightedness) is a condition in which the refractive power of the eye is greater than required. The most frequent complaint of people... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Myopia (near-sightedness or short-sightedness) is a condition in which the refractive power of the eye is greater than required. The most frequent complaint of people with myopia is blurred distance vision, which can be eliminated by conventional optical aids such as spectacles or contact lenses, or by refractive surgery procedures such as photorefractive keratectomy (PRK) and laser epithelial keratomileusis (LASEK). PRK uses laser to remove the corneal stroma. Similar to PRK, LASEK first creates an epithelial flap and then replaces it after ablating the corneal stroma. The relative benefits and harms of LASEK and PRK, as shown in different trials, warrant a systematic review.
OBJECTIVES
The objective of this review is to compare LASEK versus PRK for correction of myopia by evaluating their efficacy and safety in terms of postoperative uncorrected visual acuity, residual refractive error, and associated complications.
SEARCH METHODS
We searched CENTRAL (which contains the Cochrane Eyes and Vision group Trials Register) (2015 Issue 12), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to December 2015), EMBASE (January 1980 to December 2015), Latin American and Caribbean Health Sciences (LILACS) (January 1982 to December 2015), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 15 December 2015. We used the Science Citation Index and searched the reference lists of the included trials to identify relevant trials for this review.
SELECTION CRITERIA
We included in this review randomized controlled trials (RCTs) comparing LASEK versus PRK for correction of myopia. Trial participants were 18 years of age or older and had no co-existing ocular or systemic diseases that might affect refractive status or wound healing.
DATA COLLECTION AND ANALYSIS
Two review authors independently screened all reports and assessed the risk of bias of trials included in this review. We extracted data and summarized findings using risk ratios and mean differences. We used a random-effects model when we identified at least three trials, and we used a fixed-effect model when we found fewer than three trials.
MAIN RESULTS
We included 11 RCTs with a total of 428 participants 18 years of age or older with low to moderate myopia. These trials were conducted in the Czech Republic, Brazil, Italy, Iran, China, Korea, Mexico, Turkey, USA, and UK. Investigators of 10 out of 11 trials randomly assigned one eye of each participant to be treated with LASEK and the other with PRK, but did not perform paired-eye (matched) analysis. Because of differences in outcome measures and follow-up times among the included trials, few trials contributed data for many of the outcomes we analyzed for this review. Overall, we judged RCTs to be at unclear risk of bias due to poor reporting; however, because of imprecision, inconsistency, and potential reporting bias, we graded the quality of the evidence from very low to moderate for outcomes assessed in this review.The proportion of eyes with uncorrected visual acuity of 20/20 or better at 12-month follow-up was comparable in LASEK and PRK groups (risk ratio (RR) 0.98, 95% confidence interval (95% CI) 0.92 to 1.05). Although the 95% CI suggests little to no difference in effect between groups, we judged the quality of the evidence to be low because only one trial reported this outcome (102 eyes). At 12 months post treatment, data from two trials suggest no difference or a possibly small effect in favor of PRK over LASEK for the proportion of eyes achieving ± 0.50 D of target refraction (RR 0.93, 95% CI 00.84 to 1.03; 152 eyes; low-quality evidence). At 12 months post treatment, one trial reported that one of 51 eyes in the LASEK group lost one line or more best-spectacle corrected visual acuity compared with none of 51 eyes in the PRK group (RR 3.00, 95% CI 0.13 to 71.96; very low-quality evidence).Three trials reported adverse outcomes at 12 months of follow-up or longer. At 12 months post treatment, three trials reported corneal haze score; however, data were insufficient and were inconsistent among the trials, precluding meta-analysis. One trial reported little or no difference in corneal haze scores between groups; another trial reported that corneal haze scores were lower in the LASEK group than in the PRK group; and one trial did not report analyzable data to estimate a treatment effect. At 24 months post treatment, one trial reported a lower, but clinically unimportant, difference in corneal haze score for LASEK compared with PRK (MD -0.22, 95% CI -0.30 to -0.14; 184 eyes; low-quality evidence).
