Surgical outcomes of laser in situ keratomileusis (LASIK) in patients with stable systemic disease.

PURPOSE: To evaluate the surgical outcome in terms of safety, efficacy, predictability, and retreatment rate of LASIK surgery in patients with controlled systemic diseases in comparison with healthy individuals. METHODS: The retrospective study included data from 1936 eyes of 976 patients with stable systemic diseases who underwent LASIK surgery between January 2016 and June 2019. The safety, efficacy, predictability of the surgery, and retreatment rate were evaluated in comparison with a control group comprising 1951 patients. The study was approved by the local ethics committee and adhered to the principles of the Declaration of Helsinki. Statistical analysis was performed using R team and the level of statistical significance was set at p < 0.05. RESULTS: All treatment groups demonstrated high safety and efficacy indices after LASIK surgery. Furthermore, the study arms demonstrated comparable predictability and retreatment rates to the control group in nearly all cases. Retreatment rates were significantly higher in the rheumatoid arthritis group (p = 0.03), while safety indices were significantly lower in the hay fever group compared to the control group (p = 0.004). No intra- or postoperative sight-threatening complications were documented. CONCLUSION: Our findings suggest that selected patients with stable systemic conditions can safely undergo LASIK surgery and achieve comparable outcomes to healthy individuals. Further research is needed to better understand the treatment outcomes in this challenging patient population.

Influence of the patient's age on the safety, efficacy, and prediction accuracy of the microkeratome in laser-assisted in situ keratomileusis.

The purpose of this retrospective pseudonymised data analysis was to determine whether the patient's age has an influence on the safety, efficacy, and prediction accuracy of laser in situ keratomileusis (LASIK) treatment of myopic and hyperopic eyes. This study was performed at CARE Vision GmbH (Düsseldorf, Germany) and included two patient cohorts: an older group with patients > 55 years old and a younger group with patients 30-40 years old. Each patient had a single LASIK treatment. The safety, efficacy, and prediction accuracy of the refractive results were analysed. In total, 682 patients were analysed, with 341 patients in each patient group (one eye per patient). There were 570 myopic eyes and 112 hyperopic eyes. In myopic eyes, the efficacy was significantly influenced by the patient's age but only in myopic eyes (myopic: p ≤ 0.05; hyperopic: p = 0.085), while safety was not significantly influenced by the patient's age in hyperopic or myopic eyes (p = 0.204). We found that LASIK treatment at an older age (> 55 years) resulted in almost the same safety outcomes as a LASIK treatment at a younger age (30-40 years) but with a lower efficacy; the efficacy correlated with the patient's age. If the patient was hyperopic, their age did not influence safety or efficacy.

Exploring the Potential of ChatGPT-4 in Predicting Refractive Surgery Categorizations: Comparative Study.

BACKGROUND: Refractive surgery research aims to optimally precategorize patients by their suitability for various types of surgery. Recent advances have led to the development of artificial intelligence-powered algorithms, including machine learning approaches, to assess risks and enhance workflow. Large language models (LLMs) like ChatGPT-4 (OpenAI LP) have emerged as potential general artificial intelligence tools that can assist across various disciplines, possibly including refractive surgery decision-making. However, their actual capabilities in precategorizing refractive surgery patients based on real-world parameters remain unexplored. OBJECTIVE: This exploratory study aimed to validate ChatGPT-4's capabilities in precategorizing refractive surgery patients based on commonly used clinical parameters. The goal was to assess whether ChatGPT-4's performance when categorizing batch inputs is comparable to those made by a refractive surgeon. A simple binary set of categories (patient suitable for laser refractive surgery or not) as well as a more detailed set were compared. METHODS: Data from 100 consecutive patients from a refractive clinic were anonymized and analyzed. Parameters included age, sex, manifest refraction, visual acuity, and various corneal measurements and indices from Scheimpflug imaging. This study compared ChatGPT-4's performance with a clinician's categorizations using Cohen κ coefficient, a chi-square test, a confusion matrix, accuracy, precision, recall, F1-score, and receiver operating characteristic area under the curve. RESULTS: A statistically significant noncoincidental accordance was found between ChatGPT-4 and the clinician's categorizations with a Cohen κ coefficient of 0.399 for 6 categories (95% CI 0.256-0.537) and 0.610 for binary categorization (95% CI 0.372-0.792). The model showed temporal instability and response variability, however. The chi-square test on 6 categories indicated an association between the 2 raters' distributions (χ²5=94.7, P<.001). Here, the accuracy was 0.68, precision 0.75, recall 0.68, and F1-score 0.70. For 2 categories, the accuracy was 0.88, precision 0.88, recall 0.88, F1-score 0.88, and area under the curve 0.79. CONCLUSIONS: This study revealed that ChatGPT-4 exhibits potential as a precategorization tool in refractive surgery, showing promising agreement with clinician categorizations. However, its main limitations include, among others, dependency on solely one human rater, small sample size, the instability and variability of ChatGPT's (OpenAI LP) output between iterations and nontransparency of the underlying models. The results encourage further exploration into the application of LLMs like ChatGPT-4 in health care, particularly in decision-making processes that require understanding vast clinical data. Future research should focus on defining the model's accuracy with prompt and vignette standardization, detecting confounding factors, and comparing to other versions of ChatGPT-4 and other LLMs to pave the way for larger-scale validation and real-world implementation.

