Lens Changes Research Articles

Влияние биофлавоноидов (кверцетина и рутина) на развитие патологических изменений в хрусталике при моделировании возрастной катаракты

Влияние биофлавоноидов (кверцетина и рутина) на развитие патологических изменений в хрусталике при моделировании возрастной катаракты

Improvement in the field of binocular single vision following bilateral phacoemulsification with toric intraocular lens implantation in a patient with a partial third nerve palsy

A 44-year-old female teacher with partial third (oculomotor) nerve palsy had a small central field of binocular single vision (BSV) following three strabismus procedures. Over several years her field of BSV constricted further, coincident with the development of myopia in one eye secondary to early lens change and in the presence of significant astigmatism. Following bilateral lens extraction with toric intraocular lens implants, her field of BSV reexpanded.

Risk for radiation‐induced cataract for staff in interventional cardiology: Is there reason for concern?

To examine the prevalence of radiation-associated lens opacities among interventional cardiologists and nurses and correlate with occupational radiation exposure. Interventional cardiology personnel are exposed to relatively high levels of X-rays and based on recent findings of radiation-associated lens opacities in other cohorts, they may be at risk for cataract without use of ocular radiation protection. Eyes of interventional cardiologists, nurses, and age- and sex-matched unexposed controls were screened by dilated slit lamp examination and posterior lens changes graded using a modified Merriam-Focht technique. Individual cumulative lens X-ray exposure was calculated from responses to a questionnaire and personal interview. The prevalence of radiation-associated posterior lens opacities was 52% (29/56, 95% CI: 35-73) for interventional cardiologists, 45% (5/11, 95% CI: 15-100) for nurses, and 9% (2/22, 95% CI: 1-33) for controls. Relative risks of lens opacity was 5.7 (95% CI: 1.5-22) for interventional cardiologists and 5.0 (95% CI: 1.2-21) for nurses. Estimated cumulative ocular doses ranged from 0.01 to 43 Gy with mean and median values of 3.4 and 1.0 Gy, respectively. A strong dose-response relationship was found between occupational exposure and the prevalence of radiation-associated posterior lens changes. These findings demonstrate a dose dependent increased risk of posterior lens opacities for interventional cardiologists and nurses when radiation protection tools are not used. While study of a larger cohort is needed to confirm these findings, the results suggest ocular radio-protection should be utilized.

Topical KINOSTAT™ ameliorates the clinical development and progression of cataracts in dogs with diabetes mellitus

To determine whether topical administration of the aldose reductase inhibitor Kinostat™ can ameliorate the onset or progression of cataracts in dogs with naturally occurring diabetes mellitus (DM). A randomized, prospective, double-masked placebo control pilot study was conducted with 40 dogs newly diagnosed with DM with no or minimal lens changes. Twenty-eight dogs received Kinostat™ and 12 dogs received placebo. Owners administered the agent into both eyes three times daily for 1 year and compliance was monitored with log sheets. Complete ophthalmic examinations were performed on dilated eyes at the time of enrollment and 1, 2, 3, 6, and 12 months into treatment. Cataract severity was assessed on a scale of 0-3. At 12 months, full bloodwork, including HbA1C and blood Kinostat™ levels were performed. After 12 months of treatment, the cataract score in the placebo group significantly increased with seven dogs (14 eyes) developing mature cataracts, two dogs (4 eyes) developing cortical opacities, and one dog (2 eyes) developing equatorial vacuoles with mild punctate cortical opacities. In contrast, the cataract score in the Kinostat™ treated dogs was significantly less with seven developing anterior equatorial vacuoles, two developing incipient anterior cortical cataracts, and four developing mature cataracts. In fact, the cataract scores of the Kinostat™ group at 12 months did not significantly increase from the score at the time of enrollment. The HbA1C values between the two groups after 12 months of treatment were similar, and no blood levels of Kinostat™ were found in any enrolled dog. The onset and/or progression of cataracts in dogs with DM can be significantly delayed by topical administration of Kinostat™.

