Accuracy of intraocular lens formulas in combined phacovitrectomy.

PURPOSE: To assess the refractive accuracy of eight intraocular lens (IOL) formulas in eyes that underwent combined phacovitrectomy. METHODS: A retrospective chart review of 59 eyes that underwent uncomplicated phacovitrectomy between 2017 and 2020 at the Johns Hopkins Wilmer Eye Institute. Inclusion criteria were postoperative best corrected visual acuity of 20/40 or better within 6 months of surgery and IOL implantation in the capsular bag. The Barrett Universal II (BUII), Emmetropia Verifying Optical (EVOv2.0), Hill-Radial Basis Function (Hill-RBFv3.0), Hoffer Q, Holladay I, Kane, Ladas Super Formula (LSF), and SRK/T formulas were compared for accuracy in predicting postoperative spherical equivalents (SE) using Wilcoxon rank sum tests. Pearson's correlation coefficients were used to assess correlations between biometric parameters and errors for all formulas. RESULTS: Prediction errors of SE ranged from - 1.69 to 1.43 diopters (D), mean absolute errors (MAE) ranged from 0.39 to 0.47 D, and median absolute errors (MedAE) ranged from 0.23 to 0.37 D among all formulas. The BUII had the lowest mean error (- 0.043), MAE (0.39) and MedAE (0.23). The BUII also had the highest percentage of eyes with predicted error within ± 0.25 D (51%) and ± 0.50 D (83%). Based on MedAE however, no pairwise comparisons resulted in statistically significant differences. Axial length (AL) was positively correlated with the error from the Hoffer Q and Holladay I formulas (correlation coefficients = 0.34, 0.30, p values < 0.01, 0.02 respectively). CONCLUSION: While all eight IOL formulas had comparable accuracy in predicting refractive outcomes in eyes undergoing combined phacovitrectomy, the BUII and Kane formulas had a tendency to greater accuracy.

Improvement of Multiple Generations of Intraocular Lens Calculation Formulae with a Novel Approach Using Artificial Intelligence.

Purpose: Cataract surgery is the most common eye surgery. Appropriate optimization of intraocular lens (IOL) calculation formulae can result in improved patient outcomes. The purpose of this article is to describe a methodology of optimizing existing IOL formulae and develop hybrid formulae based on artificial intelligence (AI). Methods: Preoperative biometric and postoperative outcomes data were obtained from medical records at a single institution. A numeric computing environment was used to analyze these data and refine IOL formulae using supervised learning AI. The mean absolute error of each IOL formulae with and without AI enhancement was determined, as well as the number of eyes within 0.5 diopter of the predicted refraction. Results: AI algorithms improved the mean absolute error as well as number of eyes within 0.5 diopters of predicted refraction for each of the formulae tested (P < 0.05). Conclusions: A novel methodology is described that uses AI to improve existing IOL formulae. This methodology has the potential to improve clinical outcomes for cataract surgery patients. Translational Relevance: Artificial intelligence can be used to improve existing IOL formulae.

Artificial intelligence in cornea, refractive, and cataract surgery.

PURPOSE OF REVIEW: The subject of artificial intelligence has recently been responsible for the advancement of many industries including aspects of medicine and many of its subspecialties. Within ophthalmology, artificial intelligence technology has found ways of improving the diagnostic and therapeutic processes in cornea, glaucoma, retina, and cataract surgery. As demands on the modern ophthalmologist grow, artificial intelligence can be utilized to help address increased demands of modern medicine and ophthalmology by adding to the physician's clinical and surgical acumen. The purpose of this review is to highlight the integration of artificial intelligence into ophthalmology in recent years in the areas of cornea, refractive, and cataract surgery. RECENT FINDINGS: Within the realms of cornea, refractive, and cataract surgery, artificial intelligence has played a major role in identifying ways of improving diagnostic detection. In keratoconus, artificial intelligence algorithms may help with the early detection of keratoconus and other ectatic disorders. In cataract surgery, artificial intelligence may help improve the performance of intraocular lens (IOL) calculation formulas. Further, with its potential integration into automated refraction devices, artificial intelligence can help provide an improved framework for IOL formula optimization that is more accurate and customized to a specific cataract surgeon. SUMMARY: The future of artificial intelligence in ophthalmology is a promising prospect. With continued advancement of mathematical and computational algorithms, corneal disease processes can be diagnosed sooner and IOL calculations can be made more accurate.

Accuracy of Intraocular Lens Formulas in Eyes With Keratoconus.

