-
Journal of Refractive Surgery... Dec 2018To determine how photorefractive keratectomy (PRK) and mitomycin C (MMC) affect corneal nerves and their regeneration over time after surgery.
PURPOSE
To determine how photorefractive keratectomy (PRK) and mitomycin C (MMC) affect corneal nerves and their regeneration over time after surgery.
METHODS
Twenty-eight New Zealand rabbits had corneal epithelial scraping with (n = 3) and without (n = 3) MMC 0.02% or -9.00 diopter PRK with (n = 6) and without (n = 16) MMC 0.02%. Corneas were removed after death and corneal nerve morphology was evaluated using acetylcholinesterase immunohistochemistry and beta-III tubulin staining after 1 day for all groups, after 1 month for PRK with and without MMC, and 2, 3, and 6 months after PRK without MMC. Image-Pro software (Media Cybernetics, Rockville, MD) was used to quantitate the area of nerve loss after the procedures and, consequently, regeneration of the nerves over time. Opposite eyes were used as controls.
RESULTS
Epithelial scraping with MMC treatment did not show a statistically significant difference in nerve loss compared to epithelial scraping without MMC (P = .40). PRK with MMC was significantly different from PRK without MMC at 1 day after surgery (P = .0009) but not different at 1 month after surgery (P = .90). In the PRK without MMC group, nerves regenerated at 2 months (P < .0001) but did not return to the normal preoperative level of innervation until 3 months after surgery (P = .05). However, the morphology of the regenerating nerves was abnormal-with more tortuosity and aberrant innervation compared to the preoperative controls-even at 6 months after surgery.
CONCLUSIONS
PRK negatively impacts the corneal nerves, but they are partially regenerated by 3 months after surgery in rabbits. Nerve loss after PRK extended peripherally to the excimer laser ablated zone, indicating that there was retrograde degeneration of nerves after PRK. MMC had a small additive toxic effect on the corneal nerves when combined with PRK that was only significant prior to 1 month after surgery. [J Refract Surg. 2018;34(12):790-798.].
Topics: Acetylcholinesterase; Alkylating Agents; Animals; Cornea; Debridement; Epithelium, Corneal; Female; Lasers, Excimer; Microscopy, Confocal; Mitomycin; Models, Animal; Nerve Regeneration; Photorefractive Keratectomy; Rabbits; Trigeminal Nerve; Wound Healing
PubMed: 30540361
DOI: 10.3928/1081597X-20181112-01 -
Journal of Refractive Surgery... Feb 2023To provide a comprehensive analysis of the most highly cited articles and authors in refractive surgery. (Review)
Review
PURPOSE
To provide a comprehensive analysis of the most highly cited articles and authors in refractive surgery.
METHODS
The Scopus database was searched for articles pertaining to refractive surgery using multiple search terms to identify the top 100 most cited articles in refractive surgery. A publicly available database of more than 100,000 scientists that provides standardized information on multiple variables resulting in a composite indicator (C score) was searched to identify refractive surgery authors. A refractive surgery-specific composite score was created using only the authors' publications that were directly related to refractive surgery.
RESULTS
The 100 most cited articles and 40 refractive surgery authors with the highest ranked C score were identified. The article with the most citations by Trokel et al has garnered nearly 800 citations to date. All articles included in the top 100 had 200 or more citations. The peak publication years were 1998 to 2001. Laser in situ keratomileusis (22), photorefractive keratectomy (18), and postoperative corneal ectasia and/or corneal biomechanics (16) were the most represented topics. Emory University generated the most articles (7) and the majority of publications (48%) originated in the United States. Steven E. Wilson, MD, had the highest refractive C score and Jorge L. Alió, MD, PhD, had the most refractive surgery articles and citations. Among all authors listed, the average number of refractive surgery publications was 97, with 35% of the group having more than 100 refractive surgery articles published. All authors on the list had more than 2,000 citations for their refractive surgery articles, whereas 38% had 4,000 or more citations.
CONCLUSIONS
This list provides a comprehensive assessment of the most cited articles and authors in refractive surgery and demonstrates key focuses and trends in the field over time. .
Topics: Humans; United States; Bibliometrics; Keratomileusis, Laser In Situ; Ophthalmology; Photorefractive Keratectomy; Databases, Factual
PubMed: 36779469
DOI: 10.3928/1081597X-20221213-01 -
Journal Francais D'ophtalmologie Oct 2023To evaluate the safety and efficacy of combined simultaneous photorefractive keratectomy (PRK) with collagen cross-linking (CXL) in keratoconus suspects (KCS).
PURPOSE
To evaluate the safety and efficacy of combined simultaneous photorefractive keratectomy (PRK) with collagen cross-linking (CXL) in keratoconus suspects (KCS).
