Comparative clinical accuracy analysis of the newly developed ZZ IOL and four existing IOL formulas for post-corneal refractive surgery eyes.

BACKGROUND: Intraocular lens (IOL) calculation using traditional formulas for post-corneal refractive surgery eyes can yield inaccurate results. This study aimed to compare the clinical accuracy of the newly developed Zhang & Zheng (ZZ) formula with previously reported IOL formulas. STUDY DESIGN: Retrospective study. METHODS: Post-corneal refractive surgery eyes were assessed for IOL power using the ZZ, Haigis-L, Shammas, Barrett True-K (no history), and ray tracing (C.S.O Sirius) IOL formulas, and their accuracy was compared. No pre-refractive surgery information was used in the calculations. RESULTS: This study included 38 eyes in 26 patients. ZZ IOL yielded a lower arithmetic IOL prediction error (PE) compared with ray tracing (P = 0.04), whereas the other formulas had values like that of ZZ IOL (P > 0.05). The arithmetic IOL PE for the ZZ IOL formula was not significantly different from zero (P = 0.96). ZZ IOL yielded a lower absolute IOL PE compared with Shammas (P < 0.01), Haigis-L (P = 0.02), Barrett true K (P = 0.03), and ray tracing (P < 0.01). The variance of the mean arithmetic IOL PE for ZZ IOL was significantly smaller than those of Shammas (P < 0.01), Haigis-L (P = 0.03), Barrett True K (P = 0.02), and ray tracing (P < 0.01). The percentages of eyes within ± 0.5 D of the target refraction with the ZZ IOL, Shammas, Haigis-L, Barrett True-K, and ray-tracing formulas were 86.8 %, 45.5 %, 66.7 %, 73.7 %, and 50.0 %, respectively (P < 0.05 for Shammas and ray tracing vs. ZZ IOL). CONCLUSIONS: The ZZ IOL formula might offer superior outcomes for IOL power calculation for post-corneal refractive surgery eyes without prior refractive data.

Wavefront-guided photorefractive keratectomy with and without iris registration: comparison of astigmatic correction.

This study aimed to compare the visual outcomes after photorefractive keratectomy (PRK), with and without the iris registration (IR) technology. The retrospective cohort study was performed for wavefront-guided PRK using the Technolas 217z100 excimer laser system in patients with myopic astigmatism (cylinder error - 2 to - 4 diopter [D]). Eyes were divided into IR group (IRPRK) and non-IR group (non-IRPRK). Visual acuity (VA), cylindrical refraction, and the astigmatic vector components using the Alpins method were compared between the two groups preoperatively and 6 months postoperatively. Fifty IRPRK patients (66% female, mean age 30.56 ± 6.31 years) and 50 non-IRPRK (60% female, mean age 29.60 ± 5.63 years) were enrolled. The mean logMAR uncorrected VA improved from 0.89 ± 0.44 to 0.032 ± 0.05 in the IRPRK group (P < 0.001) and from 0.89 ± 0.46 to 0.042 ± 0.06 postoperatively while follow-up in the non-IRPRK group (P < 0.001). No statistically significant differences were observed between the two groups regarding mean uncorrected distance VA (P = 0.4), corrected distance VA (P = 0.5), spherical equivalent (P = 0.16), defocus equivalent (P = 0.18), and absolute cylinder (P = 0.94). More than 90% eyes were within ± 1.00 D of emmetropia in both groups. Moreover, Alpins vector analysis revealed that no significant differences were found in any astigmatic parameters between the two groups (P > 0.05). Wavefront-guided PRK independent of the IR status is effective, safe, and predictable in patients with myopic astigmatism. No statistical significance was observed supporting data for the better outcome of visual acuity and astigmatism correction using IR in comparison with a non-IR system.

[The rapid development and changes of corneal refractive surgery in China].

Corneal refractive surgery in China, represented by laser corneal surgery, has undergone great changes in recent 30 years. Almost one million corneal refractive surgeries are performed each year. With the rapid technological innovation, the corrective effect is constantly higher, and complications are continuously controlled and reduced. The team of practitioners keeps expanding, and the academic strength is approaching the international level. With the application and promotion of various new technologies, the formulation of relevant norms and the increase of academic researches, corneal refractive surgery in China has stepped into the stage of diversification, intelligence and standardization. However, we should recognize the shortcomings while facing the great achievements. More efforts are still needed to provide the best visual quality and natural vision correction effect for patients. We would like to send congratulations on the 70th anniversary of Chinese Journal of Ophthalmology with this article. (Chin J Ophthalmol, 2020, 56: 81-85).