PURPOSE: To evaluate the refractive accuracy of current intraocular lens (IOL) formulas in eyes with keratoconus. DESIGN: Retrospective case series. METHODS: Preoperative optical biometry, Pentacam topography, and postoperative outcomes were collected from eyes with keratoconus that had uncomplicated cataract surgery between 2014 and 2018 at a single institution. Exclusion criteria include postoperative best-corrected spectacle visual acuity worse than 20/40, multifocal lens, prior ophthalmic surgeries, and prior ocular trauma. The Hoffer Q, SRK/T, Holladay I, Holladay II, Haigis, and Barrett Universal II formulas were analyzed in each eye stratified by keratoconus severity. RESULTS: A total of 73 eyes were included. All formulas had a positive mean predicted error ranging from 0.10 to 4.38 diopters (D). The Barrett Universal II formula had the lowest median absolute error for stage I (n = 46, 0.445 D) and II (n = 22, 0.445 D) eyes, and the highest percentage of eyes with predicted error within ±0.50 D for both stage I (52%) and II (50%) eyes. In stage III eyes (n = 5), the Haigis formula had the lowest median predicated error (1.90 D) and the highest percentage of eyes with predicted error within ±0.50 D (40%). Corneal power measured by optical biometers was higher than measurements by Pentacam keratometry. CONCLUSIONS: All formulas tend to have a hyperopic surprise. The Barrett Universal II formula was the most accurate for mild to moderate disease. Pentacam keratometry may help avoid hyperopic outcomes.

Intraocular lens calculations in atypical eyes.

Cataract surgery is the most performed surgical procedure in the field of ophthalmology. The process of intraocular lens (IOL) calculations is a critical step to achieving successful outcomes. Many IOL formulae exist to guide surgeons through the difficult process of picking the most appropriate lens to achieve a certain target refraction. However, these formulae reach within 0.50 diopters of the target refraction only 75% of the time, leaving 25% of the eyes with a significant refractive surprise. A literature review was performed to investigate all the relevant published material on the history, progress, and recent advancements of IOL calculations. Based on this review, the appropriate history, evolution, progress, limitations, and recent advancements are analyzed and explained. Although the modern IOL formulae and biometric devices perform well for average eyes, they are suboptimal for eyes with atypical biometric parameters and also those that are postrefractive and keratoconic. There has not been a single, perfect formula that can resolve the complexities of this process. Various methods of formula optimization and newer generation of IOL formulae and devices may hold the key to improving outcomes in both typical and atypical eyes. These solutions minimize refractive error by introducing new input parameters and complex mathematical techniques to better estimate postoperative lens position.

Comparison of distance and near visual acuity in patients with vision loss due to cataract.

The purpose of this study was to assess whether there is a disparity in distance and near best-corrected visual acuity (BCVA) in cataract eyes. 102 patients with cataract (N = 121 eyes) were seen in clinic between January and November 2013 at the Wilmer Eye Institute Comprehensive Eye Service. An age-related macular degeneration (ARMD) group (N = 27 eyes) was also identified for comparison. Distance and near BCVA were measured as part of the standard ophthalmic evaluation. Snellen measurements were converted to their LogMAR equivalents for statistical analysis. Near was better than distance BCVA with mean difference of 1.38 lines (P < 0.001) in the cataract eyes. This disparity was not seen in the ARMD eyes. Near-distance BCVA disparity is a statistically significant finding seen with cataracts. This may have further implications in patients with both cataract and ARMD as the presence of disparity may suggest a cataract etiology playing a greater role in vision loss. This comparison may be useful for surgical prognostication and as a quick triage tool in conjunction with, or in place of, a potential acuity meter and dilated near-pinhole test.

Vestibular and oculomotor influences on visual dependency.

The degree to which a person relies on visual stimuli for spatial orientation is termed visual dependency (VD). VD is considered a perceptual trait or cognitive style influenced by psychological factors and mediated by central reweighting of the sensory inputs involved in spatial orientation. VD is often measured with the rod-and-disk test, in which participants align a central rod to the subjective visual vertical (SVV) in the presence of a background that is either stationary or rotating around the line of sight-dynamic SVV. Although this task has been employed to assess VD in health and vestibular disease, what effect torsional nystagmic eye movements may have on individual performance is unknown. Using caloric ear irrigation, 3D video-oculography, and the rod-and-disk test, we show that caloric torsional nystagmus modulates measures of VD and demonstrate that increases in tilt after irrigation are positively correlated with changes in ocular torsional eye movements. When the direction of the slow phase of the torsional eye movement induced by the caloric is congruent with that induced by the rotating visual stimulus, there is a significant increase in tilt. When these two torsional components are in opposition, there is a decrease. These findings show that measures of VD can be influenced by oculomotor responses induced by caloric stimulation. The findings are of significance for clinical studies, as they indicate that VD, which often increases in vestibular disorders, is modulated not only by changes in cognitive style but also by eye movements, in particular nystagmus.

