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Safir M, Sorkin N, Kaiserman I, Sela T, Munzer G, Spierer O, Mimouni M. Factors Predicting Slow Visual Recovery Following Hyperopic LASIK. J Refract Surg 2024; 40:e42-e47. [PMID: 38190557 DOI: 10.3928/1081597x-20231212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
PURPOSE To identify factors predicting slow visual recovery following hyperopic laser in situ keratomileusis (LASIK). METHODS The study included consecutive patients who underwent hyperopic LASIK between January 2005 and December 2019 at a single medical center. Patients were divided into two groups according to whether they experienced normal recovery of visual acuity (1-week visit) or slow visual recovery (1-month visit). Visual recovery was defined as achieving an efficacy index of 0.9 or greater. Efficacy index was calculated as postoperative uncorrected distance visual acuity / preoperative corrected distance visual acuity. A comparison of baseline and intraoperative parameters was performed. Binary logistic regression was performed to identify potential predictors of slow visual recovery. RESULTS Overall, 861 eyes of 861 patients were included. Mean age was 48.0 ± 9.5 years and 55.9% were women. Two hundred forty-nine patients (28.9%) experienced slow visual recovery. Younger age (P = .01), a larger preoperative spherical equivalence (P = .002), and greater maximum ablation depth (P = .002) were predictors of slow visual recovery. In binary logistic regression, female gender (P = .036) and greater spherical equivalence (P = .007) remained significant predictors of slow visual recovery. CONCLUSIONS Female gender and greater preoperative spherical equivalence were associated with slow visual recovery. Patients may be advised accordingly. [J Refract Surg. 2024;40(1):e42-e47.].
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Safir M, Sorkin N, Kaiserman I, Sela T, Munzer G, Spierer O, Mimouni M. Factors Predicting Slow Visual Recovery Following Hyperopic LASIK. J Refract Surg 2024; 40:e42-e47. [PMID: 38190563 DOI: 10.3928/1081597x-20231212-05] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
PURPOSE To identify factors predicting slow visual recovery following hyperopic laser in situ keratomileusis (LASIK). METHODS The study included consecutive patients who underwent hyperopic LASIK between January 2005 and December 2019 at a single medical center. Patients were divided into two groups according to whether they experienced normal recovery of visual acuity (1-week visit) or slow visual recovery (1-month visit). Visual recovery was defined as achieving an efficacy index of 0.9 or greater. Efficacy index was calculated as postoperative uncorrected distance visual acuity / preoperative corrected distance visual acuity. A comparison of baseline and intraoperative parameters was performed. Binary logistic regression was performed to identify potential predictors of slow visual recovery. RESULTS Overall, 861 eyes of 861 patients were included. Mean age was 48.0 ± 9.5 years and 55.9% were women. Two hundred forty-nine patients (28.9%) experienced slow visual recovery. Younger age (P = .01), a larger preoperative spherical equivalence (P = .002), and greater maximum ablation depth (P = .002) were predictors of slow visual recovery. In binary logistic regression, female gender (P = .036) and greater spherical equivalence (P = .007) remained significant predictors of slow visual recovery. CONCLUSIONS Female gender and greater preoperative spherical equivalence were associated with slow visual recovery. Patients may be advised accordingly. [J Refract Surg. 2024;40(1):e42-e47.].
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Tangmonkongvoragul C, Supalaset S, Tananuvat N, Ausayakhun S. Two-Step Transepithelial Photorefractive Keratectomy with WaveLight EX500 Platform for Adolescents and Adults with Low to Moderate Myopia: A 12-Month Comparative Evaluation. Clin Ophthalmol 2021; 15:4109-4119. [PMID: 34675478 PMCID: PMC8520963 DOI: 10.2147/opth.s336727] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 10/01/2021] [Indexed: 11/29/2022] Open
Abstract
Purpose To compare the visual and refractive results obtained after two-step TransPRK using an EX500 excimer laser for low to moderate myopic correction in adolescents and adults. Patients and Methods Retrospectively, 91 eyes of 52 patients were categorized into four groups based on age and level of myopia. The demographics, data of efficacy, safety, predictability, stability, and post-operative complications were evaluated at 1, 3, 6, and 12 months post-operatively. Results At 1-month, adolescents with low myopia achieved the highest mean efficacy index (P =0.034). The efficacy indices continuously increased during the 1-year follow-up in all groups, except in adolescents with moderate myopia. The highest safety and efficacy indices were recorded in adolescents with low myopia at 1-year. Post-operative spherical equivalent within ±0.50 D at 1 year was 48.75% of all treated eyes; however, the final mean refractive spherical equivalent (MRSE) was under-corrected in all groups. By month 3, the percentage of eyes that had grade 0.5 haze was most prevalent in adolescents with moderate myopia (P <0.001). Conclusion two-step TransPRK using an EX500 proved to be an effective, predictable, stable and safe procedure for the correction of low to moderate myopia with or without astigmatism at 1 year. Adolescents with low myopia achieved the best-post-operative UDVA, efficacy and safety indices. Adolescents tolerated night visual problems and dry eye symptoms better than adults.
