Artificial intelligence applications in cataract and refractive surgeries.

PURPOSE OF REVIEW: This review highlights the recent advancements in the applications of artificial intelligence within the field of cataract and refractive surgeries. Given the rapid evolution of artificial intelligence technologies, it is essential to provide an updated overview of the significant strides and emerging trends in this field. RECENT FINDINGS: Key themes include artificial intelligence-assisted diagnostics and intraoperative support, image analysis for anterior segment surgeries, development of artificial intelligence-based diagnostic scores and calculators for early disease detection and treatment planning, and integration of generative artificial intelligence for patient education and postoperative monitoring. SUMMARY: The impact of artificial intelligence on cataract and refractive surgeries is becoming increasingly evident through improved diagnostic accuracy, enhanced patient education, and streamlined clinical workflows. These advancements hold significant implications for clinical practice, promising more personalized patient care and facilitating early disease detection and intervention. Equally, the review also highlights the fact that only some of this work reaches the clinical stage, successful integration of which may benefit from our focus.

Repeatability of a Combined Adaptive Optics Visual Simulator and Hartman-Shack Aberrometer in Pseudophakic Eyes With and Without Previous Corneal Refractive Surgery.

PURPOSE: To evaluate the intrasession repeatability of wavefront aberrations obtained by a combined adaptive optics visual simulator and Hartman-Shack aberrometer in pseudophakic eyes with and without previous corneal refractive surgery. METHODS: Three consecutive measurements were performed in one eye of each individual. Total ocular aberrations were recorded up to the 5th Zernike order for a 4.5-mm pupil. Repeatability was assessed by calculating the within-subject standard deviation (Sw), the repeatability limit (R), and the intraclass correlation coefficient (ICC). Vector analysis was performed to assess astigmatism variability between scans. RESULTS: The study enrolled 32 normal individuals and 24 individuals with a history of refractive surgery. In normal and eyes that had previous refractive surgery, respectively, the Sw values were 0.155 and 0.176 diopters (D) for sphere and 0.184 and 0.265 D for cylinder. The Sw values for all 3rd order terms ranged from 0.037 to 0.047 µm in normal eyes and 0.044 to 0.063 µm in eyes that had previous refractive surgery. The Sw for primary spherical aberration was 0.020 µm in normal eyes and 0.026 µm in eyes that had previous refractive surgery. ICC values for measurements of astigmatism yielded larger variability (ICC = 0.751 and 0.879). However, both groups demonstrated excellent repeatability (ICC > 0.9) for root mean square higher order aberrations (RMS-HOA) and total RMS values. CONCLUSIONS: In pseudophakic eyes, the adaptive optics Hartmann-Shack device demonstrated acceptable repeatability for measurement of sphere and 3rd and 4th order HOAs with higher variability for astigmatism measurements, especially in eyes with a prior history of corneal refractive surgery. [J Refract Surg. 2024;40(9):e645-e653.].

Culture positivity and distribution of the conjunctival sac bacteria in the perioperative period of corneal refractive surgery.

The objective of this study was to investigate the culture positivity and distribution of the conjunctival sac bacteria in the perioperative period of corneal refractive surgery. The selected time points of the perioperative period included before the use of antibiotic eye drops, before eye wash (after the use of antibiotic eye drops), after eye wash, and immediately after surgery. Conjunctival specimens obtained at the four time points were cultured to detect the positivity and distribution of bacteria. Before prophylactic antibiotic eye drops were administered, 49 eyes (50%) had positive bacterial culture results, with 45 isolates (91.8%) identified as Staphylococcus epidermidis. The culture positivity rates of the conjunctival sac specimens before eye wash, after eye wash, and immediately after surgery were 19.4%, 3.1%, and 4.1%, respectively. The difference was significant before and after the use of antibiotics and before and after eye wash (both P < 0.001). Staphylococcus epidermidis was the major pathogen in the conjunctival sac before corneal refractive surgery, and the culture positivity rate of the conjunctival bacteria was higher in males. Sixteen of 37 eyes (43.2%) with contact lenses had positive culture results, compared to 33 of 61 eyes (54.1%) without contact lenses (P > 0.05). The judicious preoperative use of antibiotic eye drops combined with the surgical sterile eye wash procedure maximised the removal of conjunctival sac bacteria. Skilled surgical manipulations generally did not increase the risk of infection.