Pre- and postoperative angle kappa in MIOL patients after touch-up LASIK.

PURPOSE: To study the influence of angle kappa (κ) on visual acuity after implantation of a multifocal intraocular lens (MIOL) and consecutive "touch-up" corneal refractive surgery with Laser-in-situ-Keratomileusis (LASIK). METHODS: This retrospective multicenter study included patients who underwent MIOL surgery and consecutive LASIK (= Bioptics) in the period from 2016 to 2020 at Care Vision Refractive Centers in Germany. Our study was approved by the local ethics committee at the University in Duesseldorf (approval date: 23.04.2021) and conducted according to the tenets of the Declaration of Helsinki and Good Clinical Practices Guidelines. The pre- and post-operative κ of 548 eyes were measured using a Scheimpflug-based imaging system. Corrected distance visual acuity (CDVA) and the safety index (SI) were analyzed in relation with κ. For a more detailed analysis, the cohort was divided into pre-operative hyperopic and myopic patients to show group-specific differences. RESULTS: There was a significant decrease (p<0.001) in the magnitude of κ after MIOL implantation and Bioptics. However, there was almost no significant correlation of κ on CDVA and SI, pre- and postoperatively. CONCLUSION: A large κ is not a significant risk factor for poor visual acuity. Therefore, it is not a suitable clinical predictor of postoperative outcomes after a Bioptic procedure.

Safety and Precision of Two Different Flap-morphologies Created During Low Energy Femtosecond Laser-assisted LASIK.

Purpose: Currently, two major principles exist to create LASIK flaps: firstly, a strictly horizontal (2D) cut similar to the microkeratome-cut and secondly an angled cut with a "step-like" edge (3D). The strictly horizontal (2D) cut method can be performed using apparatus such as the low-energy FEMTO LDV Z8 laser and its predecessors which are specific to this type. Alternatively, the low-energy FEMTO LDV Z8 laser's 3D flap design creates an interlocking flap-interface surface which potentially contributes toward flap stability. In addition, the FEMTO LDV Z8 offers flap-position adjustments after docking (before flap-creation). The current study analyzed precision, safety, efficacy, as well as patient self-reported pain and comfort levels after applying two different types of LASIK flap morphologies which were created with a low-energy, high-frequency femtosecond (fs) laser device. Methods: A prospective, interventional, randomized, contralateral eye, single-center comparison study was conducted from November 2019 to March 2020 at the Hamburg vision clinic/ zentrumsehstärke, Hamburg, Germany. Eleven patients and 22 eyes received low-energy fs LASIK treatment for myopia or myopic astigmatism in both eyes. Before the treatment, the eyes were randomized (one eye was treated with the 2D, the other eye with the 3D method). Results: The mean central flap thickness one month after surgery was 110.7 ± 1.6 µm (2D) and 111.2 ± 1.7 µm (3D); P = 0.365 (2D vs 3D). Flap thickness measured at 13 different points resulted in no statistically significant differences between any of the measurement points within/between both groups; demonstrating good planarity of the flap was achieved using both methods. Despite not being statistically significant, the surgeons recognized an increase in the presence of an opaque bubble layer in the 3D flap eyes during surgery and some patients reported higher, yet not statistically significant, pain scores in the 3D flap eyes during the first hours after the treatment. Overall, safety- and efficacy indices were 1.03 and 1.03, respectively. Conclusion: In this prospective, randomized, contralateral eye study, the low-energy fs laser yielded predictable lamellar flap thicknesses and geometry at one-month follow-up. Based on these results, efficacy and safety of the corresponding laser application, that is, 2D vs 3D, are equivalent.