METHODS
This was a retrospective, non-randomized study of KCS patients who underwent combined simultaneous PRK with CXL. The efficacy, safety, refractive outcomes, and corneal wavefront aberration changes were assessed after the surgery and compared with existing preoperative data.
RESULTS
Fifty-six eyes of 28 patients, including 20 females (71.4%), with a mean age of 30.92±4.09 years, were enrolled. The mean follow-up was 19.46±8.48 months (range: 7-35). At the conclusion of the study, mean uncorrected distance visual acuity LogMAR improved from 0.89±0.44 preoperatively to 0.04±0.09 postoperatively (P<0.001). In addition, a statistically significant corneal flattening was observed postoperatively, with a decrease in manifest refraction. A statistically significant increase was found in higher-order aberrations (P<0.001), horizontal coma (P<0.001), and spherical aberration (P<0.001) compared with preoperatively. Postoperatively, 41% exhibited refractive astigmatism of 0.50 diopter (D) or less; 83.8% showed 1.00 D or less.
CONCLUSION
The results of our study indicate that combined simultaneous PRK with CXL can be a safe and effective method for treating refractive instability in KCS patients.
Topics: Female; Humans; Adult; Photorefractive Keratectomy; Keratoconus; Visual Acuity; Photosensitizing Agents; Retrospective Studies; Riboflavin; Corneal Topography; Corneal Stroma; Collagen; Cross-Linking Reagents
PubMed: 37085363
DOI: 10.1016/j.jfo.2022.11.029 -
Journal of Optometry 2019To investigate immediate and short-term visual recovery in a large cohort of 2093 myopic eyes (with or without astigmatism) treated with SmartSurf procedure, a...
PURPOSE
To investigate immediate and short-term visual recovery in a large cohort of 2093 myopic eyes (with or without astigmatism) treated with SmartSurf procedure, a combination of Transepithelial Photo Refractive Keratectomy (PRK) and Smart Pulse Technology (SPT, SCHWIND eye-tech-solutions GmbH, Kleinostheim, Germany).
METHODS
In this retrospective case series, post-operative outcomes were evaluated immediately after the surgery (Day 0), at day 1 and 3 months postoperatively, after myopic SmartSurf treatment with mean pre-operative spherical equivalent -4.65±2.53D and range from -16.13D to -0.13D. In all cases, pre and postoperative standard examinations were performed. The analysis evaluated preoperative Corrected and Uncorrected Distance Visual Acuity (CDVA and UDVA, respectively), and postoperative UDVA, monocularly and binocularly, immediately after the surgery, at day 1 and 3 month follow up.
RESULTS
Sixty-two percent eyes achieved monocular UDVA 20/40 or better immediately after the surgery, while 82% patients achieved binocular UDVA 20/32 or better immediately after the surgery. At 3-month postoperatively, monocular UDVA 20/25 or better was achieved in 94% eyes. Treated eyes achieved immediately after the surgery or by the next day mean UDVA 20/41±8. UDVA improved significantly from Day 1 to 3-months follow up (p<0.0001 for both OS and OD) to mean UDVA 20/21±5 (equal to preoperative CDVA 20/21±8).
CONCLUSION
Immediate and short-term visual recovery after SmartSurf PRK in our large cohort was rapid, providing functional binocular UDVA immediately after the surgery.
Topics: Adolescent; Adult; Aged; Corneal Topography; Female; Humans; Lasers, Excimer; Male; Middle Aged; Myopia; Photorefractive Keratectomy; Recovery of Function; Refraction, Ocular; Retrospective Studies; Vision, Binocular; Visual Acuity
PubMed: 31473174
DOI: 10.1016/j.optom.2019.04.003 -
Scientific Reports May 2021This study was aimed to assess the outcomes of simultaneous phototherapeutic keratectomy (PTK) and photoastigmatic keratectomy (PAK), with special attention to...
This study was aimed to assess the outcomes of simultaneous phototherapeutic keratectomy (PTK) and photoastigmatic keratectomy (PAK), with special attention to astigmatic correction. We comprised 70 eyes of 70 patients who underwent simultaneous PTK and PAK in patients having granular corneal dystrophy and band keratopathy with refractive astigmatism of 1 diopter (D) or more. Preoperatively and 6 months postoperatively, we assessed corrected uncorrected distance visual acuity (UDVA), distance visual acuity (CDVA), manifest spherical equivalent, refractive astigmatism, corneal astigmatism, and higher-order aberrations (HOAs). LogMAR CDVA significantly improved, from 0.27 ± 0.27 preoperatively, to 0.13 ± 0.21 postoperatively (Paired t test, p < 0.001). LogMAR UDVA also significantly improved, from 0.70 ± 0.32 preoperatively, to 0.57 ± 0.41 postoperatively (p = 0.043). Refractive astigmatism significantly decreased, from 2.12 ± 0.95 D preoperatively, to 0.89 ± 0.81 D postoperatively (p < 0.001). Corneal astigmatism also significantly decreased, from 2.17 ± 0.90 D preoperatively, to 1.08 ± 0.71 D postoperatively (p < 0.001). Corneal HOAs did not significantly change, from 0.54 ± 0.30 µm preoperatively, to 0.48 ± 0.20 µm postoperatively (p = 0.140). No significant complications occurred in any eye. Simultaneous PTK and PAK treatment is effective not only for improving visual acuity, but also for reducing astigmatism.
