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Mohammadpour M, Heirani M, Khoshtinat N, Khorrami-Nejad M. Comparison of two different 360-degree intrastromal corneal rings combined with simultaneous accelerated-corneal cross-linking. Eur J Ophthalmol 2024; 34:126-139. [PMID: 37139606 DOI: 10.1177/11206721231171420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
PURPOSE to compare five-year outcomes of two complete intracorneal implants (MyoRing versus annular-shaped intracorneal implant [AICI]) combined with accelerated corneal cross-linking (A-CXL) in progressive KCN. METHODS In this historical cohort study, preoperative and postoperative visual, refractive, tomographic, biomechanical, and aberrometric parameters of 27 eyes of 27 patients who underwent implantation of two complete rings (13 AICI and 14 MyoRing) combined with A-CXL were recorded. RESULTS The mean age of patients in "AICI plus A-CXL" and "MyoRing plus A-CXL" groups were 28.1 ± 4.6 and 26.3 ± 3.8 years, respectively. All pre- and postoperative visual and refractive parameters between the two groups were not significantly different (p > 0.05). Comparing pre- and postoperative tomographic measurements showed that anterior corneal surface (ACS) flat-K and corneal thickness at pachymetric apex significantly improved for MyoRing plus A-CXL group after five years (p < 0.05). On the other hand, ACS K-max and mean-K values were significantly improved for AICI plus A-CXL group after five years (p < 0.05). Both groups revealed significant improvements in ACS steep-K and corneal astigmatism (p < 0.05). Five years after surgery, the high order aberration in the AICI group (2.60 ± 0.83) was significantly better than the MyoRing group (1.70 ± 0.43) (p = 0.007). CONCLUSIONS Both complete intrastromal rings (MyoRing or AICI) combined with A-CXL significantly Improved visual, refractive, and corneal aberrometric, biomechanical, and tomographic parameters and halt the progression of KCN with comparable long-term outcomes.
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Affiliation(s)
- Mehrdad Mohammadpour
- Translational Ophthalmology Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohsen Heirani
- Translational Ophthalmology Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Narges Khoshtinat
- Translational Ophthalmology Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Masoud Khorrami-Nejad
- Translational Ophthalmology Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
- School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran
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Tafti MF, Aghamollaei H, Moghaddam MM, Jadidi K, Alio JL, Faghihi S. Emerging tissue engineering strategies for the corneal regeneration. J Tissue Eng Regen Med 2022; 16:683-706. [PMID: 35585479 DOI: 10.1002/term.3309] [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: 11/23/2021] [Revised: 04/16/2022] [Accepted: 04/19/2022] [Indexed: 11/10/2022]
Abstract
Cornea as the outermost layer of the eye is at risk of various genetic and environmental diseases that can damage the cornea and impair vision. Corneal transplantation is among the most applicable surgical procedures for repairing the defected tissue. However, the scarcity of healthy tissue donations as well as transplantation failure has remained as the biggest challenges in confront of corneal grafting. Therefore, alternative approaches based on stem-cell transplantation and classic regenerative medicine have been developed for corneal regeneration. In this review, the application and limitation of the recently-used advanced approaches for regeneration of cornea are discussed. Additionally, other emerging powerful techniques such as 5D printing as a new branch of scaffold-based technologies for construction of tissues other than the cornea are highlighted and suggested as alternatives for corneal reconstruction. The introduced novel techniques may have great potential for clinical applications in corneal repair including disease modeling, 3D pattern scheming, and personalized medicine.
