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Middle East African Journal of... 2022The purpose of this study was to determine the prevalence of keratoconus (KC) and keratoconus suspect (KCS) among patients seeking refractive surgery in Syria.
PURPOSE
The purpose of this study was to determine the prevalence of keratoconus (KC) and keratoconus suspect (KCS) among patients seeking refractive surgery in Syria.
METHODS
This is a retrospective multicenter screening study. The study was conducted in Damascus University, Tishreen University, and Tartous Specialist Eye Center (a private center). Data were collected from refractive surgery candidates referred for preoperative evaluation before laser keratomileusis, photorefractive keratectomy, intrastromal corneal rings, and phakic intraocular lens implantation. Corneal parameters were obtained by Scheimpflug-Placido tomography, Sirius (CSO, Italy).
RESULTS
A total of 1479 patients were included in this analysis. The prevalence rates of KC and KCS were 18.19% (269/1479) and 13.52% (200/1479), respectively. In addition, patients with KC were found to have higher percentages of eye rubbing and astigmatism than suspect and normal ( < 0.0001).
CONCLUSION
High prevalence rate of KC was found among patients seeking refractive surgery in Syria. Although this study was carried out on a highly selective population, it may reflect a high prevalence rate in a general population in Syria.
Topics: Humans; Keratoconus; Corneal Topography; Prevalence; Syria; Cornea; Keratomileusis, Laser In Situ
PubMed: 38162559
DOI: 10.4103/meajo.meajo_50_23 -
Journal of Visualized Experiments : JoVE Dec 2023The cornea is a transparent tissue that covers the eye and is crucial for clear vision. It is the most innervated tissue in the body. This innervation provides sensation...
The cornea is a transparent tissue that covers the eye and is crucial for clear vision. It is the most innervated tissue in the body. This innervation provides sensation and trophic function to the eye and contributes to preserving corneal integrity. The pathological disruption of this innervation is termed neurotrophic keratitis. This can be triggered by injury to the eye, surgery, or disease. In this study, we propose three different protocols for inflicting damage on the innervation in ways that recapitulate the three types of cases generally encountered in the clinic. The first method consists in making an abrasion of the epithelium with an ophthalmic burr. This involves the removal of the epithelial layer, the free nerve endings, and the subbasal plexus in a manner similar to the photorefractive keratectomy surgery performed in the clinic. The second method only targets the innervation by sectioning it at the periphery with a biopsy punch, maintaining the integrity of the epithelium. This method is similar to the first steps of lamellar keratoplasty and leads to a degeneration of the innervation followed by regrowth of the axons in the central cornea. The last method damages the innervation of a transgenic mouse model using a multiphoton microscope, which specifically localizes the site of cauterization of the fluorescent nerve fibers. This method inflicts the same damage as photokeratitis, an overexposure to UV light. This study describes different options for investigating the physiopathology of corneal innervation, particularly the degeneration and regeneration of the axons. Promoting regeneration is crucial for avoiding such complications as epithelium defects or even perforation of the cornea. The proposed models can help test new pharmacological molecules or gene therapy that enhance nerve regeneration and limit disease progression.
Topics: Mice; Animals; Cornea; Keratitis; Corneal Transplantation; Epithelium; Nerve Regeneration
PubMed: 38145371
DOI: 10.3791/66182 -
Indian Journal of Ophthalmology Jan 2024To analyze the reasons for declining corneal refractive laser correction procedures in patients presenting to tertiary eye care centers in Tamil Nadu, Southern India,...
PURPOSE
To analyze the reasons for declining corneal refractive laser correction procedures in patients presenting to tertiary eye care centers in Tamil Nadu, Southern India, and review the literature.
METHODS
Retrospective case records of subjects presenting from January 2019 to December 2021 for refractive surgery workup were analyzed. Demographic details and refractive parameters of patients rejected for corneal refractive laser corrections (CRLC) were documented and reviewed.