Pupillotonia after endolaser retinopexy during vitrectomy for retinal detachment: a prospective cohort study comparing circumferential and focal retinopexy.

PURPOSE: To determine differences in postoperative pupil diameter in eyes that undergo pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment (RRD) with endolaser retinopexy (ELR), comparing 360° vs focal ELR. METHODS: Patients with uncomplicated RRD who underwent PPV were prospectively analysed regarding the postoperative pupil diameter difference (PDD) between the affected eye and the partner eye. Group 1 underwent 360° ELR and group 2 received focal ELR. Postoperative vision and complications, including redetachment rate, macular oedema and epiretinal membrane formation, were also compared. RESULTS: A total of 72 patients, 42 in group 1 and 30 in group 2, were analysed. PDD, as observed at 6 weeks, was significantly greater than the preoperative values in both groups 1 and 2. It increased by a mean of 1±1.11 mm in group 1 and by 0.5±0.78 in group 2. This initial increase in PDD receded over time, but remained statistically significant in both groups, even at 6 months. The top 20% of patients with the largest PDD change comprised 13 out of 15 eyes from group 1, which was a statistically significant overrepresentation (p=0.0435). CONCLUSIONS: Moderate pupillotonia was induced post-ELR in vitrectomy and correlated to the extent of ELR. The pupillotonia effect of ELR was significantly less marked in pseudophakic eyes.

Simultaneous screening and classification of diabetic retinopathy and age-related macular degeneration based on fundus photos-a prospective analysis of the RetCAD system.

AIM: To assess the accuracy of an artificial intelligence (AI) based software (RetCAD, Thirona, The Netherlands) to identify and grade age-related macular degeneration (AMD) and diabetic retinopathy (DR) simultaneously based on fundus photos. METHODS: This prospective study included 1245 eyes of 630 patients attending an ophthalmology day-care clinic. Fundus photos were acquired and parallel graded by the RetCAD AI software and by an expert reference examiner for image quality, and staging of AMD and DR. Adjudication was provided by a second expert examiner in case of disagreement between the AI software and the reference examiner. Statistical analysis was performed on eye-level and on patient-level, by summarizing the individual image level-gradings into and eye-level or patient-level score, respectively. The performance of the RetCAD system was measured using receiver operating characteristics (ROC) analysis and sensitivity and specificity for both AMD and DR were reported. RESULTS: The RetCAD achieved an area under the ROC (Az) of 0.926 with a sensitivity of 84.6% at a specificity of 84.0% for image quality. On image level, the RetCAD software achieved Az values of 0.964 and 0.961 with sensitivity/specificity pairs of 98.2%/79.1% and 83.9%/93.3% for AMD and DR, respectively. On patient level, the RetCAD software achieved Az values of 0.960 and 0.948 with sensitivity/specificity pairs of 97.3%/73.3% and 80.0%/90.1% for AMD and DR, respectively. After adjudication by the second expert examiner sensitivity/specificity increases on patient-level to 98.6%/78.3% and 100.0%/92.3% for AMD and DR, respectively. CONCLUSION: The RetCAD offers very good sensitivity and specificity compared to manual grading by experts and is in line with that obtained by similar automated grading systems. The RetCAD AI software enables simultaneous grading of both AMD and DR based on the same fundus photos. Its sensitivity may be adjusted according to the desired acceptable sensitivity and specificity. Its simplicity cloud base integration allows cost-effective screening where routine expert evaluation may be limited.