Glaucoma and refractive surgery: A comprehensive review.

The global surge in refractive surgeries, particularly among myopic individuals, has elicited concerns regarding potential inaccuracies in the measurement of intraocular pressure (IOP) post surgery, primarily associated with central corneal thinning. The incidence of elevated IOP after intraocular refractive surgeries is higher than expected and is multifactorial. Myopic eyes have a higher susceptibility to both primary and secondary glaucoma. Consequently, meticulous preoperative screening for glaucoma is imperative, coupled with systematic postoperative follow-up and evaluation. This comprehensive review analyses the etiology, mechanisms, and therapeutic strategies for managing elevated IOP following refractive surgery. We propose an algorithm to summarize the causative factors of elevated IOP and formulate effective interventions in these instances.

Refractive Surgery Patient Characteristics Associated With Satisfaction Scores.

PURPOSE: To determine factors influencing patient satisfaction scores in recipients of refractive surgery. METHODS: In this prospective survey-based study, patients who had refractive surgery at an outpatient refractive clinic completed a survey of selected questions from the Press Ganey survey and the National Eye Institute Visual Function Questionnaire-25. Correlation between patient-specific variables and survey questions were assessed using Student's t-tests. RESULTS: Fifty-three patients were recruited over a 3-year period. Most were male (55%) and middle aged (mean age: 34 years). Eleven percent underwent photorefractive keratectomy surgery and the rest had laser in situ keratomileusis, with no complications. Twenty-four percent of surveyed patients reported mild to moderate eye pain postoperatively, with the rest reporting no pain. All patients reported a full score for overall satisfaction. CONCLUSIONS: This study found persistent high patient satisfaction score across a variation of characteristics, suggesting that optimal scores are mainstay after refractive surgery procedures with excellent visual outcomes, independent of patient clinical and sociodemographic characteristics. [J Refract Surg. 2024;40(8):e539-e543.].

Changes in cataract and refractive surgery practice patterns among JSCRS members over the past 20 years.

PURPOSE: To evaluate changes in cataract and refractive surgery practice patterns among members of the Japanese Society of Cataract and Refractive Surgery (JSCRS) over the past 20 years. STUDY DESIGN: Questionnaire survey study. SUBJECTS AND METHODS: Clinical surveys were conducted annually between February and April from 2004 to 2023. Survey questions covered various areas, including cataract surgical techniques, anesthesia, endophthalmitis prophylaxis, toric and presbyopia-correcting intraocular lenses (IOLs), complications, and refractive surgery. RESULTS: The highest (n=554 [36.8%]) and lowest (n=316 [19.1%]) numbers of responses were collected in 2012 and 2016, respectively. In perioperative management, the intraoperative use of polyvinyl alcohol-iodine solution and topical antibiotic prescription 3 days before surgery has increased. The use of intracameral injection at the end of surgery has also significantly increased, although it has not been established as common practice. In anesthesia, there is a clear polarization between the use of topical drops and tenon injection. The use of toric IOLs and presbyopia-correcting IOLs has significantly increased from 2010 to 2023. In the latter, the use of trifocal IOLs has particularly increased. Regarding IOL power calculations, the Barrett True K and the Barrett Universal II formulas are rapidly gaining popularity for application with and without post-laser vision correction, respectively. In refractive surgery, phakic IOLs and corneal refractive therapy have attracted considerable interest, followed by laser in situ keratomileusis. CONCLUSIONS: Evaluation of annual clinical survey data over the past two decades provided valuable insights into the shifting practice patterns and clinical opinions among JSCRS members.

[Whether laser corneal refractive surgery combined with presbyopia correction technology could treat presbyopia].

Presbyopia refers to a phenomenon in which the ability of the eye to accommodate is insufficient to meet the daily demand for proximity due to age. In modern society, more and more patients over 40 years old want to solve visual problems caused by presbyopia and refractive errors, which poses new challenges for clinical laser corneal refractive surgery, and a variety of combined presbyopia correction technologies and programs have emerged. However, whether laser corneal refractive surgery combined with presbyopia correction technology could treat presbyopia deserves clinical attention. Based on the mechanism of laser corneal refractive surgery and various presbyopia correction techniques, this article deeply analyzes the purpose and effect of laser corneal refractive surgery combined with presbyopia correction technology. It is proposed that this surgical treatment could only play a role in correcting presbyopia at present and should be performed accordingly.