[Influence factors and differences of posterior corneal elevation measured by Pentacam system combined with Corvis ST].

Objective: To investigate the influence factors and differences of abnormal posterior corneal elevation by Pentacam system and Corvis ST. Methods: This retrospective case series study included 227 eyes of 144 patients (90 males, 139 eyes; 54 females, 88 eyes) from December 2017 to October 2018 who were going to receive corneal refractive surgery at the Corneal Refraction Department of Qingdao Eye Hospital. The general data of the patients including gender, age, refractive parameters, optimal correction of spherical and cylindrical diopters were collected. All patients underwent Pentacam system and Corvis ST measurement. According to the back difference (BD) of Pentacam parameters, BD<12 µm was set as the control group (59 patients, 118 eyes) and BD≥12 µm as the high BD group (85 patients, 109 eyes). In the high BD group, BD≤16 µm was set as the suspicious group (44 patients, 53 eyes), while BD>16 µm was set as the abnormal group (41 patients, 56 eyes). Seven parameters of Pentacam and 15 parameters of Corvis ST were selected. The Pentacam parameters included BD, anterior surface keratometry (ASK), posterior surface keratometry (PSK), anterior surface astigmatism (AAstig), posterior surface astigmatism (PAstig), central corneal thickness (CCT), and corneal diameter (W-W). The parameters of Corvis ST included the first applanation time (AT(1)), the first applanation length (AL(1)), the first applanation velocity (AV(1)), the second applanation time (AT(2)), the second applanation length (AL(2)), the second applanation velocity (AV(2)), highest concavity time (HCT), highest concavity peak distance (HC-PD), highest concavity deformation amplitude (HC-DA), highest concavity radius (HC-R), the ratio of deformation amplitude (DA ratio), Integr. Radius, corneal thickness thinnest/pachymetric progression (ARTh), SPA1 (resultant pressure divided by deflection amplitude at the first applanation), and the Corvis Biomechanical Index (CBI). The comparison between the groups was analyzed with Independent sample t test, Kruskal-Wallis H test, and Bonferroni test. Spearman rank correlation analysis was used to explore the correlation factors of BD, and the main factors affecting BD were found through multiple linear regression. Results: There were no statistically significant differences between the control group and the high BD group in age, spherical diopters, and cylindrical diopters (t=-3.311, -1.808, -2.359; P=0.071, 0.072, 0.121, respectively). In Pentacam parameters, ASK, PSK, PAstig, and W-W showed significant differences among groups (Z=18.492, 31.547, 10.773, 70.167; P<0.05). AAstig and CCT showed no statistical difference between groups (P>0.05). Compared with the control group [42.80 (41.98, 44.00)], ASK increased in the abnormal group [43.40 (42.20, 44.40)] significantly (t=-4.292; P<0.05). PSK of the suspicious group [-6.50 (-6.60, -6.35)] and the abnormal group [-6.50 (-6.70, -6.33)] increased significantly compared with the control group [-6.30 (-6.50, -6.20)] (t=4.492, 4.618; P<0.05). Compared with the control group [0.40 (0.30, 0.50)], PAstig of the suspicious group [0.40 (0.30, 0.40)] and the abnormal group [0.40 (0.30, 0.40)] increased significantly (t=2.796, 2.515; P=0.016, 0.036). Compared with the control group [11.50 (11.40, 11.80)], W-W of the suspicious group [11.40 (11.00, 11.60)] and the abnormal group [11.10 (10.90, 11.30)] decreased, and W-W of the abnormal group also decreased significantly compared with the suspicious group (t=3.235, 8.353, 4.282; P<0.05). The correlation analysis between BD and Pentacam parameters of patients in each group showed that BD was negatively correlated with W-W (r=-0.614, -0.304, -0.396, -0.661, P<0.05) in the control group, the suspicious group, the abnormal group, and all patients, while BD had a low correlation with other parameters or no significant correlation. The correlation analysis of BD and Corvis ST parameters in patients showed that only in the suspicious group, BD was positively correlated with AV(1), HCT, and HC-DA (r=0.332, 0.361, 0.382, P<0.05), while no significant correlation was found between BD and other Corvis ST parameters in each group. In order to further explore the main factors affecting BD, Pentacam parameters and Corvis ST parameters were selected as independent variables with BD as the dependent variable to establish a multivariate linear regression analysis model. There was no collinearity between variables W-W, ASK, PSK, HC-PD, SPA1, and CCT (tolerance<0.100). The equation test result was F=37.221, P<0.001, adjusted r(2)=0.504, and the fitting was good. Conclusions: Among the Pentacam parameters, W-W, ASK, and PSK are the main factors affecting the change of BD. HC-PD and SPA1 in the Corvis ST parameters may also have some influence on BD. The Pentacam system combined with Corvis ST is a very useful differential diagnosis system for patients with abnormal BD. (Chin J Ophthalmol, 2020, 56:110-117).