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Affiliation(s)
- Chulaluck Tangmonkongvoragul
- Department of Ophthalmology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.,CMU LASIK Center, Center of Medical Excellence, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Sumet Supalaset
- Department of Ophthalmology, Chulabhorn Hospital, HRH Princess Chulabhorn College of Medical Science, Chulabhorn Royal Academy, Bangkok, Thailand
| | - Napaporn Tananuvat
- Department of Ophthalmology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.,CMU LASIK Center, Center of Medical Excellence, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Somsanguan Ausayakhun
- Department of Ophthalmology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.,CMU LASIK Center, Center of Medical Excellence, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
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Effect of intraoperative mitomycin-C application on epithelial regeneration after transepithelial photorefractive keratectomy. J Cataract Refract Surg 2021; 47:227-232. [PMID: 32947389 DOI: 10.1097/j.jcrs.0000000000000427] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 08/16/2020] [Indexed: 11/26/2022]
Abstract
PURPOSE To investigate the effect of mitomycin-C (MMC) intraoperative application on postoperative corneal epithelial remodeling, haze incidence, and refractive correction in transepithelial photorefractive keratectomy (transPRK). SETTING Eye Hospital of Wenzhou Medical University, Wenzhou, China. DESIGN Prospective randomized controlled study. METHODS Eyes that completed all follow-ups were included. Epithelial thickness (ET) map measurement was conducted preoperatively and at 1 week, and at 1 month, 3 months, and 6 months postoperatively, generating ET in central, paracentral, and midperipheral zones. The difference between postoperative and preoperative ET (ΔET) was computed for each zone. During follow-up, haze incidence and visual acuity were assessed and compared between groups. RESULTS A total of 100 eyes completed all follow-up, including 40 eyes treated with MMC in MMC group and 60 eyes in control group without MMC treatment. For ΔET, between-group difference was found in midperipheral (P = .011) zone at 1 week postoperatively and in central (P = .036) and paracentral zones (P = .039) at 1 month postoperatively. Haze incidence was lower in MMC group at 1 week and 1 month postoperatively (P = .035 and .018, respectively). Safety index (postoperative uncorrected distance visual acuity/preoperative corrected distance visual acuity [CDVA]) and efficacy index (postoperative CDVA/preoperative CDVA) were higher in MMC group (P = .012 and P = .036, respectively) at 1 month postoperatively. No difference was found after 3 months postoperatively. CONCLUSIONS With a temporary impact on corneal epithelial regeneration and refractive correction, intraoperative MMC application in transPRK decreased the haze incidence but had no effect on epithelial remodeling.
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Rush SW, Rush RB. Optical Coherence Tomography-Guided Femtosecond LASIK in the Setting of Corneal Scarring. Clin Ophthalmol 2021; 15:1601-1606. [PMID: 33907375 PMCID: PMC8068509 DOI: 10.2147/opth.s307191] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 03/25/2021] [Indexed: 11/23/2022] Open
Abstract
Purpose To report the outcomes of femtosecond-assisted laser in situ keratomileusis (LASIK) in patients with previous corneal scarring using optical coherence tomography (OCT) imaging to determine flap depths. Methods The charts of 11 eyes of 9 patients with previous off-visual axis corneal scarring that underwent femtosecond LASIK using OCT guidance for flap depth determination were retrospectively reviewed at a single private practice institution. The baseline characteristics, intraoperative findings and postoperative outcomes were analyzed. Results All 11 eyes underwent femtosecond laser flap creation and LASIK without any significant intraoperative complications. Uncorrected visual acuity improved postoperatively (p<0.0001) and remained stable at 3 months follow-up. None of the subjects lost any lines of best spectacle corrected visual acuity or developed any flap complications during the postoperative period. Conclusion The OCT-guided femtosecond laser technique described in this report can provide a safe and effective method to deliver LASIK in the setting of previous corneal scarring. Future investigations are required to further validate the findings in this study.
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Affiliation(s)
- Sloan W Rush
- Panhandle Eye Group, Amarillo, TX, 79106, USA.,Texas Tech University Health Science Center, Department of Surgery, Amarillo, TX, 79106, USA
| | - Ryan B Rush
- Panhandle Eye Group, Amarillo, TX, 79106, USA.,Texas Tech University Health Science Center, Department of Surgery, Amarillo, TX, 79106, USA.,Southwest Retina Specialists, Amarillo, TX, 79106, USA
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Gaeckle HC. Early clinical outcomes and comparison between trans-PRK and PRK, regarding refractive outcome, wound healing, pain intensity and visual recovery time in a real-world setup. BMC Ophthalmol 2021; 21:181. [PMID: 33863311 PMCID: PMC8052644 DOI: 10.1186/s12886-021-01941-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 04/08/2021] [Indexed: 12/02/2022] Open
Abstract
PURPOSE To compare early clinical outcomes of single-step transepithelial photorefractive keratectomy (tPRK) and photorefractive keratectomy (PRK) regarding refractive outcome, visual acuity, wound healing, pain intensity and visual recovery time.d. METHODS In this prospective clinical observational study 200 eyes of 100 consecutive patients with mild to moderate myopia with or without mild astigmatism were included. One hundred eyes each were either treated with StreamLight™ tPRK or PRK with the WaveLight® EX500 excimer laser. Visual acuity (Decimal) was assessed preoperatively and at day 4, 7 and 6 weeks postoperatively. Wound healing (hours between surgery and complete epithelial closure) was monitored at the slit lamp. At day 4, patients subjectively rated the maximum pain intensity within the last 4 days using a numerical pain rating scale (0-15). RESULTS Visual recovery was significantly faster in the tPRK group. At days 4 and 7, the mean monocular UCDVA was significantly better in the tPRK group than in the PRK group (p < 0.001). Four days after surgery 72 % of eyes in the tPRK group but no eye in the PRK had a UCDVA of 0.7 or better. At six weeks postoperatively, a UCDVA of 1.0 or better was achieved in both groups. Complete epithelial wound closure was achieved significantly faster in the tPRK group (p < 0.0001) and maximum pain level within the first 4 days after surgery was significantly lower in the tPRK group (p < 0.0001). No patient had lost a line of BCDVA and no complications or adverse effects were observed. CONCLUSIONS According to our early clinical results, both treatments options appear to be safe and effective methods for the correction of low to moderate myopia with and without astigmatism. However, in our study, StreamLight™ tPRK offered faster visual recovery and epithelial healing and was associated with less pain compared to PRK. It can therefore be considered a good treatment option for patients who refuse or are not eligible for Femto-LASIK, but at the same time demand a faster and more comfortable recovery time than PRK can offer.
