Various Types Of Cataract Research Articles

Possibilities of Conservative Treatment and Prevention of Cataract Development Using an Anti-cataract Drug

The priority directions of the state policy of the Russian Federation are medical and preventive measures related to the physical and social improvement of the country’s population. These measures are aimed at improving the quality and effectiveness of medical rehabilitation activities and at reducing the morbidity and disability of various groups of patients. Clouding of the lens (cataract) is very different in terms of time of occurrence, localization, flow and is always accompanied by weakening of vision. Existing theories explain the pathogenesis of cataracts by the general state of the body (dysfunction of the glands of internal secretion, hidden tetany, violation of the functions of the autonomic nervous system, main exchange, etc.), unfavorable heredity, negative external influences, etc.The results of various studies strongly show that Quinax (azapentacen 5,12-dihydroazapentacene sodium disulfonate), 0.015 %, is an anticataract agent on all layers of the lens. In 2023, PROFIT-PHARM (PROFIT-PHARM LLC) developed domestic Quinax eye drops. It is necessary to conduct a study of their clinical effectiveness in patients with various types of cataracts, as well as to prevent its occurrence.

Анализ частоты сопутствующей офтальмопатологии у лиц с катарактой (результаты популяционного исследования)

Aim: to assess the prevalence and characteristics of various types of cataracts and to analyze most common eye comorbidities from the population study "Ural Eye and Medical Study" (UEMS). Patients and Methods: this population study included 5899 individuals (3400 living in the rural area and 2499 living in the city). Eye examinations included uncorrected and best-corrected visual acuity measurements, autorefractometry, slit lamp examination, A-scan ultrasound biometry, non-contact tonometry, fundoscopic examination, corneal topography, fundus photography, static perimetry, and optical coherence tomography. Results: cataracts were diagnosed in 2616 patients (44.3%). These patients were more commonly rural residents and women. Nuclear cataracts (n=1575, 60.2%) were detected 1.5 times more often than cortical cataracts (n=1041, 39.8%). Eye comorbidities were diagnosed in 975 patients (37.3%). The most common eye comorbidities were retinal diseases. Among them, age-related macular degeneration (AMD) ranked first (13.46%). Glaucomatous optic neuropathy (GON)/glaucoma) and myopic macular degeneration/myopia were also common (6.77% and 4.93%, respectively). Diabetic retinopathy (DR) was reported less common (2.26%). The rate of eye comorbidities in patients was 43.6% in cortical cataracts and 33.1% in nuclear cataracts. As to individual conditions, the greatest difference was reported for AMD rate (19.12%) and macular hole/MH (1.8%), which were diagnosed twice more often in cortical cataracts (p<0.05) than in nuclear cataracts (9.71% and 0.8%, respectively). Conclusion: the structure of eye comorbidities in patients with nuclear and cortical cataracts was almost similar to that in patients with cataracts overall. However, the rate of eye comorbidities in patients with cortical cataracts was significantly higher than in patients with nuclear cataracts. This particularly applies to AMD and MH. In general, the rate of AMD, GON, DR, and MH in patients with complicated cataracts increases with age. These diseases were most often diagnosed in women and urban residents, except for AMD (more patients with AMD live in rural areas). KEYWORDS: cataract, nuclear, cortical, eye comorbidities, population study. FOR CITATION: Bikbov M.M., Orenburkina O.I., Gilmanshin T.R., Babushkin A.E. The rate of eye comorbidities in patients with cataracts (results of a population study). Russian Journal of Clinical Ophthalmology. 2023;23(3):146–151 (in Russ.). DOI: 10.32364/2311-7729-2023-23-3-6

Cataract as a progressive or degenerative ophthalmological ailment

Cataracts are the most common ophthalmologic disease that causes vision loss in the world. Likewise, of the various types of cataract existing, the most frequent is senile or degenerative. The disease is that the lens becomes increasingly opaque making it difficult to see until it causes blindness. The mostfrequent cases are seen in elderly people and may gradually affect both eyes. The aim of this article is to systematize information about the description of its main characteristics, etiology, epidemiology and appropriate treatments for this ophthalmological disease. A critical review of scientific documents andpublications was carried out. There is a consensus in the scientific community about the usefulness of surgical treatment in the care of the disease.

