Laser In Situ Keratomileusis Research Articles

Pseudo Corneal Ectasia Due to Corneal Endothelial Disease

Purpose To describe two patients referred for presumed ectasia after laser in situ keratomileusis (LASIK) based on increasing myopia and corneal steepening years after LASIK. In both patients, further testing confirmed endothelial disease with central corneal edema as the cause of topographic changes. Methods Two patients showing symptoms similar to post-LASIK ectasia were assessed with Scheimpflug imaging (Pentacam; Oculus Optikgeräte GmbH) and subsequently treated with endothelial keratoplasty. Results Case 1 was a 66-year-old woman with increasing myopia after LASIK that was initially diagnosed as post-LASIK ectasia. Pentacam imaging revealed central corneal steep-ening with central corneal edema, and the clinical presence of guttata was consistent with Fuch's endothelial dystrophy. Case 2 was a 49-year-old man who also had increasing myopia and corneal steepening after LASIK, but no guttata. Pentacam imaging showed a similar pattern of central corneal swelling. Both patients underwent endothelial keratoplasty with reversal of corneal steepening. Conclusions Several conditions can mimic corneal ectasia, necessitating thorough clinical examination and tomography. This report describes two cases of central corneal edema resulting in myopia and corneal steepening that mimicked corneal ectasia. [ Journal of Refractive Surgery Case Reports. 2024;4(3):e24–e29.]

High hyperopic LASIK with reduction of corneal prolateness to control-induced spherical aberration.

To evaluate visual outcomes of high hyperopic laser in situ keratomileusis (LASIK), using corneal aspherization to control the induced spherical aberration. Fondation Ophtalmologique Adolphe de Rothschild, Paris, France. Prospective interventional case series. Prospective interventional study of consecutive high hyperopes (≥+3 diopters [D] of spherical equivalent [SE]) undergoing LASIK with the WaveLight FS200 femtosecond and EX500 excimer laser platform. An aspheric ablation profile (planned change in corneal asphericity ΔQ = +0.2) was delivered using the Custom-Q nomogram on an optical zone of ≥6.5 mm centered near the corneal vertex. Uncorrected corrected distance visual acuity (UDVA) and corrected distance visual acuity, as well as changes in SE, corneal asphericity (ΔQ), and higher-order aberrations, were analyzed preoperatively and on day 1, 1, 3, 6, and 12 months. 117 eyes of 63 patients (mean age of 30.1 ± 5.6 years) were included. Preoperatively and at 12 months postoperatively, the mean SE was 5.1 ± 1.1 D and 0.00 ± 0.7 D, respectively. 88% of eyes achieved 0 logMAR or better UDVA at 12 months. 1 month postoperatively, there was a statistically significant induction of positive spherical aberration decreasing progressively and significantly until the last visit (preop SA4 = 0.09 ± 0.11 μm, day 1 SA4 = 0.30 ± 0.32 μm, 12 months SA4 = 0.08 ± 0.21 μm, P = .056). 2 eyes needed enhancement at 12 months. LASIK for high levels of hyperopia showed good outcomes mainly due to aspheric-customized ablation profile with a change of ΔQ = +0.2 in corneal asphericity.

Laser refractive correction of presbyopia.

Presbyopia is an inevitable and progressive loss of the eye's ability to focus on nearby objects due to aging, which affects everyone regardless of their refractive error. Uncorrected presbyopia is a significant burden worldwide and affects the quality of life. Conservative options include spectacle correction, contact lenses, and pharmacologic agents. Spectacles are commonly used to correct vision, but have certain drawbacks such as peripheral blur and impaired depth perception. These limitations have been associated with an increased risk of accidental falls. Several surgical options are available to address these issues, including cornea-based, lens-based, or scleral procedures. These procedures involve modifying the cornea's optics, replacing the crystalline lens, or attempting to restore accommodation. Each of the options has its benefits and limitations. One of the most common surgical methods of presbyopic correction that has recently become popular is presbyopic Laser assisted In situ keratomileusis (LASIK) due to its improved safety and efficacy. This article is a review of all the currently available data and studies regarding the various methods of correction of presbyopia, with an emphasis on the principles and outcomes of the corneal laser refractive procedures for presbyopia correction, such as PresbyLASIK, Supracor, PRESBYOND laser blended vision, and Custom Q.

Lens Factor Choice in IOL Power Calculation after Laser Refractive Surgery: The Right Constant for Advanced Lens Measurement Approach (ALMA).