Effect of Postoperative Ocular Residual Astigmatism (ORA) on Treatment Outcome After Myopic Laser in situ Keratomileusis (LASIK).

Purpose: To analyze the impact of postoperative ocular residual astigmatism (ORA) on refraction, visual acuity and subjective satisfaction after myopic laser-in-situ-keratomileusis (LASIK) by a comprehensive analysis, which includes clinically relevant data and patient-reported outcomes. Material and Methods: To evaluate the influence of ORA, comparison groups were built following Archer et al. Myopic patients were subdivided by the fraction ORA/MRC (matched and not matched for MRC) (MRC = manifest refractive cylinder), ORA magnitude and CA magnitude in high ORA eyes (CA = corneal astigmatism). Refractive and visual data were analyzed via retrospective cross-sectional analysis for multiple parameters. The subjective satisfaction was analyzed retrospectively 3-4 years after having LASIK via patient reported outcome analysis. Results: Refractive outcome: Only when grouped by ORA magnitude only, high ORA eyes resulted in approximately twice as cylinder magnitude compared to eyes with preoperative lower ORA. Furthermore, there appeared to be no statistically significant differences in any case. Visual outcome: There appeared to be no statistically significant differences for visual acuity parameters (safety index, efficacy index). Patient reported outcome: When grouped by the rate of ORA/MRC not matching for MRC, there were statistically significant differences in the subjective satisfaction (p = 0.006) and the postoperative side effects (p = 0.001, p = 0.01, p = 0.006), those differences appeared less strong when matched for MRC treated and result better for a higher ratio of ORA/MRC. Conclusion: Patients with postoperatively high ORA report on higher satisfaction with treatment results than patients with postoperatively low ORA. This did not correlate with differences in the refractive nor visual outcome. As a matter of fact, there is a discrepancy between the objective analysis results and the subjective satisfaction of patients.

Predicting speed of progression of lens opacification after pars plana vitrectomy with silicone oil.

PURPOSE: An increasing number of posterior segment disorders is routinely managed with pars plana vitrectomy (PPV). In older, phakic patients cataract formation is expected within the first two years after surgery. For younger patients its progression is individually fluctuating. This study uses an objective quantitative measurement for lens-status-monitoring after PPV with silicone oil to derive predictions for progression and severity of post-operative lens opacification evaluated in patients with rhegmatogenous retinal detachment (RRD). METHODS: Data acquisition was performed prospectively between March 2018 and March 2021. PentacamHR® Nucleus Staging mode (PNS) was used to objectively gather data about nuclear cataracts after PPV at different time points. Data was grouped into training and test sets for a mathematical prediction model. Via backward variable selection method a mathematical formula was set up by means of which predictions about lens densitometry (LD) can be calculated. RESULTS: 20 males [58.8%] and 14 females [41.2%] matched the inclusion criteria (mean age 50.6 years [23-75; ±12.3]). Average follow-up was 8.1 months (3,4-17.4; ±3.4). Mean baseline LD of the treated and fellow eye before surgery was 11.1% (7.7%-17.6%; ±2.0) and 11.2% (7.7%-14.8%; ±1.5), respectively. Predicted LD values by the model for five pre-selected patients closely match the observed data with an average deviation of 1.06%. CONCLUSIONS: Using an objective parameter like LD delivered by the PentacamHR® PNS mode additionally to the patient's age allows us to make an individual prediction for any time after PPV with silicone oil due to RRD for all ages. The accuracy of the model was stronger influenced by baseline LD as cofactor in the equation than patient's age. The application for the prediction lens opacification [which can be accessed for free under the following link (https://statisticarium.com/apps/sample-apps/LensDensityOil/)] can help vitreoretinal surgeons for patient consultation on the possibility to combine PPV with cataract surgery.

Topographic, tomographic, and corneal wavefront asymmetry in keratoconus: towards an eye asymmetry index EASIX.

