Illumination levels in commonly used ophthalmic devices.

Pupil diameter is a key parameter for corneal and multifocal intraocular lens surgery. Many devices are dedicated to measure the pupil size, but do not specify the illumination during capture. The aim of this study was to present illumination levels in routinely used ophthalmic devices which present pupil sizes. To obtain measurements, the lux meter was placed in the chin rest in the corneal plane and the room was completely dimmed. Ten measurements were taken for each device. The illumination levels for white and red Placido disk corneal topographers were 1253.1 ± 0.2 and 329.0 ± 0.2 lux, respectively (both photopic conditions). Scheimpflug corneal tomography should be considered as a mesopic measurement (14.5 ± 0.1 lux). Optical coherence tomography and autorefractometry are scotopic measurements (0.4-0.6 lux). We postulate that producers should provide illumination levels of their devices measuring pupil size. Moreover, when mentioning a pupil size, one should consider presenting to what lighting conditions it refers to.

Evaluation of color vision related quality of life changes due to cataract surgery.

Questionnaires have been used as research tools to provide a standardized approach to assess quality of life at various time periods and populations. However, literature shows only a few articles about self-reported color vision changes. Our aim was to evaluate the subjective patient feelings before and after cataract surgery and compare the results with a color vision test result. Our method was as follows: 80 cataract patients filled out a modified color vision questionnaire and performed the Farnsworth-Munsell 100 Hue Color Vision Test (FM100) before, two weeks, and six months after cataract surgery. We analyzed the correlations between these two types of results, which reveal that FM100 hue performance and subjective perception improved after surgery. Additionally, subjective patient questionnaire scores correlate well with the FM100 test results before and two weeks after the cataract surgery, but this effect decreased with longer follow-up times. We conclude that subjective color vision changes can only be noticed at longer periods after the cataract surgery. Health care professionals can use this questionnaire to better understand the subjective feelings of patients and monitor their color vision sensitivity changes.

Recommendation for Presbyopia-Correcting Intraocular Lenses: A Delphi Consensus Statement by the ESASO Study Group.

PURPOSE: To establish consensus among experts in lens and refractive surgery to guide general ophthalmologists on issues related to presbyopia-correcting intraocular lenses (IOLs). DESIGN: A modified Delphi method to reach a consensus among experts. METHODS: A steering committee formulated 105 relevant items grouped into four sections (preoperative considerations, IOL selection, intraoperative considerations, and postoperative considerations). The consensus was defined as ≥ 70% of experts agreeing with the evaluation of a statement. RESULTS: Ten experts participated and completed all rounds of questionnaires (100% response rate). Of 68 items considered in the preoperative considerations, consensus was achieved in 48 (70.6%). There was a lack of consensus over IOL selection, the experts only agreed on the importance of the patient's habits for the optical IOL design selection. Of the 14 considerations related to intraoperative issues, the experts reached a consensus on 10 (71.4%). The postoperative considerations section reached the highest consensus in 10 items of 13 (76.9%). CONCLUSIONS: Key recommendations for a diffractive multifocal IOL were a potential postoperative visual acuity > 0.5, a keratometry between 40-45 diopters, a pupil >2.8 mm under photopic conditions and <6.0 mm under scotopic conditions, a root mean square of higher order corneal aberrations <0.5 µm for 6-mm pupil size, while monofocal or non-diffractive IOLs should be considered for patients with coexisting eye disorders. A lack of agreement was found in the issues related to the IOL selection.

Trade-off between coding efficiency and color space in outer retinal circuits with colored oil droplets.

To enhance color vision, animals adapt diverse strategies according to their environmental conditions. For instance, zebrafish use clever retinal circuits to encode spectral information in aquatic environments. Other species, such as birds, develop colored oil droplets to expand their plethora of distinguishable colors. Studies on these species provide insights into each strategy. Nevertheless, there is no data on retinas using both strategies simultaneously. In this work, we combine our knowledge of colored oil droplets and circuits for efficient spectral coding in different species to explore the outcome of retinas exhibiting both strategies simultaneously. Our findings suggest the existence of a trade-off between coding efficiency and color-space area in zebrafish-like retinal circuits. More specifically, we find that spectral encoding becomes compromised with the presence of colored oil droplets while the accessible color space expands significantly.