Background/Objectives: To evaluate the advanced lens measurement approach (ALMA) formula accuracy using different lens constants available on the user group for laser interference biometry (ULIB) and IOL Con platforms. Methods: In this retrospective, comparative, case-series study, 150 eyes of 160 patients with previous myopic Photorefractive Keratectomy (PRK) or laser-assisted in situ keratomileusis (LASIK), who underwent uneventful cataract surgery and IOL implantation, were examined. The ALMA formula was evaluated to calculate the refractive prediction error (PE), analysing four different categories of lens constants: both nominal and optimized A-Constant for SRKT, which are available on the ULIB and IOL Con platforms. An additional analysis was carried out in this study, evaluating if a decreased ULIB optimized constant (DUOC) with different fixed factors (-1.2 -1.3 -1.4 -1.5) could improve refractive outcomes. Median absolute error (MedAE) and percentage of eyes within ±0.50 and ±1.00 diopters (D) of prediction error were measured as the main outcomes. Results: Comparing the lens factors available on ULIB and IOL Con platforms, the ALMA formula reported a lower MedAE and higher percentages of eyes with a refractive PE within 1.0 D using ULIB nominal constants (all p < 0.05). Using DUOC (-1.3), and there was a statistically significant improvement of both MedAE and of the percentages of eyes with PE within ±0.50 D with the ALMA method compared to nominal ULIB constants (all p < 0.05). Conclusions: The impact of different lens factors in the IOL power calculation after myopic LRS should be carefully evaluated. The ALMA formula, in the absence of optimized constants by zeroing the mean error, should be used by subtracting 1.3 from the optimized ULIB constants available on the IOL Con website. This finding suggests further studies to test which of these constants could work better with the other post-refractive surgery formulas.

Effect of Posterior Keratometry and Corneal Radius Ratio on the Accuracy of Intraocular Lens Formulas After Myopic LASIK/PRK.

To investigate the impact of back-to-front corneal radius ratio (B/F ratio) and posterior keratometry (PK) on the accuracy of intraocular lens power calculation formulas in eyes after myopic laser in situ keratomileusis (LASIK)/photorefractive keratectomy (PRK) surgery. A retrospective, consecutive case series study included 101 patients (132 eyes) with cataract after myopic LASIK/PRK. Mean prediction error (PE), mean absolute PE (MAE), median absolute error (MedAE), and the percentage of eyes within ±0.25, ±0.50, and ±1.00 diopters (D) of PE were determined. The Barrett True K-TK formula exhibited the lowest MAE (0.59 D) and MedAE (0.48 D) and the highest percentage of eyes within ±0.50 D of PE (54.55%) in total. In eyes with a B/F ratio of 0.70 or less and PK of -5.70 D or greater, the Potvin-Hill formula displayed the lowest MAE (0.46 to 0.67 D). The Barrett True-TK exhibited the highest prediction accuracy in eyes after myopic LASIK/PRK overall. However, for eyes with a low B/F ratio and flat PK, the Potvin-Hill performed best. [J Refract Surg. 2024;40(9):e635-e644.].

A comparison of the results of old-generation (MEL 60) and new-generation (SCHWIND AMARIS) refractive excimer laser treatments

AbstractPurposeThe present study compares the efficacy of refractive surgery using third-generation and sixth-generation laser vision correction procedures in terms of postoperative visual acuity. The goal of the authors was to determine whether advances in laser technology had improved patients' uncorrected visual acuity, as measured at six-month follow-ups.Materials/MethodsResults were reported from one of Europe's leading laser eye clinics, which has performed an outstandingly high number of treatments (over 100,000). The results of the clinic's first 10,000 treatments and most recent 10,000 treatments were evaluated.ResultsThe analysis was performed by treated dioptric range and age group. The raw six-month visual acuity results show a statistically significant improvement over the last 10,000 interventions. The treatments resulted in significant improvements in all groups compared to the previous technology. With the new devices, visual acuity increased to above 1.0 in young myopes. The best results were seen in patients between 18 and 45 years of age, in the dioptric range between −1.0 D and −6.0 D.ConclusionsIt can be concluded that advances in technology improved refractive outcomes in all patient groups. This conclusion has excellent reliability and predictability due to the particularly high number of cases.

Posterior corneal surface stability after femtosecond laser-assisted in situ keratomileusis in patients with myopia and myopic astigmatism.