PURPOSE: The study aims to explore the intereye asymmetry in normal and keratoconic individuals and to evaluate the discriminant power of single and combined asymmetry parameters. METHODS: This is a retrospective designed study including 414 patients who had Pentacam Scheimpflug topographic and tomographic imaging in both eyes: 124 subjects with bilateral normal corneas evaluated for refractive surgery and 290 with keratoconus. All elevation-, pachymetric-, and volumetric-based data (56 parameters) were electronically retrieved and analyzed. Intereye asymmetry was determined by subtracting the lowest value from the highest value for each variable. The degree of asymmetry between each subject's eyes was calculated with intraclass correlation coefficients for all the parameters. Receiver operating characteristic curve was used to determine predictive accuracy and to identify optimal cutoffs of these values and combinations thereof. RESULTS: In the normal/keratoconus subjects the median intereye asymmetries were 0.30/3.45 for K2 (flat) meridian, 0.03/0.25 for BFS front, 1.00/15.00 for elevation back BFS apex, and 7.00/29.00 for pachy min. CONCLUSIONS: In addition to Rabinowitz's Kmax intereye asymmetry we propose pachymetric, elevation-based, and high-order corneal wavefront intereye asymmetry parameters to improve the diagnostic armamentarium of keratoconus.

A novel temporary keratoprosthesis technique for vitreoretinal surgery.

AIM: To investigate the safety of vitreoretinal surgery when using a soft contact lens as a temporary keratoprosthesis (TKP) in patients with severe corneal opacifications. METHODS: Three patients with simultaneous corneal and vitreoretinal pathology were treated with a soft contact lens that was used as a TKP to facilitate vitreoretinal surgery. The soft contact lens was fixated with sutures onto the globe so that no leakage was possible. RESULTS: Vitreoretinal surgery with excellent fundus view was possible in all cases. The soft contact lens allowed safe central and peripheral vitrectomy. Surgery was successful in all cases. CONCLUSION: A soft contact lens properly fixated on the globe can successfully replace a TKP. This surgical procedure has several advantages like one size fits all, low costs, and easy access to the material.

Reliability of the ocular trauma score for the predictability of traumatic and post-traumatic retinal detachment after open globe injury.

AIM: To elucidate the question of whether the ocular trauma score (OTS) and the zones of injury could be used as a predictive model of traumatic and post traumatic retinal detachment (RD) in patients with open globe injury (OGI). METHODS: A retrospective observational chart analysis of OGI patients was performed. The collected variables consisted of age, date, gender, time of injury, time until repair, mechanism of injury, zone of injury, injury associated vitreous hemorrhage, trauma associated RD, post traumatic RD, aphakia at injury, periocular trauma and OTS in cases of OGI. RESULTS: Totally 102 patients with traumatic OGI with a minimum of 12mo follow-up and a median age at of 48.6y (range: 3-104y) were identified. Final best corrected visual acuity (BCVA) was independent from the time of repair, yet a statistically significant difference was present between the final BCVA and the zone of injury. Severe trauma presenting with an OTS score I (P<0.0001) or II (P<0.0001) revealed a significantly worse BCVA at last follow up when compared to the cohort with an OTS score >III. OGI associated RD was observed in 36/102 patients (35.3%), whereas post traumatic RD (defined as RD following 14d after OGI) occurred in 37 patients (36.3%). OGI associated RD did not correlate with the OTS and the zone of injury (P=0.193), yet post traumatic RD correlated significantly with zone III injuries (P=0.013). CONCLUSION: The study shows a significant association between lower OTS score and zone III injury with lower final BCVA and a higher number of surgeries, but only zone III could be significantly associated with a higher rate of RD.

Prediction model of free flaps in microkeratome-assisted LASIK.