A Comparison Between Three Computer-Based Cone Specific Color Vision Tests.

INTRODUCTION: Computerized color contrast sensitivity (CS) tests that aim to determine presence, type, and severity of color vision deficiency have been developed and are available, but data on agreement between tests is lacking. The purpose of the present study was to determine data agreement between three computerized color vision tests.METHODS: A total of 50 subjects, 25 color vision normal (CVN) and 25 color vision deficient (CVD), were tested with the Konan CCT-HD®, NCI, and a modified version of the Innova CCT. Sensitivity and specificity were compared across systems as well as differences in log CS values and how these relate to standards used to classify occupational performance.RESULTS: Each test showed 100% sensitivity for detection of hereditary red-green CVDs as well as type (protan vs. deutan). Each test showed 100% specificity for confirming normal red-green color vision in CVNs. Innova CCT and NCI showed 100% specificity in CVNs and CVDs for S cone CS. Konan CCT-HD® showed 96% specificity in CVNs and 92% in CVDs for S cone CS.DISCUSSION: These findings indicate that each test reliably identifies hereditary CVD and confirms normal color vision. However, the three tests differ slightly in log CS values used to determine pass/fail scores of red-green color vision using a 100-point scale, and all show that protans consistently score lower than deutans on cone CS. Hence, depending on the criterion used in occupational settings, a single score may not prove equitable for individuals who have a protan deficiency.Lovell J, Rabin J. A comparison between three computer-based cone specific color vision tests. Aerosp Med Hum Perform. 2023; 94(2):54-58.

Reliability and agreement of apparent chord mu measurements between static and dynamic evaluations.

PURPOSE: To assess the repeatability and agreement of Cartesian coordinates and the length of apparent chord mu and pupil diameter measurements during static (Galilei G4) and dynamic (Topolyzer Vario) evaluations. SETTING: IOBA-Eye Institute, Valladolid, Spain. DESIGN: Case series. METHODS: 3 consecutive measurements per scenario (Galilei G4 and Topolyzer Vario under low mesopic and photopic conditions) were performed by the same clinician. The intrasession repeatability was assessed using the within-subject SD (Sw), the precision, the coefficient of variation, and the intraclass correlation coefficient (ICC). The agreement was analyzed using repeated-measures analysis of variance and the Bland-Altman method. RESULTS: Thirty-seven healthy participants were recruited. The Sw values for chord mu parameters and pupil diameter ranged from 0.01 to 0.03 and 0.08 to 0.21, respectively. The ICC was ≥0.89 for all parameters. Galilei G4 and Topolyzer Vario under low mesopic and photopic conditions provided significantly different measures of apparent chord mu length (0.23 ± 0.11 mm, 0.30 ± 0.10 mm, and 0.25 ± 0.11 mm, respectively, P ≤ .02), X-coordinate (-0.18 ± 0.12 mm, -0.27 ± 0.11 mm, and -0.21 ± 0.12 mm, respectively, P < .001), and pupil diameter (3.38 ± 0.50 mm, 6.29 ± 0.60 mm, and 3.04 ± 0.41 mm, respectively, P < .001). Y-coordinate values obtained by Galilei G4 and Topolyzer Vario under low mesopic conditions were significantly different (0.06 ± 0.13 mm vs 0.03 ± 0.11 mm, respectively, P = .02), in contrast to Galilei G4 and Topolyzer Vario under photopic conditions (0.05 ± 0.13 mm, P = .82) and both illumination conditions of Topolyzer Vario (P ≥ .23). CONCLUSIONS: Galilei G4 and Topolyzer Vario provide consistent measurements of apparent chord mu Cartesian coordinates and length, as well as pupil diameter; however, the measurements are not interchangeable. Ophthalmic surgeons should consider these findings when planning customized intraocular lens implantation and refractive surgery procedures.

[Opto-functional results in keratoconus patients after intrastromal keratoplasty]. / Optiko-funktsional'nye rezul'taty posle intrastromal'noi keratoplastiki pri keratokonuse.