Deflection and Stress Analysis of Glass Plate in Elastic Deformation Processing

As the consumer market in the optics, electronics and aerospace industries grows, the demand of ultra-precision aspheric surface increases. The shape accuracy of the optical lens changes significantly with deformation conditions and optical properties of the lens varies with stress distribution within the lens. Therefore, determining the deflection and stress of glass lens is very important to improve the quality of the lens. In this paper, the deflection and stress theoretical results of BK7 glass plate have been presented in different cases of elastic deformation processing. The results are compared with the finite element analysis (FEA) to demonstrate the robustness and accuracy of algorithm in calculation of stress and deflection. The mentioned finite element models were established using the software Abaqus/CAE. The analytical and FEA results showed that if the edge of plate is simply supported, the maximum deflection is 4 times larger than in the fixed edge case. Otherwise if the edge and centre point of plate is simply supported, the maximum deflection is 2.5 times lower than in the fixed edge case and 11.3 times lower than in the simply supported at edge case.

Radiation Cataract Risk in Interventional Cardiology Personnel

The lens of the eye is one of the most radiosensitive tissues in the body, and exposure of the lens to ionizing radiation can cause cataract. Cumulative X-ray doses to the lenses of interventional cardiologists and associated staff can be high. The International Commission on Radiological Protection recently noted considerable uncertainty concerning radiation risk to the lens. This study evaluated risk of radiation cataract after occupational exposure in interventional cardiology personnel. Comprehensive dilated slit-lamp examinations were performed in interventional cardiologists, associated workers and controls. Radiation exposures were estimated using experimental data from catheterization laboratories and answers to detailed questionnaires. A total of 116 exposed and 93 similarly aged nonexposed individuals were examined. The relative risk of posterior subcapsular opacities in interventional cardiologists compared to unexposed controls was 3.2 (38% compared to 12%; P < 0.005). A total of 21% of nurses and technicians had radiation-associated posterior lens changes typically associated with ionizing radiation exposure. Cumulative median values of lens doses were estimated at 6.0 Sv for cardiologists and 1.5 Sv for associated medical personnel. A significantly elevated incidence of radiation-associated lens changes in interventional cardiology workers indicates there is an urgent need to educate these professionals in radiation protection to reduce the likelihood of cataract.

Comparative study on aging, UV treatment, and radiation on cataract formation

Four randomized groups of male mice F1 (C57Black/CBA) were investigated: a) UV-irraidated (UV-A, 15 min daily during 9 months, dose 5.6 + 1.2 W/m2), b) gamma-rays irradiated (2 Gy), single, c) influence for combination of UV- and gamma-rays treatment, d) aging. The lens opacities were measured on 7th and 10th month. The expert method based on six grade scale was used for cataract measure. On 7th month the median of lens opacities were Aging group = 0; UV-irradiated group = 2.5; gamma-irradiated group = 4.75; gamma- and UV-irradiated group = 6.0. The difference between all groups was significant (p < 0.004, Kruskall-Wallis ANOVA test). The Conover post hock test has shown the significant difference for all comparison pairs (p < 0.002) with the exception of UV-irradiated group, gamma-irradiated group, gamma- and UV-irradiated group. On 10th month the lens opacities were strongly increased: Aging group = 2.5; UV-irradiated group = 5.0; gamma-irradiated group = 6.5; gamma- and UV-irradiated group = 7.5 (median). The difference between groups was significant (p < 0.0001, Kruskall-Wallis ANOVA test). The Conover post hock test has shown the significant difference for all comparison pairs (p <0.003) with the exception ofthe UV-irradiated group and gamma-irradiated group. The formation of the specific lens opacities for any group was not found. Morphology and protein composition have been investigated on 10th month. The results of morphological changes study show destructive and degenerative impairments of capsule, epithelium cells and lens fibers. However, no specific changes related to some particular actions have been found. In addition, there were no specific changes of protein composition of both water-soluble and water-insoluble fractions estimated with Differential Gel Electrophoresis technique. Obtained data mean that aging, UV-treatment, and gamma-radiation causes the similar changes of lens. It was supposed that UV-treatment or/and gamma-radiation act as an aging factor on the lens.