PURPOSE: To identify mechanical factors, as well as patients' biometric and surgeons' experience factors that correlate with the FF incidence in microkeratome (MK)-assisted LASIK and to construct a predictive model based on these parameters. METHODS: 55,700 consecutive LASIK treatments of 28,506 patients between January 2017 and April 2020 done by 50 surgeons in 10 centers, all with Sub Bowman Keratome (SBK) and 90µ head (OUP) were analyzed retrospectively for the incidence of FF and their correlation to mean keratometry, central corneal thickness, MK ring height and stop, as well as surgeons' experience. A prediction model was built and tested for sensitivity and specificity. RESULTS: The incidence of FF using the SBK MK was 0.276%. Risk factors were low central corneal thickness, very flat (-1) or very thick (+2) ring height, and higher stop values (p<0.001). Mean keratometry and low surgeon experience were not correlated to FF incidence. A prediction model with a cut-off FF risk of 0.274%, a 76% specificity, and a 73% sensitivity was applied. CONCLUSIONS: Free flaps are rarely seen in modern MK LASIK. However, the incidence of this complication using the SBK MK increases using higher stop values, very thick and very thin MK rings, and in eyes with thin corneas.

Quality of life in stable and progressive 'early-stage' keratoconus patients.

PURPOSE: To analyse the vision-related quality of life (vr-QoL) in stable and progressive keratoconus (KC) patients with a still good visual acuity. METHODS: Combined prospective/cross-sectional study design. The Refractive Status and Vision Profile (RSVP) and the National Eye Institute Visual Functioning - 25 (NEI-25) questionnaire were used in 16 emmetropic, 32 myopic and 56 KC patients, whereby KC patients with a stable (n = 26) and patients with a progressive stage (n = 30) and some of them before and after corneal cross-linking (CXL; n = 10) were included. All patients had a DCVA in at least one eye of ≥0.7 (decimal chart). RESULTS: The analyses revealed a minor decline of the vr-QoL from emmetropes to myopes to early KC patients with a stable disease. Nonetheless, sociological subscales (i.e. 'social functioning', 'role difficulties' and 'dependency') did not display statistically significant differences comparing these groups. In progressive KC, we could demonstrate a statistically significant decline also of these sociological subscales, which did not improve after CXL. CONCLUSION: Due to a still high and almost unaffected vr-QoL in early KC patients and the distinct decline after progression without rehabilitation after CXL, a reconsideration of current strategies to perform CXL only after a progression is diagnosed should be re-evaluated.

Surgical management of submacular hemorrhage due to n-AMD: a comparison of three surgical methods.

BACKGROUND: To compare and assess the efficacy of three surgical methods for the treatment of acute submacular hemorrhage (ASH): pneumatic displacement with C2F6, in combination with intravitreal injection of bevacizumab and rtPA, pars plana vitrectomy (PPV) with intravitreal injection of gas (C2F6), bevacizumab and subretinal injection of recombinant tissue plasminogen activator (rtPA), pars plana vitrectomy (PPV) with intravitreal injection of gas (C2F6), bevacizumab and intravitreal injection of recombinant tissue plasminogen activator (rtPA). METHODS: The study included 85 patients with ASH. In the group without PPV (A), patients were treated with intravitreal injection of C2F6, bevacizumab and rtPA. In the second and third group, patients underwent a PPV, intravitreal injection of bevacizumab, pneumatic displacement with C2F6 and a subretinal (B) or intravitreal (C) injection of recombinant tissue plasminogen activator (rt PA). RESULTS: In group A, mean BCVA increased from preop logMAR 1.41 to 1.05, in group B from 1.46 to 1.28 and in group C from 1.63 to 1.33. In group A, CFT changed from 764 ± 340 µm at time point 0 to 246 ± 153 µm at time point 1, in group B from 987 ± 441 µm to 294 ± 166 µm and in group C from 642 ± 322 µm to 418 ± 364 µm. Patients had an average of 5 injections after surgery. CONCLUSION: Our study demonstrates that the three methods are equally effective in improving the morphology and the BCVA of patients with ASH.

Diffractive trifocal lens implantation with or without excimer laser enhancement: is a touch-up procedure a negative predictor for refractive and subjective outcome?