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Affiliation(s)
- Harald C Gaeckle
- Augenlaserzentrum Neu-Ulm, Edisonallee 19, 89231, Neu-Ulm, Germany.
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Haze prevention following photorefractive keratectomy in brown eyes. J Fr Ophtalmol 2021; 44:835-841. [PMID: 33858699 DOI: 10.1016/j.jfo.2020.11.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 11/09/2020] [Accepted: 11/09/2020] [Indexed: 11/22/2022]
Abstract
OBJECTIVES To study corneal haze following myopic photorefractive keratectomy (PRK) in a high-risk population and to assess methods for minimizing the risk. METHODS The medical records of 150 patients who underwent PRK were reviewed. A total of 300 eyes were included. All patients underwent myopic PRK using the Allegretto Wave Concerto 500Hz (Wavelight AG, Erlangen, Germany)excimer laser platform with intraoperative mitomycin-C (MMC) application. Demographic data including age, gender and ethnicity in addition to preoperative and postoperative subjective manifest refraction, spherical equivalent, best-corrected distance visual acuity, uncorrected distance visual acuity (UDVA), postoperative corneal haze grade and other possible postoperative complications were retrieved. Hanna grading (0-4+) was used to evaluate corneal haze. RESULTS The patients were comprised of 74 men (49.3%) and 76 women (50.7%). The mean age at the time of surgery was 26.5±6.0 (range, 17-46) years. All patients were Saudis with brown irides. UDVA improved to 20/25 in 93.8% at 3 months. The mean and standard deviation of preoperative spherical equivalent was -3.02±1.63 (range, -7.63 - -0.13). At 3 months, postoperative spherical equivalent improved to 0.05±0.50 (-1.00 - +1.00). At 6 months, 13.6% exhibited corneal haze of grade 1, and none exhibited grades 2 or 3. CONCLUSIONS The results of this study confirmed that patients with brown irides can achieve favorable outcomes after PRK. MMC, postoperative topical steroids and ultraviolet protection evidently play a major role in preventing corneal haze in high-risk populations.
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Alasmari M, M Alfawaz A. Transepithelial photorefractive keratectomy to treat mild myopia. Int Ophthalmol 2021; 41:2575-2583. [PMID: 33761045 DOI: 10.1007/s10792-021-01816-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 03/11/2021] [Indexed: 11/26/2022]
Abstract
PURPOSE To assess the safety and effectiveness of transepithelial photorefractive keratectomy (T-PRK) in patients with mild myopia using the Schwind Amaris 750 s Excimer laser system which take corneal epithelium variability in consideration during ablation. METHODS A prospective case series study of patients with mild myopia with or without astigmatism (spherical equivalent ≤ -3 diopters), who underwent T-PRK as a single-step treatment, was carried out at King Abdulaziz University Hospital, Riyadh between May 2017 and January 2018. The main outcomes included postoperative uncorrected distance visual acuity (UDVA), residual refraction (manifest refraction) and complications. RESULTS A total of 42 patients (84 eyes) underwent bilateral T-PRK with a preoperative spherical equivalent ranging from - 0.75 to - 3.00 D. Median spherical equivalent before Trans-PRK was - 1.75 (- 1.25to - 1.75). The spherical equivalent six months after Trans-PRK was 0.0 (- 0.25 to 0.5). All patients had a postoperative UDVA of 20/20 or better in the last follow-up. Transient postoperative corneal haze was observed in five eyes (6%). CONCLUSION T-PRK appears to be safe and effective in patients who have mild myopia, with or without astigmatism. The normal variation in corneal epithelial thickness seems not to affect the outcomes.
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Affiliation(s)
- Mohammed Alasmari
- Department of Ophthalmology, College of Medicine, King Saud University, Airport Road, P.O. Box 245, Riyadh, 11411, Saudi Arabia
| | - Abdullah M Alfawaz
- Department of Ophthalmology, College of Medicine, King Saud University, Airport Road, P.O. Box 245, Riyadh, 11411, Saudi Arabia.
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Sudanaboina P, Murthy SI, Rathi VM. Excimer laser phototherapeutic keratectomy with mitomycin C application to treat haze after myopic photorefractive keratectomy. Indian J Ophthalmol 2020; 68:3030-3031. [PMID: 33229692 PMCID: PMC7856928 DOI: 10.4103/ijo.ijo_1845_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
| | | | - Varsha M Rathi
- Department of Cornea, L V Prasad Eye Institute, Hyderabad, Telangana, India
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Kundu G, D'Souza S, Lalgudi VG, Arora V, Chhabra A, Deshpande K, Shetty R. Photorefractive keratectomy (PRK) Prediction, Examination, tReatment, Follow-up, Evaluation, Chronic Treatment (PERFECT) protocol - A new algorithmic approach for managing post PRK haze. Indian J Ophthalmol 2020; 68:2950-2955. [PMID: 33229676 PMCID: PMC7857001 DOI: 10.4103/ijo.ijo_2623_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Purpose The aim of this study was to discuss the possible risk factors predisposing to post photorefractive keratectomy (PRK) haze formation and develop and validate a risk scoring system, so that this could be applied to our clinical practice as an algorithmic approach. Methods Study was divided into 2 arms, in the retrospective arm we looked at 238 eyes of patients undergoing PRK where certain presumed risk factors from literature and clinical experience were identified and statistical significance of association was studied in the development of corneal haze. The risk scoring system was applied to the 450 eyes in the prospective arm for validation. This was then used to formulate an algorithmic approach to manage post-PRK haze. Results 22 out of 238 eyes in the retrospective arm developed haze where risk factors such as contact lens intolerance, altered tear film break up time, meibomian gland drop out and vitamin d levels were significantly associated with post-PRK haze (p < 0.05) and these factors were identified in the prospective arm. Treatment of these modifiable factors led to a significant reduction in post-PRK haze. Conclusion Thus identifying and treating risk factors of haze in patients undergoing PRK could improve surgical outcomes and patient satisfaction.