To evaluate the variation and stability of the posterior cornea surface parameters (posterior cornea curvature [PCC], posterior cornea astigmatism [PCA], and posterior cornea elevation [PCE]) after femtosecond laser-assisted in situ keratomileusis (LASIK) in patients with myopia and myopic astigmatism over a period of 6 months or longer. This retrospective study comprised 284 right eyes. Patients aged 18 years or older with myopia up to -12.00 D and/or astigmatism up to -6.00 DC and who underwent femtosecond LASIK were recruited. Patients were divided into three subgroups: low myopia (-0.50 to -3.00 D), moderate myopia (>-3.00 to ≤-6.00 D), and high myopia (>-6.00 D), according to their pre-LASIK spherical equivalent (SE). The variables included for analysis were PCC (central 0-3.0 mm, pericentral 3.0-6.0 mm, and peripheral region 6.0-9.0 mm), PCE, PCA, internal anterior chamber depth, intraocular pressure, and central cornea thickness at the pre- and post-LASIK stages. The central PCC remained unchanged across all three myopia subgroups at 1 month when compared to the pre-LASIK stage and remained stable at 6 months. The pericentral regions became flatter across all myopia subgroups at 1 month postsurgery (P < 0.001) and remained unchanged at 6 months. This trend was not seen in the peripheral cornea regions, which remained unchanged at 1 and 6 months post-LASIK when compared to pre-LASIK mean readings. There were minimal changes in post-LASIK posterior cornea astigmatism throughout follow-up. There was no incidence of post-LASIK surgery ectasia in this study population. Post-LASIK, the different cornea subregions behaved differently. Overall, the posterior cornea surface remained stable post-LASIK across all myopia subgroups throughout follow-up.

Safety and Effectiveness of Laser in Situ Keratomileusis Using the Teneo 317 Model 2 for Correcting Myopia and Myopic Astigmatism: Results of the U.S. FDA Clinical Trial.

To evaluate the safety and effectiveness of a new aspheric ablation profile for correcting myopia and myopic astigmatism. This prospective, multicenter study included patients who underwent laser in situ keratomileusis (LASIK) using a new aspheric ablation profile of the Technolas Teneo 317 (Model 2) excimer laser (version 1.28 US SW) by Technolas Perfect Vision, Bausch+Lomb, Inc. No nomogram adjustments were made, and the patient's manifest refraction was entered into the laser (for treatment). Postoperative assessments included visual and refractive outcomes. Patients were asked to complete the Patient-Reported Outcomes With LASIK (PROWL) questionnaire preoperatively and postoperatively. A total of 333 eyes from 168 patients with a mean age of 33 ± 7 years were included. At postoperative 9 months, uncorrected and corrected distance visual acuities of 20/25 or better were seen in 97.8% and 100% of eyes, respectively. None of the eyes lost two or more lines of corrected distance visual acuity. The mean manifest spherical refraction improved from -5.67 ± 2.52 diopters (D) preoperatively to -0.04 ± 0.32 D postoperatively, with 92.7% of eyes achieving residual refractive error within ±0.50 D. Residual refractive cylinder within ±0.50 and ±1.00 D was seen in 93% and 99.4% eyes, respectively. The refractive outcomes were stable throughout the follow-up of 9 months. The proportion of patients satisfied with their vision rose from 27.7% preoperatively to 98.1% postoperatively. LASIK performed using a new aspheric ablation profile of the Technolas Teneo 317 (Model 2) excimer laser is safe and effective for correcting myopia and myopic astigmatism, yielding excellent visual and refractive outcomes that were stable over 9 months. [J Refract Surg. 2024;40(8):e544-e553.].

Intraocular lens power calculation using shammas pl no history formula in eyes with previous laser in situ keratomileusis