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Affiliation(s)
- Mahsa Fallah Tafti
- Stem Cell and Regenerative Medicine Group, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | - Hossein Aghamollaei
- Chemical Injuries Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | | | - Khosrow Jadidi
- Vision Health Research Center, Semnan University of Medical Sciences, Semnan, Iran
| | - Jorge L Alio
- Department of Research and Development, VISSUM, Alicante, Spain.,Cornea, Cataract and Refractive Surgery Department, VISSUM, Alicante, Spain.,Department of Pathology and Surgery, Division of Ophthalmology, Faculty of Medicine, Miguel Hernández University, Alicante, Spain
| | - Shahab Faghihi
- Stem Cell and Regenerative Medicine Group, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
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Nuzzi R, Tripoli F, Rossi A, Ghilardi A. A Combined Procedure of Intrastromal Corneal Rings Explantation and Penetrating Keratoplasty in a Patient With Keratoconus: A Case Report. Front Med (Lausanne) 2022; 9:853702. [PMID: 35360745 PMCID: PMC8961690 DOI: 10.3389/fmed.2022.853702] [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: 01/12/2022] [Accepted: 02/18/2022] [Indexed: 12/05/2022] Open
Abstract
Keratoconus is a non-inflammatory and degenerative corneal ectasia that determinate progressive steepening of paracentral cornea with development of irregular astigmatism and visual function deterioration. According to the stage of the pathology, different methods of correction can be used: rigid contact lenses may be used to alter corneal shape and partially correct astigmatism, corneal collagen cross-linking (CXL) and intrastromal corneal ring segment (ICRS) implantation can reinforce corneal stroma to slow disease progression. Late-stage treatment comprehend anterior lamellar keratoplasty or penetrating keratoplasty. We evaluated a 31-year-old patient who was subjected to bilateral ICRS implantation combined with CXL due to keratoconus. This led, after 9 months, to ring extrusion in his left eye, corneal thinning and microperforation into the aqueous chamber with residual irregular astigmatism of 4.50 D. cyl. 10°. The patient underwent ICRS explantation and PKP during the same surgical session. After 15 months of follow-up, the BCVA was 0.2 LogMAR with a residual astigmatism of 6.3 dpt.
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Shetty R, Israni NA, Ramuka S, Dadachanji Z, Roy AS, Mehra R, Lalgudi VG. Intracorneal Ring Segments Followed by Simultaneous Topography-Guided Removal of Epithelium and Stroma With Accelerated Collagen Cross-Linking For Keratoconus (I-TRESK/CXL). Asia Pac J Ophthalmol (Phila) 2020; 10:152-160. [PMID: 33369925 DOI: 10.1097/apo.0000000000000342] [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: 11/26/2022] Open
Abstract
PURPOSE The aim of this study was to assess the visual, topographic, and aberrometric outcomes of a novel tissue sparing technique, topography-guided removal of epithelium, and stroma in keratoconus (TRESK) along with accelerated collagen cross-linking (CXL), 1 month after Intacs insertion. DESIGN Prospective interventional study. METHODS Fourty-eight eyes (45 patients) with keratoconus underwent femto-assisted Intacs insertion. After 1 month, TRESK and CXL (9 mW/cm2 for 10 minutes) was done. TRESK is a decentered trans-PTK (phototherapeutic keratectomy) with center and area of ablation at the location of the steepest tangential anterior curvature and area of the cone respectively. Total ablation (epithelium plus stroma) was limited to 75 μm. Postoperative measurements were performed 1 month after Intacs, 6 weeks after Intacs followed by TRESK/CXL, and at the final visit 12 months after Intacs followed by TRESK/CXL. RESULTS For all eyes studied, uncorrected distance visual acuity and corrected distance visual acuity (CDVA) (logMAR) improved from preoperative means of 1.05 ± 0.05 and 0.31 ± 0.03 logMAR to postoperative means of 0.52 ± 0.05 (P < 0.001) and 0.20 ± 0.02 logMAR (P = 0.009), respectively. The mean preoperative sphere, cylinder and mean refractive spherical equivalent decreased from -4.52 ± 0.98 D, -4.81 ± 0.25 D, -6.93 ± 0.99 D to -0.77 ± 0.53 D (P = 0.029), -3.13 ± 0.24 D (P = 0.002), and -2.34 ± 0.53 D (P = 0.021), respectively with a mean keratometric flattening of 5.06D (P < .0001) at the final visit. In total, 2.08% of the eyes lost 1 Snellen line of CDVA. Sixty eight percent and 27% of the eyes gained 2 Snellen lines or more of uncorrected distance visual acuity and CDVA, respectively. CONCLUSIONS Simultaneous TRESK with CXL done 1 month after Intacs insertion (I-TRESK) in keratoconus eyes provided significant visual gain with refractive and topographic improvement. This novel procedure involving customized PTK before CXL is safe, easy to plan and perform, and provides good outcomes.
