-
Clinical Ophthalmology (Auckland, N.Z.) 2024To evaluate the efficiency, safety, and stability of a revised tissue-saving treatment protocol in a cohort having pellucid marginal degeneration (PMD).
Application of a Revised Tissue Saving Protocol for Combined Topography-Guided Photorefractive Keratectomy and Cross-Linking in a Cohort Having Pellucid Marginal Degeneration.
PURPOSE
To evaluate the efficiency, safety, and stability of a revised tissue-saving treatment protocol in a cohort having pellucid marginal degeneration (PMD).
METHODS
A retrospective cohort study was conducted on patients with PMD and no previous treatments. A revised protocol of topo-guided photorefractive keratectomy to be followed by customized phototherapeutic keratectomy and then corneal crosslinking was evaluated by comparing the pre and postoperative outcomes regarding visual (subjective refraction) and topographic (using data from Sirius CSO topography software) outcomes.
RESULTS
There were both statistically significant and clinically relevant improvements in the postoperative parameters, where each of the unaided and corrected visual acuity, spherical equivalent, refractive cylinder, K readings, topographic cylinder, inferior minus superior difference at the 2- and 4- mm diameters, coma aberration, and higher order aberrations were significantly better postoperatively (all p values were less than 0.01, except for maximum k readings where the p-value was 0.017). The safety and efficacy indices for the surgical procedure were remarkably high (1.53 ± 0.70 and 0.90 ± 0.32, respectively).
CONCLUSION
Our proposed tissue-saving protocol (which showed satisfactory results in keratoconus cases according to a previously published article by our research team) has proven its successful outcomes (both topographically and visually) in cases of PMD, which is a rare ectatic entity with guarded prognosis using the available conventional ectasia treatment modalities.
PubMed: 38317793
DOI: 10.2147/OPTH.S449766 -
Journal of Cataract and Refractive... May 2024Corneal crosslinking (CXL) is used for treating keratoconus and post-laser in situ keratomileusis ectasia. However, refractive surgery is not usually performed with... (Meta-Analysis)
Meta-Analysis Comparative Study
Corneal crosslinking (CXL) is used for treating keratoconus and post-laser in situ keratomileusis ectasia. However, refractive surgery is not usually performed with prophylactic CXL. Therefore, we performed a meta-analysis comparing outcomes of refractive surgeries with vs without prophylactic CXL. We systematically searched databases for studies comparing refractive surgeries for myopic correction with vs without prophylactic corneal crosslinking. Review Manager 5.4.1 was used to perform statistical analysis. We included 2820 eyes from 28 studies. Compared with refractive surgery alone, surgery with prophylactic CXL resulted in decreased central corneal thickness, corrected distance visual acuity logMAR, and safety and efficacy indices. There were no significant differences in postoperative uncorrected distance visual acuity of 20/20 or better at ≥12 months and other visual outcomes among both groups. More randomized controlled trials with standard crosslinking protocols are needed to analyze the prophylactic use of crosslinking with refractive surgeries.
Topics: Humans; Cross-Linking Reagents; Photosensitizing Agents; Keratomileusis, Laser In Situ; Riboflavin; Collagen; Visual Acuity; Myopia; Photorefractive Keratectomy; Photochemotherapy; Lasers, Excimer; Corneal Stroma; Ultraviolet Rays; Keratoconus; Corneal Surgery, Laser; Refraction, Ocular
PubMed: 38288954
DOI: 10.1097/j.jcrs.0000000000001405 -
Cornea Aug 2024The aim of this study was to evaluate the 1-year outcomes of using processed amniotic fluid (pAF) postoperatively after photorefractive keratectomy (PRK). (Randomized Controlled Trial)
Randomized Controlled Trial
PURPOSE
The aim of this study was to evaluate the 1-year outcomes of using processed amniotic fluid (pAF) postoperatively after photorefractive keratectomy (PRK).
METHODS
Sixty-one participants were randomized to receive either placebo or pAF drops. The drops were instilled 4 times daily for 1 week after PRK along with routine postoperative medications. The primary outcome measures included uncorrected visual acuity, topographic corneal irregularity measurement, and surface staining over 1 year.
RESULTS
A statistically significant difference in uncorrected distance visual acuity between the placebo and treatment groups was seen at 1 month post-PRK, with a visual advantage evident in the pAF group. A suggestive difference in corneal irregularity measurement was also seen between the placebo and treatment groups at 1 month postsurgery, with less irregularity noted in the pAF group. No differences in uncorrected distance visual acuity or corneal irregularity measurement were found at 3, 6, and 12 months. There was also no significant difference in corneal staining scores between the 2 groups at any of the measured time points.