The study evaluated the results of IOL power calculation using Shammas PL no history formula in eyes with previous laser in situ keratomileusis (LASIK). This was a longitudinal follow-up descriptive analysis study. IOL power was calculated with Shammas PL formula with the ASCRS online calculator. Results: 41 eyes of 27 patients matched the inclusion and exclusion criteria. The mean uncorrected distance vision acuity (UDVA) and corrected distance vision acuity (CDVA) 3 months after surgery were 0.42 ± 0.23; 0.25 ± 0.19 logMAR, respectively. The number of eyes within ± 0.5 D; ± 1.0 D accounted for 48.8%, 75.6%, respectively. Mean absolute error (MAE) 3 months after surgery was 0.68 ± 0.59. Of the 41 eyes, 20 eyes were relatively myopic-shifted (&lt;-0.5 D), 20 eyes showed an emmetropic shift (-0.5 D ◊ +0.5 D), and one eye showed a hyperopic shift (&gt; 0.5 D). There was no statistically significant difference in MAE between axial length groups. 82.7% were satisfied and very satisfied. Conclusion: Shammas PL formula may be a suitable option for eyes after previous LASIK with all different axial length with the high rate of satisfaction. With Shammas PL no history formula, myopic shifting was more common than emmetropic and hyperopic shifting.

Adopting Machine Learning to Automatically Identify a Suitable Surgery Type for Refractive Error Patients

efractive error is a visual impairment that arises when the ocular anatomy hinders the proper focusing of light onto the retina, the light-sensitive tissue layer located at the posterior region of the eye. This condition poses difficulties in achieving clear vision. Refractive error stands as the prevailing kind of visual impairment. The objective of this study is to classify two surgical approaches utilized in the treatment of refractive defects. Two commonly performed refractive surgeries are Photo-Refractive Keratectomy (PRK) and Laser-Assisted In-Situ Keratomileusis (LASIK). Artificial Intelligence (AI) encompasses a specific branch known as Machine Learning (ML), which is the focal point of this investigation. ML is dedicated to the advancement and use of algorithms that possess the capacity to acquire knowledge from data and enhance their predictive capabilities without explicit programming. The present study employs sophisticated ML methods to classify different types of refractive defect surgeries using a dataset of 124 samples obtained from Al-Rabee Hospital in Iraq, specifically focusing on corneal topography data. Two ML approaches, namely K-Nearest Neighbor (KNN) and Artificial Neural Network (ANN), are employed to predict the kind of refractive defect surgery. The findings produced from the experiment demonstrated an accuracy rate of 90.32% for the KNN algorithm and a perfect accuracy rate of 100% for the ANN algorithm. Additionally, the KNN algorithm exhibited a sensitivity of 90% and a specificity of 90.54%. The study’s findings indicate that the ANN classifier outperforms the KNN classifier.

Comparison of clinical outcomes of a corneal wavefront- and topography-guided platforms for laser in situ keratomileusis on virgin eyes: an expanded cohort study

PurposeTo compare the clinical outcomes of myopiacorrected with corneal-wavefront-guided (CWG) laser in situ keratomileusis (LASIK) with AMARIS 1050S (SCHWIND eye-tech-solutions GmbH & Co. KG) and corneal-topography-guided (CTG) LASIK with WaveLight EX500 (Alcon Laboratories, Fort Worth, TX).MethodsIn this prospective, pseudo-randomized expanded cohort study, a total of 266 patients were subjected to binocular LASIK surgery, either with WaveLight EX500 (WaveLight group) or Amaris 1050S (AMARIS group) platforms. Data related to right eyes were selected for analysis. Corneal higher-order aberration (HOA) was selected as the primary endpoint; while visual acuity and refraction were the secondary endpoints. All the endpoints were assessed at 3 months postoperatively.ResultsThere were 134 eyes in the AMARIS group and 132 eyes in the WaveLight group. After 3 months of postoperative follow-up, spherical and coma aberrations were significantly lower (P < 0.05) in the WaveLight group (spherical aberration: − 0.104 ± 0.199 µm; coma aberration: − 0.117 ± 0.202 µm) in comparison with the AMARIS group (spherical aberrations: 0.254 ± 0.146 µm; coma aberrations: 0.316 ± 0.297 µm). In the AMARIS group, 96.3% of the eyes achieved an uncorrected distance visual acuity (UDVA) of 20/20 while in the WaveLight group, 96.2% of the eyes achieved an UDVA of 20/20. Furthermore, the mean postoperative manifest refraction spherical equivalent (MRSE) was − 0.02 ± 0.28 in the AMARIS group and − 0.05 ± 0.21 in the WaveLight group (P = 0.34).ConclusionsBoth WaveLight EX500 and Amaris 1050S LASIK showed excellent refractive and visual outcomes. In addition, the WaveLight group showed minimal spherical and coma aberrations when compared to the AMARIS group.