[Explore the safety and efficiency of mild myopia retention in patients with myopia and presbyopia].

Objective: To explore the corrective effects of a personalized corneal refractive surgery design that retains mild myopia in patients over 40 years old with refractive errors and presbyopia. Methods: A retrospective case series study was conducted, including 60 patients (120 eyes) over 40 years old who underwent corneal refractive surgery at Peking Union Medical College Hospital l from January 2023 to December 2023. The patients were divided into two groups based on their preference: Group A (retained mild myopia) and Group B (fully corrected), with 30 patients (60 eyes) in each group. Preoperative and postoperative visual acuity, subjective refraction, slit-lamp examination, corneal topography, and intraocular pressure were assessed at 1 day, 1 week, 1 month, 3 months, 6 months, and 12 months after surgery. The effectiveness and safety indices were calculated based on visual acuity before and after surgery. The National Eye Institute Refractive Quality of Life questionnaire was used to evaluate patient satisfaction and postoperative visual symptoms. Results: There were no significant differences in preoperative uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), spherical equivalent (SE), corneal thickness, and intraocular pressure between the two groups (all P>0.05). At the final follow-up, the proportions of eyes with UDVA≥0.8 and≥1.0 were 93.3% (56/60) and 60.0% (36/60) in Group A, and 100% (60/60) and 83.3% (50/60) in Group B, respectively. The SE was significantly different between Group A [(-0.35±0.52) D] and Group B [(-0.07±0.55) D] (P<0.05). Near visual acuity was better in Group A than in Group B (P<0.05). The effectiveness indices were 0.96±0.23 and 0.99±0.12, and the safety indices were 1.02±0.11 and 1.02±0.07 for Groups A and B, respectively. Both groups had high overall satisfaction, but Group A had higher scores for near vision, reading, and computer screen viewing. Conclusion: The personalized corneal refractive surgery design that retains mild myopia provides good corrective effects for patients over 40 years old with refractive errors, improving patient satisfaction and quality of life.

[Chinese expert consensus on the perioperative medication in laser corneal refractive surgery (2024)].

With the increasing incidence of myopia year by year and the continuous progress of various treatment techniques, laser corneal refractive surgery has become one of the important ways to correct refractive errors. The rational drug use in the perioperative period is important for the success of surgery and reduction of complications. In 2019, based on the development of laser corneal refractive surgery in China, experts from the Refractive Surgery Experts Group of Ocular Microcirculation Branch of Chinese Society of Microcirculation and the Ophthalmology Branch in the Chinese Medical Association formed the "Chinese Expert Consensus on the Perioperative Medication in Laser Corneal Refractive Surgery (2019)". To further promote the expansion of new clinical technologies and surgical methods, and to improve surgical efficacy, the Refractive Surgery Experts Group of Ocular Microcirculation Branch of Chinese Society of Microcirculation, according to the latest domestic and foreign research results, has recently updated the consensus after a collective discussion.

[Accuracy comparison of total keratometry and standard keratometry in intraocular lens power calculations for post-corneal refractive surgery cataract patients].

Objective: To compare the accuracy of intraocular lens (IOL) power calculations using total keratometry (TK) versus standard keratometry (K) in post-corneal refractive surgery cataract patients. Methods: This retrospective case series study included 30 patients (36 eyes) with a history of laser corneal refractive surgery who underwent cataract extraction and IOL implantation at Qingdao Eye Hospital, Affiliated to Shandong First Medical University, from September 2022 to December 2023. The cohort comprised 16 males and 14 females, with an average age of (53.6±8.1) years. IOL power was calculated using the K-based Haigis-L and Barrett True-K formulas, as well as the TK-based Haigis and Barrett Universal Ⅱ formulas. Postoperative objective refraction was performed to obtain the actual refractive status of the operated eyes. The refractive prediction error (RPE) was defined as the difference between the actual spherical equivalent and the predicted refraction. The absolute value of the RPE was taken as the refractive absolute error (RAE). Differences in errors calculated by the four formulas were compared. Results: TK showed good consistency with K, with TK being on average 0.50 D lower than K. Analysis of variance revealed statistically significant differences in RPE among the four formulas (P<0.001). The RPE for the TK-based Haigis formula was (0.17±0.09) D, and for the Barrett Universal Ⅱ formula, it was (0.21±0.11) D, both significantly better than the K-based Haigis-L formula (-0.61±0.12) D and Barrett True-K formula (-0.57±0.11) D (all P<0.001). The percentage of eyes with postoperative RPE<±1.00 D was higher for the TK-based Haigis (92%, 33 eyes) and Barrett Universal Ⅱ (86%, 31 eyes) formulas compared to the TK-based Barrett True-K (75%, 27 eyes) and Haigis-L formulas (67%, 24 eyes), with statistically significant differences (P<0.05). Conclusions: Compared with K, TK improves the accuracy of IOL power calculation in post-corneal refractive surgery patients. Both the TK-based Barrett Universal Ⅱ and Haigis formulas demonstrate high accuracy.

