Laser Epithelial Keratomileusis Research Articles

Factors affecting long-term myopic regression after corneal refractive surgery for civilian pilots in southwest China

BackgroundThe purpose of this study was to analyze myopic regression after corneal refractive surgery (CRS) in civilian pilots and to explore the factors that may cause long-term myopic regression.MethodsWe included civilian pilots who had undergone CRS to correct their myopia and who had at least 5 years of follow-up. We collected retrospective data and completed eye examinations and a questionnaire to assess their eye habits.ResultsA total of 236 eyes were evaluated in this study. 211 eyes had Intrastromal ablations (167 eyes had laser in situ keratomileusis, LASIK, 44 eyes had small incision lenticule extraction, SMILE) and 25 eyes had subepithelial ablations (15 eyes had laser epithelial keratomileusis, LASEK and 10 eyes had photorefractive keratectomy, PRK). The mean preoperative spherical equivalent (SE) was − 2.92 ± 1.11 D (range from − 1.00 to -5.00 D). A total of 56 eyes (23.6%) suffered from myopic regression after CRS. Comparisons of individual and eye characteristics between the regression and non-regression groups revealed statistically significant differences in age, cumulative flight time, postoperative SE (at 6 months and current), uncorrected visual acuity (UCVA), accommodative amplitude (AA), positive relative accommodation (PRA), postoperative period, types of CRS and eye habits. Generalized propensity score weighting (GPSW) was used to balance the distribution of covariates among different age levels, types of CRS, cumulative flying time, postoperative period and continuous near-work time. The results of GPS weighted logistic regression demonstrated that the associations between age and myopic regression, types of CRS and myopic regression, continuous near-work time and myopic regression were significant. Cumulative flying time and myopic regression, postoperative period and myopic regression were no significant. Specifically, the odds ratio (OR) for age was 1.151 (P = 0.022), and the OR for type of CRS was 2.769 (P < 0.001). The OR for continuous near-work time was 0.635 with a P value of 0.038.ConclusionsThis is the first report to analyze myopic regression after CRS in civilian pilots. Our study found that for each year increase in age, the risk of civilian pilots experiencing myopic regression was increased. Intrastromal ablations had a lower risk of long-term myopia regression than subepithelial ablations. There is a higher risk of myopic progression with continuous near-work time > 45 min and poor accommodative function may be related factors in this specific population.

Comparison of Corneal Densitometry and Visual Quality after Small Incision Lenticule Extraction (SMILE) and Laser Epithelial Keratomileusis (LASEK): One-Year Comparative Study.

To investigate changes in corneal densitometry (CD) and visual quality following small incision lenticule extraction (SMILE) and laser epithelial keratomileusis (LASEK) in patients with mild-to-moderate myopia. A retrospective analysis was performed on 24 and 25 patients (46 eyes each) who underwent SMILE and LASEK, respectively, for mild-to-moderate myopia. The visual quality and CD values were recorded. Using the Pentacam Scheimpflug system, CD values were collected in three concentric optical zones at the depths of the anterior, central, and posterior layers. Efficacy, safety, predictability, corneal wavefront aberrations, and QoV scores were measured to evaluate visual quality. A correlation analysis was performed between changes in CD and clinical characteristics. There were no statistical differences in efficacy and safety indices between the two groups. At 3 months postoperatively, a pronounced reduction in several zones was observed in the LASEK group (p < 0.05), whereas no obvious change was observed in the SMILE group. There were obvious changes in the CD values in several zones in the SMILE and LASEK groups (p < 0.05) after 1 year. The magnitude of the CD changes in the anterior and central corneal layers was smaller in the SMILE group than in the LASEK group (all p < 0.05). Lower HOAs, spherical aberration, and horizontal comas of the anterior and whole corneal surfaces were observed in the SMILE group. QoV scores were similar between the two groups. CD decreased in the SMILE and LASEK groups after 1 year; there was a smaller reduction in SMILE than in LASEK. SMILE and LASEK did not differ significantly in terms of safety and effectiveness in correcting mild-to-moderate myopia.