Delayed interface fluid syndrome in a post laser-assisted in situ keratomileusis: A rare complication

Interface fluid syndrome (IFS) is a rare complication seen post-laser-assisted in situ keratomileusis (post-LASIK). This report describes two unusual cases in which patients underwent ocular surgeries and developed delayed onset interface fluid. Both the patients had undergone uneventful laser-assisted in situ keratomileusis (LASIK) decades ago; case 1 underwent uneventful phacoemulsification and vitrectomy with gas tamponade and case 2 underwent uneventful phacoemulsification with intraocular lens implantation. Possible causes of IFS could be steroid-induced intraocular pressure (IOP) spike, intraocular inflammation, or both. IFS can be seen any time after refractive surgeries and can be a lifelong complication after LASIK surgery. Inaccurate IOP measurement due to underestimation should be borne in mind while measuring IOP in such patients. This report highlights the challenges in diagnosing IFS and the importance of correct IOP measurement in such cases to avoid irreversible vision loss.

A simultaneous post-LASIK sequential bilateral implantation of multifocal IOLs aimed at refraction correction. A clinical case

The article presents a clinical example of intraocular presbyopia correction in a patient who previously underwent laser vision correction by LASIK for mild myopia. Before the surgery, the distance VA mono- and binocular was 1.0, ADD for reading distance 40 cm +2.0 D, objective refraction sph +0.5 D cyl -0.25 D ax 980, left eye sph +0.75 D cyl -0.25 D ax 660. The patient was given a simultaneous bilateral refractive lens exchange with an implantation of a trifocal aspheric intraocular lens in the right eye and a trifocal toric aspheric intraocular lens in the left eye. We used the following IOL calculation formulas: ASCRS mean IOL power, Shammas formula, Barrett true K formula, Masket formula, Modified Masket formula, Haigis-L formula. 1 week postop: UDVA OU = 1.0, UNVA 40 cm = 1.0, UVA 70 cm = 0.7. The objective refraction OD was sph +0.0, D cyl -0.75 D ax 163, OS sph +0.25 D, cyl -0.0 D. The compliance with the modified algorithms of pre-and intraoperative behavior of the operating team, thorough preparation of the patient, careful calculation of the IOL allowed us to obtain the predictive refractive result with a high level of visual satisfaction and absence of undesirable postoperative phenomena. The patient underwent the examination with Salzburg reading desk before and after the surgery, to confirm the excellent functional results of the treatment. Despite the fact that simultaneous same day IOL implantation in both eyes, especially in eyes with previously operated corneas, is still disputable, the above case confirms that with modern equipment, precise multi formula calculation, and ample experience help achieve excellent functional and refractive results.

Laser vision correction and binocular vision – case reports

Laser vision correction (LVC) is the removal of refractive errors, by changing the geometry of the cornea. It doesn’t directly affect binocular vision. However, the condition of the patient’s binocular vision is a very important. That affects the quality of life, which also indirectly translates into the patient’s satisfaction with the LVC procedure. Based on the presented cases, this article proves how important it is to examine binocular vision before laser vision correction. The influence of the prismatic effect of spectacle lenses on the control of binocular vision and the risk of strabismus decompensation, whichis most often associated with double vision. The described cases are people with problems with binocular vision. The article includes methods of treatment (contact lens test, vision therapy) to check and eliminate the above-mentioned problem.

Topographic and Surgical Risk Factors for Early Myopic Regression between Small Incision Lenticule Extraction and Laser In Situ Keratomileusis.

Our objective was to evaluate the topographic and surgical factors of early myopic regression between laser in situ keratomileusis (LASIK) and small-incision lenticule extraction (SMILE). A retrospective case-control study was conducted, and 368 and 92 eyes were enrolled in the LASIK and SMILE groups via propensity score matching (PSM). Visual acuity, refractive status, axial length, and topographic/surgical parameters were collected. Multiple linear regression was applied to the yield coefficient and the 95% confidence interval (CI) of the parameters. The cumulative incidence of early myopic regression was higher in the LASIK group (p < 0.001). In the SMILE group, a lower central corneal thickness (CCT) thinnest value and a higher corneal cylinder associated with early myopic regression were observed; meanwhile, in the LASIK group, a lower CCT thinnest value, a higher steep corneal curvature, a larger optic zone, and a lower flap thickness related to early myopic regression were observed (all p < 0.05). In the SMILE group, a higher CCT difference correlated with early myopic regression was observed compared to the LASIK group (p = 0.030), and higher steep corneal curvature and lower cap/flap thickness (both p < 0.05) correlated with early myopic regression were observed in the LASIK group compared to the SMILE group. In conclusion, CCT differences significantly influence early myopic regression in the SMILE group; meanwhile, corneal curvature and flap thickness affect early myopic regression principally in the LASIK group.