Mitomycin C 0.02 and 0.002% efficacy in preventing haze after photorefractive keratectomy.

PURPOSE: To compare MMC 0.002% efficacy in preventing haze after PRK in relation to MMC 0.02%. PATIENTS AND METHODS: We conducted a prospective study with patients with myopia or myopic astigmatism undergoing PRK in the same conditions. After PRK, MMC was applied for 30 s in a concentration of 0.02% on the right eye (group 1) and 0.002% on the left eye (group 2). Age, gender, spherical equivalent and haze intensity (1, 3, 6 and 12 months postoperatively) were assessed. Haze was quantified at biomicroscopy (0-4 +). P < 0.05 was considered statistical significant. RESULTS: We evaluated 130 patients, 77 women and 53 men, with a mean age of 30.2 ± 9 years. The spherical equivalent was - 3.66 D in the group 1 and - 3.77 D in the group 2. In the 1st month after PRK, incidence of haze was 13.9% eyes in group 1 and 14.6% in group 2. In the 3rd month, incidence of haze was 50.0% eyes in group 1 and 48.5% in group 2 which presented with 3 +/4 + traces of haze. In the 12th month, incidence of haze was 7.7% eyes in group 1 and 5.4% in group 2. There was no correlation between haze and age (p = 0.279/0.333), gender (p = 0.345/0.367) or spherical equivalent (p = 0.100/0.054) in groups 1 and 2, respectively. There was no difference in haze between groups 1 and 2 (p = 0.56). CONCLUSION: MMC 0.002% was effective in preventing haze after PRK. As MMC long-term safety has not been proved, we suggest its use in a lower concentration, in order to prevent potential complications.

[Incipient observation of cornea astigmatism after combined cataract phacoemulsification and Callisto Eye-assisted arcuate keratotomy].

Objective: To research the change of cornea astigmatism after combined cataract phacoemulsification and Callisto Eye-assisted arcuate keratotomy and to assess the effectiveness and safety of this surgery for improving patients' uncorrected visual acuity. Methods: Prospective interventional non-randomized controlled study. Consecutive cataract patients with cornea astigmatism greater than 0.75 D were recruited at the southern part of Beijing Tongren Hospital, Capital Medical University and Beijing Tongren Eye Center, between October 2017 and March 2018, and were divided into the experimental group and the controlled group. In the experimental group the patients are further divided into three subgroups of A(0.75-1.24 D), B(1.25-1.74 D) and C(≥1.75 D) according to the degrees of their cornea astigmatism before surgery. The combined cataract phacoemulsification and Callisto Eye-assisted arcuate keratotomy were performed for the experimental group with the depth and length of the corneal arcuate incision differing in subgroups, while only cataract phacoemulsification was performed for the control group. The complications on and after the surgery were observed and the change of cornea astigmatism and uncorrected visual acuity in three months after surgery were recorded. Independent sample t test was used for statistical analysis. Results: A total of 108 patients (108 eyes) were enrolled, including 46 males and 62 females, the age was (68±11) years old.The experimental group included 76 eyes of 76 patients (subgroup A 38 eyes, subgroup B 18 eyes, subgroup C 20 eyes). The controlled group included 32 eyes of 32 patients. The preoperative cornea astigmatism and postoperative cornea astigmatism of the experimental group are (1.54±0.90) D and 0.62 (0.36-0.95) D. The change of cornea astigmatism of the experimental group is (1.15±0.58) D. The index of correction and flattening are 0.97±0.20 and 0.61±0.31 respectively, the error of axial deviation is 9.55°±5.22°. The index of success is 0.51±0.36. In the experimental group, subgroup C has the highest correction efficiency of corneal astigmatism (axial deviation error 8.07°±3.13°, flattening index 0.72±0.31) which is followed by subgroup B, and subgroup A ranked the last one (axial deviation error 10.27°±6.47°, flattening index 0.42±0.30).The uncorrected distance visual acuity (logarithm of the minimum angle of resolution) of the experimental group and the control group are significantly different (0.15±0.12 vs. 0.24±0.17, t=-4.129, P<0.01). None of the patients recruited have complications including poor wound healing and cornea penetration and cornea edema and cystoid macular edema on or after the surgery. Conclusions: Combined cataract phacoemulsification and Callisto Eye-assisted arcuate keratotomy are of favorable effect on improving the uncorrected visual acuity and have relatively good accuracy and predictability on the correction of cornea astigmatism. It is a safe surgery with considerable efficency. (Chin J Ophthalmol, 2019, 55: 502-508).