Tear Proteins Altered in Patients with Persistent Eye Pain after Refractive Surgery: Biomarker Candidate Discovery.

Some patients develop persistent eye pain after refractive surgery, but factors that cause or sustain pain are unknown. We tested whether tear proteins of patients with pain 3 months after surgery differ from those of patients without pain. Patients undergoing refractive surgery (laser in situ keratomileusis or photorefractive keratectomy ) were recruited from 2 clinics, and tears were collected 3 months after surgery. Participants rated their eye pain using a numerical rating scale (NRS, 0-10; no pain-worst pain) at baseline, 1 day, and 3 months after surgery. Using tandem mass tag proteomic analysis, we examined tears from patients with pain [NRS ≥ 3 at 3 months (n = 16)] and patients with no pain [NRS ≤ 1 at 3 months (n = 32)] after surgery. A subset of proteins (83 of 2748 detected, 3.0%) were associated with pain 3 months after surgery. High-dimensional statistical models showed that the magnitude of differential expression was not the only important factor in classifying tear samples from pain patients. Models utilizing 3 or 4 proteins had better classification performance than single proteins and represented differences in both directions (higher or lower in pain). Thus, patterns of protein differences may serve as biomarkers of postsurgical eye pain as well as potential therapeutic targets.

BCLA CLEAR Presbyopia: Management with corneal techniques.

Corneal techniques for enhancing near and intermediate vision to correct presbyopia include surgical and contact lens treatment modalities. Broad approaches used independently or in combination include correcting one eye for distant and the other for near or intermediate vision, (termed monovision or mini-monovision depending on the degree of anisometropia) and/or extending the eye's depth of focus [1]. This report reviews the evidence for the treatment profile, safety, and efficacy of the current range of corneal techniques for managing presbyopia. The visual needs and expectations of the patient, their ocular characteristics, and prior history of surgery are critical considerations for patient selection and preoperative evaluation. Contraindications to refractive surgery include unstable refraction, corneal abnormalities, inadequate corneal thickness for the proposed ablation depth, ocular and systemic co-morbidities, uncontrolled mental health issues and unrealistic patient expectations. Laser refractive options for monovision include surface/stromal ablation techniques and keratorefractive lenticule extraction. Alteration of spherical aberration and multifocal ablation profiles are the primary means for increasing ocular depth of focus, using surface and non-surface laser refractive techniques. Corneal inlays use either small aperture optics to increase depth of field or modify the anterior corneal curvature to induce corneal multifocality. In presbyopia correction by conductive keratoplasty, radiofrequency energy is applied to the mid-peripheral corneal stroma, leading to mid-peripheral corneal shrinkage and central corneal steepening. Hyperopic orthokeratology lens fitting can induce spherical aberration and correct some level of presbyopia. Postoperative management, and consideration of potential complications, varies according to technique applied and the time to restore corneal stability, but a minimum of 3 months of follow-up is recommended after corneal refractive procedures. Ongoing follow-up is important in orthokeratology and longer-term follow-up may be required in the event of late complications following corneal inlay surgery.

Refractive Surgery in a Patient with Alport Syndrome. A Case Report.