CONCLUSIONS
This 1-year study evaluating the safety and efficacy of pAF as an additional postoperative topical medication after PRK demonstrated that pAF offered a mild visual advantage at 1 month post-PRK. There were no late adverse events, and the intervention proved safe at 1 year.
Topics: Humans; Photorefractive Keratectomy; Female; Visual Acuity; Adult; Amniotic Fluid; Double-Blind Method; Male; Ophthalmic Solutions; Lasers, Excimer; Myopia; Young Adult; Corneal Topography; Treatment Outcome
PubMed: 38277050
DOI: 10.1097/ICO.0000000000003474 -
Frontiers in Medicine 2023To evaluate the impact of incomplete blink rate on corneal epithelial thickness after transepithelial photorefractive keratectomy (Trans-PRK) surgery.
PURPOSE
To evaluate the impact of incomplete blink rate on corneal epithelial thickness after transepithelial photorefractive keratectomy (Trans-PRK) surgery.
METHODS
Trans-PRK patients were divided into two groups based on preoperative incomplete blinking rates, namely rates ≤0.5 (41 right eyes, group A) and rates >0.5 (65 right eyes, group B). We used anterior segment optical coherence tomography to measure the corneal epithelial thickness (CET) and lipiview to measure the number of blinks, incomplete blinking rate, and lipid layer thickness (LLT).
RESULTS
In both groups, CET decreased at 1 week and 1 month, and the thicknesses in the IT, T, and ST regions exceeded the preoperative levels. Three months after Trans-PRK, the thickness exceeded the preoperative levels and continued to increase during subsequent follow-ups. The blinking times and LLT in both groups decreased at 1 week and gradually increased but did not return to preoperative levels. Group A maintained an incomplete blinking rate of over 0.5 at all postoperative periods. The incomplete blinking rate of group B remained above 0.5 postoperatively, although there was an improvement compared with preoperative rates. Both groups showed a correlation between changes in CET and incomplete blinking rate. There was a correlation between changes in LLT and the incomplete blinking rate after surgery.
CONCLUSION
Both groups showed uneven corneal epithelia thickening, which became more pronounced approaching the peripheral areas. In addition, changes in CET after surgery were positively correlated with the incomplete blinking rate in both patient groups. There was a negative correlation between postoperative LLT and incomplete blinking rate.
PubMed: 38259844
DOI: 10.3389/fmed.2023.1305461 -
Experimental Eye Research Feb 2024The purpose of this study was to evaluate transforming growth factor beta (TGFβ) isoform localization in rabbit corneas with spontaneous persistent epithelial defects...
The purpose of this study was to evaluate transforming growth factor beta (TGFβ) isoform localization in rabbit corneas with spontaneous persistent epithelial defects (PEDs) after photorefractive keratectomy (PRK). Four cryofixed corneas from a previously reported series of PEDs in rabbits that had PRK were evaluated with triplex immunohistochemistry (IHC) for TGFβ3, myofibroblast marker alpha-smooth muscle actin (α-SMA) and mesenchymal marker vimentin. One cornea had sufficient remaining tissue for triplex IHC for TGFβ1, TGFβ2, or TGFβ3 (each with α-SMA and vimentin) using isoform-specific antibodies. All three TGFβ isoforms were detected in the subepithelial stroma at and surrounding the PED. Some of each TGFβ isoform co-localized with α-SMA of myofibroblasts, which could be TGFβ isoform autocrine production by myofibroblasts or TGFβ-1, -2, and -3 binding to these myofibroblasts.
Topics: Animals; Rabbits; Photorefractive Keratectomy; Vimentin; Transforming Growth Factor beta; Corneal Stroma; Cornea; Protein Isoforms; Actins
PubMed: 38237715
DOI: 10.1016/j.exer.2024.109794 -
Vestnik Oftalmologii 2023This article presents a retrospective analysis of the research findings by professor A.A. Kasparov, who developed and implemented a novel approach to treating ocular...