Effect of Sorbitol on Alpha-Crystallin Structure and Function.

Loss of eye lens transparency due to cataract is the leading cause of blindness all over the world. While aggregation of lens crystallins is the most common endpoint in various types of cataracts, chaperone-like activity (CLA) of α-crystallin preventing protein aggregation is considered to be important for maintaining the eye lens transparency. Osmotic stress due to increased accumulation of sorbitol under hyperglycemic conditions is believed to be one of the mechanisms for diabetic cataract. In addition, compromised CLA of α-crystallin in diabetic cataract has been reported. However, the effect of sorbitol on the structure and function of α-crystallin has not been elucidated yet. Hence, in the present exploratory study, we described the effect of varying concentrations of sorbitol on the structure and function of α-crystallin. Alpha-crystallin purified from the rat lens was incubated with varying concentrations of sorbitol in the dark under sterile conditions for up to 5 days. At the end of incubation, structural properties and CLA were evaluated by spectroscopic methods. Interestingly, different concentrations of sorbitol showed contrasting results: at lower concentrations (5 and 50 mM) there was a decrease in CLA and subtle alterations in secondary and tertiary structure but not at higher concentrations (500 mM). Though, these results shed a light on the effect of sorbitol on α-crystallin structure-function, further studies are required to understand the mechanism of the observed effects and their implication to cataractogenesis.

Effect of complicated ocular surgery in stress-related parameters: A novel outlook into surgeon's health.

Purpose:To assess the stress-related physiological parameters of ophthalmic surgeons during complicated cataract surgery and compare them with uncomplicated routine cataract surgery.Methods:In this cross-sectional observational study, 110 patients of various types of cataract were divided into two groups: Group 1 included 55 patients with simple cataract (Grade ≤3) with no ocular or systemic comorbidities, whereas Group 2 included 55 patients with complicated cataracts (Grade >3) and ocular/systemic comorbidities. All patients underwent phacoemulsification with intraocular lens implantation in the right eye only. The outcome measures were systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), and saturation of peripheral oxygen (SpO2).Results:The average SBP, DBP, MAP, and HR were significantly higher in the surgeon operating Group 2 (complicated cataract) compared with Group 1 (uncomplicated cataract; P < 0.05). The average SBP of the surgeon while operating Group 1 patients preoperatively and postoperatively was 125.42 ± 2.49 mmHg and 122.45 ± 2.10 mmHg, respectively, whereas in Group 2, the average SBP of the surgeon taken preoperatively and postoperatively was 145.98 ± 3.80 mmHg and 137.44 ± 3.45 mmHg, respectively (P < 0.05). The surgeon’s SpO2 showed no significant difference between the two groups.Conclusion:There is a significant level of increase in stress-related parameters of operating surgeons while doing complicated cataract surgery.

Ultrasound biomicroscopy in ophthalmology

This review presents data on the use of the method of ultrasonic biomicroscopy (UBM) of the anterior segment of the eye in ophthalmological practice in adults and children. Ultrasound biomicroscopy (UBM) is a contact non-invasive method for visualizing structures of the anterior segment of the eye using high-frequency ultrasound in the range from 35 to 100 MHz. Literature data indicate that UBM can be used to visualize almost all structures of the anterior segment, including the cornea, iridocorneal angle, anterior chamber, iris, ciliary body and lens, as well as the peripheral parts of the retina, vasculature and vitreous. There is data on the use of this method in the study of pathogenetic aspects of glaucoma, pseudoecfoliative syndrome, various types of cataracts, post-traumatic injuries of the anterior segment of the eye, meimobium gland dysfunction and other ophthalmopathologies. The use of UBM in children, due to the peculiarities of its implementation, is not widespread, but due to the specificity of the data obtained using it, it is promising. The limited information about the use of UBM in retinopathy of prematurity and the diagnostic capabilities of the method makes its use especially relevant in this severe retinal disease of premature newborns.