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Affiliation(s)
- Gairik Kundu
- Department of Cornea and Refractive Surgery, Narayana Nethralaya Eye Hospital, Bengaluru, Karnataka, India
| | - Sharon D'Souza
- Department of Cornea and Refractive Surgery, Narayana Nethralaya Eye Hospital, Bengaluru, Karnataka, India
| | | | | | - Aishwarya Chhabra
- Department of Cornea and Refractive Surgery, Narayana Nethralaya Eye Hospital, Bengaluru, Karnataka, India
| | | | - Rohit Shetty
- Department of Cornea and Refractive Surgery, Narayana Nethralaya Eye Hospital, Bengaluru, Karnataka, India
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Montorio D, Cennamo G, Menna F, Donna P, Napolitano P, Breve MA, Fiore U, Cennamo G, Rosa N. Evaluation of corneal structures in myopic eyes more than twenty-two years after photorefractive keratectomy. JOURNAL OF BIOPHOTONICS 2020; 13:e202000138. [PMID: 32668101 DOI: 10.1002/jbio.202000138] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 07/05/2020] [Accepted: 07/12/2020] [Indexed: 06/11/2023]
Abstract
The aim of this study is to evaluate corneal epithelial thickness (CET), corneal densitometry (CD) in 84 myopic eyes (57 patients) more than 22 years after photorefractive keratectomy, using anterior segment-optical coherence tomography (AS-OCT) and Scheimpflug imaging system. The CET was significantly higher in all operated eyes than in unoperated eyes in central sector. A statistically significant increase in CD in corneal anterior layer of central sector was shown in groups of operated eyes with greater ablation depth respect to unoperated eyes. While there was no significant difference in CD between the operated eyes groups with lower ablation depth and unoperated eyes. A significant trend toward higher values in anterior CD with deeper ablations in central sector was found. These noninvasive imaging techniques allow to better understand the corneal remodeling process after photoablation and to monitor the patients over time.
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Affiliation(s)
- Daniela Montorio
- Department of Neurosciences, Reproductive Sciences and Dentistry, University of Naples Federico II, Naples, Italy
| | - Gilda Cennamo
- Eye Clinic, Public Health Department, University of Naples Federico II, Naples, Italy
| | - Feliciana Menna
- Department of Neurosciences, Reproductive Sciences and Dentistry, University of Naples Federico II, Naples, Italy
| | - Piero Donna
- Department of Neurosciences, Reproductive Sciences and Dentistry, University of Naples Federico II, Naples, Italy
| | - Pasquale Napolitano
- Department of Neurosciences, Reproductive Sciences and Dentistry, University of Naples Federico II, Naples, Italy
| | - Maria Angelica Breve
- Department of Neurosciences, Reproductive Sciences and Dentistry, University of Naples Federico II, Naples, Italy
| | - Ugo Fiore
- Department of Management and Quantitative Studies, Parthenope University, Naples, Italy
| | - Giovanni Cennamo
- Department of Neurosciences, Reproductive Sciences and Dentistry, University of Naples Federico II, Naples, Italy
| | - Nicola Rosa
- Department of Medicine, Surgery and Dentistry, "Scuola Medica Salernitana", University of Salerno, Salerno, Italy
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Carlos de Oliveira R, Wilson SE. Biological effects of mitomycin C on late corneal haze stromal fibrosis following PRK. Exp Eye Res 2020; 200:108218. [PMID: 32905844 DOI: 10.1016/j.exer.2020.108218] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 08/25/2020] [Accepted: 08/30/2020] [Indexed: 12/12/2022]
Abstract
This review details the current understanding of the mechanism of action and corneal effects of mitomycin C (MMC) for prophylactic prevention of stromal fibrosis after photorefractive keratectomy (PRK), and includes discussion of available information on dosage and exposure time recommended for MMC during PRK. MMC is an alkylating agent, with DNA-crosslinking activity, that inhibits DNA replication and cellular proliferation. It acts as a pro-drug and requires reduction in the tissue to be converted to an active agent capable of DNA alkylation. Although MMC augments the early keratocyte apoptosis wave in the anterior corneal stroma, its most important effect responsible for inhibition of fibrosis in surface ablation procedures such as PRK is via the inhibition of mitosis of myofibroblast precursor cells during the first few weeks after PRK. MMC use is especially useful when treating eyes with higher levels of myopia (≥approximately 6 D), which have shown higher risk of developing fibrosis (also clinically termed late haze). Studies have supported the use of MMC at a concentration of 0.02%, rather than lower doses (such as 0.01% or 0.002%), for optimal reduction of fibrosis after PRK. Exposure times for 0.02% MMC longer than 40 s may be beneficial for moderate to high myopia (≥6D), but shorter exposures times appear to be equally effective for lower levels of myopia. Although MMC treatment may also be beneficial in preventing fibrosis after PRK treatments for hyperopia and astigmatism, more studies are needed. Thus, despite the clinical use of MMC after PRK for nearly twenty years-with limited evidence of harmful effects in the cornea-many decades of experience will be needed to exclude late long-term effects that could be noted after MMC treatment.