Effectiveness of Laser Refractive Surgery to Address Anisometropic Amblyogenic Refractive Error in Children: A Report by the American Academy of Ophthalmology

To review the published literature assessing the safety and effectiveness of laser refractive surgery to treat anisometropic amblyogenic refractive error in children aged ≤ 18 years. A literature search of the PubMed database was conducted in October 2021 with no date limitations and restricted to publications in English. The search yielded 137 articles, 69 of which were reviewed in full text. Eleven articles met the criteria for inclusion and were assigned a level of evidence rating. The 11 included articles were all level III evidence and consisted of 1 case-control study and 10 case series. Six studies used laser-assisted in situ keratomileusis (LASIK), 1 used photorefractive keratectomy (PRK), 1 used refractive lenticule extraction/small incision lenticule extraction, and the rest used a combination of LASIK, PRK, laser epithelial keratomileusis (LASEK), or refractive lenticule extraction/small incision lenticule extraction. Five studies enrolled patients with anisometropic myopia, 2 studies enrolled patients with anisometropic hyperopia, and the remainder were mixed. Although all studies demonstrated an improvement in best-corrected visual acuity (BCVA), the magnitude of improvement varied widely. As study parameters varied, a successful outcome was defined as residual refractive error of 1 diopter (D) or less of the target refraction because this was the most commonly used metric. Successful outcomes ranged between 38% and 87%, with a mean follow-up ranging from 4 months to 7 years. Despite this wide range, all studies demonstrated an improvement in the magnitude of anisometropia. Regression in refractive error occurred more frequently and to a greater degree in myopic eyes and eyes with longer follow-up, and in younger patients. Although one study reported 2 free flaps, most studies reported no serious adverse events. The most common complications were corneal haze and striae. Findings from included studies suggest that laser refractive surgery may address amblyogenic refractive error in children and that it appears to decrease anisometropia. However, the evidence for improvement in amblyopia is unclear and long-term safety data are lacking. Long-term data and well-designed clinical studies that use newer refractive technologies in standardized patient populations would help address the role of refractive surgery in children and its potential impact on amblyopia.

A New Corneal Remodeling Technique with Laser Asymmetric Keratectomy Using Semi-Cylindrical Ablation Pattern Reducing Regional Asymmetry of Corneal Thickness, Case Series

Laser asymmetric keratectomy using semi-cylindrical ablation pattern (LAK-SCAP) is a new customized corneal remodeling method reducing regional asymmetry of corneal thickness, so could be to avoid and treat conventional laser refractive surgery adverse effects. Three eyes (3 patients) had laser epithelial keratomileusis (LASEK) linked LAK-SCAP (L-LAK-SCAP) to reduce regional asymmetry of corneal thickness and correct refractive errors. On Orbscan map, the cones of the corneas were located in the peripheral side, the corneal thickness imbalance was severe due to the sum of 4 direction differences in corneal thickness &gt;80µm.

Effect of mitomycin-C on corneal endothelial cell parameters after refractive surface ablation procedures.