[Effect of different medication time prior to corneal refractive surgery on tear film stability].

Objective: To investigate the effect of different medication time prior to corneal refractive surgery on tear film stability. Methods: Prospective cohort study. A total of 60 patients (60 eyes), including 38 males (63.3%) and 22 females (37.7%) with an average age of (24.2±5.1) years (form 18 to 37 years), who had planned for corneal refractive surgery with normal ocular surface disease index score were included in this study. The patients were divided into 1d group (medication of 1 day, 30 eyes) and 3d group (medication of 3 days, 30 eyes) randomly. The first tear break up time (FBUT), the average tear break up time (AVBUT) and the dry eye grade score were recorded on the examination day and the operation day with Keratograph 5M. The difference of FBUT and AVBUI between the two groups was compared with the independent sample t test. The difference of FBUT and AVBUT between the examination day and the operation day was compared with the paired t test. The difference of the dry eye classification between the two groups was compared using chi-square test. Results: The FBUT and AVBUT of 1d group and 3d group were (10.89±5.19)s and (10.88±6.82)s, (16.24±3.62)s and (16.21±4.74)s respectively in preoperative examination, and (10.65±6.03)s and (8.14±5.75)s, (15.14±5.30)s and (12.86±5.92)s respectively in operation day. There was no significant difference in FBUT and AVBUT between the two groups (t=0.01, 1,47, 0.02, 1.44; P>0.05). However, in the 3d group, the AVBUT of operation day decreased as compared with that of the examination day, and the difference was statistically significant (t=2.31, P<0.05). There was no significant difference in the distribution of dry eye classification between the two groups (χ(2)=0.07, 3.36; P>0.05). Conclusion: Both of medication of 1 day and medication of 3 days prior to corneal refractive surgery can provide a similar tear film stability, however more attention should be paid to the medication for patients with asymptomatic but abnormal BUT. (Chin J Ophthalmol, 2018, 54: 744-747).

Corneal topographic alterations after selective laser trabeculoplasty.

PURPOSE: To investigate the presence of corneal alterations in the long term among patients with primary open-angle glaucoma (POAG) after a single session of selective laser trabeculoplasty (SLT) treatment. MATERIALS AND METHODS: The files of the POAG patients who had been treated with SLT were evaluated retrospectively. The Pretreatment Scheimpflug corneal topographic (SCT) findings were then compared with the post-treatment findings. RESULTS: The files of 33 patients were eligible. The changes in central corneal thickness, thinnest point of cornea, and posterior corneal asphericity at 5 and 8 mm were statistically significant (p = 0.03, 0.01, 0.02, and 0.04 respectively). On the other hand, the simulated K, anterior 3 mm K, anterior 5 mm K, posterior 3 mm K, posterior 5 mm K, anterior asphericity at 3 mm, posterior asphericity at 3 mm, and Zernike values did not change significantly following the treatment (p = 0.19, 0.08, 0.1, 0.3, 0.2, 0.75, 0.09, and 0.3 respectively). CONCLUSION: SLT can slightly alter pretreatment SCT findings in 3-6 months. Clinicians should wait for at least 6 months after SLT before performing any subsequent surgeries that depend on corneal parameters.

[The clinical analysis of corneal interface fluid syndrome after Laser lamellar corneal refractive surgery].