Риск катаракты различных типов в когорте работников, подвергшихся профессиональному хроническому облучению

Purpose: To assess cataract type specific risks in a cohort of workers occupationally exposed to ionizing radiation over prolonged periods.&#x0D; Material and methods: The present retrospective cohort study included 22,377 workers first employed at a nuclear production facility in 1948–1982 and followed up till the end of 2008. By the end of the follow-up period in the study worker cohort 3123 cases of cortical cataract, 1239 cases of posterior subcapsular cataract (PSC) and 2033 cases of nuclear cataracts were registered over 486,245, 489,162, 492,004 person-years of follow-up, respectively.&#x0D; Results: The incidence of PSC, cortical and nuclear cataracts was significantly linearly associated with the cumulative radiation dose. The excess relative risk per unit dose of external gamma-ray exposure (ERR/Sv) was 0.91 (95 % CI: 0.67–1.20) for PSC, 0.63 (95 % CI: 0.49–0.76) for cortical cataracts and 0.47 (95 % CI: 0.35–0.60) for nuclear cataracts. Exclusion of an adjustment for neutron dose and inclusion of additional adjustments for body mass index and smoking index reduced ERRs/Sv for all types of cataracts. However, an additional adjustment for glaucoma increased the incidence risks of cortical and nuclear cataracts just modestly (but not for PSC). Inclusion of an adjustment for diabetes mellitus reduced the ERR/Sv of external gamma-ray exposure only for PSC incidence. Increased incidence risks of all cataract types were observed in both males and females of the study cohort, but ERR/Sv was significantly higher in females (p &lt; 0.001), especially for PSC.&#x0D; Conclusion: The incidence of various types of cataracts in the cohort of workers occupationally chronically exposed to ionizing radiation was associated with the cumulative dose of external gamma-ray exposure.

Risk of various types of cataracts in a cohort of Mayak workers following chronic occupational exposure to ionizing radiation.

This study is the first to report cataract type specific risks in a cohort of Russian Mayak Production Association workers following chronic occupational exposure to ionizing radiation. In this retrospective cohort study, 22,377 workers (females 25.4%) first employed in 1948-1982 were followed up till the end of 2008. All cataract subtypes were significantly dependent on sex, attained age, diabetes mellitus, myopia and glaucoma. For each of posterior subcapsular (PSC), cortical and nuclear cataracts, the risk of cataract incidence significantly linearly increased with increasing radiation dose. Excess relative risk per unit effective dose (ERR/Sv) from external γ-rays based on the linear model was 0.91 [95% confidence intervals (CIs) 0.67, 1.20] for PSC, 0.63 (95% CIs 0.49, 0.76) for cortical, and 0.47 (95% CIs 0.35, 0.60) for nuclear cataracts. For all three types of cataracts, exclusion of an adjustment for neutron dose as well as inclusion of additional adjustments for body mass index and smoking index decreased ERR/Sv of external γ-rays. Inclusion of an additional adjustment for glaucoma, however, modestly increased incidence risks for cortical and nuclear cataracts, but not PSC cataracts. Inclusion of an adjustment for diabetes mellitus decreased ERR/Sv of external γ-rays only for PSC incidence. Both males and females had increased risks for all three types of cataracts, but ERR/Sv was significantly higher in females than in males (p < 0.001), particularly for PSC cataracts. The results suggest that chronic occupational radiation exposure significantly increases risks of PSC, cortical and nuclear cataracts, and that such risks are higher in females than in males.