Progressive Paracentral Visual Field Loss at Low Intraocular Pressures Following LASIK.

Intraocular pressure is currently the only known reliable, modifiable risk factor for the development and progression of glaucoma. Other risk factors for glaucoma include increasing age, myopia, decreased central corneal thickness, and low corneal hysteresis (CH) measurements. Photoablative keratorefractive surgery including laser assisted in situ keratomileusis (LASIK) has become a common way to treat refractive error, with over 25 million procedures performed in the United States alone. Though myopic LASIK has been associated with a decrease in CH measurements, relatively little is known about the risk of LASIK on glaucoma onset and progression. Here we present an observational study of 4 consecutive relatively young and otherwise healthy glaucoma patients with a history of myopic LASIK who showed progression of paracentral visual field deficits at intraocular pressures of 12mmHg or less while being carefully monitored. Therefore, these patients required lower targets of intraocular pressure, in the single-digit range, to slow or halt progression. In this cohort, the average corneal hysteresis was more than 2 standard deviations below normal values. This series suggests that additional study into the association of LASIK and glaucoma is warranted, including the potential risk contribution of diminished CH. These studies may be particularly relevant as patients who underwent LASIK procedures in the early 2000s may now be at increased risk of glaucoma due to the risk factor of age.

Postoperative Astigmatism after Keratoplasty: A Systematic Review Meta-Analysis Based on PRISMA.

Background: The number of corneal transplants is rising, with the aim to treat a spectrum of diseases ranging from dystrophies to corneal opacities caused by trauma or chemical burns. Refractive outcomes after this procedure are often impossible to predict and associated with high levels of astigmatism. However, there are many techniques that affect the reduction of astigmatism and improve the quality of life of patients. Objectives: The aim was to compare the improvement in postoperative visual acuity (logMAR) and amount of corneal astigmatism (Diopters) after corneal keratoplasty in patients who additionally underwent a surgical procedure, which affects the reduction in postoperative astigmatism, and to determine the most effective method. Search Methods and Selection Criteria: A thorough search was carried out across online electronic databases including PubMed, Embrase, Ovid MEDLINE, Scopus, and Web of Science, using combinations containing the following phrases: postoperative astigmatism, post-keratoplasty astigmatism, anterior lamellar keratoplasty (ALK), deep anterior lamellar keratoplasty (DALK), posterior lamellar keratoplasty, endothelial keratoplasty (EK), penetrating keratoplasty (PK), corneal transplant, keratoplasty, refractive surgery, kerato-refractive surgery, laser in situ keratomileusis (LASIK), and femtosecond LASIK. This was to determine all English-language publications that discuss refractive operations for postoperative or post-keratoplasty astigmatism. These bibliographies were searched for English-language publications published between 2010 and 2023. We proceeded to review each detected record's reference list. Data Extraction: Study characteristics such as study design, sample size, participant information, operations performed, and clinical outcomes were all extracted. Data Statistical Analyses: The Comprehensive Meta-Analysis software (version 3.3.070, 2014) was used to perform the analysis. The threshold of 0.05 for p-values was considered statistically significant. All effect sizes are reported as standardized differences (Std diff) in means with a 95% confidence interval (CI) and visualized graphically as forest plots. Publication bias is presented as a funnel plot of standard error by Std diff in means. Four methods were used to evaluate the heterogeneity among the studies: Q-value, I2, chi-square (χ2), and tau-squared. Main Results: We included 21 studies that randomized 1539 eyes that underwent corneal transplantation surgery either by PKP, DALK, or DSEAK techniques. The results showed the most significant improvement in the visual acuity and significant decrease in the corneal astigmatism after laser surgery procedures, like femtosecond-assisted keratotomy after DALK and PKP and LASIK after DSEAK.