RESULTS
A total of 2358 patients presented for refractive surgery evaluation during the study period, and out of them, 395 patients (16.8%) were not considered ideal candidates for undergoing CRLC. The common reasons for rejecting the patients were unfit topography (n = 110, 27.8%), unstable refraction over a one-year duration (n = 9, 2.27%), low corneal thickness (n = 85, 21.5%), keratoconus (n = 5, 12.9%), and other ocular and systemic disorders (n = 48, 12.1%).
CONCLUSION
There was a marked change in magnitude and rationalization for not performing either laser-assisted in situ keratomileusis (LASIK) or photorefractive keratectomy in our study. The reasons are unfit topography, keratoconus, and systemic disorders, which were diagnosed during pre-LASIK screening workup, being the most common cause for rejecting patients for corneal refractive corrections.
Topics: Humans; Keratoconus; Retrospective Studies; India; Cornea; Photorefractive Keratectomy; Keratomileusis, Laser In Situ; Refraction, Ocular; Lasers, Excimer; Corneal Topography
PubMed: 38131581
DOI: 10.4103/IJO.IJO_1595_23 -
Indian Journal of Ophthalmology Jan 2024This study aimed to report practice patterns in the management of keratoconus in India.
PURPOSE
This study aimed to report practice patterns in the management of keratoconus in India.
METHODS
An e-survey was conducted among members of the Cornea Society of India to assess preferred practice patterns for keratoconus.
RESULTS
Of the 912 members, 234 (25.7%) completed the survey. About 88.4% worked in private eye care facilities and 76.1% in cities. Of all the respondents, 91.5% had access to a Scheimpflug-based device or an Orbscan II®; 71.4% of the respondents dispensed scleral contact lenses, and 66.7% dispensed Rose K contact lenses; 92.7% of the respondents performed corneal cross-linking (CXL); and 73.1% of the respondents performed deep anterior lamellar keratoplasty (DALK). A Scheimpflug device or Orbscan II®, Rose K or scleral contact lenses, and CXL were more readily available (P < 0.05) in private eye care facilities. The diagnostic criteria for keratoconus followed by the majority of the respondents (52.1%) were increase in corneal curvature, elevation, and thickness. An increase in keratometry values greater than 0.5 or 1.0D in a 6-month to 1-year period was considered the most favored criterion for keratoconus progression. Epithelium-off, 0.1% riboflavin solution in dextran, and accelerated protocol were the more commonly reported techniques in CXL. About 77.2% of the respondents routinely performed CXL in corneas <400 microns thick. Spectacles (91.0% of the respondents) and topography-guided photorefractive keratectomy (37.6% of the respondents) were, respectively, the preferred optical and surgical methods used to improve vision.
CONCLUSION
While keratoconus management in India is comparable to other developed healthcare systems, the concentration of trained corneal surgeons in cities and private eyecare facilities may lead to less equitable distribution of treatment across the country.
Topics: Humans; Collagen; Cornea; Corneal Topography; Cross-Linking Reagents; Follow-Up Studies; Keratoconus; Photochemotherapy; Photosensitizing Agents; Riboflavin; Ultraviolet Rays; Visual Acuity
PubMed: 38131580
DOI: 10.4103/IJO.IJO_817_23 -
Indian Journal of Ophthalmology Jan 2024This study aimed to evaluate the corneal epithelial thickness changes after photorefractive keratectomy (PRK) and the impact of long-term artificial tear usage on... (Randomized Controlled Trial)
Randomized Controlled Trial
PURPOSE
This study aimed to evaluate the corneal epithelial thickness changes after photorefractive keratectomy (PRK) and the impact of long-term artificial tear usage on epithelial thickness changes in these patients.