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Affiliation(s)
| | - Steven E Wilson
- The Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA.
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Establishing a Porcine Eye Model for Manual Sub-Bowman Layer Photorefractive Keratomileusis. J Ophthalmol 2020; 2020:9834760. [PMID: 32733701 PMCID: PMC7378610 DOI: 10.1155/2020/9834760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 04/26/2020] [Accepted: 06/22/2020] [Indexed: 11/17/2022] Open
Abstract
Objective To establish a porcine eye model for manual sub-Bowman layer photorefractive keratomileusis (SBPRK), which is a reformed surface ablation refractive surgery that results in preserving the corneal Bowman layer (BL). Methods The SBPRK group consisted of eleven eyes of 8 healthy pigs with BL flaps by mechanical technique followed by laser ablation. Regarding the remaining 5 eyes, 3 random eyes had transepithelium photorefractive keratectomy (TransPRK) (the TransPRK group), while the other 2 eyes were untreated (the blank control group). All the pigs were followed up for 8 weeks. Slit-lamp biomicroscopy and optical coherence tomography (OCT) were examined before the surgeries and at 1 week, 4 weeks, and 8 weeks after the surgeries. Results In a few days after the surgery, 3 eyes of the SBPRK group were excluded from the study because of poor healing of the corneal flaps. At the 1st postoperative week, one eye had an irregular defect of about 3 mm in the central corneal epithelium area; the cornea of the other 7 eyes had just light edema with intact epithelium just like the cornea of the TransPRK group. At the 4th week, in the SBPRK group, the cornea was slightly hazy (haze stage 1). While in the TransPRK group, the cornea was hazier (haze stage 2). At the 8th week, in the SBPRK group, both corneas were almost transparent, and the edges of the BL flaps could not be clearly seen. Meanwhile, in the TransPRK group, the corneal haze became lighter and thinner. OCT showed that, in the SBPRK group, there was high reflection in the BL layer, and it was obvious at 1 week postoperation, decreased at 4 weeks, and calmed down at 8 weeks. However, in the TransPRK group, the high reflection diffused in the anterior corneal stroma at 1 week postoperation, enhanced at 4 weeks, and weakened at 8 weeks. Conclusions Preserving the BL while conducting surface refractive surgery may result in less haze than TransPRK. However, further study is still needed, and this technique still requires refining until it becomes a standard clinical procedure.
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Ang BCH, Yap SC, Toh ZH, Lim EWL, Tan MMH, Nah GKM, Zhao PSB, Tan MCL. Refractive outcomes, corneal haze and endothelial cell loss after myopic photorefractive keratectomy in an Asian population: The Singapore Armed Forces' experience. Clin Exp Ophthalmol 2020; 48:558-568. [DOI: 10.1111/ceo.13759] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 03/17/2020] [Accepted: 04/04/2020] [Indexed: 10/24/2022]
Affiliation(s)
- Bryan Chin Hou Ang
- Vision Performance Centre Military Medicine Institute, Singapore Armed Forces Singapore Singapore
- National Healthcare Group Eye Institute Tan Tock Seng Hospital Singapore Singapore
| | - Sae Cheong Yap
- Department of Family Medicine National University Health System Singapore Singapore
| | - Zhi Hong Toh
- National Healthcare Group Eye Institute Tan Tock Seng Hospital Singapore Singapore
| | - Edmund Wei Long Lim
- Vision Performance Centre Military Medicine Institute, Singapore Armed Forces Singapore Singapore
| | - Mellisa Mei Hui Tan
- DSO National Laboratories Defence Medical and Environmental Research Institute Singapore Singapore
| | - Gerard Kwang Ming Nah
- Vision Performance Centre Military Medicine Institute, Singapore Armed Forces Singapore Singapore
- W Eye Clinic Singapore Singapore
| | - Paul Song Bo Zhao
- Vision Performance Centre Military Medicine Institute, Singapore Armed Forces Singapore Singapore
- Department of Ophthalmology National University Health System Singapore Singapore
| | - Marcus Chiang Lee Tan
- Vision Performance Centre Military Medicine Institute, Singapore Armed Forces Singapore Singapore
- Department of Ophthalmology Jurong Health Services Singapore Singapore
- Raffles Hospital Raffles Medical Group Singapore Singapore
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15
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Khattak A, An-Nakhli F. Incidence and quantification of corneal haze by Pentacam Scheimpflug densitometry following photorefractive keratectomy for myopia in virgin and post corneal transplant eyes with dark irides. Saudi J Ophthalmol 2020; 34:8-12. [PMID: 33542980 PMCID: PMC7849850 DOI: 10.4103/1319-4534.301295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 07/26/2019] [Accepted: 02/26/2020] [Indexed: 12/03/2022] Open
Abstract
PURPOSE: To assess the incidence and quantification of corneal haze after myopic photorefractive keratectomy in virgin and post corneal transplant eyes with dark irides. METHODS: In this retrospective study at the tertiary eye hospital, the corneal haze was evaluated by slit-lamp and quantified by Pentacam Scheimpflug densitometry after myopic photorefractive keratectomy with mitomycin C in virgin eyes (group I) and post corneal transplant eyes (group II) with dark irides over 12 months. RESULTS: Group I compromised 126eyes from 77patients (35males and 42females) aged 31.31 years (24.11–36.18 years), and group II compromised 44eyes from 33patients (18males and 15females) aged of 32.25 years (26.15–36.66 years). The incidence of corneal haze was 9.5% (95%CI: 5.0%–16%) and 6.8% (95%CI: 1.4–18.7%) in group I and II respectively (P = 0.587). The corneal densitometry was 22.69 ± 8.28GSU preoperatively and 17.98 ± 3.13GSU at 12 months postoperatively (P = 0.010) in group I. The corneal densitometry was 21.86 ± 6.22GSU preoperatively and 21.23 ± 4.29GSU at 12 months postoperatively (P = 0.815) in group II. High corneal maximal densitometry was associated with the thin central corneal thickness (P = 0.027), the presence of haze (P = 0.028), post-keratoplasty (P = 0.004), steep keratometry (P = 0.035). CONCLUSION: The incidence of corneal haze was comparable in virgin and post corneal transplant eyes. The Pentacam Scheimflug densitometry can be helpful in the diagnosis of corneal haze; however, the cutoff values need to be studied further in larger studies.