Intrastromal keratoplasty with allograft implantation can stop the progression of keratoconus (KC) and improve visual acuity (VA). Although optimization of keratometric parameters and an increase in VA improve the quality of vision (QoV), there are other indicators that affect the QoV and the quality of life (QoL) of patients and require further study. PURPOSE: Analysis of quantitative and qualitative characteristics of vision in patients with stage II and III keratoconus who underwent intrastromal allokeratoplasty. MATERIAL AND METHODS: The study included 15 patients (15 eyes) with stage II-III KC (Amsler-Krumeich classification) aged 17 to 38 years old (28.8±6.2). All patients underwent intrastromal keratoplasty with implantation of an allograft in the form of a wide incomplete ring. The following parameters were assessed before and 6 months after surgery: distance VA with and without correction, near VA with and without correction, VA with glare effect, high-order aberrations (HOA), thickness of the tear film lipid layer, spatial contrast sensitivity (SCS) under photopic and mesopic conditions with light filters, reading speed. RESULTS: VA without correction increased from 0.15 to 0.7; with correction from 0.35 to 0.7. The glare effect with varying degrees of illumination did not affect VA either before or after surgery. Statistically significant changes were observed when comparing the aberrations «coma¼, «spherical¼, «trefoil¼ before and after the intervention, they became inverted. The thickness of the tear film lipid layer did not change significantly when comparing pre- and postoperative data. The use of light filters (orange, yellow) did not lead to significant changes in the VA and SCS under photopic and mesopic conditions. CONCLUSION: The use of a wide intrastromal allograft to correct deformity and stabilize the cornea in keratoconus improves the patients' quality of vision and visual performance.

Color Vision and Microperimetry Changes in Nonexudative Age-Related Macular Degeneration After Risuteganib Treatment: Exploratory Endpoints in a Multicenter Phase 2a Double-Masked, Randomized, Sham-Controlled, Crossover Clinical Trial.

BACKGROUND AND OBJECTIVE: To explore the association between best-corrected visual acuity (BCVA) improvement and changes in microperimetry (MP) and color vision in patients with nonexudative age-related macular degeneration following administration of two 1.0-mg intravitreal doses of risuteganib. PATIENTS AND METHODS: In a phase 2a, prospective, double-masked, sham-controlled study, eyes with nonexudative age-related macular degeneration and Early Treatment Diabetic Retinopathy Study BCVA between 20/40 and 20/200 were randomized to intravitreal risuteganib (1.0 mg) or sham injection. The risuteganib group received a second 1.0-mg dose, and patients in the sham group crossed over to receive 1.0 mg of risuteganib at week 16. Exploratory endpoints included changes in color vision and mesopic MP. RESULTS: Thirty-nine patients (risuteganib, n = 25; sham, n = 14) completed the study. There was a significant (P < .05) correlation between BCVA and the total error score (TES) for both Lanthony and Hue Style. Confusion index was close to the criterion for significance (P = .056) in the risuteganib group. All color vision metrics demonstrated a trend toward improvement in risuteganib responders (BCVA letter gain ≥8 letters) and no change in the nonresponders, with significant differences seen in confusion index between the risuteganib and control group (P = .0493) and between responders and nonresponders (P = .0478). MP showed that risuteganib responders improved in mean sensitivity and change in number of loci ≤11 dB and ≤0 dB, whereas nonresponders worsened. CONCLUSION: All color vision and MP parameters tested trended toward improvement in risuteganib-treated patients and risuteganib responders. Statistically significant improvement was evident in two metrics: confusion index (in risuteganib-treated patients and responders) and number of loci with decreased sensitivity (in responders). A significant correlation between BCVA and both TES Lanthony and TES Hue Style in risuteganib patients provides concurrent evidence of objective and subjective improvement of retinal function. [Ophthalmic Surg Lasers Imaging Retina 2022;53:430-438.].