Objective: To analysis, the clinical characteristics, refractive changes, and clinical treatment of interface fluid syndrome after laser lamellar corneal refractive surgery. Methods: During Dec. 2010 to Apr. 2016. In total 6 cases(9 eyes), 3 cases were bilateral, 3 cases were unilateral. Five patients were male and 1 was female. The age of the patients ranged from 20 to 29 years was (24.83±4.02) years. Six cases(9 eyes)of IFS were diagnosed at our hospital. The history and complete ophthalmic examination that include Slit-lamp examination, Slit-lamp photography, refraction, corneal thickness measurement, corneal endothelial cell counting, IOP, anterior segment OCT(AS-OCT), exams were recorded. Results: Post-lasik Primary open angle glaucoma was 2 eyes in 1 patient. 1 patient(1 eye)was Posner-Schlossmann Syndrome and 1 patient(1 eye)was iritis after femtosecond laser. Post-small incision lenticule extraction by steroid drops induced elevated IOP were 5 eyes in 3 patients. Slit-lamp exam indicated edematous corneal flap or cap, lamellar haze, interface fluids accumulation. AS-OCT showed obvious interface dark area. The corneal flap or cap thickening and wrinkles, IOP change, diopter myopic shift, Corneal thickening. Conclusions: IFS is a rare but serious complication after Laser lamellar corneal refractive surgery. The main causes are high intraocular pressure and/or dysfunction of corneal endothelium. For patients with high IOP after laser lamellar corneal refractive surgery, follow up should be observed closely. accurate diagnosis by OCT and corneal endothelial cell counting. Early diagnosis, accurate treatment, its prognosis is good. (Chin J Ophthalmol, 2017, 53: 847-854).

Risk Factors for Postoperative Refractive Error in New-Generation Intraocular Lens Calculation Formulas.

Purpose: We examined differences in the accuracy of three intraocular lens (IOL) calculation formulas: the traditional Sanders-Retzlaff-Kraff/Theoretical (SRK/T) formula; the Barrett Universal II (BU II) formula, which is a new-generation IOL calculation formula; and the postoperative spherical equivalent prediction using artificial intelligence and linear algorithms developed by Debellemanière, Gatinel, and Saad formula (PEARL-DGS [PEARL]) formula, and evaluated factors that cause postoperative refractive error (PE). Patients and Methods: The study included 205 patients (205 eyes) with a mean age of 75.2 ± 8.7 years who underwent cataract surgery at our institution from December 2018 to October 2023. The PE of the three IOL calculation formulas was calculated and compared. Multivariate logistic regression analysis was performed with a PE higher than ±0.50 D as the dependent variable, and age, sex, axial length (AL), mean keratometry (mean K), anterior chamber depth (ACD), lens thickness (LT), and white-to-white (WTW) as independent variables. Results: The mean PE (ME) ± standard deviation of the SRK/T, BU II, and PEARL formulas was 0.11 ± 0.52, 0.11 ± 0.50, and 0.21 ± 0.50 D, respectively. MEs of the three IOL calculation formulas were significantly different from 0 (p < 0.01). The median absolute error (MedAE) was not significantly different among the three IOL calculation formulas (p = 0.83). The percentage of PE within ±0.50 D was not significantly different among the three IOL calculation formulas (p = 0.13). Multivariate logistic regression analysis showed that the significantly associated factors with PE higher than ±0.50 D were AL, ACD, and LT for the SRK/T formula, sex and LT for the BU II formula, and LT for the PEARL formula (all p < 0.05). Conclusion: In the BU II and PEARL formulas, AL was excluded as a factor affecting PE, indicating that LT was a risk factor.

Refractive surgery to correct visual impairments in 267 children with autism spectrum and related neuro-developmental disorders: improvements in vision and behavior.