The authors present a case of a thirty-eight-year-old patient with Alport syndrome. The patient had several ocular symptoms of the disease and has been treated for systemic problems in connection with Alport syndrome since he was fifteen years old. At that age the patient also underwent a kidney transplant in order to deal with renal insufficiency. To date, he still uses immunosuppressants and antihypertensives. Furthermore, the patient suffers from perceptive deafness. The patient visited our clinic in 2021 with a request to solve his high refractive error, in which the diopters were so high that it was not possible to place them in spectacles. The patient's best corrected visual acuity was 0.6 with -8.0sph/-4.0cyl/ax15 in the right eye and 0.7partim with -8.0sph/-4.0cyl/ax155 in the left eye. The autorefractometer values were -6.25sph/-6.75cyl/ax17 in the right eye and -6.75sph/-6.5cyl/ax155 in the left eye. During the eye examination we found a number of ocular manifestations that are typical of Alport syndrome. On the cornea there were opacities as a residue of corneal erosions, and at one of the following check-ups we also found a newly developed corneal erosion. Subsequently, we found an anterior lenticonus and incipient cataract. Upon performing OCT, a typical temporal macular atrophy was evident. Fundus examination in artificial mydriasis showed just a minimal manifestation of fleck retinopathy. Due to the clinical manifestation we decided to perform cataract surgery and implant a monofocal toric intraocular lens in both eyes. There were no complications during the operations, however the surgeon registered a non-standard structure of the lens capsule. The capsule was more fragile, and performing capsulorhexis was much more complicated. A week after the surgery, higher cylinder diopters were still present. A decrease of the higher diopters was noticeable one month after surgery. The time interval between the first operation and the second operation was one month. The patient was highly satisfied with result, and uncorrected visual acuity improved by over four lines. After surgery the patient needed low diopters for near as well as far distance. In the case of this patient, the ocular manifestations were detected and treated in adulthood. Nevertheless, early detection of ocular symptoms of Alport syndrome in young patients before renal failure could lead to timely start of the treatment and delay a possible renal transplant. In case of any suspicion of Alport syndrome it is advised to send the patient to a pediatrician, and at an older age to an internal medicine specialist, for further examination.

Refractive surgical approaches to keratoconus: A systematic review and network meta-analysis.

Advancements in diagnostic methods and surgical techniques for keratoconus (KC) have increased non-invasive treatment options. Successful surgical planning for KC involves a combination of clinical science, empirical evidence, and surgical expertise. Assessment of disease progression is crucial, and halting the progression should be the focus if it is progressive. While surgeons used to rely on experience alone to decide the surgical method, comparing the network of primary factors, such as visual acuity, across studies can help them choose the most appropriate treatments for each patient and achieve optimal outcomes. Meticulous tabulation methods facilitate interpretation, highlighting the importance of selecting the correct surgical and rehabilitation approach based on each patient's condition and stage of the disease. We detail the outcomes of a comprehensive network meta-analysis comparing the effectiveness of various combined therapeutic refractive treatments for KC at identical stages of the disease, spanning 4 distinct follow-up intervals. Additionally, the comprehensive analysis suggests that for corneas with optimal best corrected visual acuity (BCVA) preoperatively (classified as regular), combining phakic intraocular lenses with intracorneal ring segments (ICRS) and corneal cross-linking (CXL) could offer the best therapeutic approach provided the disease stage does not exceed stage 3. For irregular corneas, although initial follow-ups show a significant difference in BCVA with surface ablation, longer-term follow-ups recommend combining surface ablation with ICRS and CXL, especially at higher stages.

Pediatric refractive surgery: current opinion in ophthalmology.

PURPOSE OF REVIEW: Pediatric refractive surgery has been growing at a steady pace since its introduction in the early 1980 s. This article will review common laser refractive surgeries performed on pediatric patients along with controversies regarding the practice. RECENT FINDINGS: Pediatric refractive surgery is reserved for a small population of children who fail amblyopic treatment due to high anisometropic refractive errors. Publications over the years have treated these children with various types of laser refractive surgery. SUMMARY: Laser pediatric refractive surgery appears to be well tolerated and effective for the population of children that need it. It provides an alternative for anisometropic amblyopia treatment for children who would have otherwise not been able to improve their vision.

Does the introduction of streamlight decrease refractive surgery operating time?