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Affiliation(s)
- Rohit Shetty
- Department of Cornea and Refractive surgery, Narayana Nethralaya, Bangalore, India
| | - Neeraj Ashok Israni
- Department of Cornea and Refractive surgery, Narayana Nethralaya, Bangalore, India
| | - Saurabh Ramuka
- Department of Cornea and Refractive surgery, Narayana Nethralaya, Bangalore, India
| | - Zelda Dadachanji
- Department of Cornea and Refractive surgery, Narayana Nethralaya, Bangalore, India
| | - Abhijit Sinha Roy
- Imaging, Biomechanics and mathematical modelling solutions lab, Narayana Nethralaya foundation, Bangalore, India
| | - Rohan Mehra
- Department of Cornea and Refractive surgery, Narayana Nethralaya, Bangalore, India
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Kankariya VP, Dube AB, Grentzelos MA, Kontadakis GA, Diakonis VF, Petrelli M, Kymionis GD. Corneal cross-linking (CXL) combined with refractive surgery for the comprehensive management of keratoconus: CXL plus. Indian J Ophthalmol 2020; 68:2757-2772. [PMID: 33229651 PMCID: PMC7856931 DOI: 10.4103/ijo.ijo_1841_20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The past two decades have witnessed an unprecedented evolution in the management of keratoconus that demands a holistic approach comprising of inhibiting the ectatic progression as well as visual rehabilitation. The advent of corneal cross-linking (CXL) in the late 1990s resulted in long-term stabilization of the ectatic cornea along with limited reduction in corneal steepening and regularization of corneal curvature. However, CXL as a standalone procedure does not suffice in rehabilitating the functional vision especially in patients who are unwilling or intolerant towards contact lenses. The concept of “CXL plus” was proposed which incorporates adjunctive use of refractive procedures with CXL in order to overcome the optical inefficiency due to corneal irregularity, decrease the irregular astigmatism, correct the residual refractive error and improve functional visual outcome in keratoconus. Several refractive procedures such as conductive keratoplasty (CK), photorefractive keratectomy (PRK), transepithelial phototherapeutic keratectomy (t-PTK), intrastromal corneal ring segments (ICRS) implantation, phakic intraocular lens (PIOL) implantation and multiple other techniques have been combined with CXL to optimize and enhance the CXL outcome. This review aimed to summarize the different protocols of CXL plus, provide guidelines for selection of the optimum CXL plus technique and aid in decision-making for the comprehensive management of cases with primary keratoconus in addition to discussing the future and scope for innovations in the existing treatment protocols.