The effect of mitomycin-C (MMC) on the reduction of endothelial cell count in the cornea remains controversial. We aimed to evaluate the effect of MMC on corneal endothelial cell parameters after refractive surface ablation procedures, including photorefractive keratectomy (PRK) and laser epithelial keratomileusis (LASEK). In this interventional, comparative, follow-up study, 342 eyes of 171 patients were followed up for 6 months. Patients undergoing PRK or LASEK were included and were divided into two groups: group one (188 eyes of 94 patients) with an ablation depth of ≥ 65 µm and who received intraoperative 0.02% MMC for 30 s, and group two (154 eyes of 77 patients) with an ablation depth of < 65 µm and who received balanced salt solution for 30 s. Changes in endothelial cell density (ECD), central corneal thickness (CCT), coefficient of variation (CV), and hexagonality values were compared between the groups at 3 and 6 months after surgery. The mean (standard deviaiton [SD]) age of the patients was 28.11 (6.56) years. The mean (SD) ECD did not change significantly in either group between the baseline and at 3 and 6 months postoperatively. The baseline mean ECD was significantly higher in group one than that in group two (P < 0.001) and remained so at 3 (P = 0.002) and 6 months (P = 0.022) postoperatively. The baseline hexagonality value was lower in group one (P = 0.173), with a gradual decrease during the postoperative follow-up as compared with that in group two (P = 0.016 and 0.001 at 3 and 6 months postoperatively, respectively). Group one had a significantly lower CCT at 3 and 6 months postoperatively (both P < 0.001) and a higher mean CV (3 months: P = 0.028; 6 months: P = 0.328). A single intraoperative application of MMC for 30 s as prophylaxis for corneal haze development during refractive surface ablation procedures had no significant effect on ECD up to 6 months postoperatively. Future studies with a contralateral-eye design (to neutralize factors specific to the individual patient), a larger sample size, and longer follow-up are necessary to confirm or disprove our observations.

Laser Asymmetric Keratectomy Using a Semi-Cylindrical Ablation Pattern to Avoid Adverse Effects of Laser Refractive Surgery

Purpose: This study aimed to present a novel technique for Laser Epithelial Keratomileusis (LASEK)-Linked Laser Asymmetric Keratectomy using a Semi- Cylindrical Ablation Pattern (L-LAK-SCAP) that can prevent adverse effects following LASEK and simultaneously improve refractive errors and corneal symmetry. Design: This is a single-center retrospective study. Methods: We retrospectively compared the postoperative 1-year clinical results after LASEK only or L-LAK-SCAP for each group of 42 eyes of 21 patients with myopia, with a sum of deviations in the corneal thickness in four directions (SUM) on the Orbscan map of &gt;80multaneously corrected the refractivem. L-LAK-SCAP simultaneously corrected the refractive error (LASEK) and myopic shift by selectively ablating thicker cornea (by LAK), thereby improving corneal symmetry and visual acuity concomitantly. Results: The following measures were similar in both groups (p &gt;0.05): preoperative age, Spherical Equivalent (SE), cylinder, Uncorrected Distance Visual Acuity (UDVA), pupil size, Intraocular Pressure (IOP), and corneal symmetry on Orbscan map. At 1-year postoperatively, the L-LAK-SCAP group showed better results, and the following measures differed significantly between the two groups: SE (p=0.024), UDVA (p=0.001), kappa angle (p=0.030), corneal irregularities in the 3.0mm and 5.0mm zones on the Orbscan map (p=0.033 and 0.034, respectively), SUM (p=0.000), the distance between the maximum posterior elevation (best-fit-sphere) and the visual axis (DISTANCE) (p=0.040), blurring scores (p=0.000), and myopic regression (p=0.004). Conclusion: L-LAK-SCAP improved corneal symmetry, was associated with excellent outcomes, and may prevent adverse events following LASEK.

Short-term Comparison of Refractive Errors between Two Different Age Groups after LASEK for Moderate Myopia

Purpose: To investigate the safety of laser epithelial keratomileusis (LASEK) by drawing a comparison between two groups divided according to age (18-19 vs. 20-21 years old).Methods: The study was conducted as a retrospective analysis including 339 patients (678 eyes) who underwent LASEK between January 2017 and April 2020. Patients were divided by age group, group I (18-19 years old) and group II (20-21 years old). The objectives of the study included determination of visual acuity and refractive errors before and at 1, 3, and 6 months after the procedure.Results: The preoperative mean spherical equivalents (SEs) were -4.73 ± 0.88 diopters (D) in group I and -4.58 ± 0.87 D in group II (&lt;i&gt;p&lt;/i&gt; = 0.34). At 1 month postoperatively, mean SEs were 0.32 ± 0.46 D in group I and 0.26 ± 0.59 D in group II (&lt;i&gt;p&lt;/i&gt; = 0.18). At 3 months postoperatively, the mean SEs were 0.30 ± 0.47 D in group I and 0.28 ± 0.50 D in group II (&lt;i&gt;p&lt;/i&gt; = 0.67). At 6 months postoperatively, the mean SEs were 0.15 ± 0.47 D in group I and 0.14 ± 0.50 D in group II (&lt;i&gt;p&lt;/i&gt; = 0.89). There were no significant differences in postoperative best corrected visual acuity between group I and group II at 1, 3, or 6 months (&lt;i&gt;p&lt;/i&gt; = 0.20, &lt;i&gt;p&lt;/i&gt; = 0.13, and &lt;i&gt;p&lt;/i&gt; = 0.11, respectively).Conclusions: There were no significant differences in postoperative mean SE or safety of LASEK between moderate myopia patients 18-19 years old and those 20-21 years old.