This article presents a retrospective analysis of the research findings by professor A.A. Kasparov, who developed and implemented a novel approach to treating ocular herpes. The treatment system is fundamentally different from the conventional chemotherapeutic approach and revolves around non-specific immunotherapy using an endogenous interferon inducer - a biosynthetic complex of polyriboadenylic and polyribouridylic acids, known as Poludan. This approach also incorporates personalized cell therapy based on Poludan, along with herpes vaccine aimed at preventing recurrence. The regenerative and antiviral properties of this approach have proven successful in treating other corneal conditions such as adenovirus infections, early postoperative bullous keratopathy, as well as in stimulation of epithelialization after refractive surgeries (photorefractive keratectomy, phototherapeutic keratectomy).
Topics: Humans; Interferons; Retrospective Studies; Keratitis, Herpetic; Corneal Diseases; Photorefractive Keratectomy; Lasers, Excimer; Polyribonucleotides
PubMed: 38235646
DOI: 10.17116/oftalma2023139061183 -
Vestnik Oftalmologii 2023This study compares the trends of changes in corneal asphericity, corneal and total aberrations and peripheral refraction in myopic eyes after excimer laser and...
PURPOSE
This study compares the trends of changes in corneal asphericity, corneal and total aberrations and peripheral refraction in myopic eyes after excimer laser and orthokeratology correction.
MATERIAL AND METHODS
Aberrometry (OPD-Scan III; Nidek, Japan) was performed in 63 patients (126 eyes) with moderate and high myopia before and after femtosecond laser-assisted in situ keratomileusis (Femto-LASIK; 88 eyes, group 1) and photorefractive keratectomy (PRK; 38 eyes, group 2). Peripheral refraction (Grand Seiko AutoRef/Keratometer) at 15° and 30° from the center of the fovea was observed in 12 patients of group 1 and in 18 patients with a background of orthokeratology correction (group 3).
RESULTS
Corneal asphericity factor Q transitioned to positive values after PRK and Femto-LASIK. Corneal aberrations: root mean square higher order aberration (RMS HOA) increased in both groups, Tilt 1 increased in group 1 and became negative in group 2, Tilt 2 increased in group 2 and went negative in group 1. Trefoil 6 did not change in group 1 and decreased in group 2. Coma 7 and 8 increased synchronously in both groups. Spherical aberrations (SA) increased in group 1, and went negative in group 2. Total aberrations changed to a lower degree, and these changes were not synchronous with the corneal ones; RMS HOA decreased in group 1 (while corneal RMS increased significantly), and in the PRK group it increased, but much less than the corneal. Total SA increased in group 1 and did not change in group 2. Peripheral myopic defocus formed in all cases, after Femto-LASIK the maximum was in the zone of 30º, after orthokeratology lenses - in the zone of 15º.
CONCLUSION
Using excimer laser and orthokeratology to reshape the cornea in full accordance with its different profiles have different effects on the wavefront and peripheral refraction of the eye. The internal optics of the eye partially compensates corneal aberrations induced by the excimer laser.
Topics: Humans; Lasers, Excimer; Corneal Topography; Visual Acuity; Cornea; Myopia; Photorefractive Keratectomy; Keratomileusis, Laser In Situ; Refraction, Ocular
PubMed: 38235634
DOI: 10.17116/oftalma202313906187 -
Case Reports in Ophthalmology 2024Significant corneal flattening and haze are important complications that can occur after combined corneal collagen cross-linking (CXL) and photorefractive keratectomy...
INTRODUCTION
Significant corneal flattening and haze are important complications that can occur after combined corneal collagen cross-linking (CXL) and photorefractive keratectomy (PRK) procedures (CXL Plus).
CASE PRESENTATION
We present a 24-year-old man who underwent combined standard CXL and PRK. The patient experienced satisfactory vision for approximately 4 years after the surgery. However, after this period, he began to complain of visual blurring. Subsequent examination revealed significant corneal haze, excessive flattening in both eyes, and thinning (thinnest point 227 μm in the right eye, 244 μm in the left eye) 4 years postoperatively. Upon presentation, the corrected distance visual acuity (CDVA) was 20/200 in the right eye and 20/400 in the left eye. The presenting refraction was +2.50 sph, -3.50 cyl *114 in the right eye and +11.5 sph, -9.75 cyl *81 in the left eye. With rigid gas permeable contact lenses, the corrected visual acuity was 20/50 in both eyes. Before the CXL Plus surgery, initial refraction and CDVA were 20/50 in the right eye (-5.50 sph, -3.00 cyl *175) and 20/30 in the left eye (-5.50 sph, -2.75 cyl *175). The patient was treated by penetrating keratoplasty. The CDVA reached 20/30 at the final follow-up.