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Affiliation(s)
| | - Ankita B Dube
- Asian Eye Hospital and Laser Institute, Pune, Maharashtra, India
| | - Michael A Grentzelos
- Asian Eye Hospital and Laser Institute, Pune, Maharashtra, India; Department of Ophthalmology, University of Lausanne, Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, Lausanne, Switzerland
| | - George A Kontadakis
- Laboratory of Vision and Optics, Medical School, University of Crete, Heraklion, Greece
| | | | - Myrsini Petrelli
- Department of Ophthalmology, University of Lausanne, Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, Lausanne, Switzerland
| | - George D Kymionis
- Department of Ophthalmology, University of Lausanne, Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, Lausanne, Switzerland
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Nicula CA, Popescu R, Rednik AM, Nicula D, Bulboaca AE, Stanescu I. Refractive Lens Exchange in Hyperopic Presbyopes with the Acrysof IQ Panoptix Intraocular Lens: One-Year Results and Analysis of the Literature. Ther Clin Risk Manag 2020; 16:1125-1137. [PMID: 33239878 PMCID: PMC7682609 DOI: 10.2147/tcrm.s279065] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 11/02/2020] [Indexed: 11/23/2022] Open
Abstract
PURPOSE To assess the functional and refractive outcomes in hyperopia and presbyopia correction by clear lens exchange with the intraocular trifocal artificial lens (IOL) Acrysof IQ Panoptix implant at 1 year. MATERIALS AND METHODS A number of 128 eyes (64 patients) underwent clear lens exchange with placement of the trifocal IOL Acrysof IQ Panoptix implant for hyperopia and presbyopia. Prior to the surgery the patients had a complete ocular examination. In all cases the artificial lens was implanted in the bag without any intraoperative complications. Visual acuity (VA) at distance, intermediate and near and ocular refraction were evaluated at 4 weeks, 6 and 12 months postoperatively. RESULTS The mean age was 53.49 ±7.377 years old (range 40-73 years). As high as 51.57% of the patients were males and 48.43% were females. The mean achieved refraction was 0.26 ± 0.73D. Almost 60.93% of patients were within ±0.25D of the target refraction, with 82.03% eyes within ±0.50D of the planned correction. At 1 year after surgery, 96.45% of eyes had a stable refraction (p >0.05). At 1 year, a total of 92.25%, 89.92% and 91.47% achieved a monocular uncorrected distance, intermediate and near visual acuity of 0.2 logarithm of the minimum angle of resolution or better, respectively. At the same time point, a total of 95.35%, 91.47% and 93.80% achieved a binocular uncorrected distance, intermediate and near visual acuity of 0.2 logarithm of the minimum angle of resolution or better, respectively. There was no statistically significant difference (p>0.05) between the postoperative uncorrected and best corrected VA (distance, intermediate, near) at 6 months and postoperative uncorrected and best corrected VA (distance, intermediate, near) at 12 months. None of our patients had any intraoperative complications. Two cases (1.56%) developed posterior capsule opacification. Twelve patients (18.75%) complained about photic phenomena such as glare and haloes, but this symptom disappeared after 6 months postoperatively. As high as93.56% of patients had a high satisfaction with the outcomes of the surgery. Spectacle independence was obtained in 97.65% eyes. CONCLUSION The Acrysof Panoptix trifocal artificial lens offers a good vision at distance, intermediate and near, with a good quality of vision and refraction.
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Affiliation(s)
- Cristina Ariadna Nicula
- Department of Ophthalmology, Medicine and Pharmacy University “Iuliu Hațieganu”, Cluj Napoca, Romania
- Oculens Clinic, Cluj-Napoca, Romania
| | | | - Anca Maria Rednik
- Department of Ophthalmology, Eye County Hospital, Cluj-Napoca, Romania
| | | | - Adriana Elena Bulboaca
- Department of Pathophysiology, Medicine and Pharmacy University “Iuliu Hațieganu”, Cluj Napoca, Romania
| | - Ioana Stanescu
- Department of Neurology, Medicine and Pharmacy University “Iuliu Hațieganu”, Cluj Napoca, Romania
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Mounir A, Mostafa EM. Combined accelerated corneal collagen crosslinking and intrastromal Kerarings implantation for treatment of advanced superior keratoconus. GMS OPHTHALMOLOGY CASES 2020; 10:Doc10. [PMID: 32269908 PMCID: PMC7113618 DOI: 10.3205/oc000137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Purpose: To report early results of combined accelerated corneal collagen crosslinking (CXL) and intrastromal Kerarings implantation by femtosecond laser in a case of advanced superior keratoconus. Methods: The patient was a 27-year-old male with left eye grade 3 keratoconus with superior cone. He was diagnosed by Sirius Scheimpflug corneal topography (CSO, Florence, Italy). The right eye had previously been subjected to penetrating keratoplasty. The uncorrected visual acuity (UCVA) in the right eye (RE) was 1.2 LogMAR, best corrected visual acuity (BCVA) was 0.8 by a refraction of –7.50Ds –3.00Dc @12. The UCVA in the left eye (LE) was 1.2 LogMAR, BCVA was 0.9 by a refraction of –8.50 Ds –5.50Dc @169. Intrastromal Kerarings implantation by femtosecond laser was carried out by IntraLase (iFS, Abbott) along with accelerated transepithelial corneal collagen crosslinking by KXL system (Avedro, USA) in the same session. Follow-up was done for a period of 12 months after surgery. Results: The patient was followed up for 12 months with improvement of visual acuity as regards UCVA and BCVA and improvement of corneal topographic parameters including keratometry and front and back elevations. Conclusion: Combined accelerated corneal collagen crosslinking and intrastromal Kerarings implantation by femtosecond laser is an effective method in the treatment of this uncommon type of keratoconus.