Three-year stability of an angle-supported foldable hydrophobic acrylic phakic intraocular lens evaluated by Scheimpflug photography

To examine the postoperative positional stability of a new angle-supported, hydrophobic acrylic phakic intraocular lens (pIOL). Department of Ophthalmology, Goethe-University, Frankfurt am Main, Germany. In this prospective nonrandomized clinical trial, eyes with moderate to high myopia had implantation of an angle-supported pIOL (AcrySof Cachet). Scheimpflug imaging was performed preoperatively and postoperatively at 1, 3, 6 to 12, and 24 to 36 months. The main outcome measures were the distance between the corneal endothelium and the IOL and between the IOL and the crystalline lens. The overall significance threshold was P = .05. Twenty-one of the 26 eyes (26 patients) evaluated were included in the statistical analysis. Analysis of variance showed no statistically significant differences in absolute endothelium-IOL or IOL-crystalline lens measurements at any postoperative visit. The mean endothelium-IOL distance was 2.05 mm +/- 0.25 (SD) at 1 month and 2.15 +/- 0.29 mm at 24 to 36 months and the mean IOL-crystalline distance, 0.92 +/- 0.23 mm and 0.86 +/- 0.22 mm, respectively. A 1-way t test showed a small but significant difference compared with zero in the overall change in the endothelium-IOL distance (mean 0.08 +/- 0.16 mm) and thus in the overall calculated anterior chamber depth (mean 0.07 +/- 0.08 mm); the difference was not significant for the IOL-crystalline lens change (mean -0.05 +/- 0.13 mm). The angle-supported foldable hydrophobic pIOL maintained adequate central clearance distances to the corneal endothelium and the natural crystalline lens over 3 years. Neither author has a financial or proprietary interest in any material or method mentioned. Additional disclosure is found in the footnotes.

Mechanical stretching forces oppose osmotic lens swelling

Mechanical stretching forces oppose osmotic lens swelling

Sexual Assault: A Matter of Civil Rights and Title IX

Sexual Assault: A Matter of Civil Rights and Title IX

Alopecia and ocular alterations: a role for Minoxidil?

Research into ocular alterations in alopecia patients is limited and tends to overlook hypertrichotic agents medication. It was very recently reported that retinal changes in the form of degenerative changes, pigmentary clumping, and abnormal vascular changes are significantly more prevalent in alopecia areata (AA) patients than in the sex- and age-matched controls (1). Symptomless punctate lens opacities were significantly higher in patients than in control patients. Also, fundus alterations were significantly higher in AA patients than in the controls (2). Ophthalmological examinations showed significantly higher percentages of lens changes and alterations in the retinal epithelium in AA patients than in the controls (3). However, there is currently no proposed mechanism to explain this observation. Ocular findings are not rare conditions in other types of alopecia. In fact, a review of the literature will reveal a considerable number of similar reports. It would be difficult to establish a precise figure on what percent of AA patients or other types of alopecia patients apply topical Minoxidil. However, if it proved to be a significant figure, it would logically account for at least part of the high number of cases with retinal changes in patients using this agent. As there is scant data in the literature regarding possible angiogenic properties of Minoxidil—a potent hypertrichotic agent and one of the most commonly used medications in alopecia—the relation of an anti-hair loss product to retinal changes is less well-documented and has received little attention. The problem with Minoxidil is that it lacks tissue selectivity (4).

Long-term Changes in Posterior Chamber Phakic Intraocular Collamer Lens Vaulting in Myopic Patients