Pérdida no orgánica de la visión de colores / Nonorganic loss of color vision

La pérdida no orgánica de la visión o pérdida funcional, es un trastorno en el cual se presenta cierta sintomatología visual, sin que haya causa alguna que pueda justificarlo. Se presenta un caso de una paciente adolescente femenina de 16 años de edad, color de piel blanca, con antecedentes oculares de ptosis palpebral derecha congénita y malos hábitos alimentarios. Su motivo de consulta fue pérdida de la visión de colores no constatada inicialmente; luego, debido a su insistencia, comenzamos a notar una disminución progresiva e incongruente de la visión cromática, con parámetros funcionales visuales normales, defectos en campos visuales computarizados no reproducibles y exámenes de electrofisiología visual normales, con recuperación total de este defecto sin tomarse ninguna conducta terapéutica específica. La pérdida no orgánica de la visión se refiere a cualquier defecto visual en la que no se demuestra alteración de las estructuras que se encuentran entre la córnea y la corteza cerebral occipital. Los trastornos de la vía aferente constituyen la manifestación más frecuente. Puede existir disminución, unilateral o bilateral, de la visión, afectación del campo visual o ambos. La visión de colores es usualmente anormal, pero rara vez, es el motivo de consulta. El origen psicógeno es corriente en niños y es más frecuente en mujeres que en hombres. El déficit adquirido de la visión de colores ocurre a consecuencia de una patología ocular, lesión intracraneal o uso excesivo de algún medicamento y, por lo general, se acompaña de pérdida variable de la agudeza visual(AU)

Non-organic loss of vision or functional loss is a disorder in which certain visual symptomatology is present, without any cause that could justify it. We present a case of a 16-year-old female adolescent patient, white skin color, with ocular history of congenital right palpebral ptosis and bad eating habits. Her reason for consultation was loss of color vision not initially detected; then, due to her insistence, we began to notice a progressive and incongruent decrease in color vision, with normal visual functional parameters, defects in non-reproducible computerized visual fields and normal visual electrophysiology tests, with total recovery of this defect without any specific therapeutic behavior. Non-organic vision loss refers to any visual defect in which no alteration of the structures between the cornea and the occipital cerebral cortex is demonstrated. Disorders of the afferent pathway constitute the most frequent manifestation. There may be unilateral or bilateral decreased vision, visual field impairment, or both. Color vision is usually abnormal, but rarely, it is the reason for consultation. Psychogenic origin is common in children and is more frequent in women than in men. Acquired color vision deficits occur as a consequence of an ocular pathology, intracranial injury or excessive use of medication and are usually accompanied by variable loss of visual acuity(AU)

Deficits in color detection in patients with Alzheimer disease.

Deficits in color vision and related retinal changes hold promise as early screening biomarkers in patients with Alzheimer's disease. This study aimed to determine a cut-off score that can screen for Alzheimer's dementia using a novel color vision threshold test named the red, green, and blue (RGB) modified color vision plate test (RGB-vision plate). We developed the RGB-vision plate consisting of 30 plates in which the red and green hues of Ishihara Plate No.22 were sequentially adjusted. A total of 108 older people participated in the mini-mental state examination (MMSE), Ishihara plate, and RGB-vision plate. For the analyses, the participants were divided into two groups: Alzheimer's dementia (n = 42) and healthy controls (n = 38). K-means cluster analysis and ROC curve analysis were performed to identify the most appropriate cut-off score. As a result, the cut-off screening score for Alzheimer's dementia on the RGB-vision plate was set at 25, with an area under the curve of 0.773 (p<0.001). Moreover, there was a negative correlation between the RGB-vision plate thresholds and MMSE scores (r = -0.36, p = 0.02). In conclusion, patients with Alzheimer's dementia had a deficit in color vision. The RGB-vision plate is a potential early biomarker that may adequately detect Alzheimer's dementia.

Dysphotopsia and functional quality of vision after implantation of an intraocular lens with a 7.0 mm optic and plate haptic design.