A Comparative Histopathological Study of Lens Capsule and Epithelial Cells in Various Types of Cataract

A Comparative Histopathological Study of Lens Capsule and Epithelial Cells in Various Types of Cataract

Supplementation of Mango (Mangifera indicaL.) Peel in Diet Ameliorates Cataract in Streptozotocin-Induced Diabetic Rats

Cataract is a secondary complication of diabetes and consumption of diet rich in antioxidants and dietary fiber exerts beneficial effects. The effect of mango peel on delay in progression of cataract was evaluated in streptozotocin-induced diabetic rats. Diets supplemented with mango peel at 5 and 10% levels ameliorated cataract formation. On treatment of diabetic rats with peel for 16 weeks, lens soluble protein content, glutathione levels and antioxidant enzyme activities were increased by 1.5–2.5 fold while lipid peroxidation and protein carbonyl levels as well as advanced glycation end products formation in lens proteins of diabetic rats were significantly decreased. Mango peel supplementation also inhibited polyol pathway enzyme activities in diabetic rats. Thus, mango peel was effective against development of diabetic cataract mainly through augmentation of antioxidant levels, inhibition of polyol pathway enzymes and AGEs formation in lens of diabetic rats. PRACTICAL APPLICATIONS Oxidative damage to the constituents of eye lens is considered to be the major mechanism for development of various types of cataract and intake of food rich in antioxidants has been reported to delay progression of cataract. Mango peel is a by-product of mango pulp processing industry and is rich in antioxidants and exhibits antidiabetic properties. This study found that mango peel supplemented diet delayed the progression of diabetic cataract formation. Thus, mango peel can be supplemented in foods for management of diabetes and its complications.

Cell death pattern in lens epithelium of cataract patients.

Apoptosis, a type of programmed cell death, is observed in various types of cataract and in cultured lens epithelium subjected to oxidative damage. We have recently described oxidative DNA base damage in epithelium in age-related cataract and cultured cells, and we here aimed to examine such epithelium for markers for proliferation, initiation of apoptosis and morphological patterns of cell damage. Samples (n=75) were analysed by light microscopy/electron microscopy (LM/EM); immunohistochemistry (IHC) for PCNA and Ki67 (DNA synthesis/proliferation); TUNEL assay (DNA fragmentation/apoptosis); and protein/gene expression of Caspase-3 (apoptotic effector molecule) and BAX/Bcl2 (pro-/anti-apoptotic marker) in fresh/cultured epithelium by IHC and qRT-PCR. In fresh samples, the majority of cells were Ki67-/PCNA+. BAX/BCL-2-ratio was approximately 1, and Caspase-3 levels were low. TUNEL stained scattered nuclei/nuclear fragments (9/6302 cells). Main morphological signs of cell damage included rupture of cell membranes and hydration of cytoplasm and nuclei. Cultivation increased levels of BAX and Bcl2 by IHC and qRT-PCR (approximately 10-fold upregulation). Caspase-3 levels remained low by IHC with similar expression in fresh and cultured samples by qRT-PCR. Genomic stress and DNA repair may explain the contrasting expression of Ki67/PCNA in fresh epithelium. Despite low levels of Caspase-3 and similar expression of BAX/Bcl-2, a low incidence of apoptosis may be detected in epithelium in age-related corticonuclear cataract. Epithelium may be transferred to culture without an increase in expression of Caspase-3, one of the central mediators of apoptosis.

Effect of Chronic Cigarette Smoking On Cataract:

Objective: The purpose of this study was to examine the effects of chronic smoking on various types of cataracts in healthy male smokers. Tobacco use as the single most important preventable risk factor to human health in developed countries and an important cause of cataract. Out of 4000 chemical in cigarette, 100 are toxic. smoke contains harmful free radicals that potentially damaging lens proteins and the fiber cell membrane in the lens. smoking reduces the body's levels of antioxidants and certain enzymes which may help to remove damaged proteins from the lens.

UVR‐effects in human versus animal eyes: more contradictions or more similarities?

Abstract Purpose To compare the characteristics and time scales of UV‐radiation effects in the eye, especially the lens, investigated and documented in human and various animal species. The target is to test the predictability potential of animal experiments for characterization of human UV‐risk scenarios. Methods Experimental studies on UV‐effects to the cornea and lens in mice and rats are critically compared to epidemiological studies on UV‐ effects to the human eye. Results Animal studies provide a broad spectrum of data on genetical and environmental factors leading to various types of cataracts and corneal alterations. Many patho‐physiological factors are identified. Epidemiological studies in humans identify other noxious factors but the most important difference seems to be the time scale and thus the age‐related difference in UV‐sensitivity of the lens and the anterior eye segment. Conclusion Future studies should focus more on species‐ and age‐related sensitivities of the lens to UVR effects and on the influence of systemic effects, also in relation to ocular immunology.