PURPOSE: The aim of the study was to analyze the time-savings associated with introduction of Streamlight™ (Alcon Laboratories, Fort Worth, TX, USA) transepithelial photorefractive keratectomy (PRK) in surface corneal ablations. METHODS: All refractive surgeries were performed using the Alcon WaveLight® EX500 at the ArtLife Clinic, Gdansk, Poland. The study included patients treated for refractive errors with transepithelial PRK between April 2019 and October 2021, who were matched with patients treated with alcohol-assisted PRK during the same period. Only results for the left eye were analyzed. RESULTS: One-hundred-five patients underwent transepithelial PRK (age 33.42 ± 8.67 years) and were matched with 105 patients that underwent alcohol-assisted PRK (age 33.05 ± 10.16 years; p = 0.11). The mean preoperative spherical equivalent refraction was - 2.04 ± 2.28 D, and - 1.9 ± 1.71 D for the transepithelial and alcohol-assisted PRK group, respectively (p = 0.20). The total surgery time was non-significantly shorter in transepithelial PRK (349.46 ± 47.83 s) than in alcohol-assisted PRK (354.93 ± 137.63 s; p = 0.7); however, the variance of surgical time was significantly lower in transepithelial PRK (p < 0.001). The laser treatment duration was greater in transepithelial PRK (41.78 ± 17.2 s) than in alcohol-assisted PRK (8.48 ± 6.12 s; p < 0.001), and so was the number of breaks during the laser treatment (0.95 ± 0.63 vs. 0.53 ± 0.88, respectively; p < 0.001). CONCLUSION: The introduction of transepithelial PRK did not bring significant time-associated savings into the refractive surgery suite.

Magnitude and Determinants of Awareness Regarding Refractive Surgeries Among Saudi Adults.

Objectives: This study aimed to present the magnitude and determinants of awareness about refractive surgery among the adult Saudi population and recommend knowledge improvement. Methods: This web-based cross-sectional study was conducted between June 2020 and May 2021 across various regions of Saudi Arabia on the adult Saudi population. A total of 11 close-ended questions regarding indication, contraindication, preparation and surgery procedures were asked. The awareness scores were grouped as 'good' (≥6) or 'poor' (≤5). Demographic and ocular parameters were associated with the outcomes. Results: Of the 6,746 participants, 6,580 (response rate = 97.5%) completed the survey. The participation of younger women and older men was greater than their proportions in the population, while older women participated less than their proportion. Good awareness about refractive surgery was noted in 1,165 (17.7%; 95% confidence interval: 16.2-18.0) participants. Women (P <0.001), the 18-29 age group (P <0.001), residents of the central region of Saudi Arabia (P <0.001), health professionals (P <0.001), health sector students (P = 0.0004), people with myopia (P <0.001) and history of refractive surgery (P <0.001) were associated with good awareness. Women (adjusted odds ratio [AOR] = 1.5; P <0.001), health sector students (AOR = 1.57; P <0.001), and residents in the central region (AOR = 1.27; P <0.001) were independent predictors of awareness. Knowledge about contraindications for surgery was good in more than one-third of the participants. Of the 535 participants who underwent surgery in the past, 452 (84.5%) were satisfied with their outcomes. Conclusion: Awareness of refractive surgeries is low in the adult Saudi population. Targeted counseling is recommended to improve the knowledge and acceptance of refractive surgery.

New forays into measurement of ocular biomechanics.

PURPOSE OF REVIEW: The field of corneal biomechanics has rapidly progressed in recent years, reflecting technological advances and an increased understanding of the clinical significance of measuring these properties. This review will evaluate in-vivo biomechanical properties obtained by current technologies and compare them regarding their relevance to established biomechanical properties obtained by gold-standard ex-vivo techniques normally conducted on elastic materials. RECENT FINDINGS: Several new technologies have appeared in recent years, including vibrational optical coherence tomography (VOCT) and the corneal indentation device (CID). These techniques provide promising new opportunities for minimally invasive and accurate measurements of corneal viscoelastic properties. SUMMARY: Alterations in corneal biomechanics are known to occur in several corneal degenerative diseases and after refractive surgical procedures. The measurement of corneal biomechanical properties has the capability to diagnose early disease and monitor corneal disease progression. Several new technologies have emerged in recent years, allowing for more accurate and less invasive measurements of corneal biomechanical properties, most notably the elastic modulus.