PURPOSE: To investigate the refractive results of a LASIK enhancement and its impact on treatment safety, efficacy, predictability and patient reported outcome in eyes after clear lens extraction and diffractive trifocal lens implantation. METHODS: A retrospective cohort multicentre study of Care Vision Refractive Centres in Germany compared two groups of patients. Group 1 consisted of eyes that had non-toric MIOL surgery only, whereas group 2 had a consecutive laser enhancement after 3 months follow-up. Refractive and subjective results of the two groups were compared. Patient reported outcome measurements were assessed by using a 30-item questionnaire with four subscales. (Spectacle Dependence, Eye Comfort, Freedom and Looking/Feeling Well). Refractive results were reported following standard reporting in refractive surgery. RESULTS: 139 eyes of 79 patients were included in which either MIOL surgery or MIOL surgery plus LASIK enhancement had been performed between January and December 2017. UDVA reached 0.1logMAR (0.8; 20/25) in 94% in group 2 and 85% in group 1. Compared to preoperative CDVA no change in Snellen lines of CDVA was shown in 89% in group 1 and in 93% in group 2. Spectacle dependence (P = 0.41), eye comfort (P = 0.15), freedom (P = 0.48) and looking/feeling well (P = 0.45) showed no statistically significant difference between both the groups. CONCLUSIONS: In patients with residual ametropia after MIOL implantation, LASIK provides a reliable, safe and efficient way to achieve the desired refractive outcome and patient satisfaction. We recommend performing Laser enhancement at 3 months after MIOL implantation (Bioptics) in trifocal MIOL patients that benefit from improvement of residual ametropia.

Analysis of excimer laser treatment outcomes and corresponding angle κ in hyperopic astigmatism.

PURPOSE: To investigate the prevalence of preoperative, intraoperative, and postoperative angle κ in hyperopic eyes and its effect on the refractive outcomes of excimer laser vision correction. SETTING: University Hospital Hamburg and Care Vision Refractive Centers, Germany. DESIGN: Retrospective multicenter study. METHODS: Hyperopic patients after laser in situ keratomileusis and before retreatment because of hyperopic regression were included. Three treatment groups were defined based on the magnitude of preoperative angle κ defined as low (<0.25 mm), moderate (0.25 to 0.50 mm), or high (>0.50 mm). RESULTS: The study analyzed 170 hyperopic eyes of 112 patients (mean age 29.8 years ± 10.04 [SD], range 21 to 62 years). The preoperative angle κ was low, moderate, or high in 23, 49, and 98 cases, respectively. In eyes with a preoperative angle κ of 0.25 mm or more, changes in the x-axes and y-axes of angle κ and its magnitude were statistically significant (P < .05) between preoperative and intraoperative measurements. In these eyes, intraoperative angle κ (offset) was statistically significantly smaller (P < .05), and Purkinje images were statistically significantly more caudal (P < .001). Treatment predictability was independent from using preoperative or intraoperative angle κ, and there were no statistically significant differences in efficacy or safety. CONCLUSIONS: A preoperative magnitude of angle κ as high as 0.50 mm or higher was present in more than 50% of regressed hyperopic eyes. Measuring angle κ preoperatively did not reflect its real-time intraoperative magnitude. Using the preoperatively larger angle κ as an intraoperative offset might result in a too nasally centered ablation that causes topographic and optical drawbacks; therefore, centering the ablation based on the intraoperative measured offset is recommended.

Safety and complications after three different surface ablation techniques with mitomycin C: a retrospective analysis of 2757 eyes.

BACKGROUND: To evaluate the safety and spectrum of complications of three excimer laser surface ablation techniques (SATs) with an intraoperative application of mitomycin C (MMC) 0.02%. A retrospective, non-comparative large case series. METHODS: SATs were performed on 2757 eyes with a preoperative spherical equivalent (SE) of - 4.41 ± 2.44 and a Wavelight Allegretto 200 platform. Ablation zone diameters between 6.0 and 7.0 mm were used according to mesopic pupil size. All patients were treated with an intraoperative application of MMC for 30 to 90 s depending on refractive error. The mean follow-up time was > 3 months (107 ± 24 days). Complication range and incidence were analyzed retrospectively and safety index was calculated. RESULTS: Two thousand seven hundred and fifty-seven eyes met the inclusion criteria for surface ablation. Two thousand five hundred and seventy-three eyes were assigned to alcohol-assisted photorefractive keratectomy (APRK), 135 eyes to transepithelial photorefractive keratectomy (TPRK), and 49 eyes to off-flap epithelial laser in situ keratomileusis (EpiLASIK/EpiK). Overall, the safety index was 1.06 ± 0.28. Haze was graded according to the Fantes scale. Haze incidence rates were highest in the TPRK group (14.81%) and comparably low in APRK (2.95%) and EpiK (4.08%) groups. CONCLUSIONS: Intraoperative topical application of MMC (0.02%) results in good safety and no severe side effects. However, highest incidence of haze was observed after TPRK. The more frequent peripheral localization of haze might be attributed to large ablation zones and the wavefront optimized ablation profile especially in the PTK modus of the laser platform.