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Affiliation(s)
- Ashbala Khattak
- Dhahran Eyes Specialist Hospital, Eastern Province, Saudi Arabia
| | - Fouad An-Nakhli
- Dhahran Eyes Specialist Hospital, Eastern Province, Saudi Arabia
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Kumar NR, Khamar P, Shetty R, Sharma A, Shetty N, Pahuja N, Abilash VG, Jhanji V, Ghosh A, Mohan RR, Vangala RK, Ghosh A. Identification of novel predictive factors for post surgical corneal haze. Sci Rep 2019; 9:16980. [PMID: 31740714 PMCID: PMC6861263 DOI: 10.1038/s41598-019-53123-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 10/22/2019] [Indexed: 12/13/2022] Open
Abstract
Molecular factors altered in corneas that develop haze post refractive surgery have been described, but pre-existing factors that predispose clinically normal corneas to aberrant fibrosis post surgery and the role of the corneal epithelium remains unknown. We analyzed the global gene expression in epithelium collected intraoperatively from subjects undergoing photorefractive keratectomy. Subjects were grouped into those that developed haze 12 months post surgery (n = 6 eyes; haze predisposed) and those that did not develop haze in a similar follow up duration (n = 11 eyes; controls). Ontological analysis of 1100 upregulated and 1780 downregulated genes in the haze predisposed group revealed alterations in pathways associated with inflammation, wnt signaling, oxidative stress, nerve functions and extra cellular matrix remodeling. Novel factors such as PREX1, WNT3A, SOX17, GABRA1and PXDN were found to be significantly altered in haze predisposed subjects and those with active haze(n = 3), indicating their pro-fibrotic role. PREX1 was significantly upregulated in haze predisposed subjects. Ectopic expression of PREX1 in cultured human corneal epithelial cells enhanced their rate of wound healing while its ablation using shRNA reduced healing compared to matched controls. Recombinant TGFβ treatment in PREX1 overexpressing corneal cells led to enhanced αSMA expression and Vimentin phosphorylation while the converse was true for shPREX1 expressing cells. Our data identify a few novel factors in the corneal epithelium that may define a patient’s risk to developing post refractive corneal haze.
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Affiliation(s)
- Nimisha R Kumar
- GROW Research Laboratory, Narayana Nethralaya Foundation, Bangalore, India.,Department of Biomedical Sciences, School of Bio Sciences and Technology, VIT, Vellore, India
| | - Pooja Khamar
- Cornea and Refractive Surgery Division, Narayana Nethralaya, Bangalore, India
| | - Rohit Shetty
- Cornea and Refractive Surgery Division, Narayana Nethralaya, Bangalore, India.,Singapore Eye Research Institute, Singapore, Singapore
| | | | - Naren Shetty
- Cornea and Refractive Surgery Division, Narayana Nethralaya, Bangalore, India
| | - Natasha Pahuja
- Cornea and Refractive Surgery Division, Narayana Nethralaya, Bangalore, India
| | | | - Vishal Jhanji
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China.,Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Anuprita Ghosh
- GROW Research Laboratory, Narayana Nethralaya Foundation, Bangalore, India
| | - Rajiv R Mohan
- Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO, 65211, USA.,Mason Eye Institute, School of Medicine, University of Missouri, Columbia, MO, 65212, USA.,Harry S Truman Veterans' Memorial Hospital, Columbia, MO, 65201, USA
| | | | - Arkasubhra Ghosh
- GROW Research Laboratory, Narayana Nethralaya Foundation, Bangalore, India. .,Singapore Eye Research Institute, Singapore, Singapore.