PURPOSE: To determine the impact of an intraocular lens (IOL) with a 7.0 mm optic and plate haptic design on incidence of dysphotopsia and visual functions after cataract surgery. SETTING: Day-care clinic. DESIGN: Prospective monocentric randomized patient-blinded comparative clinical study. METHODS: Following preoperative measurements, patients underwent cataract surgery with implantation of 2 IOL designs-with 7.0 mm optic and plate haptics (Group 1) or with 6.0 mm optic and C-loop haptics (Group 2). In month 1, 3, and 12 follow-ups, patients were examined, answered a questionnaire regarding satisfaction, spectacle dependence, frequency, and extent of positive and negative dysphotopsia, and underwent contrast sensitivity (CS), mesopic vision, and glare sensitivity testing. The data were analyzed as nominal, ordinal, and metric with chi-square, Mann-Whitney U, Wilcoxon, and t tests. RESULTS: Out of a total number of 120 eyes (86 patients), Group 1 comprised 57 eyes (43 patients), Group 2 comprised 63 eyes (43 patients). Corrected distance visual acuity was the same between groups throughout the study. Group 1 showed significantly lower incidence of positive and negative dysphotopsia in month 1 follow-up (P = .021 and .015, respectively) and a higher satisfaction rate in month 3 follow-up (P = .006). Mean CS and mesopic vision with and without glare were the same in both groups. Positive dysphotopsia cases in month 12 follow-up revealed lower photopic CS (P = .005, .036, and 0.047, respectively), longer axial length, and greater preoperative pupil dynamics (P = .04 and .06). CONCLUSIONS: The IOL design with 7.0 mm optic diameter and plate haptics reduced dysphotopsia and provided good visual acuity, CS, mesopic vision with and without glare, and high patient satisfaction.

Chromatic and flicker threshold changes in age-related macular degeneration following anti-VEGF treatment.

CLINICAL RELEVANCE: Red-green chromatic sensitivity and photopic (cone-mediated) flicker sensitivity showed marked improvement after anti-VEGF treatment. The use of flicker and chromatic sensitivities as potential functional tests to monitor treatment outcomes in age-related macular degeneration highlights the clinical importance. BACKGROUND: High-contrast visual acuity (VA) is not a sensitive clinical marker in the management of age-related macular degeneration (AMD). Therefore, flicker and chromatic sensitivity changes were assessed following anti-VEGF treatment in subjects with neovascular AMD. METHODS: Subjects diagnosed with neovascular AMD were recruited. VA was measured using a COMPlog chart. Flicker (in central 5°) and chromatic thresholds (red-green and yellow-blue) were measured using Flicker-plus test and Colour Assessment and Diagnosis (CAD) tests, respectively. Baseline thresholds and foveal thickness were measured on the same day, just before anti-VEGF injection delivery and 5 weeks ± 5 days later. RESULTS: Thirteen subjects (8 males, 5 females) with a mean age of 67.5 ± 8.2 years completed the study. Median VA was not significantly different post-treatment (0.57 logMAR [~6/22: Snellen equivalent], IQR: 0.33) compared to baseline (0.56 logMAR, IQR: 0.33), Wilcoxon matched-pair test, p = 0.55). Median Red-Green thresholds improved significantly post-treatment (22.15 CAD units, IQR: 26.06, n = 9), compared to baseline (24.24 CAD units, IQR: 26.21, p = 0.02). Median photopic and mesopic FMT did not show significant change post treatment compared to baseline (p > 0.01, statistical significance of p-value corrected for multiple comparisons was set to 0.01). Similarly, the foveal thickness was not significantly different at post-treatment visit than baseline (p = 0.53). CONCLUSION: Red/green sensitivity recovered better than yellow/blue sensitivity, thus, providing insight into recovery mechanisms in AMD and usefulness of these tests as clinical markers in the management of AMD.

Effect of long-term chronic hyperhomocysteinemia on retinal structure and function in the cystathionine-ß-synthase mutant mouse.