Evaluation of central and midperipheral vaulting of the posterior chamber phakic intraocular Collamer lens (ICL; Staar Surgical Inc., Monrovia, CA) in eyes with moderate to high myopia. Retrospective analysis of prospectively collected data. Eighty-four eyes treated with the latest ICL (V4 model) and 27 eyes treated with early ICL models were examined. After standardized ICL implantation, patients underwent complete ophthalmologic examinations before surgery and at 1 week, 1 month, 3 months, 6 months, and at yearly intervals thereafter. Central vaulting was measured using the Jaeger device (Haag-Streit, Bern, Switzerland). From 2006 onward, vaulting was measured additionally by optical coherence tomography (Visante OCT; Carl Zeiss Meditec, Jena, Germany). Using the Visante OCT, the crystalline lens rise and the midperipheral vaulting of the ICL were assessed. Central vaulting after ICL implantation. The mean duration of follow-up was 74.1+/-23.1 months and 96.3+/-50.2 months in eyes treated with V4 and early models, respectively. Postoperative central vaulting was 466+/-218 microm (range, 30-900 microm) in eyes treated with the V4 models and 321+/-200 microm (range, 150-900 microm) in those treated with early ICL models. From the 6-month follow-up onward, a continuous and nearly linear reduction of central vaulting was observed. At the 10-year follow-up, the mean central vaulting was reduced to 184+/-159 microm (range, 6-500 microm) and 138+/-218 microm (range, 0-820 microm) in eyes treated with V4 or early models, respectively. Eyes with total vaulting had a mean central vaulting of 407+/-202 microm (range, 180-730 microm), whereas those with midperipheral contact had a significantly lower central vaulting of 105+/-87 microm (range, 0-200 microm). This study revealed consistent reduction of central vaulting over a 10-year period and provides further evidence that insufficient vaulting of the ICL is responsible for the development of anterior subcapsular cataract. A minimum central vaulting of 230 microm seems to be necessary to ensure total vaulting of the ICL. If an ICL is chosen for the correction of myopia, targeting for the greatest possible postoperative central vaulting is advised to achieve safe and complete vaulting for several years.

Causes of visual loss and their risk factors: an incidence summary from the Barbados Eye Studies

To summarize incidence and risk factors for each main cause of visual loss in an African-Caribbean population and discuss the implications of these data from a public health perspective. A nationally representative cohort (n = 4 709; ages 40-84 years at baseline) had ophthalmic and other examinations over 9 years. Incidence rates were estimated by the product-limit approach. Risk factors were evaluated from Cox regression models. Average incidence was ~ 0.1% per year for blindness (< 6/120) and 0.7% per year for low vision (< 6/18 to 6/120), increasing steeply with age (P < 0.05) and affecting related quality of life (P < 0.05). Age-related cataract and open-angle glaucoma (OAG) accounted for 73.2% of blindness and diabetic retinopathy (DR) for 8.9%; cataract caused two-thirds of low vision. Average incidence was 5.1% per year for all lens changes (gradable/ungradable opacities or aphakia) and 0.4% per year for cataract surgery. Incidence of definite OAG was 0.5% per year (0.9% for suspect or probable); 53% of the affected were unaware. Persons with diabetes mellitus (DM) had a DR incidence of 4.4% per year. Age-related macular degeneration was rare (0.08% per year). Main cataract risk factors were age and DM. OAG incidence increased with age, intraocular pressure, family history, low ocular perfusion pressures, and thinner corneas. DR risk increased with early DM onset, DM duration, oral/insulin treatment, increased systolic and diastolic blood pressures, and hyperglycemia. Antihypertensive treatment halved DR risk. Incidence of visual impairment was high and significantly affected quality of life. Age-related cataract and OAG caused ~ 75% of blindness, indicating the need for public health action to increase appropriate cataract surgery and early OAG detection and treatment. Controlling DM and hypertension would help prevent DR-related complications and could lower cataract risk, further decreasing visual loss.

Four-Year Incidence and Progression of Lens Opacities: The Los Angeles Latino Eye Study

To estimate the 4-year incidence and progression of lens opacities. Population-based longitudinal study. A total of 4658 adult Latinos from Los Angeles County were examined at baseline and 4-year follow-up. Examination included assessment of lens opacities using the Lens Opacities Classification System II (LOCS II). Incidences of cortical, nuclear, and posterior subcapsular opacities (with LOCS II scores >or=2) were defined as opacity development in persons without that opacity at baseline. Single and mixed opacities were defined in persons without any opacity at baseline. Incidence of all lens changes included development of at least 1 opacity or cataract surgery among those without any opacity at baseline. Four-year progressions were defined as increase of >or=2 in LOCS II score. The 4-year incidence of all lens opacities was 14.2%. Four-year incidence of cataract surgery was 1.48%. The incidences were 4.1% for cortical-only, 5.8% for nuclear-only, 0.5% for PSC-only, and 2.5% for mixed. The incidences for any opacities were 7.5% for cortical, 10.2% for nuclear, and 2.5% for PSC. Incidence increased with age (P < .0001 for all). The progressions were 8.5% for cortical, 3.7% for nuclear, and 2.9% for PSC opacities. Our Latino population had a higher incidence of nuclear than cortical opacities, but a greater progression of cortical than nuclear opacities. Incidence and progression of PSC was low. Additional understanding of the natural history and progression of various lens opacities will give us a better understanding of the pathogenesis and management of lens opacities.

