Burksjoyner8787

To develop a method for predicting postoperative anterior chamber depth (ACD) in cataract surgery patients based on preoperative biometry, demographics, and intraocular lens (IOL) power.

Patients who underwent cataract surgery and had both preoperative and postoperative biometry measurements were included. Patient demographics and IOL power were collected from the Sight Outcomes Research Collaborative (SOURCE) database. A gradient-boosting decision tree model was developed to predict the postoperative ACD. The mean absolute error (MAE) and median absolute error (MedAE) were used as evaluation metrics. The performance of the proposed method was compared with five existing formulas.

In total, 847 patients were assigned randomly in a 41 ratio to a training/validation set (678 patients) and a testing set (169 patients). Using preoperative biometry and patient sex as predictors, the presented method achieved an MAE of 0.106 ± 0.098 (SD) on the testing set, and a MedAE of 0.082. MAE was significantly lower than that of the five existing methods (

< 0.01). When keratometry was excluded, our method attained an MAE of 0.123 ± 0.109, and a MedAE of 0.093. When IOL power was used as an additional predictor, our method achieved an MAE of 0.105 ± 0.091 and a MedAE of 0.080.

The presented machine learning method achieved greater accuracy than previously reported methods for the prediction of postoperative ACD.

Increasing accuracy of postoperative ACD prediction with the presented algorithm has the potential to improve refractive outcomes in cataract surgery.

Increasing accuracy of postoperative ACD prediction with the presented algorithm has the potential to improve refractive outcomes in cataract surgery.

To determine longitudinal alterations in corneal nerve fiber morphology, dendritic cell (DC) density, and retinal nerve fiber layer (RNFL) thickness over 2 years in patients with multiple sclerosis (MS).

Thirty-one consecutive patients with relapsing-remitting MS (RRMS) underwent assessment of the Kurtzke Expanded Disability Status Scale (EDSS), Multiple Sclerosis Severity Score (MSSS), corneal confocal microscopy to quantify corneal subbasal nerve morphology and DC density, and spectral-domain optical coherence tomography to quantify RNFL thickness at baseline and after 2 years.

There was a significant reduction in corneal nerve fiber area (CNFA) (

= 0.003), nerve fiber width (CNFW) (

= 0.005), and RNFL thickness (

= 0.004) with an increase in EDSS (

= 0.01) over 2 years. The change in corneal nerve fiber density (CNFD) correlated with the change in EDSS (ρ = -0.468;

= 0.008), MSSS (ρ = -0.442;

= 0.01), DC density (ρ = -0.550;

= 0.001), and RNFL (ρ = 0.472;

= 0.007). The change in corneal nerve fiber length (CNFL) correlated with the change in EDSS (ρ = -0.445;

= 0.01) and MSSS (ρ = -0.490;

= 0.005). Furthermore, there was a significant decrease in CNFL (

< 0.001), CNFA (

= 0.02), CNFW (

= 0.04), corneal total branch density (

= 0.01), and RNFL thickness (

= 0.02) and a significant increase in DC density (

= 0.04) in patients with worsening EDSS (

= 15).

Corneal confocal microscopy can be used to detect progressive corneal nerve fiber loss that relates to a progression of disability in patients with RRMS.

Corneal confocal microscopy acts as a sensitive imaging biomarker for progressive nerve degeneration in patients with MS.

Corneal confocal microscopy acts as a sensitive imaging biomarker for progressive nerve degeneration in patients with MS.

To determine whether multicolor scanning laser ophthalmoscopy (MC-SLO) was better than color fundus photography (CFP) to enhance residents and specialists' preoperative decision-making and intraoperative performance on the epiretinal membrane (ERM).

Consecutive patients with idiopathic ERM were recruited prospectively. All the patients underwent MC-SLO and CFP imagings and were randomized into MC-SLO (n = 20) and CFP (n = 20) groups. Preoperatively, residents and specialists were required to have ERM delineation and select an optimal location for initial ERM peeling independently, based on the MC-SLO (MC-SLO group) or CFP (CFP group) images. Intraoperative optical coherence tomography (iOCT) was introduced to evaluate the accuracy.

Preoperatively, residents and specialists acted more effectively in ERM delineation and selection of initial grasping location in the MC-SLO group (both

< 0.001). In the MC-SLO group, higher resident-specialist agreements were achieved in ERM delineation (

= 0.002) and selection of initial grasping location (

= 0.035). The iOCT revealed greater interobserver (iOCT-resident and iOCT-specialist) agreements of ERM delineation in MC-SLO group (

< 0.001 and = 0.027, respectively). Surgeons acted more effectively on completely peeling the ERM in the MC-SLO group (

< 0.001).

MC-SLO provided a better visual reference for residents and specialists in ERM delineation and the selection of an initial grasping location for the surgery, compared with CFP.

MC-SLO is able to help surgeons achieve better intraoperative performance and shorten the learning process for residents.

MC-SLO is able to help surgeons achieve better intraoperative performance and shorten the learning process for residents.

The aim of this study was to investigate safety and comfort of two versions of a placebo-microsphere filled ocular coil (straight and curved) in healthy subjects.

The study was a single-center intervention study. One ocular coil was placed in the inferior conjunctival fornix for the intended duration of 28 days. Forty-two healthy adult subjects were included. At baseline, 30 minutes, 8 hours, 24 hours, 48 hours, 7 days, 14 days, 21 days, and 28 days after insertion, examinations were performed, including slit lamp evaluation to score ocular redness, intraocular pressure measurement, visual acuity, tear secretion test, and questionnaires.