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Affiliation(s)
- Amr Mounir
- Sohag Faculty of Medicine, Ophthalmology Department, Sohag University, Sohag, Egypt
| | - Engy Mohamed Mostafa
- Sohag Faculty of Medicine, Ophthalmology Department, Sohag University, Sohag, Egypt
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Balmus IM, Alexa AI, Ciuntu RE, Danielescu C, Stoica B, Cojocaru SI, Ciobica A, Cantemir A. Oxidative stress markers dynamics in keratoconus patients' tears before and after corneal collagen crosslinking procedure. Exp Eye Res 2019; 190:107897. [PMID: 31836491 DOI: 10.1016/j.exer.2019.107897] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 11/19/2019] [Accepted: 12/09/2019] [Indexed: 10/25/2022]
Abstract
Keratoconus (KC) is a controversial ophthalmological disease, often considered both multifactorial and multigenic with poor or not entirely understood etiopathogenesis. Corneal collagen crosslinking (CXL) procedure is the most common surgical therapy for KC which both slows corneal thinning and halts disease progression. While extensive studies provide consistent evidence on systemic oxidative stress in KC patients and animal models, little is known on the tear fluid oxidative stress markers such as antioxidant enzymes activity or lipid peroxidation markers. Also, little is known considering the oxidative status dynamics following CXL. In this way, we aimed to evaluate three oxidative stress markers in the tears of KC patients before and after CXL procedure. Total superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzymatic activity and malondiladehyde (MDA) levels were assessed from the tears of 20 kC patients who received the recommendation for CXL procedure. Significantly decreased SOD activity (p = 0.0014) was observed in KC patients tears, as compared to age and sex-matched controls which could lead to significant lipid peroxidation boost (p < 0.001). Significantly higher GPx enzyme activity was observed in KC patients, as compared to control (p < 0.001), suggesting a compensatory response to intense lipid peroxidation. Following CXL, SOD activity significantly decreases and GPx activity extensively increases, as compared to baseline KC levels and controls (p < 0.001). This work provides additional evidence on oxidative stress status in the tears of KC considering general oxidative stress markers dynamics both before and after the CXL procedure. We also demonstrated that the CXL procedure could have further relevance in the management of this disorder.
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Affiliation(s)
- Ioana-Miruna Balmus
- Department of Interdisciplinary Research in Science, Alexandru Ioan Cuza University of Iasi, Carol I Avenue, no. 11, 700506, Iasi, Romania.
| | - Anisia Iuliana Alexa
- Department of Ophthalmology, Faculty of Medicine, "Gr. T. Popa" University of Medicine and Pharmacy, Iasi, Romania.
| | - Roxana-Elena Ciuntu
- Department of Ophthalmology, Faculty of Medicine, "Gr. T. Popa" University of Medicine and Pharmacy, Iasi, Romania.
| | - Ciprian Danielescu
- Department of Ophthalmology, Faculty of Medicine, "Gr. T. Popa" University of Medicine and Pharmacy, Iasi, Romania.
| | - Bogdan Stoica
- "Gr. T. Popa" University of Medicine and Pharmacy, Department of Biochemistry, Iasi, Romania.
| | - Sabina Ioana Cojocaru
- Department of Biochemistry, "Alexandru Ioan Cuza" University of Iasi, Iasi, Romania.
| | - Alin Ciobica
- "Alexandru Ioan Cuza" University of Iasi, Faculty of Biology, Department of Research, Iasi, Romania.