Эффективность методов LASIK и LASЕK в достижении прогнозированного результата при эксимерлазерной коррекции миопии и миопического астигматизма

Эксимерлазерная коррекция аномалий рефракции вошла в офтальмологическую практику как одна из самых эффективных хирургических методик, позволяющая путем изменения кривизны роговицы корригировать нарушения рефракции, в том числе при миопии и миопическом астигматизме. Как правило, такая коррекция применяется у пациентов молодого трудоспособного возраста, приобретает особую социальную значимость и требует использования наиболее точных и безопасных технологий, которые бы гарантировали достижение быстрого эффекта с минимальным периодом реабилитации. В работе были проанализированы результаты оперативного лечения 60 пациентов (103 глаза) с миопией различной степени и миопическим астигматизмом. Среди пациентов было 28 мужчин (41 %) и 32 женщины (59 %) в возрасте от 18 до 47 лет (средний возраст 25,0 ± 2,5 года). Исследуемые пациенты были распределены на две группы. Первую группу составили 29 пациентов (50 глаз), которым была выполнена коррекция зрения методом laser-assisted in situ keratomileusis (LASIK). Всем пациентам проводились стандартные офтальмологические обследования (визометрия, ауторефрактометрия, биомикроскопия, прямая офтальмоскопия, тонометрия, периметрия) и рефракционная диагностика, включавшая кератотопографию с пахиметрией (Orbscan, Bausch &amp; Lomb Inc., США), аберрометрию (Zуwave, Bausch &amp; Lomb Inc., США), оптическую когерентную томографию переднего отрезка глаза (Visante OCT, Carl Zeiss Meditec, Германия), оптическую биометрию оптическим биометром IOLMaster (Carl Zeiss Meditec, Германия). Достижение рефракционного результата оценивалось на 1-й день, через 1 месяц, через 6 месяцев и через 1 год после операции. Все оперативные вмешательства выполнялись на эксимерном лазере Allegretto WaveLight EX500 (Alcon, США). Через месяц после эксимерлазерной коррекции методом LASIK ожидаемый результат остроты зрения был достигнут на 46 глазах (80,7 %), а при применении методики laser epithelial keratomileusis (LASEK) — на 31 глазу (58,5 %), что свидетельствует о более долгом периоде реабилитации при применении методики LASEK. Через полгода прогнози­руемая острота зрения без коррекции в группе, где оперативное вмешательство выполнялось методом LASЕK, была достигнута на 46 глазах (86,8 %), в то время как в группе, где оперативное вмешательство выполнялось методом LASIK, была достигнута на 50 глазах (100 %) (разница не достоверна, р &gt; 0,05). Через 1 год после проведенной эксимерлазерной коррекции некорригированная острота зрения независимо от степени миопии составила 0,92 ± 0,04 Ед в первой группе при максимальной остроте зрения с коррекцией на этих глазах до операции — 0,86 ± 0,05 Ед (разница не достоверна, р &gt; 0,05) и 0,74 ± 0,10 Ед во второй группе при максимальных показателях корригируемой остроты зрения до операции — 0,92 ± 0,03 Ед (разница достоверна, р &lt; 0,05). Несколько большая разница достигнутых показателей максимальной некорригированной остроты зрения до операции при выполнении эксимерлазерной коррекции по методу LASЕK объясняется развитием субэпителиальной фиброплазии в 3,77 % случаев, что влияло на средние показатели конечного результата.

