Clinical History Method versus Corneal Tomographers in Estimating Corneal Power after Photorefractive Surgery

AIMS: To investigate the concordance between the corneal power determined by various approaches with two tomographers (MS-39® and Galilei G6®) and the clinical history method (CHM) in patients undergoing photorefractive surgery with excimer laser for myopic errors. MATERIAL AND METHODS: Prospective cohort study. Patients undergoing keratorefractive surgery, and having pre- and postoperative keratometries, and tomographies, were included. RESULTS: In 90 eyes, the differences in the power estimated by the CHM and the one determined by four approaches with the corneal tomographers, which included measurements of the posterior cornea, did not show statistically significant differences in their averages. However, the 95% limits of agreement were very wide. After obtaining regression formulas to adjust the values of these four variables, the results of the agreement analysis were similar. CONCLUSION: Although certain values either directly determined or derived from measurements with the Galilei® and MS-39®corneal tomographers, approximated the estimated value of postoperative corneal power according to the CHM, due to the amplitude of their limits of agreement, these calculations must be taken with care, because they may not be accurate in a given eye.

Determination of progressive endothelial cell loss after posterior chamber phakic intraocular lens implantation.

Comments about endothelial cell loss after posterior chamber phakic intraocular lens are provided, with a particular emphasis on the importance of determining progressive postoperative cell density reduction, excluding that related to surgical trauma.

Effectiveness and Safety of Non-Invasive Neuromodulation for Vision Restoration: A Systematic Review and Meta-Analysis.

We carried out a systematic review and meta-analysis to determine the effectiveness and safety of non-invasive electrical stimulation (NES) for vision restoration. We systematically searched for randomised controlled trials (RCTs) comparing NES with sham stimulation, for vision restoration between 2000 and 2022 in CENTRAL, MEDLINE, EMBASE, and LILACS. The main outcomes were as follows: visual acuity (VA); detection accuracy; foveal threshold; mean sensitivity as the parameter for the visual field; reading performance; contrast sensitivity (CS); electroencephalogram; quality of life (QoL), and safety. Two reviewers independently selected studies, extracted data, and evaluated the risk of bias using the Cochrane risk of bias 2.0 tool. The certainty in the evidence was determined using the GRADE framework. Protocol registration: CRD42022329342. Thirteen RCTs involving 441 patients with vision impairment indicate that NES may improve VA in the immediate post-intervention period (mean difference [MD] = -0.02 logMAR, 95% confidence intervals [CI] -0.08 to 0.04; low certainty), and probably increases QoL and detection accuracy (MD = 0.08, 95% CI -0.25 to 0.42 and standardised MD [SMD] = 0.09, 95% CI -0.58 to 0.77, respectively; both moderate certainty). NES likely results in little or no difference in mean sensitivity (SMD = -0.03, 95% CI -0.53 to 0.48). Compared with sham stimulation, NES increases the risk of minor adverse effects (risk ratio = 1.24, 95% CI 0.99 to 1.54; moderate certainty). The effect of NES on CS, reading performance, and electroencephalogram was uncertain. Our study suggests that although NES may slightly improve VA, detection accuracy, and QoL, the clinical relevance of these findings remains uncertain. Future research should focus on improving the available evidence's precision and consistency.

Assessing Fuchs Corneal Endothelial Dystrophy Using Artificial Intelligence-Derived Morphometric Parameters From Specular Microscopy Images.

PURPOSE: The aim of this study was to evaluate the efficacy of artificial intelligence-derived morphometric parameters in characterizing Fuchs corneal endothelial dystrophy (FECD) from specular microscopy images. METHODS: This cross-sectional study recruited patients diagnosed with FECD, who underwent ophthalmologic evaluations, including slit-lamp examinations and corneal endothelial assessments using specular microscopy. The modified Krachmer grading scale was used for clinical FECD classification. The images were processed using a convolutional neural network for segmentation and morphometric parameter estimation, including effective endothelial cell density, guttae area ratio, coefficient of variation of size, and hexagonality. A mixed-effects model was used to assess relationships between the FECD clinical classification and measured parameters. RESULTS: Of 52 patients (104 eyes) recruited, 76 eyes were analyzed because of the exclusion of 26 eyes for poor quality retroillumination photographs. The study revealed significant discrepancies between artificial intelligence-based and built-in microscope software cell density measurements (1322 ± 489 cells/mm 2 vs. 2216 ± 509 cells/mm 2 , P < 0.001). In the central region, guttae area ratio showed the strongest correlation with modified Krachmer grades (0.60, P < 0.001). In peripheral areas, only guttae area ratio in the inferior region exhibited a marginally significant positive correlation (0.29, P < 0.05). CONCLUSIONS: This study confirms the utility of CNNs for precise FECD evaluation through specular microscopy. Guttae area ratio emerges as a compelling morphometric parameter aligning closely with modified Krachmer clinical grading. These findings set the stage for future large-scale studies, with potential applications in the assessment of irreversible corneal edema risk after phacoemulsification in FECD patients, as well as in monitoring novel FECD therapies.