Dose-response relationship between ingested arsenic and cataracts among residents in Southwestern Taiwan

This association study was carried out to examine the effect of long-term exposure to ingested arsenic on various types of cataract. A total of 349 residents living in arseniasis-hyperendemic villages of southwestern Taiwan were recruited. Cumulative arsenic exposure was derived from the history of consuming artesian well water and the arsenic level in well water. The Lens Opacities System III was used to classify different types of cataract. The cataract surgery prevalence was 10% for the age group of 50 or more years. Cortical opacity was most common (35%), while nuclear and posterior subcapsular opacities were observed in 24% and 22% of subjects, respectively. Diabetes mellitus was a significant risk factor for all types of cataract. Occupational sunlight exposure was associated with cortical and posterior subcapsular opacities in a dose–response relationship. The cumulative exposure to arsenic from artesian well water and the duration of consuming artesian well water were associated with an increased risk of all types of lens opacity. But statistically significant dose-response relations with the cumulative arsenic exposure and the duration of consuming artesian well water were observed only for posterior subcapsular opacity (P = 0.014 and P = 0.023, respectively) after adjustment for age, sex, diabetes status, and occupational sunlight exposure. It was concluded that there was an increasing prevalence of posterior subcapsular opacity with the increase in exposure to ingested arsenic.

A laser retinometer for determining visual acuity when cataract is present

This paper shows that the resolving power of the retina of the human eye when any type of cataract is present can be determined by means of a He-Ne laser retinometer (λ=633 nm). The results of a measurement of the retinal visual acuity of more than two hundred patients with various types of cataract before extraction of the crystalline lens and after replacement and the determination of the corresponding correction coefficient, reaching 0.7-0.9, make it possible to use the laser retinometer for pre-operative diagnosis.

Reading performance depending on the type of cataract and its predictability on the visual outcome

Purpose: To investigate the influence of various types of cataract on reading performance in a standardized reading test setting. Setting: Department of Ophthalmology, University of Vienna, Vienna, Austria. Methods: The reading performance of 94 eyes with age-related cataract and normal macular function was evaluated with the Radner Reading Charts preoperatively and 4 weeks after cataract surgery. Distance visual acuity was tested with the ETDRS charts. Cataracts were graded using the Lens Opacities Classification System (LOCS) III, on which NO is nuclear opalescence and NC is nuclear color. Results: Patients with pure nuclear cataracts (LOCS III: NO/NC 2.1-5) achieved a normally high MRS (99.84% ± 7.65% of their postoperative MRS): preoperative MRS 1: 190.6 ± 30.74 words per minute (wpm); postoperative MRS 2: 191.21 ± 29.36 wpm. Patients with mixed nuclear-cortical cataracts (LOCS III: NO/NC 2.1-5; C>2) preoperatively achieved 96.96% ± 5.6% of their postoperative MRS (MRS 1: 175.77 ± 31.54 wpm; MRS 2: 181.34 ± 30.56 wpm). In dense nuclear cataracts (LOCS III: NO/NC>5), the MRS was significantly reduced, achieving only 72.64 ± 19.19% of the postoperative MRS (MRS 1: 133.06 ± 39.43 wpm; MRS 2: 185.76 ± 40.18 wpm). In posterior subcapsular cataracts, the preoperative MRS (134.1 ± 33.72 wpm) was significantly lower than postoperatively (191.14 ± 27.08 wpm). Conclusions: In contrast to dense nuclear cataracts and posterior subcapsular cataracts, the preoperative reading speed of patients with pure nuclear or nuclear-cortical cataracts was normal at large print sizes. The preoperative evaluation of reading acuity and speed with standardized reading tests can therefore be used to estimate the postoperative reading performance in the latter 2 types of cataract.