METHODS
This study was performed on 71 patients (142 eyes) without dry eye disease who received PRK for myopic refractive correction. The corneal epithelial thickness profile was obtained before, one, three, and six months after surgery using anterior segment optical coherence tomography. Patients were randomly divided into two groups: group A, who received preservative-free artificial tears post-surgery, and group B, who did not receive artificial tears.
RESULTS
The epithelial thickness decreased universally in the first month and then increased in the 3- and 6-month follow-ups. Group A had a significantly thicker epithelium in central, paracentral, and midperipheral zones compared with group B in the 3-month follow-up. In the 6-month follow-up, no significant differences were detected between groups. At the last follow-up, the central, paracentral, and midperipheral zone epithelial thicknesses in all patients were significantly higher than preoperative values, but peripheral zone thickness only increased to preoperative values.
CONCLUSIONS
Patients using artificial tears showed a faster thickening, especially in the central and paracentral zones, but there were no significant differences between the two groups in the final follow-up. Artificial tear usage may increase the rate of the epithelial remodeling process in post-PRK patients without significantly altering the final epithelial thickness profile. Further studies are warranted to evaluate the influence of different factors on epithelial remodeling.
Topics: Humans; Photorefractive Keratectomy; Lubricant Eye Drops; Epithelium, Corneal; Refraction, Ocular; Myopia; Lasers, Excimer
PubMed: 38131572
DOI: 10.4103/IJO.IJO_1354_23 -
American Journal of Ophthalmology Case... Dec 2023We report a sequential approach in the management of a case with advanced pellucid marginal degeneration (PMD). The management was tailored based on the patient's...
PURPOSE
We report a sequential approach in the management of a case with advanced pellucid marginal degeneration (PMD). The management was tailored based on the patient's corneal topography and degree of corneal astigmatism. Full thickness corneal transplants in cases of PMD carry a prolonged rehabilitation period and the risk of graft failure.This case consisted of lamellar wedge resection followed by wavefront guided transepithelial photorefractive keratectomy (wTPRK) combined with accelerated corneal crosslinking (aCXL) in preparation for a cataract extraction with intraocular lens.
OBSERVATION
A 68-year-old gentleman with advanced PMD underwent phacoemulsification with toric intraocular lens (T-IOL) for the right eye and a lamellar wedge resection, followed by wTPRK combined with aCXL for the contralateral eye. The left eye underwent a sequential approach to regularize the cornea, minimize the higher order aberrations (HoA) and degree of corneal astigmatism. Effective visual rehabilitation was achieved with significant visual improvement.
CONCLUSION AND IMPORTANCE
Although advanced PMD may have limited options for visual rehabilitation, a sequential stepwise approach may be considered in such cases, permitting a better quality with less invasive options.
PubMed: 38077780
DOI: 10.1016/j.ajoc.2023.101966 -
Journal of Refractive Surgery... Dec 2023To evaluate the outcome of sequential customized therapeutic keratectomy (SCTK) in reducing higher order aberrations (HOAs) and improving quality of vision in highly...
PURPOSE
To evaluate the outcome of sequential customized therapeutic keratectomy (SCTK) in reducing higher order aberrations (HOAs) and improving quality of vision in highly aberrated corneas consequent to previous radial keratotomy (RK).
METHODS
A retrospective review of patients undergoing SCTK treatment from January 2012 to October 2020 was conducted in the Eye Center, Humanitas Clinical and Research Center (Rozzano, Italy). Indications for treatment in patients who had RK were significantly and/or progressively reduced corrected distance visual acuity (CDVA) combined with visual symptoms critically affecting quality of life. Preoperative and postoperative CDVA, corneal topography and aberrometry, Scheimpflug tomography, and anterior segment optical coherence tomography were registered.
RESULTS
Thirty-four patients who underwent RK a mean of 26.62 ± 7.10 years before SCTK treatment were included. SCTK induced a significant improvement of CDVA from 0.44 ± 0.82 logMAR preoperatively to 0.15 ± 0.64 logMAR postoperatively ( < .001). No patient experienced worsening of CDVA, whereas 8 patients (23,50%) gained one line and 23 patients (67.65%) gained two lines or more. A significant decrease in corneal coma, trefoil, and spherical aberrations was also noted ( = .003, .003, and .004, respectively).