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Clinical outcomes of mechanical and transepithelial photorefractive keratectomy in low myopia with a large ablation zone. J Cataract Refract Surg 2019; 45:977-984. [PMID: 31029476 DOI: 10.1016/j.jcrs.2019.02.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 01/22/2019] [Accepted: 02/09/2019] [Indexed: 11/23/2022]
Abstract
PURPOSE To evaluate the clinical outcomes, vector parameters, and aberrations between mechanical photorefractive keratectomy (PRK) and transepithelial PRK in eyes with low myopia. SETTING Yonsei University College of Medicine and Eyereum Eye Clinic, Seoul, Korea. DESIGN Retrospective, comparative case series. METHODS Eighty-four eyes of 84 patients with low myopia (≤2.00 diopters) were treated with mechanical or transepithelial PRK (41 eyes and 43 eyes, respectively), with the application of a large optical zone (OZ). Visual acuity, manifest refraction, slitlamp evaluation, autokeratometry, corneal topography, and the evaluation of corneal wavefront aberrations were measured preoperatively and at 1, 3, and 6 months after surgery. The efficacy, predictability, vector parameters, corneal aberrations, and safety at 6 months after surgery were compared between the two treatment groups. RESULTS The mean uncorrected distance visual acuity was comparable, at -0.13 ± 0.05 (SD) and -0.15 ± 0.05, in the mechanical and transepithelial PRK groups, respectively, at 6 months after surgery. The safety and efficacy indices, vector parameters, and aberrometric values were also comparable between the two groups. The OZ was large in both groups (7.09 ± 0.20 mm and 7.12 ± 0.27 mm in the mechanical PRK and transepithelial PRK groups, respectively), and showed no significant difference between groups. The corneal total root-mean-square higher-order aberrations and coma significantly reduced after treatment in both groups, and spherical aberrations significantly decreased after transepithelial PRK. CONCLUSIONS Mechanical and transepithelial PRK with a large OZ provided effective and safe outcomes for the correction of low myopia without differences in visual acuity and refractive outcomes between procedures.
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Ibrahim Al-Mashahedah AM, Kanwar RK, Kanwar JR. Utility of nanomedicine targeting scar-forming myofibroblasts to attenuate corneal scarring and haze. Nanomedicine (Lond) 2019; 14:1049-1072. [DOI: 10.2217/nnm-2017-0305] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Corneal scarring refers to the loss of normal corneal tissue, replaced by fibrotic tissue (during wound repair) thereby affecting corneal transparency and vision quality. The corneal wound healing process involves a complex series of physiological events resulting in the transformation of transparent keratocytes into opaque myofibroblasts; the prominent cause of irregular extracellular matrix synthesis leading to the development of corneal opacity/hazy vision. Globally, corneal scarring/haze is one of the most prevalent causes of blindness. Ocular trauma (physical and chemical) and microbial infections induce corneal tissue damage. Although great progress has been made in the clinical management of ocular diseases, the global rates of corneal blindness remain high, nonetheless. The topical conventional modalities treating corneal wounds/injuries have inherent limitations/side effects such as low bioavailability of a therapeutic agent, upregulation of the intraocular pressure and the toxicity/allergy of the drug. These limitations/side effects rather than treating the wound, often negatively affect the healing process, especially, when applied frequently for longer periods. Recently, there has been an increasing evidence provided by the preclinical studies that nanotechnology-based drug-delivery systems can improve drug bioavailability, through controlled drug release and targeted delivery. After reviewing the epidemiology, risk factors of corneal scarring/haze and the conventional ocular medicines, we review here the different nanodrug-delivery systems and potential drug candidates including nanoherbal formulations investigated for their efficacy to heal the damaged cornea. Finally, we discuss the challenges of using these nanomedicinal platforms.
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Affiliation(s)
- Aseel Mahmood Ibrahim Al-Mashahedah
- Nanomedicine-Laboratory of Immunology & Molecular Biomedical Research (NLIMBR), School of Medicine (SOM), Faculty of Health, Deakin University, Waurn Ponds, Geelong 3216, Australia
| | - Rupinder Kaur Kanwar
- Nanomedicine-Laboratory of Immunology & Molecular Biomedical Research (NLIMBR), School of Medicine (SOM), Faculty of Health, Deakin University, Waurn Ponds, Geelong 3216, Australia
| | - Jagat Rakesh Kanwar
- Nanomedicine-Laboratory of Immunology & Molecular Biomedical Research (NLIMBR), School of Medicine (SOM), Faculty of Health, Deakin University, Waurn Ponds, Geelong 3216, Australia
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Mifflin MD, Betts BS, Nguyen J, Pouly S. High myopic photorefractive keratectomy outcomes with the Alcon Wavelight ® EX500 excimer laser. Clin Ophthalmol 2018; 12:1041-1048. [PMID: 29922033 PMCID: PMC5995275 DOI: 10.2147/opth.s164110] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Purpose To present refractive outcomes from consecutive cases with the Alcon Wavelight® EX500 excimer laser using photorefractive keratectomy (PRK) in patients with high myopia. Methods A retrospective chart review of consecutive cases of high myopic eyes (≥6.0 Diopters [D]) undergoing PRK with the Alcon Wavelight EX500 excimer laser (Alcon Laboratories, Fort Worth, TX, USA) was done. Moderately high myopic eyes (6.0 to <8.0 D [6 D]) were compared with high myopic eyes (8.0 D or greater [8 D]). Outcomes measured included pre- and postoperative refractive error, uncorrected distance visual acuity (UDVA), corrected distance visual acuity, spherical equivalent correction (SEQ), haze incidence, and intraocular pressure (IOP). Results One hundred eighteen eyes of 63 patients were evaluated, with 59 eyes having 12 months of follow-up. Thirty-one eyes of 19 patients had 8.0 D or more of myopia. Twelvemonth average LogMAR UDVA was -0.06 (20/17) for the 6 D group and -0.08 (20/16) for the 8 D group. Average 12-month SEQ was -0.18 D and preoperatively was -7.52 D for the 6 D group and -0.09 and -9.02 in the 8 D group. Sixty-five eyes (86%) and 24 eyes (96%) had an SEQ within 0.50 D of emmetropia at 3 months in the 6 and 8 D groups, respectively. One eye had visually significant haze developed at 8 months. Three eyes had IOP elevation that resolved with addition of short-term topical IOP-lowering medication. Conclusion High myopic PRK with the Alcon Wavelight EX500 excimer laser yields excellent refractive outcomes with a low incidence of complications.