Tomographic and Biomechanical Scheimpflug Imaging for Keratoconus Characterization: A Validation of Current Indices.

PURPOSE: To analyze the potential benefit of the newly developed Tomography and Biomechanical Index (TBI) for early keratoconus screening. METHODS: In this retrospective study, the discriminatory power of the corneal tomography Belin/Ambrósio Enhanced Ectasia Display (BAD-D) index and the newly developed Corvis Biomechanical Index (CBI) and TBI to differentiate between normal eyes, manifest keratoconus eyes (KCE), very asymmetric keratoconus eyes with ectasia (VAE-E), and their fellow eyes with either regular topography (VAE-NT) or regular topography and tomography (VAE-NTT) were analyzed by applying the t test (for normal distribution), Wilcoxon matched-pairs test (if not normally distributed), and receiver operating characteristic curve (ROC). The DeLong test was used to compare the area under the ROC (AUROC). Further, the cut-offs of the analyzed indices presented in a study by Ambrósio et al. from 2017 were applied in the study population to enable a cross-validation in an independent study population. RESULTS: All indices demonstrated a high discriminative power when comparing normal and advanced keratoconus, which decreased when comparing normal and VAE-NT eyes and further when analyzing normal versus VAE-NTT eyes. The difference between the AUROCs reached a statistically significant level when comparing TBI versus BAD-D analyzing normal versus all included keratoconic eyes (P = .02). The TBI presented with the highest AUROCs throughout all conducted analyses when comparing different keratoconus stages, although not reaching a statistically significant level. Applying the cut-offs presented by Ambrósio et al. to differentiate between normal and VAE-NT in the study population, the accuracy was reproducible (accuracy in our study population with an optimized TBI cut-off: 0.72, with the cut-off defined by Ambrósio et al. 0.67). CONCLUSIONS: The TBI enables karatoconus screening in topographical and tomographical regular keratoconic eyes. To further improve the screening accuray, prospective studies should be conducted. [J Refract Surg. 2018;34(12):840-847.].

Ocular manifestation in Marfan syndrome: corneal biomechanical properties relate to increased systemic score points.

PURPOSE: To evaluate corneal deformation to an air puff as a new noninvasive tool to document disease status in Marfan syndrome (MFS) METHODS: Prospective observational cohort study. We included patients diagnosed with MFS who had their routine cardiovascular follow-up and applied the revised Ghent nosology to define two subgroups according to a high (≥ 7) and a low (< 7 points) systemic score. Dynamic Scheimpflug-based biomechanical analyses (CorvisST® [CST; Oculus GmbH]) were performed. The main outcome measure was the displacement of the corneal apex as given by the parameters highest concavity (HC; in ms), peak distance (PD; in mm), and highest concavity deformation amplitude (DA; mm). RESULTS: Forty-three eyes of 43 individuals (19 female, 24 male; mean age 42.0 ± 12.0 years, range 18-67 years) diagnosed with MFS were included. Applying the Ghent criteria, 21 patients had an advanced systemic score of ≥ 7, and 22 had score points < 7. There were no differences in age or sex between both groups. In contrast, HC was faster (P = 0.004), and PD (P < 0.001) was longer in those individuals with systemic score ≥ 7; maximum DA did not result in a statistically significant difference between the groups (P = 0.250). CONCLUSIONS: In vivo noninvasive biomechanical analyses with CST offer a new, non-invasive method to identify pathologic corneal deformation responses in adults with MFS. In the future, corneal deformation to an air puff could thus assist early identification of patients with high Ghent score as an adjunct to existing diagnostic tests.