CONCLUSIONS
SCTK proved to be a safe and effective option to treat highly aberrated eyes following RK. The authors suggest the use of SCTK as a first-line approach for the treatment of HOAs after RK and avoiding more invasive procedures such as corneal transplantation or intraocular lens implantation. .
Topics: Humans; Keratotomy, Radial; Refraction, Ocular; Photorefractive Keratectomy; Quality of Life; Corneal Topography; Keratectomy; Tomography, Optical Coherence; Retrospective Studies
PubMed: 38063831
DOI: 10.3928/1081597X-20231018-03 -
The American Journal of Case Reports Dec 2023BACKGROUND We report a case of late-onset chronic fistula in a decompensated cornea after multiple ocular surgeries and a recent phototherapeutic keratectomy (PTK). CASE...
BACKGROUND We report a case of late-onset chronic fistula in a decompensated cornea after multiple ocular surgeries and a recent phototherapeutic keratectomy (PTK). CASE REPORT A 73-year-old woman presented to our service with a past ocular history of bilateral chronic angle closure glaucoma and pseudophakic bullous keratopathy in the left eye. Given a history of long-term uncontrolled glaucoma with advanced disc cupping and poor visual potential, the patient underwent multiple palliative procedures, including, most recently, a PTK. Few years later she presented with a spontaneous late onset of slowly appearing corneal leak on fluorescein staining upon routine clinical examination. Corrected distance visual acuity was hand motion and intraocular pressure (IOP) was 40 mmHg in the affected eye. Serial anterior segment optical coherence tomography (AS-OCT) sections were obtained, which aided in understanding the current presentation and revealed distinctive multilayer corneal changes during the healing process. The patient was successfully managed with cyanoacrylate corneal gluing and ocular hypotensive medications, which halted the corneal leak. CONCLUSIONS We report a case of a rare finding of corneal fistula in an eye with multiple previous ocular surgeries, and provide an explanation of the possible etiopathogenesis. We also highlight the pivotal role of AS-OCT for evaluating such cases and stress the importance of early detection of similar subtle leaks in the setting of a formed anterior chamber, which can often be missed, carrying a risk of infection.
Topics: Aged; Female; Humans; Cornea; Lasers, Excimer; Photorefractive Keratectomy; Tomography, Optical Coherence; Visual Acuity; Fistula; Chronic Disease; Corneal Diseases; Eye Diseases
PubMed: 38051696
DOI: 10.12659/AJCR.942279 -
Journal of Cataract and Refractive... Jan 2024To compare photorefractive keratectomy (PRK) outcomes in patients with different corneal steepness.
PURPOSE
To compare photorefractive keratectomy (PRK) outcomes in patients with different corneal steepness.
SETTING
Care-Vision Laser Center, Tel-Aviv, Israel.
DESIGN
Retrospective comparative chart review.
METHODS
Patients included in this study underwent wavefront optimized myopic PRK between January 2013 and December 2019. Patients were divided into 3 groups based on the steepness of the cornea (steep keratometry) (flat: <42 diopters [D], normal: 42 to 46 D and steep: >46 D). One to one matching was performed to verify that baseline parameters (age, preoperative visual acuity and refractive error) were similar between groups. Primary outcome measures were: postoperative corrected/uncorrected distance visual acuity (CDVA/UDVA), efficacy index (postoperative UDVA/preoperative CDVA), safety index (postoperative CDVA/preoperative CDVA), spherical equivalence (SEQ) and cylinder.