Wavefront excimer laser refractive surgery for adults with refractive errors.

Wavefront excimer laser refractive surgery for adults with refractive errors.

Effects of taking pregabalin (Lyrica) on the severity of dry eye, corneal sensitivity and pain after laser epithelial keratomileusis surgery

BackgroundCorneal nerve damage after laser epithelial keratomileusis (LASEK) is thought to be the cause of dry eye and pain. Therefore, we investigated whether taking pregabalin (Lyrica), which reduces peripheral neuropathic...

Therapeutic Contact Lenses in the Treatment of Corneal and Ocular Surface Diseases-A Review.

Therapeutic contact lenses (TCLs) are often used in the management of a wide variety of corneal and ocular surface diseases (OSDs). Indications of TCL include pain relief, enhancing corneal healing, corneal sealing, corneal protection, and drug delivery. For painful corneal diseases such as bullous keratopathy, epidermolysis bullosa, and epithelial abrasions/erosions, bandage contact lenses (BCLs) provide symptomatic relief. Postoperatively in photorefractive keratectomy or laser epithelial keratomileusis, BCLs also alleviate pain. In severe OSDs such as severe dry eye, Stevens-Johnson syndrome/toxic epidermal necrolysis, gas-permeable scleral contact lenses are often used to enhance corneal healing. BCLs are used post-keratoplasty, post-trabeculectomy, and post-amniotic membrane transplantation to enhance healing. BCLs, with or without glue adhesives, are used to seal small corneal perforations and sometimes also used as bridging treatment before penetrating keratoplasty in larger corneal perforations. In patients with eyelid conditions such as trichiasis, ptosis, and tarsal scarring, BCLs are also effective in forming a mechanical barrier to protect the cornea. A relatively new use for TCLs is in ocular drug delivery where TCLs are used to maintain therapeutic concentrations of medication on the ocular surface. Contraindications of the use of TCLs include infective keratitis, corneal anesthesia, and significant exposure keratopathy with inadequate eyelid position or movement. Complications of TCL include infective keratitis, corneal hypoxia and associated complications, corneal allergies and inflammation, and poor lens fit. Overall, TCLs are effective in the treatment of corneal and OSDs but contraindications and complications must be considered.

Explainable Machine Learning Approach as a Tool to Understand Factors Used to Select the Refractive Surgery Technique on the Expert Level.

PurposeRecently, laser refractive surgery options, including laser epithelial keratomileusis, laser in situ keratomileusis, and small incision lenticule extraction, successfully improved patients’ quality of life. Evidence-based recommendation for an optimal surgery technique is valuable in increasing patient satisfaction. We developed an interpretable multiclass machine learning model that selects the laser surgery option on the expert level.MethodsA multiclass XGBoost model was constructed to classify patients into four categories including laser epithelial keratomileusis, laser in situ keratomileusis, small incision lenticule extraction, and contraindication groups. The analysis included 18,480 subjects who intended to undergo refractive surgery at the B&VIIT Eye center. Training (n = 10,561) and internal validation (n = 2640) were performed using subjects who visited between 2016 and 2017. The model was trained based on clinical decisions of highly experienced experts and ophthalmic measurements. External validation (n = 5279) was conducted using subjects who visited in 2018. The SHapley Additive ex-Planations technique was adopted to explain the output of the XGBoost model.ResultsThe multiclass XGBoost model exhibited an accuracy of 81.0% and 78.9% when tested on the internal and external validation datasets, respectively. The SHapley Additive ex-Planations explanations for the results were consistent with prior knowledge from ophthalmologists. The explanation from one-versus-one and one-versus-rest XGBoost classifiers was effective for easily understanding users in the multicategorical classification problem.ConclusionsThis study suggests an expert-level multiclass machine learning model for selecting the refractive surgery for patients. It also provided a clinical understanding in a multiclass problem based on an explainable artificial intelligence technique.Translational RelevanceExplainable machine learning exhibits a promising future for increasing the practical use of artificial intelligence in ophthalmic clinics.