Ocular Trauma Characterization in a Reference Emergency Eye Centre in Colombia (FOSCAL).

BACKGROUND: Ocular trauma is one of the most important causes of ocular morbidity and inadequate visual acuity in developed and developing countries. In some countries, eye trauma is the leading cause of monocular blindness. Studies conducted in developing countries like Colombia suggest that there is a lack of awareness of preventive measures. In Colombia, there is no countrywide ocular trauma registry. The purpose of the present study is to describe and analyse characteristics of ocular trauma at a tertiary ophthalmology emergency department in Colombia. PATIENTS/METHODS AND MATERIAL: Patients who consulted or were referred to the ophthalmologic emergency department of FOSCAL due to eye injuries between March 1, 2022, and January 10, 2023, were included in this cross-sectional study. RESULTS: Of 1 957 patients, 2 088 eyes were included. Men comprised 78.5% of the patients, the median age was 36 years, and 75.0% lived in urban areas. The median latency between trauma and ophthalmology consultation was 21.8 hours. Of the eyes, 1 805 (88.4%) had suffered mechanical or mixed (mechanical plus burn) trauma. Of the injuries, 87.5% were unilateral. In terms of the circumstances, 45.9% of injuries occurred during working or educational activities (in 85.6% of these cases, without eye protection), 28.2% in home accidents, and 14.0% in transportation situations. According to the Birmingham Eye Trauma Terminology System (BETT), 1 735 eyes (91.1%) were closed globe injuries, and 49 eyes (2.7%) were open globe injuries. Fifty eyes (2.8%) could not be categorised according to BETT at the initial consultation and were classified as "still to be determined". In the Ocular Trauma Score (OTS), 85.8% were category 5. Of the ocular burn cases, 93.0% were categorised as grade I according to the Roper Hall classification. CONCLUSIONS: In line with global literature, a much higher proportion of men than women sought consultation for ocular trauma. The findings suggest a need for improvement in the referral process from institutions with the lowest level of care. Lack of awareness about eye protection is an issue. Surgical exploration or additional tests may be necessary for precise injury classification. We therefore propose adding a "still to be determined" category to the BETT initial classification. These cases may be reclassified later, thus improving the accuracy of OTS calculation.

Agreement between Two Swept-source Optical Coherence Tomography: Optic Nerve Head, Retinal Nerve Fiber Layer and Ganglion Cell Layers in Healthy Eyes.

Aim and background: Precision of optical coherence tomography (OCT) measurements of the optic nerve head (ONH), retinal nerve fiber layer (RNFL), and macular ganglion cell layer (GCL) is essential for the diagnosis and monitoring of glaucoma. The purpose of this research was to evaluate the repeatability and reproducibility of retinal and ONH parameters measured with two identical swept-source optical coherence devices. Methods: A cross-sectional study was conducted. A total of 30 eyes of 15 healthy subjects were included. Two technicians performed four OCT-wide protocol scans in the same visit using two identical Triton swept-source OCT (DRI-OCT) instruments. The interdevice and interobserver reproducibility and the repeatability of both instruments for all ONH, RNFL, and macular GCL parameters were evaluated by the intraclass correlation coefficient (ICC). Additionally, Bland-Altman test analysis was used for repeatability and reproducibility measurements. Results: Intraclass correlation coefficient (ICCs) of the ONH, RNFL, and GCL measurements were excellent for repeatability and interdevice reproducibility (>0.9). Interobserver reproducibility was good for all parameters except for RNFL clock hour 11 (ICC = 0.72). The variability of the average RNFL was from -4.103 to 4.97 µm, with a mean percentage of the difference (PD) of 0.37 ± 2.03%. Among GCL parameters, the greatest variability was found in the inferior sector (PD = -0.88 ± 5.39%, limits of agreement (LoA) = -8.345-7.078 µm). Conclusion: Using two identical swept-source OCT instruments for the evaluation of the structural parameters of the ONH, RNFL, and macular GCL showed high repeatability and reproducibility. This allows the clinician to make a therapeutic decision based on OCT findings coupled with the clinical evaluation of the patient. When evaluating RNFL clock hours measurements, interobserver reproducibility might decrease. Clinical significance: The understanding of measurement variability while using different devices and the impact of the observer capturing the images, is clinically relevant. How to cite this article: Prada AM, Tello A, Rangel CM, et al. Agreement between Two Swept-source Optical Coherence Tomography: Optic Nerve Head, Retinal Nerve Fiber Layer and Ganglion Cell Layers in Healthy Eyes. J Curr Glaucoma Pract 2023;17(2):85-90.