CONCLUSION
Our report highlights significant corneal haze and flattening that occurred 4 years after combined CXL and PRK treatment. These findings suggest that this procedure might not be safe in suspected patients of keratoconus. Further long-term follow-up research is necessary to evaluate the safety of combined CXL and PRK procedures.
PubMed: 38234306
DOI: 10.1159/000535987 -
Translational Vision Science &... Jan 2024To assess changes in corneal epithelial thickness (ET) within 9-mm diameter cornea after photorefractive keratectomy (PRK) retreatment after small-incision lenticule...
PURPOSE
To assess changes in corneal epithelial thickness (ET) within 9-mm diameter cornea after photorefractive keratectomy (PRK) retreatment after small-incision lenticule extraction (SMILE).
METHODS
A total of 28 eyes of 19 patients with mean spherical equivalent of -1.30 ± 0.60 D who underwent retreatment after SMILE were included in this retrospective study. ET mapped across a 9-mm diameter area was obtained using wide-field optical coherence tomography (OCT) before and at one, three, and six months after surgery. The ET changes were compared between the different time points and analyzed zones.
RESULTS
Before enhancement, the ET were 63.64 ± 6.01 µm and 61.25 ± 4.32 µm in central and paracentral zones, respectively. The ET of central and paracentral zones significantly decreased at one month and subsequently increased until six months. Six months after surgery, significant epithelial thickening occurred in 2- to 9-mm diameter cornea (all P < 0.05), whereas no significant change was observed in central 2-mm diameter cornea (P = 0.460). There was no significant difference in the ET between the central and paracentral zones (P = 1.00). The degree of myopic correction significantly correlated with the average ET in the central (P = 0.046) and paracentral (P = 0.033) zones at six months after PRK enhancement. No significant correlation was detected between the average ET of all zones and the postoperative spherical equivalent at six months after surgery (all P > 0.05).
CONCLUSIONS
PRK enhancement did not alter the overall trend of corneal epithelial remodeling induced by SMILE. An asymmetric and flatter lenticule-like pattern of epithelial remodeling was observed six months after surgery, which did not affect the refractive outcomes.
TRANSLATIONAL RELEVANCE
An asymmetric and centrally flattened lenticule-like pattern of epithelial remodeling was observed after PRK enhancement. Surgeons should consider expanding the intended optical zones for enhancement surgery after SMILE.
Topics: Humans; Photorefractive Keratectomy; Retrospective Studies; Cornea; Myopia; Refraction, Ocular
PubMed: 38231497
DOI: 10.1167/tvst.13.1.14 -
Experimental Eye Research Mar 2024HSV1 presents as epithelial or stromal keratitis or keratouveitis and can lead to sight-threatening complications. KLF4, a critical transcription factor, and regulator...
HSV1 presents as epithelial or stromal keratitis or keratouveitis and can lead to sight-threatening complications. KLF4, a critical transcription factor, and regulator of cell growth and differentiation, is essential in corneal epithelium stratification and homeostasis. Here, we want to understand the epigenetic modification specifically the methylation status of KLF4 in epithelium samples of HSV1 keratitis patients. After obtaining consent, epithelial scrapes were collected from 7 patients with clinically diagnosed HSV1 keratitis and 7 control samples (patients undergoing photorefractive keratectomy). Genomic DNA was isolated from the collected samples using the Qiagen DNeasy Kit. Subsequently, bisulfite modification was performed. The bisulphite-modified DNA was then subjected to PCR amplification using specific primers designed to target the KLF4, ACTB gene region, allowing for the amplification of methylated and unmethylated DNA sequences. The amplified DNA products were separated and visualized on a 3% agarose gel. KLF4 hypermethylation was found in 6 out of 7 (85.71%) eyes with viral keratitis, while 1 eye showed hypomethylation compared to PRK samples. Out of these 6, there were 2 each of epithelial dendritic keratitis, epithelial geographical keratitis, and neurotrophic keratitis. The patient with hypomethylated KLF4 had a recurrent case of HSV1 keratitis with multiple dendrites and associated vesicular lesions of the lip along with a history of fever. KLF4 hypermethylation in most viral keratitis cases indicated the under functioning of KLF4 and could indicate a potential association between KLF4 hypermethylation and the development or progression of HSV1 keratitis.
Topics: Humans; DNA; DNA Methylation; Epithelium, Corneal; Eye Infections, Viral; Keratitis
PubMed: 38163580
DOI: 10.1016/j.exer.2023.109771