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Affiliation(s)
- Mark D Mifflin
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | | | - Jason Nguyen
- Department of Ophthalmology, West Virginia University School of Medicine, Morgantown, WV, USA
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Wilson SE, Marino GK, Torricelli AAM, Medeiros CS. Injury and defective regeneration of the epithelial basement membrane in corneal fibrosis: A paradigm for fibrosis in other organs? Matrix Biol 2017. [PMID: 28625845 DOI: 10.1016/j.matbio.2017.06.003] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Myofibroblast-mediated fibrosis is important in the pathophysiology of diseases in most organs. The cornea, the transparent anterior wall of the eye that functions to focus light on the retina, is commonly affected by fibrosis and provides an optimal model due to its simplicity and accessibility. Severe injuries to the cornea, including infection, surgery, and trauma, may trigger the development of myofibroblasts and fibrosis in the normally transparent connective tissue stroma. Ultrastructural studies have demonstrated that defective epithelial basement membrane (EBM) regeneration after injury underlies the development of myofibroblasts from both bone marrow- and keratocyte-derived precursor cells in the cornea. Defective EBM permits epithelium-derived transforming growth factor beta, platelet-derived growth factor, and likely other modulators, to penetrate the stroma at sustained levels necessary to drive the development of vimentin+ alpha-smooth muscle actin+ desmin+ (V+A+D+) mature myofibroblasts and promote their persistence. Defective versus normal EBM regeneration likely relates to the severity of the stromal injury and a resulting decrease in fibroblasts (keratocytes) and their contribution of EBM components, including laminin alpha-3 and nidogen-2. Corneal fibrosis may resolve over a period of months to years if the inciting injury is eliminated through keratocyte-facilitated regeneration of normal EBM, ensuing apoptosis of myofibroblasts, and reorganization of disordered extracellular matrix by repopulating keratocytes. We hypothesize the corneal model of fibrosis associated with defective BM regeneration and myofibroblast development after epithelial or parenchymal injury may be a paradigm for the development of fibrosis in other organs where chronic injury or defective BM underlies the pathophysiology of disease.
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Affiliation(s)
- Steven E Wilson
- The Cole Eye Institute, The Cleveland Clinic, Cleveland, OH, United States.
| | | | | | - Carla S Medeiros
- The Cole Eye Institute, The Cleveland Clinic, Cleveland, OH, United States
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Mifflin MD, Betts BS, Frederick PA, Feuerman JM, Fenzl CR, Moshirfar M, Zaugg B. Efficacy and safety of a 3-month loteprednol etabonate 0.5% gel taper for routine prophylaxis after photorefractive keratectomy compared to a 3-month prednisolone acetate 1% and fluorometholone 0.1% taper. Clin Ophthalmol 2017; 11:1113-1118. [PMID: 28652697 PMCID: PMC5476723 DOI: 10.2147/opth.s138272] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Purpose To compare the outcome of photorefractive keratectomy (PRK) and complications in patients treated with either loteprednol etabonate 0.5% gel or prednisolone acetate 1% suspension and fluorometholone (fml) 0.1% suspension. Setting John A Moran Eye Center, University of Utah, Salt Lake City, UT, USA. Design Prospective, randomized, partially masked trial. Methods PRK was performed on 261 eyes of 132 participants. Patients were randomized to a postoperative corticosteroid regimen of either loteprednol etabonate 0.5% gel (loteprednol) or prednisolone 1% acetate suspension followed by fluorometholone 0.1% suspension (prednisolone/fml). Primary outcome measures included incidence and grade of postoperative corneal haze and incidence of increased intraocular pressure of 10 mmHg above baseline, or any intraocular pressure over 21 mmHg. Secondary outcome measures included uncorrected distance visual acuity, best corrected distance visual acuity, and manifest refraction spherical equivalent. Results The incidence of haze in the first 3 months was 2.6% (3/114 eyes) in the loteprednol group and 4.8% (7/147 eyes) in the prednisolone/fml group and was not statistically significant between groups (P=0.37). The incidence of elevated intraocular pressure was 1.8% (2/114 eyes) in the loteprednol group and 4.1% (6/147 eyes) in the prednisolone/fml group, and was not statistically significant between the groups (P=0.12). The mean 3-month postoperative logMAR uncorrected visual acuity was −0.078±0.10 and −0.075±0.09 in the loteprednol and prednisolone/fml groups, respectively (P=0.83). Conclusion Postoperative corneal haze and elevated intraocular pressure were uncommon in both treatment arms. There was no statistically significant difference between each postoperative regimen. Refractive results were similar and excellent in both treatment arms. A tapered prophylactic regimen of loteprednol 0.5% gel is equally effective to prednisolone 1%/fml 0.1% after PRK.
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Affiliation(s)
- Mark D Mifflin
- Department of Ophthalmology and Visual Sciences, John A Moran Eye Center, University of Utah, Salt Lake City, UT
| | - Brent S Betts
- Department of Ophthalmology and Visual Sciences, John A Moran Eye Center, University of Utah, Salt Lake City, UT
| | | | | | | | - Majid Moshirfar
- Department of Ophthalmology and Visual Sciences, John A Moran Eye Center, University of Utah, Salt Lake City, UT.,Hoopes Vision, Draper, UT, USA
| | - Brian Zaugg
- Department of Ophthalmology and Visual Sciences, John A Moran Eye Center, University of Utah, Salt Lake City, UT
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