Background: Children with autism spectrum disorder (ASD) may have impaired vision owing to high refractive errors and aversion to spectacles or contact lenses. Visual blurring is caused by near-sighted myopia, far-sighted hyperopia, or astigmatism in one or both eyes. Refractive surgery can restore sharp vision and eliminate the need for spectacles and contact lenses. Restoration of sharp vision may improve ASD behavior. We aimed to determine the refractive outcomes in this cohort using ophthalmic measures and behavioral and school performance alterations after refractive surgery by employing parent-proxy reports. Methods: This interventional, retrospective case series included data from 267 children with refractive errors and neurodevelopmental disorders (NDDs) diagnosed as ASD alone or NDD with ASD-like behaviors over a 15-year period. One of three refractive surgery methods was employed, with the choice of method uniquely tailored to the child's eye anatomy. Laser photorefractive keratectomy (PRK) was performed in 131 children, implantation of a phakic intraocular lens (pIOL) in 115 children, and removal of the crystalline lens and implantation of an intraocular lens (refractive lens exchange, RLE) in 21 children. All procedures were performed under brief general anesthesia, with the child returning home on the same day. Results: The median age at surgery was 10.9 years and the median follow-up period was 3.1 years. Pre-operative refractive errors ranged from a mean (standard deviation) +7.5 (0.09) D to -14.3 (4.8) D. Surgery corrected 87% of the children to normal focal length (± 1 D). Visual acuity improved an average of 0.6 logarithm of the minimum angle of resolution, the equivalent of 6 lines on a standard eye chart. Change in visual acuity was significant (all P < 0.01) between baseline and the most recent follow-up examination in each of subgroups. Change in spherical equivalent refractive error at 3, 12, 24, 36, 60, and > 60 months post-operatively were significant (all P < 0.01) between baseline and each follow-up visit in each of subgroups. Social interactions and ASD behaviors improved in 72% (192) of the treated children (P < 0.01). The incidence of sight-threatening complications was low. Conclusions: Refractive surgery improves both visual function and behavior in most children with ASD and major myopia, hyperopia, or astigmatism. The PRK, pIOL, and RLE procedures appear to be effective and reasonably safe methods for improving refractive error, visual acuity, and behavior in many ametropic children with ASD and ASD-like NDDs.

The Effect of Amniotic Membrane Extracted Eye Drop on Repairing The Corneal Epithelial in Patients after Trans-Epithelial Photorefractive Keratectomy: An Interventional and Historical Study.

OBJECTIVE: Recent studies imply extensive applications for the human amniotic membrane (hAM) and its extract in medicine and ophthalmology. The content of hAM meets many requirements in eye surgeries, such as refractive surgery as the most important and commonly used method for treating the dramatically increasing refractive errors. However, they are associated with complications such as corneal haziness and corneal ulcer. This study was designed to evaluate the impact of amniotic membrane extracted eye drop (AMEED) on Trans-PRK surgery complications. MATERIALS AND METHODS: This randomized controlled trial was performed during two years (July 1, 2019-September 1, 2020). Thirty-two patients (64 eyes), including 17 females and 15 males, aged 20 to 50 years (mean age of 29.59 ± 6.51) with spherical equivalent between -5 to -1.5 underwent Trans Epithelial Photorefractive Keratectomy (Trans-PRK) surgery. One eye was selected per case (case group) and the other eye was considered as control. Randomization was done using the random allocation rule. The case group was treated with AMEED, and the artificial tear drop every 4 hours. The control eyes received artificial tear drops instilled every 4 hours. The evaluation continued for three days after the Trans-PRK surgery. RESULTS: A significant decrease in CED size was found in the AMEED group on the second day after surgery (P=0.046). Also, this group had a substantial reduction in pain, hyperemia, and haziness. CONCLUSION: This study showed that AMEED drop can increase the healing rate of corneal epithelial lesions after Trans- PRK surgery and reduce the early and late complications of Trans-PRK surgery. Researchers and Ophthalmologists should consider AMEED as a selection in patients with persistent corneal epithelial defects and patients who have difficulty in corneal epithelial healing. We understood AMEED has a different effect on the cornea after surgery; therefore, the researcher must know AMEED's exact ingredients and help expand AMEED uses (registration number: TCTR20230306001).

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.

The Pentacam® AXL Wave provides a reliable wavefront-based objective refraction when compared to manifest subjective refraction: A prospective study.

Purpose: Accurate refraction is arguably the most important parameter for a successful laser vision correction surgery and is based on a combination of manifest and cycloplegic refraction. Wavefront-based objective refraction may be useful in the evaluation of patients. So far, the reliability of objective refraction as measured using the Pentacam® AXL Wave has not been published in the literature. Methods: This was a prospective study including a total of 168 eyes belonging to 84 young non-presbyopic patients evaluated for refractive surgery. Pentacam® AXL Wave full sequence was taken for all patients. Then, a clinician who was unaware of the objective refraction results performed a full physical examination, including manifest refraction starting from an autorefractometer value. All refraction values were transferred to astigmatic power vectors as per the Thibos method. Reliability of the different vectors and a unifying blur value were compared using Spearman correlation, Bland-Altman plot, and intraclass correlation coefficient. Results: The mean age was 28.8 ± 5.4 years, with a female preponderance (60.7%). The correlation between both eyes was high. The difference in M vector between subjective and objective refraction was 0.16 D, while the difference was 0.04 and 0.01 D for the J0 and J45 vectors, respectively. Paired samples Student t was non-significant for all comparisons. Spearman rho correlations were high (0.666-0.924, all P < 0.001). Intraclass correlation coefficients were also high (0.890-0.966). Bland-Altman plots did not demonstrate any systematic errors. Conclusion: Wavefront-based refractive refraction obtained using the Pentacam® AXL Wave is highly agreeable and correlated with measurements obtained by manifest subjective refraction.