Elevated levels of the excitatory amino acid homocysteine (Hcy) have been implicated in retinal diseases in humans including glaucoma and macular degeneration. It is not clear whether elevated Hcy levels are pathogenic. Models of hyperhomocysteinemia (Hhcy) have proven useful in addressing this including mice with deficiency in the enzyme cystathionine ß-synthase (CBS). Cbs+/- mice have a ∼two-fold increase in plasma and retinal Hcy levels. Previous studies of visual function and structure in Cbs+/- mice during the first 10 months of life revealed mild ganglion cell loss, but minimal electrophysiological alterations. It is not clear whether extended, chronic exposure to moderate Hhcy elevation will lead to visual function loss and retinal pathology. The present study addressed this by performing comprehensive analyses of retinal function/structure in 20 month Cbs+/- and Cbs+/+ (WT) mice including IOP, SD-OCT, scotopic and photopic ERG, pattern ERG (pERG), and visual acuity. Eyes were harvested for histology and immunohistochemical analysis of Brn3a (ganglion cells), dihydroethidium (oxidative stress) and GFAP (gliosis). The analyses revealed no difference in IOP between groups for age/strain. Visual acuity measured ∼0.36c/d for mice at 20 months in Cbs+/- and WT mice; contrast sensitivity did not differ between groups at either age. Similarly SD-OCT, scotopic/photopic ERG and pERG revealed no differences between 20 month Cbs+/- and WT mice. There was minimal disruption in retinal structure when eyes were examined histologically. Morphometric analysis revealed no significant differences in retinal layers. Immunohistochemistry revealed ∼5 RGCs/100 µm retinal length in both Cbs+/- and WT mice at 20 months. While there was greater oxidative stress and gliosis in older (20 month) mice versus young (4 month) mice, there was no difference in these parameters between the 20 month Cbs+/- and WT mice. We conclude that chronic, moderate Hhcy (at least due to deficiency of Cbs) is not accompanied by retinal structural/functional changes that differ significantly from age-matched WT littermates. Despite considerable evidence that severe Hhcy is toxic to retina, moderate Hhcy appears tolerated by retina suggesting compensatory cellular survival mechanisms.

Weeklong improved colour contrasts sensitivity after single 670 nm exposures associated with enhanced mitochondrial function.

Mitochondrial decline in ageing robs cells of ATP. However, animal studies show that long wavelength exposure (650-900 nm) over weeks partially restores ATP and improves function. The likely mechanism is via long wavelengths reducing nanoscopic interfacial water viscosity around ATP rota pumps, improving their efficiency. Recently, repeated 670 nm exposures have been used on the aged human retina, which has high-energy demands and significant mitochondrial and functional decline, to improve vision. We show here that single 3 min 670 nm exposures, at much lower energies than previously used, are sufficient to significantly improve for 1 week cone mediated colour contrast thresholds (detection) in ageing populations (37-70 years) to levels associated with younger subjects. But light needs to be delivered at specific times. In environments with artificial lighting humans are rarely dark-adapted, hence cone function becomes critical. This intervention, demonstrated to improve aged mitochondrial function can be applied to enhance colour vision in old age.

Conditional Deletion of Cytoplasmic Dynein Heavy Chain in Postnatal Photoreceptors.

Purpose: Cytoplasmic dynein-1 (henceforth dynein) moves cargo in conjunction with dynactin toward the minus end of microtubules. The dynein heavy chain, DYNC1H1, comprises the backbone of dynein, a retrograde motor. Deletion of Dync1h1 abrogates dynein function. The purpose of this communication is to demonstrate effects of photoreceptor dynein inactivation during late postnatal development and in adult retina. Methods: We mated Dync1h1F/F mice with iCre75 and Prom1-CreERT2 mice to generate conditional rod and tamoxifen-induced knockout in rods and cones, respectively. We documented retina degeneration with confocal microscopy at postnatal day (P) 10 to P30 for the iCre75 line and 1 to 4 weeks post tamoxifen induction (wPTI) for the Prom1-CreERT2 line. We performed scotopic and photopic electroretinography (ERG) at P16 to P30 in the iCre75 line and at 1-week increments in the Prom1-CreERT2 line. Results were evaluated statistically using Student's t-test, two-factor ANOVA, and Welch's ANOVA. Results: Cre-induced homologous recombination of Dync1h1F/F mice truncated DYNC1H1 after exon 23. rodDync1h1-/- photoreceptors degenerated after P14, reducing outer nuclear layer (ONL) thickness and combined inner segment/outer segment (IS/OS) length significantly by P18. Scotopic ERG a-wave amplitudes decreased by P16 and were extinguished at P30. Cones were stable under rod-knockout conditions until P21 but inactive at P30. In tamDync1h1-/- photoreceptors, the IS/OS began shortening by 3wPTI and were nearly eliminated by 4wPTI. The ONL shrank significantly over this interval, indicating rapid photoreceptor degeneration following the loss of dynein. Conclusions: Our results demonstrate dynein is essential for the secretory pathway, formation of outer segments, and photoreceptor maintenance.