Advantages of Surface Ablation in Excimer Laser Surgery

In this article, we review the advantages of corneal laser surface surgery to explain the current trend toward this technique. The excimer laser in corneal surface surgery can be used for two reasons. On the one hand, to correct a refractive error by photorefractive keratectomy (PRK) and its two variants; Laser epithelial keratomileusis (LASEK) and Epithelial Laser-assisted in situ keratomileusis (Epi-lasik).&#x0D; On the other hand, it is used to perform superficial corneal capacities photoablation, among other uses, by Phototherapeutic keratectomy (PTK).&#x0D; PRK is regaining popularity thanks to its better safety profile, mitomycin C usage and improvement of photoablation profiles. Lasek and Epilasik are less frequently performed nowadays.&#x0D; PTK is an important element in the techniques used to improve visual acuity in a wide range of corneal conditions such as corneal scars, recurrent erosion syndrome and corneal dystrophies.

Comparison of Visual Quality with Ocular Higher-Order Aberrations in Laser Epithelial Keratomileusis and Soft Contact Lens Wear

Purpose : To compare visual quality with ocular higher-order aberrations (HOA) in laser epithelial keratomileusis (LASEK) and soft contact lens wear for myopia. Methods : Eighty eyes of 40 subjects who had undergone LASEK, 40 eyes of 20 subjects who have successfully fitted soft contact lenses and 38 eyes of 19 emmetropes were enrolled. The subjects’ criteria were best unaided monocular visual acuity of 20/20 or better. High and low contrast visual acuities (HCVA and LCVA) test, and contrast sensitivity test were measured under photopic and mesopic conditions. Ocular HOAs were measured using Wavefront Analyzer (KR-1W, Topcon) for 4 mm and 6 mm pupils. Results : HCVA and LCVA under photopic conditions were not statistically different between LASEK and contact lens wear groups compared with an emmetropic group. However, HCVA and LCVA under mesopic conditions were statistically different among the three groups (HCVA; p=0.031, LCVA; p=0.025, respectively). There were statistically significant differences in contrast sensitivity at 6, 12, and 18 cpd both under photopic and mesopic conditions between LASEK and contact lens wear groups (6cpd; p=0.000, 12cpd; p=0.000, 18cpd; p=0.000, redpectively). There were significant differences in ocular HOAs for both 4 mm and 6 mm pupils between LASEK and contact lens wear groups (total HOAs; p=0.000, coma; p=0.000, spherical aberration; p=0.000). Conclusion : LASEK, soft contact lens wear and emmetropic groups could not affect the quality of vision under photopic conditions. Nevertheless, the higher pupil size in the LASEK, the larger the amount of HOAs, the more likely it would have an influence on the visual quality during the night.

Clinical outcomes after laser epithelial keratomileusis (LASEK) and transepithelial photorefractive keratectomy (TPRK) in myopia