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Osipyan GA, Sheludchenko VM, Khraystin K. [Modern methods of surgical treatment of keratectasias]. Vestn Oftalmol 2019; 135:138-143. [PMID: 31215545 DOI: 10.17116/oftalma2019135021138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Keratectasia (KE) ranks as one of the main causes of impaired vision. The pathology is characterized by progressive thinning of the cornea, which causes its deformation, the appearance of irregular astigmatism, and the reduction of vision acuity. The article reviews modern surgical methods that can be used to prevent the progression and treat various types of KE.
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Affiliation(s)
- G A Osipyan
- Research Institute of Eye Diseases, 11, A, Rossolimo St., Moscow, Russian Federation, 119021
| | - V M Sheludchenko
- Research Institute of Eye Diseases, 11, A, Rossolimo St., Moscow, Russian Federation, 119021
| | - Kh Khraystin
- Research Institute of Eye Diseases, 11, A, Rossolimo St., Moscow, Russian Federation, 119021
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10
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Song YW, He R, Ma JX, Koch DD, Wang L. Long-term safety of laser in situ keratomileusis in eyes with thin corneas: 5-year follow-up. Int J Ophthalmol 2018; 11:1227-1233. [PMID: 30046544 DOI: 10.18240/ijo.2018.07.25] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 02/05/2018] [Indexed: 01/01/2023] Open
Abstract
AIM To investigate the long term (≥5y) efficacy, predictability, and safety of laser in situ keratomileusis (LASIK) in eyes with thin corneas [central corneal thickness (CCT) <500 µm]. METHODS A total of 339 patients met the criteria of this study. Finally, 175 eyes of 89 patients who had thin corneas and underwent LASIK≥5y ago returned to our clinic and included in this study. Preoperative parameters recorded included uncorrected visual acuity (UCVA), corrected distance visual acuity (CDVA), manifest refraction, CCT and corneal topography. At returning visits, in addition to visual acuity and manifest refraction, ultrasound CCT and corneal topography were performed. Optical coherence tomography was used to measure the CCT, LASIK flap thickness, and residual stromal bed thickness (RSBT). Safety index, efficacy index, percentage of eyes within ±0.5 D and ±1.0 D of refraction, percent tissue altered (PTA), and percentage stromal bed thickness (PSBT) were calculated. RESULTS The safety index was 1.09 and efficacy index was 0.99. The percentages of eyes within ±0.5 D and ±1.0 D were 71.2% and 87.7%, respectively. The mean PTA was 40%±6% (range 20% to 55%); 76 eyes (43.4%) had PTA <40% and 99 eyes (56.6%) had PTA≥40%. The mean RSBT was 303±27 µm (range 240 to 390 µm), and 2 eyes had RSBT<250 µm. The mean PSBT was 61%±9% (range 51% to 85%). No eyes developed ectasia. CONCLUSION In this cohort with the PSBT of 50% or more, LASIK is safe with follow-up for at least 5y.
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Affiliation(s)
- Yao-Wen Song
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Science Key Laboratory, Beijing 100730, China
| | - Rui He
- Shanxi Eye Hospital, Taiyuan 030002, Shanxi Province, China
| | - Jack X Ma
- McGovern Medical School, University of Texas Health Science Center at Houston, TX 75835, USA
| | - Douglas D Koch
- Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, TX 75844, USA
| | - Li Wang
- Shanxi Eye Hospital, Taiyuan 030002, Shanxi Province, China.,Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, TX 75844, USA
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