AUTHORS' CONCLUSIONS
Uncertainty surrounds differences in efficacy, accuracy, safety, and adverse effects between LASEK and PRK for eyes with low to moderate myopia. Future trials comparing LASEK versus PRK should follow reporting standards and follow correct analysis. Trial investigators should expand enrollment criteria to include participants with high myopia and should evaluate visual acuity, refraction, epithelial healing time, pain scores, and adverse events.
Topics: Adult; Humans; Keratectomy, Subepithelial, Laser-Assisted; Myopia; Photorefractive Keratectomy; Randomized Controlled Trials as Topic; Time Factors; Visual Acuity
PubMed: 26899152
DOI: 10.1002/14651858.CD009799.pub2 -
Journal of Medicine and Life 2020Refractive eye surgeries are one of the most non-emergent ophthalmic surgeries due to the effect on the reduction of refractive errors, increasing visual acuity,...
Refractive eye surgeries are one of the most non-emergent ophthalmic surgeries due to the effect on the reduction of refractive errors, increasing visual acuity, enhancing the quality of vision, and indirectly increasing the quality of life of patients. The aim of this study was to determine Pentacam indices in the patients who underwent photorefractive keratectomy (PRK) during 2014-2018, as well as to show their correlation with the type of refractive error. This descriptive cross-sectional study was performed on 2215 eyes of 1125 patients undergoing PRK surgery. The patients' checklist, including demographic information, refractive index, keratometry, pachymetry, corneal surface zone indices, and progressive corneal thickness indices, was provided. All data were analyzed using the IBM SPSS software, version 25. The findings showed that there was a significant association between posterior corneal astigmatism (PCA) and anterior corneal astigmatism (ACA) (p=0.00). The mean Kmax front was recorded as 44.844 ± 1.58 D, which was significantly correlated with the type of refractive errors (p=0.00). According to the findings, there was a significant relationship between anterior chamber indices and refractive error types and their severity (p=0.00). There was also a significant correlation between the surface zone and keratoconus indices (i.e., index of surface variance - ISV, index of vertical asymmetry - IVA, index of height asymmetry - IHA, and minimum radius of curvature - Rmin) with refractive errors (p=0.00). The findings showed that some of the Pentacam indices could be related to the types of refractive errors in patients undergoing PRK surgery. Therefore, their evaluation is of great importance in this regard.
Topics: Adult; Astigmatism; Corneal Pachymetry; Cross-Sectional Studies; Female; Humans; Male; Photorefractive Keratectomy; Quality of Life; Visual Acuity
PubMed: 33456601
DOI: 10.25122/jml-2020-0057 -
Pain Physician Jul 2017Refractive surgery is a common procedure, but may be associated with severe post-operative pain. (Review)
Review
BACKGROUND
Refractive surgery is a common procedure, but may be associated with severe post-operative pain.
OBJECTIVES
To describe studies addressing the use of opioids for control of pain after ocular surgery, with an emphasis on refractive surgery.
STUDY DESIGN
This is a narrative review of relevant articles on the physiology of corneal pain and the use of opioids for its treatment after surgery.
SETTING
Single tertiary center.
METHODS
A PubMed search was conducted for studies published from January 1985 to May 2015 on the physiopathology of corneal pain and opioid treatment of post-refractive surgical pain. Reviews, meta-analyses, and randomized clinical trials were included. Inclusion criteria focused on photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK).
RESULTS
Authors found 109 articles through the search strategies. A total of 75 articles were included based on the inclusion criteria.
DISCUSSION
Pain after ocular surgery is likely to be a multifactorial phenomenon. A combination of topical and systemic analgesics is used to treat post-operative pain after refractive surgery. Pain may be severe during the first 72 to 96 hours, depending on the surgical procedure. No studies were found that directly analyze the benefits of opioids after PRK, although they are routinely prescribed in some centers.
LIMITATIONS
This is a narrative review in contrast to a systematic review and did not include studies indexed in databases other than PubMed.
CONCLUSIONS
Although opioids are used for the short-term treatment of post-operative pain in refractive surgery, their benefits and risks should be properly evaluated in randomized clinical trials before their use can be safely advised.
KEY WORDS
Photorefractive keratectomy, in situ keratomileusis, pain, analgesia, opioid, codeine, review.
Topics: Analgesics, Opioid; Humans; Ophthalmologic Surgical Procedures; Pain, Postoperative
PubMed: 28727706
DOI: No ID Found