Objective: To compare the clinical outcomes between laser epithelial keratomileusis (LASEK) and transepithelial photorefractive keratectomy (TPRK) for treatment of myopia. Methods: Case-control study. We reviewed a total of 90 right eyes that underwent either LASEK or TPRK, with 45 eyes in each group (aged between 18 and 40 years; 9 males and 16 females in the LASEK group, and 30 males and 15 females in the TPRK group) from 2015 to 2016 in Peking Union Medical College Hospital and Tangshan Eye Hospital. All the patients were followed up for 6 months postoperatively. Pain, uncorrected visual acuity (UCVA), and haze were measured at postoperative 3 days, 7 days, 1 month, 3 months and 6 months, and compared using an independent Student t-test between the two groups. Degree of haze, eye pain score, and visual acuity were compared by the Mann-Whitney U test. Results: At 3 days, the pain score was 1 (0,3) in the LASEK group versus 0 (0,1) in the TPRK group (Z=5.643, P=0.001). The UCVA was 4.80±0.10 in the LASEK group versus 4.97±0.07 in the TPRK group (Z=6.930, P=0.000) at 3 days, 4.98±0.08 in the LASEK group versus 5.05±0.06 in the TPRK group (Z=8.147, P=0.000) at 7 days, and 5.02±0.05 in the LASEK group versus 5.06±0.06 in the TPRK group (Z=2.381, P=0.017) at 1 month. The UCVA was also measured at 3 months, 5.07±0.07 versus 5.10±0.07 (Z=1.632, P=0.103), and at 6 months, 5.10±0.07 versus 5.11±0.07 (Z=0.798, P=0.425), respectively, with no statistical significance. The residual diopter was (0.17±0.19) D in the LASEK group versus (0.17±0.20) D in the TPRK group (Z=0.097, P=0.923) at 1 month, (0.03±0.11) D versus (0.07±0.14) D (Z=0.166, P=0.096) at 3 months, (0.07±0.13) D versus (0.07±0.14) D (Z=0.002, P=0.978) at 6 months, respectively. The surface regularity index (SRI) was 0.48±0.09 in the LASEK group and 0.46±0.06 in the TPRK group (t=0.88, P=0.37) at 1 month, and 0.49±0.07 in the LASEK group versus 0.47±0.06 in the TPRK group (t=1.53, P=0.132) at 3 months. Transient haze was documented in 1 eye in each group at 1 month (4.4%), with a maximum index of 0.5. No haze was observed in either group at 6 months. Conclusion: TPRK has the advantages of faster early vision recovery and significantly less pain over LASEK. (Chin J Ophthalmol, 2019, 55: 122-126).

Early Surface Ablation on Aborted LASIK Flaps

To report the outcomes of a series of 16 patients who had secondary surface ablation within 4 weeks of an aborted femtosecond laser-assisted in situ keratomileusis (FS-LASIK) procedure. A retrospective chart review of electronic medical record data from 2011 to 2015 was performed to identify eyes of patients who had an aborted FS-LASIK procedure followed by secondary surface ablation (photorefractive keratectomy or laser epithelial keratomileusis) within 4 weeks of the primary procedure. Patients were required to have at least three postoperative visits to be included in the study. The review identified 20 aborted FS-LASIK procedures of 7,142 eyes (0.003%), of which 16 met the inclusion criteria. The most common reasons for abortion were incomplete (10) and decentered (3) flaps. Thirteen of 16 eyes were treated within 2 weeks. A total of 11 of 16 eyes achieved uncorrected distance visual acuity (UDVA) of 20/20, 13 of 16 achieved UDVA of 20/25 or better, and 15 of 16 had a corrected distance visual acuity (CDVA) of 20/20. There were no intraoperative complications during the second procedure and there were no cases of diffuse lamellar keratitis. One patient developed postoperative haze with a CDVA of 20/25 and was lost to follow-up. This case series indicates that early surface ablation (within 4 weeks) after an aborted FS-LASIK procedure may be performed with good visual outcomes. [J Refract Surg. 2019;35(2):121-125.].

Corneal Surface Ablation Laser Refractive Surgery for the Correction of Myopia: A Network Meta-analysis.