A 3-D "Super Surface" Combining Modern Intraocular Lens Formulas to Generate a "Super Formula" and Maximize Accuracy.

IMPORTANCE: Cataract surgery is the most common eye surgery. Calculating the most accurate power of the intraocular lens (IOL) is a critical factor in optimizing patient outcomes. OBJECTIVES: To develop a graphical method for displaying IOL calculation formulas in 3 dimensions, and to describe a method that uses the most accurate and current information on IOL formulas, adjustments, and lens design to create one "super surface" and develop an IOL "super formula." DESIGN, SETTING, AND PARTICIPANTS: A numerical computing environment was used to create 3-D surfaces of IOL formulas: Hoffer Q, Holladay I, Holladay I with Koch adjustment, Haigis, and SRK/T. The surfaces were then analyzed to determine where the IOL powers calculated by each formula differed by more than 0.5, 1.0, and 1.5 diopters (D) from each of the other formulas. Next, based on the current literature and empirical knowledge, a super surface was rendered that incorporated the ideal portions from 4 of the 5 formulas to generate a super formula. Last, IOL power values of a set of 100 eyes from consecutive patients at an eye institute were calculated using the 5 formulas and super formula. The study was performed from December 11, 2014, to April 20, 2015. Analysis was conducted from February 18 to May 6, 2015. MAIN OUTCOMES AND MEASURES: Intraocular lens power value in diopters and the magnitude of disparity between an existing individual IOL formula and our super formula. RESULTS: In the 100 eyes tested, the super formula localized to the correct portion of the super surface 100% of the time and thus chose the most appropriate IOL power value. The individual formulas deviated from the optimal super formula IOL power values by more than 0.5 D 30% of the time in Hoffer Q, 16% in Holladay I, 22% in Holladay I with Koch adjustment, 48% in Haigis, and 24% in SRK/T. CONCLUSIONS AND RELEVANCE: A novel method was developed to represent IOL formulas in 3 dimensions. An IOL super formula was formulated that incorporates the ideal segments from each of the existing formulas and uses the ideal IOL formula for an individual eye. The expectation is that this method will broaden the conceptual understanding of IOL calculations, improve clinical outcomes for patients, and stimulate further progress in IOL formula research.

Early Therapy Intensity Level (TIL) Predicts Mortality in Spontaneous Intracerebral Hemorrhage.

BACKGROUND: Outcome from spontaneous intracerebral hemorrhage (sICH) may depend on patient-care variability. We developed as ICH-specific therapy intensity level (TIL) metric using evidence-based elements in a high severity sICH cohort. METHODS: This is a cohort study of 170 patients with sICH and any intraventricular hemorrhage treated in 2 academic neuroICUs. Pre-defined quality indicators were identified based on current guidelines, scientific evidence, and likelihood of care documentation in first 72 h of hospital admission. We assessed performance on each indicator and association with discharge mortality. Significant indicators were aggregated to develop a TIL score. The predictive validity of the best fit TIL score was tested with threefold cross-validation of multivariate logistic regression models of in-hospital survival and good outcome (modified Rankin score 0-3). RESULTS: Median ICH score was 3; discharge mortality was 51.2%. Five/19 tested variables were significantly associated with lower discharge mortality: no DNR/withdrawal of treatment within 24 h of admission, target glucose within 4 h of high glucose, no recurrent hyperpyrexia, clinical reversal of herniation/intracranial pressure >20 mmHg within 60 min of detection, and reversal of INR (<1.4) within 2 h of first elevation. One point was given for each or if not applicable. Median TIL score was significantly higher in survivors versus non-survivors (5[1] vs. 3[1]; P < 0.001). A 4-point aggregated TIL score was most predictive of discharge survival (area under receiving operating characteristic curve 0.85, 95% CI 0.80-0.90) and good outcome (AUC 0.84) and was an independent predictor of both (survival: OR 7.10; 95% CI 3.57-14.11; P < 0.001; good outcome: OR 3.10; 95% CI 1.06-8.79; P < 0.001). CONCLUSION: A simplified TIL score using evidenced-based patient-care parameters within first 3 days of admission after sICH was significantly associated with early mortality and good outcome. The next step is prospective validation of the simplified TIL score in a large clinical trial.

William John Adie: the man behind the syndrome.

William John Adie was an Australian neurologist in the early 20th century responsible for extensively describing the tonically dilated pupil associated with absent deep tendon reflexes - both features of a syndrome that now bears his name. In addition to other neurological syndromes, he was also significant in delineating narcolepsy through his clinical essays and case series. His ophthalmic and neurologic contributions have served the test of time and played an important role in the modern understanding of Adie syndrome and narcolepsy. This report reviews Adie's medical contributions, extensive descriptions of Adie syndrome, and provides a brief biographical account of his life.