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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 -
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 -
Ophthalmology and Therapy Dec 2023Photorefractive keratectomy (PRK) is a safe and popular corneal surgery performed worldwide. Nevertheless, there is potential risk of corneal haze development after... (Review)
Review
Photorefractive keratectomy (PRK) is a safe and popular corneal surgery performed worldwide. Nevertheless, there is potential risk of corneal haze development after surgery. Proper management of post PRK haze is important for good visual outcome. We performed a comprehensive review of the literature on the various risk factors and treatments for PRK haze, searching the PubMed, Google Scholar, SCOPUS, ScienceDirect, and Embase databases using relevant search terms. All articles in English from August 1989 through April 2023 were reviewed for this study, among which 102 articles were chosen to be included in the study. Depending on the characteristics of and examination findings on post PRK haze, different management options may be preferred. In the proposed framework, management of PRK haze should include a full workup that includes patient's subjective complaints and loss of vision as well as visual acuity, biomicroscopy, anterior segment optical coherence tomography, epithelial mapping, and Scheimpflug densitometry. Topical steroid treatment for haze should be stratified based on early- or late-onset haze. Mechanical debridement or superficial phototherapeutic keratectomy (PTK) may be used to treat superficial corneal haze. Deep PTK and/or PRK can be used to treat deep corneal haze. Mitomycin-C and topical steroids are prophylactic post-surgery agents to prevent recurrence of haze.
PubMed: 37603162
DOI: 10.1007/s40123-023-00782-1 -
Survey of Ophthalmology 2024Keratoconus is an ectatic corneal disorder that causes severe vision loss. Surgical options allow us to correct, partially or totally, the induced refractive error.... (Review)
Review
Keratoconus is an ectatic corneal disorder that causes severe vision loss. Surgical options allow us to correct, partially or totally, the induced refractive error. Intracorneal ring segments (ICRS) implantation represents a minimally invasive surgical option that improves visual acuity, with a high success rate and a low overall complication rate. Corneal allogenic ICRS consists of ring segments derived from allogenic eye bank-processed donor corneas. Selective topography-guided transepithelial photorefractive or phototherapeutic keratectomy combined with CXL is another way in selected cases to improve spectacles corrected distance visual acuity. The microphotoablative remodeling of the central corneal profile is generally planned by optimizing the optical zones and minimizing tissue consumption. Phakic intraocular lens (PIOL) implant is considered in patients with stable disease and acceptable anatomical requirements. The two types of pIOLs, depending on their implantation inside the eye, are anterior chamber-pIOLs, which fixate to the anterior surface of the iris by using a polymethomethacrolate claw at the two haptics, and posterior chamber-pIOLs. In patients with both cataracts and keratoconus, the correct IOL power is difficult to obtain due to the irregular corneal shape and K values. Toric IOL is recommended, but carefully judging the topography and the possible need of subsequent keratoplasties.
Topics: Humans; Prosthesis Implantation; Keratoconus; Photosensitizing Agents; Corneal Stroma; Visual Acuity; Corneal Topography; Cross-Linking Reagents; Refraction, Ocular
PubMed: 37774800
DOI: 10.1016/j.survophthal.2023.09.005 -
Turkish Journal of Ophthalmology Jun 2023Isolated from , mitomycin C (MMC) has various applications in the management of corneal and external disease due to its ability to modulate cellular proliferation. It... (Review)
Review
Isolated from , mitomycin C (MMC) has various applications in the management of corneal and external disease due to its ability to modulate cellular proliferation. It has been employed in pterygium surgery, ocular surface neoplasia, and refractive surgery. Currently, there is no definite consensus on the treatment protocols for each of the aforementioned applications. Although its benefits in the management of corneal and external diseases are promising, MMC use has potential complications including endothelial cell loss, corneal perforation, scleral melt, secondary glaucoma, iritis, and endophthalmitis. This article will review the literature regarding the use of MMC in the field of cornea and external disease and describe protocols employed with corresponding outcomes.
Topics: Humans; Mitomycin; Photorefractive Keratectomy; Lasers, Excimer; Cornea
PubMed: 37345314
DOI: 10.4274/tjo.galenos.2023.97932 -
International Ophthalmology Dec 2023The purpose of this prospective study was to evaluate the effect of combined photorefractive keratectomy (PRK) and corneal collagen cross-linking (CXL) on intraocular...
PURPOSE
The purpose of this prospective study was to evaluate the effect of combined photorefractive keratectomy (PRK) and corneal collagen cross-linking (CXL) on intraocular pressure (IOP) in patients with keratoconus (KC).