To systematically compare the efficacy, predictability, safety, postoperative haze, pain scores, and epithelial healing time of four corneal surface ablation procedures. PubMed, Embase, Cochrane Library, and the U.S. trial registry were searched up to June 2018. Randomized controlled trials were selected. Efficacy (uncorrected distance visual acuity of 20/20 or better), predictability (refractive spherical equivalent within ±0.50 diopters [D] of the target), and safety (loss of two or more lines of spectacle corrected distance visual acuity) were set as primary outcome measures. Haze, pain scores, and epithelial healing time were set as secondary outcome measures. Eighteen studies involving 1,423 eyes were included. According to the Grading of Recommendations Assessment, Development, and Evaluation, the quality of outcomes were moderate to high (70.6%). There were no differences in efficacy, predictability, safety, haze, day 1 pain, and epithelial healing time between treatments. Epithelial laser in situ keratomileusis (epi-LASIK) had statistically significantly higher pain scores on day 3 compared to photorefractive keratectomy (PRK) (weighted mean differences [WMD] = 2.2, 95% credible intervals [CrI] = 0.19 to 4.01) and transepithelial PRK (T-PRK) (WMD = 2.7, 95% CrI = 0.51 to 4.84). The surface under the cumulative ranking curve ranking results (best to worst) showed laser epithelial keratomileusis (LASEK) ranked highest for efficacy, predictability, safety, and day 1 pain scores. Epi-LASIK ranked best for grade 1 haze scores. T-PRK ranked best for haze of 0.5 or higher, haze scores day 3 pain scores, and epithelial healing time. Surface laser refractive surgeries are comparable in terms of efficacy, predictability, safety, and postoperative haze except for day 3 pain scores, with epi-LASIK being more painful compared to PRK and T-PRK. [J Refract Surg. 2018;34(11):726-735.].

Preoperative refraction, age and optical zone as predictors of optical and visual quality after advanced surface ablation in patients with high myopia: a cross-sectional study

ObjectiveTo investigate the factors associated with optical and visual quality of advanced surface ablation in high myopia.DesignA cross-sectional study of high myopic eyes treated with laser epithelial keratomileusis (LASEK)/epipolis laser...

Wavefront excimer laser refractive surgery for adults with refractive errors

Wavefront excimer laser refractive surgery for adults with refractive errors

Postoperative Efficacy, Predictability, Safety, and Visual Quality of Laser Corneal Refractive Surgery: A Network Meta-analysis

To compare the postoperative efficacy, predictability, safety, and visual quality of all major forms of laser corneal refractive surgeries for correcting myopia. Systematic review and network meta-analysis. Search of MEDLINE, EMBASE, Cochrane Library, and the US trial registry was conducted up to November 2015. Randomized controlled trials (RCT) reporting in accordance with the eligibility criteria were included in this review. We performed a Bayesian random-effects network meta-analysis. Forty-eight RCTs were identified. For efficacy (uncorrected visual acuity [UCVA]), there were no statistically significant differences between any pair of treatments analyzed. The SUCRA (surface under the cumulative ranking curve) ranking (from best to worst) was femtosecond-based laser insitu keratomileusis (FS-LASIK), LASIK, small-incision lenticule extraction, femtosecond lenticule extraction (FLEx), photorefractive keratectomy (PRK), laser epithelial keratomileusis (LASEK), epipolis (Epi)-LASIK, transepithelial PRK (T-PRK). For predictability (refractive spherical equivalent [SE]), a statistically significant difference was found when FS-LASIK was compared with LASIK (odds ratio [OR] 2.29, 95% credible interval [CrI] 1.20-4.14), PRK (OR 2.16, 95% CrI 1.15-4.03), LASEK (OR 2.09, 95% CrI 1.08-4.55), and Epi-LASIK (OR 2.74, 95% CrI 1.11-6.20). The SUCRA ranking (from best to worst) was FS-LASIK, T-PRK, LASEK, PRK, LASIK, Epi-LASIK. There were no statistically significant differences in the safety (best spectacle-corrected visual acuity) comparisons. For both postoperative higher-order aberrations (HOAs) and contrast sensitivity (CS), there were no statistically significant differences between any pair of treatments analyzed. The SUCRA ranking results show that some corneal surface ablation techniques (PRK and LASEK) rank highest. This network meta-analysis shows that there were no statistically significant differences in either visual outcomes (efficacy and safety) or visual quality (HOAs and CS). FS-LASIK behaved better in predictability than any other type of surgeries.