An Analysis of Metabolic Changes in the Retina and Retinal Pigment Epithelium of Aging Mice.

Purpose: The purpose of this study was to present our hypothesis that aging alters metabolic function in ocular tissues. We tested the hypothesis by measuring metabolism in aged murine tissues alongside retinal responses to light. Methods: Scotopic and photopic electroretinogram (ERG) responses in young (3-6 months) and aged (23-26 months) C57Bl/6J mice were recorded. Metabolic flux in retina and eyecup explants was quantified using U-13C-glucose or U-13C-glutamine with gas chromatography-mass spectrometry (GC-MS), O2 consumption rate (OCR) in a perifusion apparatus, and quantifying adenosine triphosphatase (ATP) with a bioluminescence assay. Results: Scotopic and photopic ERG responses were reduced in aged mice. Glucose metabolism, glutamine metabolism, OCR, and ATP pools in retinal explants were mostly unaffected in aged mice. In eyecups, glutamine usage in the Krebs Cycle decreased while glucose metabolism, OCR, and ATP pools remained stable. Conclusions: Our examination of metabolism showed negligible impact of age on retina and an impairment of glutamine anaplerosis in eyecups. The metabolic stability of these tissues ex vivo suggests age-related metabolic alterations may not be intrinsic. Future experiments should focus on determining whether external factors including nutrient supply, oxygen availability, or structural changes influence ocular metabolism in vivo.

Calidad visual en la cirugía bilateral del cristalino por facoemulsificación / Visual quality in bilateral crystalline lens surgery by phacoemulsification

Objetivo: Analizar la recuperación y la calidad visual posoperatoria en la cirugía bilateral del cristalino por facoemulsificación. Métodos: Se realizó un estudio prospectivo y analítico de serie de casos en 40 pacientes con el diagnóstico de catarata bilateral, operados por cirugía bilateral simultánea del cristalino, atendidos en el Centro de Microcirugía Ocular del Instituto Cubano de Oftalmología "Ramón Pando Ferrer", durante el periodo comprendido desde noviembre del año 2018 hasta marzo de 2020. Se analizaron las variables edad, sexo, dureza nuclear según LOCS III, mejor agudeza visual con y sin corrección, astigmatismo medio inducido, visión de colores, sensibilidad al contraste, velocidad de lectura y estudio de la calidad de vida por la encuesta FV-14. Se emplearon los porcentajes y los números absolutos para resumir las variables cualitativas. En el caso de las cuantitativas se usó la media con su desviación estándar y el intervalo de confianza del 95 por ciento. Resultados: Fue más frecuente el sexo femenino en el 65 por ciento; la edad media fue de 69,1 ± 8,1 años. El 55,11 por ciento de los pacientes tuvo dureza NO3. La media de la mejor agudeza visual sin corrección mejoró a 0,89 ± 0,25; la mejor agudeza visual con corrección mejoró a 0,96 ± 0,03; el resto de las variables estudiadas mostró mejoría significativa. Conclusiones: La cirugía bilateral simultánea del cristalino personalizada contribuye de manera significativa a la mejoría de la visión en cantidad y calidad, lo que permite recuperar la calidad de vida de los pacientes(AU)