Topics: Aged; Aged, 80 and over; Astigmatism; Cornea; Corneal Dystrophies, Hereditary; Corneal Topography; Female; Humans; Male; Middle Aged; Photorefractive Keratectomy; Refraction, Ocular; Retrospective Studies; Visual Acuity
PubMed: 33947941
DOI: 10.1038/s41598-021-89044-3 -
Vestnik Oftalmologii 2018The article reviews modern clinical, morphological, and genetic aspects of corneal dystrophies based on the most recent international classification updated in 2015.... (Review)
Review
The article reviews modern clinical, morphological, and genetic aspects of corneal dystrophies based on the most recent international classification updated in 2015. Corneal dystrophies is a group of slow progressing, non-inflammatory corneal pathologies, most of which are characterized by variability of the associated traits. The existence of such pathologies makes important their differential diagnosis from acute inflammatory processes of various etiology, which require urgent therapy. Conservative treatment suitable for dystrophies is usually associated with disorders of the anterior corneal surface and employ symptomatic tactic (lubricants, epithelizing agents, soft contact lenses). No effective etiopathogenetically targeted treatment is currently known. In cases with significant visual acuity decrease, it is possible to perform phototherapeutic keratectomy, abrasive polishing of Bowman's membrane with diamond bur and various types of keratoplasty depending on the depth of involvement.
Topics: Cornea; Corneal Dystrophies, Hereditary; Corneal Transplantation; Humans; Lasers, Excimer; Photorefractive Keratectomy
PubMed: 30499549
DOI: 10.17116/oftalma2018134051118 -
Journal of Cataract and Refractive... May 2021Twenty-eight case reports and case series published between 2000 and 2019 concerning laser refractive surgery in patients with corneal dystrophies, resulting in 173 eyes...
Twenty-eight case reports and case series published between 2000 and 2019 concerning laser refractive surgery in patients with corneal dystrophies, resulting in 173 eyes from 94 patients, were included in this systematic review. Best results were achieved in posterior corneal polymorphous and Cogan dystrophy. Unfavorable results were found in Avellino dystrophy and Fuchs endothelial corneal dystrophy (FECD). Photorefractive keratectomy was not indicated in Meesmann and Avellino dystrophy. Laser in situ keratomileusis was indicated in posterior polymorphous corneal dystrophy but not in FECD, Avellino, or Cogan dystrophy. Small-incision lenticule extraction and other dystrophies such as lattice, fleck, Lisch, or François did not achieve enough scientific evidence to report any recommendation.
Topics: Cornea; Corneal Dystrophies, Hereditary; Humans; Keratomileusis, Laser In Situ; Lasers, Excimer; Photorefractive Keratectomy
PubMed: 33149045
DOI: 10.1097/j.jcrs.0000000000000468 -
Indian Journal of Ophthalmology Dec 2021Photorefractive keratectomy (PRK) is considered a safe approach laser procedure with a clinical significance in correcting myopia results. PRK requires removing the... (Meta-Analysis)
Meta-Analysis Review
Photorefractive keratectomy (PRK) is considered a safe approach laser procedure with a clinical significance in correcting myopia results. PRK requires removing the whole superficial epithelium. The integrity of the epithelial basement membrane and the deposition of abnormal extracellular matrix can put the cornea in a probable situation for corneal haze formation. Mitomycin C (MMC) is applied after excimer laser ablation as a primary modulator for wound healing, limiting corneal haze formation. We aim to summarize the outcomes of MMC application after laser ablation. We searched Scopus, PubMed, Cochrane CENTRAL, and Web of Science till December 2020 using relevant keywords. The data were extracted and pooled as mean difference (MD) or risk ratio (RR) with a 95% confidence interval (CI), using Review Manager software (version 5.4). Our analysis demonstrated a statistically significant result for MMC application over the control group in terms of corneal haze formation postoperatively (RR = 0.29, 95% CI: [0.19, 0.45], P < 0.00001). Regarding corrected distance visual acuity (CDVA), no significant difference was observed between the MMC group and the control group (MD = 0.02; 95% CI: [-0.04, 0.07]; P = 0.56). Regarding the uncorrected distance visual acuity (UDVA), the analysis favored the MMC application with (MD -0.03, 95% CI: [-0.06, -0.00]; P = 0.05). There was no statistically significant increase in complications with MMC. In conclusion, MMC application after PRK is associated with a lower incidence of corneal haze formation with no statistically significant side effects. The long term effect can show improvement regarding UDVA favoring MMC. However, there is no significant effect of MMCs application regarding CDVA, and SE.