RESULTS
After matching, 650 eyes were included in each group, which were similar in baseline parameters. There were no significant postoperative differences between flat, normal, and steep corneas in terms of safety index (1.02 vs 1.03 vs 1.03, P = .28), efficacy index (1.01 vs 1.01 vs 1.02, P = .57), logMAR CDVA (0.01 vs 0.02 vs 0.01, P = .76), logMAR UDVA (0.02 vs 0.03 vs 0.02, P = .68), %SEQ within 0.50 D (73.9% vs 74.2% vs 74.6%, P = .95) or 1.00 D of target (91.9% vs 92.5% vs 92.2%, P = .92), %cylinder within 0.50 D (82.8% vs 82.2% vs 81.4%, P = .81) or 1.00 D of target (96.9% vs 97.1% vs 97.2%, P = .95).
CONCLUSIONS
No significant differences were found between flat, normal and steep corneas following wavefront-optimized myopic PRK. Thus, this procedure may be safely and effectively performed in both flat and steep corneas.
Topics: Humans; Photorefractive Keratectomy; Lasers, Excimer; Retrospective Studies; Follow-Up Studies; Cornea; Refraction, Ocular; Myopia; Treatment Outcome
PubMed: 38048136
DOI: 10.1097/j.jcrs.0000000000001307 -
Journal of Cataract and Refractive... Apr 2024To compare long-term outcomes of simultaneous accelerated corneal crosslinking (CXL) with intrastromal corneal ring segments (CXL-ICRS) with simultaneous accelerated CXL... (Clinical Trial)
Clinical Trial
PURPOSE
To compare long-term outcomes of simultaneous accelerated corneal crosslinking (CXL) with intrastromal corneal ring segments (CXL-ICRS) with simultaneous accelerated CXL with topography-guided photorefractive keratectomy (CXL-TG-PRK) in progressive keratoconus (KC).
SETTING
Kensington Eye Institute and Bochner Eye Institute, Toronto, Canada.
DESIGN
Prospective nonrandomized interventional study.
METHODS
The change in visual and topographical outcomes of CXL-ICRS and CXL-TG-PRK 4 to 5 years postoperatively were compared using linear regression models adjusted for preoperative corrected distance visual acuity (CDVA) and maximum keratometry (Kmax).
RESULTS
57 eyes of 43 patients with progressive KC who underwent simultaneous accelerated (9 mW/cm 2 , 10 minutes) CXL-ICRS (n = 32) and CXL-TG-PRK (n = 25) were included. Mean follow-up duration was 51.28 (9.58) and 54.57 (5.81) months for the CXL-ICRS and CXL-TG-PRK groups, respectively. Initial mean Kmax was higher in the CXL-ICRS group compared with the CXL-TG-PRK group (60.68 ± 6.81 diopters [D] vs 57.15 ± 4.19 D, P = .02). At the last follow-up, change (improvement) in logMAR uncorrected distance visual acuity (UDVA) compared with that preoperatively was significant with CXL-ICRS (-0.31 ± 0.27, P < .001, which is equivalent to approximately 3 lines) and not significant with CXL-TG-PRK (-0.06 ± 0.42, P = .43). The logMAR CDVA improved significantly with CXL-ICRS (-0.22 ± 0.20, P < .001), but not with CXL-TG-PRK (-0.05 ± 0.22, P = .25). Adjusting for baseline Kmax and CDVA, the improvement in UDVA was significantly greater with CXL-ICRS than with CXL-TG-PRK (-0.27, 95% CI, 0.06-0.47, P = .01). Improvement in CDVA was not significantly different.
CONCLUSIONS
In this cohort of progressive KC with long-term follow-up, UDVA showed more improvement with accelerated CXL-ICRS than with CXL-TG-PRK.
Topics: Humans; Refraction, Ocular; Photosensitizing Agents; Riboflavin; Prospective Studies; Combined Modality Therapy; Corneal Stroma; Corneal Topography; Keratoconus; Cross-Linking Reagents
PubMed: 38015419
DOI: 10.1097/j.jcrs.0000000000001369