Objective: Analyze postoperative recovery and visual quality in bilateral crystalline lens surgery by phacoemulsification. Methods: An analytical prospective study was conducted of a case series of 40 bilateral cataract patients undergoing simultaneous bilateral crystalline lens surgery at the Center for Ocular Microsurgery of Ramón Pando Ferrer Cuban Institute of Ophthalmology from November 2018 to March 2020. The variables analyzed were age, sex, nuclear hardness by LOCS III, best visual acuity with and without correction, induced medial astigmatism, color vision, contrast sensitivity, reading speed and quality of life by the VF-14 survey. Percentages and absolute numbers were used to summarize qualitative variables, whereas mean and standard deviation were used for quantitative variables, with a 95 percent confidence interval. Results: Female sex prevailed with 65 percent; mean age was 69.1 ± 8.1 years. Hardness was NO3 in 55.11 percent of the patients examined. Mean best visual acuity without correction improved to 0.89 ± 0.25; best corrected visual acuity improved to 0.96 ± 0.03; the remaining variables studied showed significant improvement. Conclusion: Simultaneous personalized bilateral crystalline lens surgery significantly contributes to visual improvement both quantitatively and qualitatively, making it possible for patients to recover their quality of life(AU)

AAV-Txnip prolongs cone survival and vision in mouse models of retinitis pigmentosa.

Retinitis pigmentosa (RP) is an inherited retinal disease affecting >20 million people worldwide. Loss of daylight vision typically occurs due to the dysfunction/loss of cone photoreceptors, the cell type that initiates our color and high-acuity vision. Currently, there is no effective treatment for RP, other than gene therapy for a limited number of specific disease genes. To develop a disease gene-agnostic therapy, we screened 20 genes for their ability to prolong cone photoreceptor survival in vivo. Here, we report an adeno-associated virus vector expressing Txnip, which prolongs the survival of cone photoreceptors and improves visual acuity in RP mouse models. A Txnip allele, C247S, which blocks the association of Txnip with thioredoxin, provides an even greater benefit. Additionally, the rescue effect of Txnip depends on lactate dehydrogenase b (Ldhb) and correlates with the presence of healthier mitochondria, suggesting that Txnip saves RP cones by enhancing their lactate catabolism.

Retinitis pigmentosa is an inherited eye disease affecting around one in every 4,000 people. It results from genetic defects in light sensitive cells of the retina, called photoreceptor cells, which line the back of the eye. Though vision loss can occur from birth, retinitis pigmentosa usually involves a gradual loss of vision, sometimes leading to blindness. Rod photoreceptors, which are responsible for vision in low light, are impacted first. The disease then affects cone photoreceptors, the cells that detect light during the day, providing both color and sharp vision. Around 100 mutated genes associated with retinitis pigmentosa have been identified, but only a handful of families with one of these mutant genes have been treated with a gene therapy specific for their mutated gene. There are currently no therapies available to treat the vast number of people with this disease. The mutations that cause retinitis pigmentosa directly affect the rod cells that detect dim light, leading to loss of night vision. There is also an indirect effect that causes cone photoreceptors to stop working and die. One theory to explain this two-step disease process relates to the fact that cone photoreceptors are very active cells, requiring a high level of energy, nutrients and oxygen. If surrounding rod cells die, cone photoreceptors may be deprived of some essential supplies, leading to cone cell death and daylight vision loss. To examine this theory, Xue et al. tested a new gene therapy designed to alleviate the potential shortfall in nutrients. The experiments used three different strains of mice that had the same genetic mutations as humans with retinitis pigmentosa. The gene therapy used a virus, called adeno-associated virus (AAV), to deliver 20 different genes to cone cells. Each of the 20 genes tested plays a different role in cells' processing of nutrients to provide energy. After administering the treatment, Xue et al. monitored the mice to see whether or not their vision was affected, and how cone cells responded. Only one of the 20 genes, Txnip, delivered using gene therapy, had a beneficial effect, prolonging cone cell survival in all three mouse strains. The mice that received Txnip also retained their ability to discern moving stripes on vision tests. Further investigations demonstrated that activating Txnip forced the cones to start using a molecule called lactate as an energy source, which could be more available to them than glucose, their usual fuel. These cells also had healthier mitochondria ­ the compartments inside cells that produce and manage energy supplies. This dual effect on fuel use and mitochondrial health is thought to be the basis for the extended cone survival and function. These experiments by Xue et al. have identified a good gene therapy candidate for treating retinitis pigmentosa independently of which genes are causing the disease. Further research will be required to test the safety of the gene therapy, and whether its beneficial effects translate to humans with retinitis pigmentosa, and potentially other diseases with unhealthy photoreceptors.