Safety of intracameral application of moxifloxacin and dexamethasone (Vigadexa®) after phacoemulsification surgery.

BACKGROUND: Intracameral antibiotics, such as moxifloxacin and cefuroxime, are safe to corneal endothelial cells and effective prophylaxis of endophthalmitis after cataract surgery. Corneal endothelial cells decrease in density after cataract surgery. Any substance used in the anterior chamber may affect corneal endothelial cells and lead to a greater decrease in density. This study wants to determine the percentage of endothelial cell loss after cataract extraction by phacoemulsification with off-label intracameral injection of moxifloxacin and dexamethasone (Vigadexa®). METHODS: An observational retrospective study was performed. The clinical records of patients undergoing cataract surgery by phacoemulsification plus intracameral injection of Vigadexa® were analyzed. Endothelial cell loss (ECL) was calculated using preoperative and postoperative endothelial cell density. The relation of endothelial cell loss with cataract grade using LOCS III classification, total surgery time, total ultrasound time, total longitudinal power time, total torsional amplitude time, total aspiration time, estimated fluid usage, and cumulative dissipated energy (CDE) was studied using univariate linear regression analysis and logistic regression analysis. RESULTS: The median loss of corneal endothelial cells was 4.6%, interquartile range 0 to 10.4%. Nuclear color and CDE were associated with increased ECL. ECL>10% was associated with age and total ultrasound time in seconds. CONCLUSIONS: The endothelial cell loss after the intracameral use of Vigadexa® at the end of cataract surgery was similar to the reported in other studies of cataract surgery without the use of intracameral prophylaxis for postoperative endophthalmitis (POE). This study confirmed the association of CDE and nuclear opalescence grade with postoperative corneal endothelial cell loss.

Corneal endothelium assessment in specular microscopy images with Fuchs' dystrophy via deep regression of signed distance maps.

Specular microscopy assessment of the human corneal endothelium (CE) in Fuchs' dystrophy is challenging due to the presence of dark image regions called guttae. This paper proposes a UNet-based segmentation approach that requires minimal post-processing and achieves reliable CE morphometric assessment and guttae identification across all degrees of Fuchs' dystrophy. We cast the segmentation problem as a regression task of the cell and gutta signed distance maps instead of a pixel-level classification task as typically done with UNets. Compared to the conventional UNet classification approach, the distance-map regression approach converges faster in clinically relevant parameters. It also produces morphometric parameters that agree with the manually-segmented ground-truth data, namely the average cell density difference of -41.9 cells/mm2 (95% confidence interval (CI) [-306.2, 222.5]) and the average difference of mean cell area of 14.8 µm 2 (95% CI [-41.9, 71.5]). These results suggest a promising alternative for CE assessment.

Phakic iris-claw intraocular lens: calculations of power and long-term endothelial cells loss.

A correction about phakic intraocular lens power calculation process, as it was stated by Li, Song & Song, is provided. It is explained that this calculation is based on the Van der Heijde formula and not on biometric formulas. A comment about the mechanisms of late endothelial cell loss following phakic intraocular lenses is done.