Advances in refractive corneal lenticule extraction.

Refractive errors are the leading cause of reversible visual impairment worldwide. In addition to the desired spectacle independence, refractive procedures can improve quality of life, working ability, and daily working performance. Refractive corneal lenticule extraction (RCLE) is a relatively new technique, dependent only on a femtosecond laser (FS). This leads to potential benefits over laser-assisted in situ keratomileusis (LASIK) including a quicker recovery of dry eye disease, a larger functional optical zone, and no flap-related complications. SMILE, available with the VisuMax FS (Carl Zeiss Meditec AG, Jena, Germany), is the most established RCLE application, offering visual and refractive outcomes comparable to LASIK. SmartSight (SCHWIND eye-tech-solutions GmbH, Kleinostheim, Germany) and CLEAR (Ziemer Ophthalmic Systems AG, Port, Switzerland) are two new RCLE applications that received Conformité Européenne (CE) approval in 2020. In this article, we review refractive and visual outcomes, advantages, and disadvantages of RCLE and also report on the latest advances in RCLE systems.

Clinical Outcomes of Small Incision Lenticule Extraction in Myopia: Study of Vector Parameters and Corneal Aberrations.

PURPOSE: To investigate clinical outcomes of small incision lenticule extraction (SMILE) including vector parameters and corneal aberrations in myopic patients. METHODS: This retrospective, observational case series included 57 eyes (29 patients) that received treatment for myopia using SMILE. Visual acuity measurement, manifest refraction, slit-lamp examination, autokeratometry, corneal topography, and evaluation of corneal wavefront aberration were performed preoperatively and at 1 and 3 months after surgery. We analyzed the safety, efficacy, vector parameters, and corneal aberrations at 3 months after surgery. RESULTS: Preoperatively, mean manifest refraction spherical equivalent refraction was -4.94 ± 1.94 D (range, -8.25 to 0 diopters [D]), and the cylinder was -1.14 ± 0.82 D (range, -3 to 0 D). Mean manifest refraction spherical equivalent improved to -0.10 ± 0.23 D at 3 months postoperatively, when uncorrected distance visual acuity was 20 / 20 or better in 55 (96%) eyes. The linear regression model of target induced astigmatism vector versus surgically induced astigmatism vector exhibited slopes and coefficients (R²) of 0.9618 and 0.9748, respectively (y = 0.9618x + 0.0006, R² = 0.9748). While total corneal root mean square higher order aberrations, coma and trefoil showed statistically significant increase, spherical aberration did not show statistically significant change after SMILE. CONCLUSIONS: SMILE has proven to be effective and safe for correcting myopia and astigmatism. We showed that SMILE did not induce spherical aberrations. A small increase in postoperative corneal higher order aberration may be associated with increase in coma and trefoil.

Fellow eye comparison between alcohol-assisted and single-step transepithelial photorefractive keratectomy: late mid-term outcomes.

Objective: To compare late mid-term results of two different surgical approaches of surface excimer laser ablation for myopic and astigmatic errors in contralateral eyes of the same patients. Methods: Prospective cohort study. A photorefractive keratectomy technique was performed on the right eye and single-step transepithelial photorefractive keratectomy on the left eye of the same patient, in 2012. Postoperative uncorrected and corrected visual acuities, manifest refraction, contrast sensitivity, objective scatter index, tear film stability assessed by serial measurements of objective scatter index and aberrometry as well as occurrence of haze, were compared between groups of eyes. Results: Thirty-two eyes of 16 patients with a mean time of follow-up of 35.2 +/ - 5.0 months (range 30-46 months) were evaluated. No significant differences were observed in postoperative results (visual acuity, spherical equivalent, defocus equivalent, higher-order aberrations, objective scatter index, tear film stability and contrast sensitivity). Contrast sensitivity tended to be better in transepithelial photorefractive keratectomy technique, under photopic lighting conditions without glare and mesopic conditions both with glare and without glare, however, no statistically significant differences were found. No eye presented corneal haze at the last examination. Conclusion: No statistically significant differences in visual acuity, refractive results, contrast sensitivity, objective scatter index, tear film stability or ocular aberrometry were observed between the two surface ablation techniques.