A comparative study of lens protein glycation in various forms of cataract

The aim of this study was to estimate and compare the levels of glycated protein in the lens extracted from patients with cataract of various etiologies. A total of 72 cataract lens were collected. The levels of total proteins, glucose and glycated protein in the lens were studied. Plasma protein and fasting glucose levels were also estimated. The amount of glycation of lens was significantly higher in case of hypermature senile cataract (p<0.01) when compared with other types of cataracts. The levels of lens glucose between the various types of cataracts did not differ significantly. These results indicate that the level of lens glucose alone is not the only determining factor of lens protein glycation.

May nitric oxide molecule have a role in the pathogenesis of human cataract?

Recent studies have shown that nitric oxide molecule may have a role in the development of cataract. In this study, we measured the levels of a nitric oxide metabolite (nitrite) in the cataractous and normal human lenses. A modified Griess assay was used to determine the nitrite levels in the lenses as a measure of nitric oxide, based on the spectrophotometric method. Nitrite was detected in 26 (44·1%) cataractous lenses and was found below the detection limit in 33 (55·9%) cataractous lenses. Mean nitrite levels in cataractous lenses (2·77±5·26 nmol/100 mg) was found higher than the normal lenses (0·77±0·79 nmol/100 mg) but this increase was not statistically significant. Comparison of nitrite levels among lenses with various types of cataracts revealed higher levels in lenses with posterior subcapsular cataracts. Hypertensive patients had also significantly higher nitrite levels in their cataractous lenses. The increased levels in the cataractous lenses display a possible role of nitric oxide in the pathogenesis of cataract in human eyes.

Aqueous and serum β2-microglobulin levels in patients with senile cataracts, and cataracts associated with uveitis or atopy

β(2)-Microglobulin (β(2) M) has been reported to be elevated in patients with a variety of neoplasms and inflammatory disorders, and is believed to be a sensitive although nonspecific marker for lymphocyte activation and/or proliferation. In order to investigate the role of inflammation in the pathogenesis of various types of cataract, the authors measured β(2)M concentrations in the aqueous humor and serum of patients with senile cataracts (82 eyes), cataracts secondary to uveitis (16 eyes) and cataracts associated with atopic dermatitis (eight eyes). In addition, measurements were made in six patients with rhegmatogenous retinal detachment (RRD) and three patients with central retinal artery occlusion (CRAO) for comparison. The average aqueous β(2)M was increased in eyes with uveitic cataracts (678 μg/1) and RRD (533 μg/1), when compared to eyes with senile cataracts (265 μg/1), atopic cataracts (309 μg/1) and CRAO (122 μg/1). However, comparison of β(2)M to albumin aqueous-to-serum ratios (protein coefficient analysis) revealed that the aqueous β(2)M elevation was specific in only uveitic cataracts, with the elevation in RRD being most likely due to breakdown of the bloodocular barrier. Higher aqueous β(2)M concentrations were also found in cataracts with a posterior subcapsular cataract component, although this was related to a higher percentage of uveitic cataracts in this group. There was no statistically significant difference found in association with a past medical history of diabetes mellitus, hypertension or heart disease. These results are discussed in the context of the pathogenesis of cataract and the role of β(2)M in inflammatory processes of the eye.

Distribution of Water-Soluble Crystallins in Microsectioned Cataractous Lenses from One Hundred Egyptian Patients

Morphologically classified lenses from 100 cataract patients from the Mansoura Eye Hospital (Egypt) were microdissected and the crystallin composition and distribution were analyzed by thin-layer isoelectric focusing (IEF). The IEF profiles of cataractous lenses were compared with each other, with those of sclerotic lenses and with a normal lens profile. The alterations in the composition of high-molecular-weight (HMW)-, alpha-, beta H-, beta L-, beta s-, and gamma-crystallins along with normal aging, are superimposed by pronounced cataract-related changes which are different for the various types of cataracts. The general feature includes a continuous loss of gamma-, beta s- and beta L-crystallins of higher IEPs and an increase of HMW material. This is highly pronounced in the nucleus of nuclear cataractous lenses. In cortical cataractous lenses, changes start in the cortical layers. No differences could be observed between alterations in Caucasian lenses and this extended Egyptian lens population.