Indigenous ecological calendars and seasonal vector-borne diseases in the Colombian Amazon: an intercultural and interdisciplinary approach / Calendarios ecológicos indígenas y enfermedades estacionales transmitidas por vectores en la Amazonia colombiana: un enfoque intercultural e interdisciplinario

Traditional ecological knowledge of indigenous groups in the southeastern Colombian Amazon coincides in identifying the two main hydrological transition periods (wet-dry: August-November; dry-wet: March-April) as those with greater susceptibility to disease in humans. Here we analyze the association between indigenous knowledge about these two periods and the incidence of two vector-borne diseases: malaria and dengue. We researched seven "ecological calendars" from three regions in the Colombian Amazon, malaria and dengue cases reported from 2007 to 2019 by the Colombian National Institute of Health, and daily temperature and precipitation data from eight meteorological stations in the region from 1990-2019 (a climatological normal). Malaria and dengue follow a seasonal pattern: malaria has a peak from August to November, corresponding with the wet-dry transition (the "season of the worms" in the indigenous calendars), and dengue has a peak in March and April, coinciding with the dry-wet transition. Previous studies have shown a positive correlation between rainfall and dengue and a negative correlation between rainfall and malaria. However, as the indigenous ecological knowledge codified in the calendars suggests, disease prediction cannot be reduced to a linear correlation with a single environmental variable. Our data show that two major aspects of the indigenous calendars (the time of friaje as a critical marker of the year and the hydrological transition periods as periods of greater susceptibility to diseases) are supported by meteorological data and by the available information about the incidence of malaria and dengue.(AU)

Los conocimientos ecológicos tradicionales de grupos indígenas del sureste de la Amazonia colombiana coinciden en identificar dos principales periodos de transición hidrológica (seco-húmedo: agosto-noviembre; húmedo-seco: marzo-abril) como los de mayor susceptibilidad a enfermedades en humanos. Aquí analizamos la asociación entre el conocimiento indígena sobre estos dos periodos y la incidencia de dos enfermedades transmitidas por vectores: malaria y dengue. Investigamos siete calendarios ecológicos de tres regiones en la Amazonia colombiana, casos de dengue y malaria reportados de 2007 hasta 2019 por el Instituto Nacional de Salud de Colombia y datos diarios de temperatura y precipitación de ocho estaciones meteorológicas en la región, de 1990 a 2019 (una normal climatológica). Malaria y dengue siguen un patrón estacional, la malaria tiene un pico de agosto a noviembre, correspondiendo con la transición húmedo-seco (el "tiempo de gusano" según los calendarios indígenas), mientras que dengue tiene un pico de marzo a abril, coincidiendo con la transición seco-húmedo. Estudios previos mostraron una correlación positiva entre precipitación y dengue, y una correlación negativa entre precipitación y malaria. Sin embargo, como lo sugiere el conocimiento ecológico codificado en los calendarios indígenas, la predicción de enfermedades no puede reducirse a una correlación lineal con una sola variable medioambiental. Nuestros datos muestran que dos aspectos principales de los calendarios indígenas (el tiempo de friaje como un marcador crítico anual y los periodos de transición hidrológica como épocas de mayor susceptibilidad a enfermedades) están soportados por datos meteorológicos e información disponible acerca de la incidencia de malaria y dengue.(AU)

ENDOPHTHALMITIS IN OPHTHALMOLOGICAL REFERRAL CENTRE IN COLOMBIA: AETIOLOGY AND MICROBIAL RESISTANCE.

AIMS: To describe the aetiology and microbial susceptibility profile of endophthalmitis cases treated at an ophthalmological referral centre in Colombia. MATERIAL AND METHODS: A retrospective descriptive study was carried out with all endophthalmitis cases referred to the Fundación Oftalmológica de Santander FOSCAL (Floridablanca, Colombia) from 1 January 2012 to 31 December 2015. RESULTS: 121 eyes of 121 patients were evaluated. 77.7% of them were male and the mean age was 42.9 years. Five of them (4.1%) corresponded to endogenous endophthalmitis, and 116 (95.9%) to exogenous endophthalmitis. Of the latter, 66.9% were associated with trauma (almost one-half of them associated with intraocular foreign body), and 29.5% with intraocular surgery. The most common isolated microorganisms in the exogenous endophthalmitis group corresponded to methicillin-resistant and methicillin-sensitive strains of Staphylococcus epidermidis and Staphylococcus aureus, which were mostly susceptible to imipenem, vancomycin and moxifloxacin and resistant to ceftazidime. CONCLUSION: Endophthalmitis is a potentially sight-threatening condition, especially in cases of inadequate treatment. Therefore, antimicrobial therapy should be guided by vitreous humour culture to assure that the causative microorganism is susceptible to the selected agent. The results of our study lead us to propose vancomycin, moxifloxacin or imipenem as first-line antimicrobial options.