METHODS
We included 64 eyes of 34 patients (19 males and 15 females; age: 19-40y) with stages 1-2 keratoconus which had undergone combined wavefront-optimized photorefractive keratectomy and corneal collagen cross linking. Two other groups of patients were added as controls: the PRK group including 110 eyes of 57 patients (23 males and 34 females; age: 18-44y) which had undergone wavefront-optimized photorefractive keratectomy for myopic refractive errors, and the CXL group including 36 eyes of 23 patients (14 males and 9 females; age: 12-38y) with keratoconus, not filling the inclusion criteria for combined PRK and CXL, which had undergone corneal collagen cross-linking. IOP was recorded preoperatively and postoperatively at 3, 6 and 12 months follow-up visits.
RESULTS
Preoperative IOP in both CXL (12.1 ± 2.53 mmHg) and PRK + CXL (13.2 ± 2.50 mmHg) groups was significantly lower than PRK group (15.8 ± 3.10 mmHg) (F = 30.505, p < 0.001). At 3 months postoperatively, IOP showed no statistically significant difference between the three studied groups (F = 1.821, p = 0.164). At 6 months postoperatively, IOP in the CXL group (14.6 ± 2.64 mmHg) was significantly higher than both PRK (13.4 ± 2.27 mmHg) and PRK + CXL (13.3 ± 2.62 mmHg) groups (F = 3.721, p = 0.026). At 12 months postoperatively, IOP in the CXL group (14.3 ± 2.69 mmHg) was significantly higher than the PRK group (13.2 ± 2.23 mmHg) and was higher than PRK + CXL group (13.3 ± 2.59 mmHg) although not statistically significant (F = 3.393, p = 0.035). Regarding the percent of change from preoperative IOP, a statistically significant difference between the three studied groups was detected at 3, 6 and 12 months postoperatively (H = 117.459, 109.303, 122.694 respectively, p < 0.001). The median percent of change from preoperative IOP in the PRK group was -16.7%, -15%, and -16.7%, in the CXL group was + 14.3%, + 19.4%, and + 19.1%, while in PRK + CXL group was 0% at 3, 6 and 12 months postoperatively. (Post-hoc power analysis 75%).
CONCLUSIONS
Combined PRK and CXL in patients with KC shows no significant effect on IOP, in contrast to either procedure performed separately.
Topics: Male; Female; Humans; Young Adult; Adult; Adolescent; Child; Photorefractive Keratectomy; Keratoconus; Corneal Cross-Linking; Intraocular Pressure; Photosensitizing Agents; Prospective Studies; Visual Acuity; Riboflavin; Cornea; Cross-Linking Reagents; Corneal Topography
PubMed: 37861937
DOI: 10.1007/s10792-023-02886-w -
Cureus Aug 2023Our purpose is to provide a comprehensive investigation into the incidence, treatment modalities, and visual prognosis of epithelial-related complications in corneal... (Review)
Review
A Literature Review of the Incidence, Management, and Prognosis of Corneal Epithelial-Related Complications After Laser-Assisted In Situ Keratomileusis (LASIK), Photorefractive Keratectomy (PRK), and Small Incision Lenticule Extraction (SMILE).
Our purpose is to provide a comprehensive investigation into the incidence, treatment modalities, and visual prognosis of epithelial-related complications in corneal refractive surgeries, including laser-assisted in situ keratomileusis (LASIK), photorefractive keratectomy (PRK), and small incision lenticule extraction (SMILE). A systematic search of multiple databases was conducted by two independent examiners using various search terms related to epithelial-related complications and corneal refractive surgeries. A total of 91 research articles were included, encompassing a sample size of 66,751 eyes across the three types of surgeries. The average incidence of epithelial-related complications varied across the different types of corneal refractive surgeries. LASIK had an average incidence of 4.9% for epithelial defects, while PRK and SMILE had lower rates of 3.3% and 3.9%, respectively. Our findings indicate that SMILE has a lower incidence of epithelial defects compared to LASIK, potentially due to the less invasive nature of lenticule incision in SMILE. Visual prognosis after epithelial complications (EC) is generally favorable, with various supportive care and surgical interventions leading to significant improvements in postoperative visual acuity and full recovery. Understanding the incidence rates and management approaches for epithelial-related complications can guide clinicians in enhancing patient safety, refining surgical techniques, and optimizing postoperative outcomes in corneal refractive surgeries.
PubMed: 37614825
DOI: 10.7759/cureus.43926