The straight and curved ocular coils had a median retention time of 5 days and 12 days, respectively. After 48 hours, 57% and 81% subjects retained the straight and curved ocular coil, respectively. Four (19%) subjects with the straight coil and six (29%) with the curved coil completed the entire study period. Minor changes in ocular hyperemia were observed in both groups. On day 7, the straight coil was more comfortable than the curved coil with a visual analogue scale (VAS) score of 77 ± 21 compared to 94 ± 11 (

= 0.028), respectively. No other ocular adverse events were observed.

Comfort and safety of the straight and curved ocular coil are high. Because the retention time is too short for long-term sustained drug release, the use in the perioperative or immediate postoperative period could prove to be more valuable.

The ocular coil is a noninvasive, comfortable and safe short-term drug delivery device.

The ocular coil is a noninvasive, comfortable and safe short-term drug delivery device.

To study alginate- and hyaluronic acid-based hydrogels in vitro as vitreous substitutes.

Biopolymeric hydrogels based on high-molecular alginate (0.5% and 1.0%) and hyaluronic acid (1.0% and Healaflow) were compared with extracted human vitreous bodies and silicone oil (SIL-5000) regarding their optical properties (refractive index, transmission) and viscoelastic characteristics (storage modulus G', loss modulus G″). The cytotoxic (metabolic activity, apoptosis) and antiproliferative profiles were determined using cultured human fibroblasts, ARPE-19, and photoreceptor cells. The hydrogel systems were applied to human fetal retinal pigment epithelial cells cultured for two months until maximum transepithelial electrical resistance (TEER) to investigate the effect of the gel matrices on tight junctions using TEER measurements and immunostainings against the tight junction protein ZO-1.

Tested alginate- and hyaluronic acid-based hydrogels resembled the natural refractive index of human vitreous bodies (1.3356-1.3360) in contrast to SIL-5000 (1.4034) and showed high optical transparency (>90%) within the visible light region. The biopolymeric hydrogels exhibited viscoelastic properties similar to juvenile vitreous bodies with G'>G″ adjustable via different gelation times, contrary to SIL-5000 (G'<G″). The metabolic activity, apoptosis and tight junctions of all tested ocular cells were unaffected by the alginate- and hyaluronic acid-based vitreous substitutes.

The present in vitro study demonstrates good optical, viscoelastic, and biocompatible properties of alginate- and hyaluronic acid-based hydrogels required for their use as vitreous substitutes.

Biopolymer-based hydrogels represent a promising vitreous replacement strategy to treat vitreoretinal diseases.

Biopolymer-based hydrogels represent a promising vitreous replacement strategy to treat vitreoretinal diseases.

The purpose of this study was to establish in vivo data acquisition and processing protocols for repeatable measurements of heartbeat-induced corneal displacements and strains in human eyes, using a high-frequency ultrasound elastography method, termed ocular pulse elastography (OPE).

Twenty-four volunteers with no known ocular diseases were recruited for this study. PKC-theta inhibitor Intraocular pressure (IOP) and ocular pulse amplitude (OPA) were measured using a PASCAL Dynamic Contour Tonometer (DCT). An in vivo OPE protocol was developed to measure heartbeat-induced corneal displacements. Videos of the central 5.7mm of the cornea were acquired using a 50-MHz ultrasound probe at 128 frames per second. The radiofrequency data of 1000 frames were analyzed using an ultrasound speckle tracking algorithm to calculate corneal displacements and quantify spectral and temporal characteristics. The intrasession and intersession repeatability of OPE- and DCT-measured parameters were also analyzed.

The in vivo OPE protocol and setup were successful in tracking heartbeat-induced corneal motion using high-frequency ultrasound. Corneal axial displacements showed a strong cardiac rhythm, with good intrasession and intersession repeatability, and high interocular symmetry. Corneal strain was calculated in two eyes of two subjects, showing substantially different responses.

We demonstrated the feasibility of high-frequency ultrasound elastography for noninvasive in vivo measurement of the cornea's biomechanical responses to the intrinsic ocular pulse. The high intrasession and intersession repeatability suggested a robust implementation of this technique to the in vivo setting.

OPE may offer a useful tool for clinical biomechanical evaluation of the cornea by quantifying its response to the intrinsic pulsation.

OPE may offer a useful tool for clinical biomechanical evaluation of the cornea by quantifying its response to the intrinsic pulsation.Visual prostheses aim to restore, at least to some extent, vision that leads to the type of perception available for sighted patients. Their effectiveness is almost always evaluated using clinical tests of vision. Clinical vision tests are designed to measure the limits of parameters of a functioning visual system. I argue here that these tests are rarely suited to determine the ability of prosthetic devices and other therapies to restore vision. This paper describes and explains many limitations of these evaluations. Prosthetic vision testing often makes use of multiple-alternative forced-choice (MAFC) procedures. Although these paradigms are suitable for many studies, they are frequently problematic in vision restoration evaluation. Two main types of problems are identified (1) where nuisance variables provide spurious cues that can be learned in repeated training, which is common in prosthetic vision, and thus defeat the purpose of the test; and (2) even though a test is properly designed and performed, it may not actually measure what the researchers believe, and thus the interpretation of results is wrong.