Topics: Alkylating Agents; Humans; Lasers, Excimer; Mitomycin; Myopia; Photorefractive Keratectomy
PubMed: 34826969
DOI: 10.4103/ijo.IJO_3768_20 -
Journal of Refractive Surgery... Nov 2022To evaluate the safety, efficacy, and predictability of photorefractive keratectomy (PRK) at least 4 years after primary laser in situ keratomileusis (LASIK) and compare...
PURPOSE
To evaluate the safety, efficacy, and predictability of photorefractive keratectomy (PRK) at least 4 years after primary laser in situ keratomileusis (LASIK) and compare it to the United States Food and Drug Administration (FDA) criteria.
METHODS
This retrospective, single-site study compared patients who underwent PRK enhancement from 2014 to 2019 after primary LASIK to those who only underwent primary LASIK without re-treatment from the same time period. Patient demographics and clinical information were compared between the two groups. Visual outcomes and postoperative complications were evaluated in the enhancement group.
RESULTS
A total of 374 eyes with PRK enhancement were compared to 472 without re-treatment. Age, sex, surgical eye, and preoperative sphere, and spherical equivalent (SE) were significantly different between the enhancement and control groups ( < .05). At 12 months post-enhancement, 67% had uncorrected distance visual acuity (UDVA) of 20/20 or better, 98% had UDVA of 20/40 or better, and 0.4% of eyes lost at least two lines of corrected distance visual acuity (CDVA). A total of 83% and 98% of eyes were within ±0.50 and ±1.00 diopters of the target, respectively. Post-enhancement complications (n = 66) included dryness (6.1%), epithelial ingrowth (2.7%), and haze (2.7%).
CONCLUSIONS
Older age at the time of the primary LASIK, female sex, right surgical eye, and more myopic sphere and SE were risk factors for enhancement. Although PRK enhancements are considered off-label procedures, they produce favorable outcomes at 3 and 12 months postoperatively while meeting FDA benchmarks for safety, efficacy, and predictability. .
Topics: Humans; Female; Photorefractive Keratectomy; Keratomileusis, Laser In Situ; Lasers, Excimer; Retrospective Studies; Myopia; Refraction, Ocular; Treatment Outcome
PubMed: 36367261
DOI: 10.3928/1081597X-20221019-01 -
Journal of Cataract and Refractive... Apr 2019To study the effect of variables on the accuracy and reliability of the optical pachymeter built into the WaveLight EX500 excimer laser during photorefractive...
PURPOSE
To study the effect of variables on the accuracy and reliability of the optical pachymeter built into the WaveLight EX500 excimer laser during photorefractive keratectomy (PRK).
SETTING
John A. Moran Eye Center, University of Utah, Salt Lake City, USA.
DESIGN
Retrospective case series.
METHODS
A chart review of 352 eyes (181 patients) that had excimer laser PRK was performed. Programmed excimer laser residual stromal bed (RSB) measurements, optical pachymeter measurements after ablation, and Scheimpflug pachymetry measurements (Pentacam) at the 1-year follow-up were compared. Variables included ablation time, preoperative spherical equivalent (SE), 1-year SE, mitomycin-C use, operating room temperature and humidity, and programmed monovision.
RESULTS
The mean programmed RSB was 27 μm greater than the optical pachymetry post-ablation measurement (P < .001). Of patients with a 1-year follow-up, the 1-year Scheimpflug pachymetry RSB was 24 μm greater than the optical pachymetry post-ablation RSB (P < .001). Comparison of the programmed RSB with the optical pachymetry post-ablation RSB showed that the preoperative SE and ablation time had a Pearson correlation coefficient of -0.36 and 0.30, respectively (P < .001). There was no correlation between operating room temperature, humidity, or programmed monovision with these differences.
CONCLUSIONS
The RSB post-ablation values measured by optical pachymetry during PRK were significantly lower than the programmed excimer laser RSB value and 1-year Scheimpflug pachymetry RSB value. Intraoperative pachymetry during PRK underpredicted the actual long-term RSB thickness. The greater temporary drying effect associated with increased ablation time in higher myopic corrections might have caused this error.
Topics: Adult; Aged; Body Temperature; Corneal Pachymetry; Corneal Stroma; Corneal Topography; Female; Follow-Up Studies; Humans; Humidity; Intraoperative Period; Lasers, Excimer; Male; Middle Aged; Operative Time; Organ Size; Photorefractive Keratectomy; Refraction, Ocular; Retrospective Studies; Surgical Flaps; Visual Acuity; Young Adult
PubMed: 30819562
DOI: 10.1016/j.jcrs.2018.11.033