[Corneal topography in practice]. / Topographie cornéenne en pratique.

Corneal surface analysis is now more and more accurate. Corneal topography is a gold standard in corneal pathology follow-up: keratoconus, corneal grafts, orthokeratology. In refractive surgery, cornea ectasia post-Lasik must be avoided. Analyzing anterior and posterior surface can detect forme fruste keratoconus FFKC. Topography allows also better predictability of premium intraocular implants surgery. Topography is key examination and its interpretation is essential.

Effects of Cyclotorsion Orientation and Magnitude in Eyes with Compound Myopic Astigmatism on the Compensation Capacity of WaveLight EX500 Photorefractive Keratectomy.

PURPOSE: To investigate the clinical effects of different orientation and magnitude of cyclotorsion on the compensation capacity of the WaveLight EX500 photorefractive keratectomy (PRK) platform. METHODS: This retrospective study comprised 400 eyes of 200 patients who underwent bilateral simultaneous PRK due to compound myopic astigmatism. The subjects were separated according to the orientation of cyclotorsion into incyclotorsion and excyclotorsion groups, and by the magnitude of cyclotorsion into group 1 (0.50 to 2.50 degrees), group 2 (3.00 to 5.00 degrees), group 3 (5.50 to 7.50 degrees), and group 4 (8.00 to 9.50 degrees). RESULTS: The mean magnitude of cyclotorsion was 3.50 ± 2.4 degrees (0.50 to 9.50 degrees) in the incyclotorsion group and 3.32 ± 2.3 degrees (0.50 to 9.50 degrees) in the excyclotorsion group (p = 0.617). The postoperative refractive outcomes of the incyclotorsion and excyclotorsion groups were similar (p > 0.05 for all). The postoperative mean cylindrical refractive error was -0.32 ± 0.3 diopters (D, -1.25 to 0.00 D) in group 1, -0.47 ± 0.2 D (-2.00 to 0.00 D) in group 2, -0.62 ± 0.2 D (-1.00 to -0.25 D) in group 3, and -0.91 ± 0.2 D (-1.50 to -0.50 D) in group 4 (p < 0.001). Preoperative cylindrical refractive error was positively correlated with magnitude of cyclotorsion (r = 0.125 and p = 0.013), which was also positively correlated with postoperative cylindrical refractive error (r = 0.600 and p < 0.001). CONCLUSIONS: Incyclotorsion and excyclotorsion can be equally compensable in the WaveLight EX500 PRK platform for compound myopic astigmatism. A value of ≤2.50 degrees cyclotorsion magnitude was observed to be more compensable than higher degrees of cyclotorsion magnitude. Preoperative high astigmatism was associated with high cyclotorsion magnitude, which was also associated with a high degree of postoperative astigmatism.

Binocular vision alterations after refractive and cataract surgery: a review.

To review binocular and accommodative disorders documented after corneal or intraocular refractive surgery, in normal healthy prepresbyopic patients. A bibliographic revision was performed; it included works published before 1st July 2017 where accommodation and/or binocularity was assessed following any type of refractive surgical procedure. The search in Pubmed yielded 1273 papers, 95 of which fulfilled the inclusion criteria. Few publications reporting binocular vision and/or accommodative changes after refractive surgery in normal subjects were found. The reduction in fusional vergence is the most frequently reported alteration. Anisometropia is an important risk factor for postoperative binocular vision-related complaints. Most diplopia-related visual complaints, irrespective of the surgical procedure, were in fact misdiagnosed preoperative disorders. The preoperative evaluation of patients seeking spectacle/contact lens independence should include a complete binocular and accommodation assessment where parameters such as the phoric posture, accommodative amplitude and facility, near point of convergence, fusional reserves and accommodative convergence/accommodation coefficient are measured. This would allow the identification of risk factors that could compromise the success of the refractive surgery and cause clinical symptoms.