An Enigmatic Fluid Accumulation Following Descemet Membrane Endothelial Keratoplasty After Prior Laser In Situ Keratomileusis

Purpose: To report a case of interface fluid syndrome (IFS) following Descemet membrane endothelial keratoplasty (DMEK) 13 years after laser in situ keratomileusis (LASIK). Methods: A 79-year-old patient with bullous keratopathy underwent uneventful DMEK. Thirteen years prior, he had undergone LASIK. After DMEK, he developed an IFS, which was confirmed by a fluid accumulation in the flap interface, visible in the anterior segment optical coherence tomography (AS-OCT). In this case, IFS is presumed to have been triggered by the corticosteroid eye drops administered postoperatively. Measurements of the intraocular pressure (IOP) via applanation tonometry yielded erroneously low results. Results: The discontinuation of the corticosteroid eye drops, along with the initiation of IOP-lowering therapy, led to an improvement in fluid accumulation and a decrease in IOP. Regular ophthalmic examinations with a palpatory assessment of IOP and monitoring of fluid via AS-OCT are recommended. In this case, no more fluid could be detected in the flap interface after 14 months, and IOP was normal. Conclusions: IFS can occur many years after LASIK treatment. Corticosteroids should be discontinued, and IOP-lowering therapy should be initiated to prevent irreversible damage to the optic nerve. Applanation tonometry leads to inaccurately low IOP measurements; therefore, a palpatory assessment of IOP is recommended. AS-OCT is a crucial imaging modality that should be employed for monitoring.

Patient-Reported Outcomes and Higher Order Aberrations Following Topography-Guided Femtosecond Laser-Assisted In Situ Keratomileusis.

To examine patient-reported outcomes and higher order aberrations following topography-guided laser-assisted in situ keratomileusis (LASIK). This was a prospective, nonrandomized observational study at a single academic center. Sixty eyes from 30 patients underwent bilateral topography-guided femtosecond LASIK for correction of myopia using the VisuMax 500 femtosecond laser (Zeiss; Oberkochen, Germany) and Allegretto Wave Eye-Q 400 Hz Excimer Laser (Alcon/Wavelight; Erlangen, Germany) with the Contoura topography system (Alcon; Geneva, Switzerland) for topography-modified refraction. The main outcomes of this study were higher order aberrations (HOAs) and results from the Patient-Reported Outcomes with LASIK questionnaire. There was a small, significant increase in HOA root mean square, spherical aberration, and coma at 1, 3, 6, and 12 months following topography-guided LASIK (all P < 0.05), but no change in trefoil. In addition, self-reported worry related to vision (P < 0.001) and ability to perform activities (P < 0.001) significantly improved after surgery. The prevalence of double images, glare, halos, or starbursts decreased from 73% preoperatively to 56%, and no participants reported "very" or "extremely" bothersome visual symptoms after 12 months. Dry eye symptoms per Ocular Surface Disease Index score decreased significantly at 6 (P = 0.01) and 12 (P = 0.002) months after surgery. There was a 100% satisfaction rate with visual outcomes and duration of time to improvement in vision following the procedure. Although there was an increase in HOAs following topography-guided LASIK, there were significant improvements in the presence of double images, glare, halos, and starbursts and vision-related quality-of-life metrics. Overall satisfaction rates in this study were high.

LASIK Videos on TikTok: A Content Analysis of the Top 100 Videos.

Social media has increasingly become a prominent source of health information. Platforms like TikTok that allow for videos to reach millions of viewers have become among the most common platforms to share and receive health information. Laser in situ keratomileusis (LASIK) videos and patients' experiences are commonly discussed on social media. The quality of these videos remains to be assessed. The aim of this study is to evaluate the content, quality, and reach of the top 100 videos related to LASIK eye surgery on TikTok. Video quality was assessed using the DISCERN, JAMA, and GQS instruments which have all been proven to be both reliable and valid. 100 videos were included in the study. Results showed that the videos have an immense reach with a total view count of 245 million views and 21.9 million likes. Two thirds of the videos were posted by personal accounts as compared ophthalmologists that only constituted 26% of the content. Healthcare professionals produced higher quality videos compared to nonhealthcare professionals (p < 0.0001) although there was no significant difference in video duration (p=0.18). Increased duration, view count, comments, shares, saves, and views/day were all associated with increased DISCERN score and quality of the videos. Educational videos were of higher quality compared to entertainment videos, and videos outlining the procedure details had the highest quality score. LASIK videos on TikTok have established a wide reach, whereby viewers are highly interacting and viewing these videos. It appeared that viewers interacted more with the higher quality videos. Ophthalmologists approximately only contributed to a quarter of the videos analyzed in this study. This highlights the need for ophthalmologists to establish a presence on TikTok and produce high quality videos.