Nanoceria have no genotoxic effect on human lens epithelial cells

There are no treatments for reversing or halting cataract, a disease of the structuralproteins in the eye lens, that has associations with other age-related degenerativeconditions such as Alzheimer’s disease. The incidence of cataract and associated conditionsis increasing as the average age of the population rises. Protein folding diseases are difficultto assess in vivo as proteins and their age-related changes are assessed after extraction.Nanotechnology can be used to investigate protein changes in the intact lens as well asfor a potential means of drug delivery. Nanoparticles, such as cerium oxide (CeO2) which have antioxidant properties, may even be used as a means of treatingcataract directly. Prior to use in treatments, nanoparticle genotoxicity mustbe tested to assess the extent of any DNA or chromosomal damage. Sisterchromatid exchanges were measured and DNA damage investigated using thealkaline COMET assay on cultured human lens epithelial cells, exposed to 5 and10 µg ml−1 ofCeO2 nanoparticles (nanoceria). Nanoceria at these dosages did not cause any DNA damage orsignificant increases in the number of sister chromatid exchanges. The absence of genotoxiceffects on lens cells suggests that nanoceria, in the doses and exposures tested in this study,are not deleterious to the eye lens and have the potential for use in studying structuralalterations, in developing non-surgical cataract treatments and in investigating otherprotein folding diseases.

Ocular pharmacokinetic study on baicalin in lens of rabbits following intragastric administration

This paper is to study the pharmacokinetic features of baicalin in lens through observing baicalin's concentration changes in lens of rabbits following intragastric administration. Forty-four rabbits were randomly divided into 11 groups. The lens were collected at the beginning without any intragastric administration, and then collected after 15 minutes following intragastric administration of 80 mg/kg baicalin, and continually collected individually after 0.5,0.75,1,1.5,2,3,5,8,12 hours: the concentration of baicalin was measured by reversed-phase high-performance liquid chromatography (RP-HPLC). There were two obvious peaks in the drug concentration-time diagram, appearing respectively at half an hour and 2 hours after the intragastric administration. The highest level of baicalin's concentration in lens (C( max ), = 4.997 microg/ml) was obtained 0.9 hour (T( max ) = 0.906 h) after application of baicalin. Area under the concentration time curve (AUC), half-life of the drug elimination (T( 1/2 )) and clearance ratio were 3.542 microg/ml*h., 1.576 h and 8.114 l/h respectively. Baicalin can penetrate blood-eye barriers and enter the lens following intragastric administration.

Aldose reductase inhibitory activity and anti catraract potential of some traditionally acclaimed antidiabetic medicinal plants

Aldose reductase (AR) has been reported to play an important role in sugar-induced cataract. In the present study, the AR inhibitory activity of Enicostemma hyssopifolium (EH), Gymnema sylvestre, Eclipta alba, and Tinospora cordifolia (TC) were studied along with their effect on sugar-induced cataractogenic changes in sheep lenses in vitro. AR inhibitory activity of the aqueous extracts of plants and their anticataract potentials were evaluated in vitro in sheep lenses, considering the activity of normal sheep lenses as 100%. The concentration of the plant extract that showed maximum activity was selected to further study its effect on galactose-induced polyol accumulation in vitro. The <TEX>$IC_50$</TEX> values of EH and TC were calculated to be 102 and 85 <TEX>${\mu}g$</TEX>/ml, respectively. EH showed a significant inhibition (61.3%) in polyol accumulation followed by TC (53.1%). EH and TC possesses a significant anticataract activity in vitro and its anticataract potential could be related with its AR inhibitory effect.

Protective effect of the thioltransferase gene on in vivo UVR‐300 nm induced cataract

Abstract Purpose To determine the protective effect of the thioltransferase glutaredoxin 1 (Grx1), a critical protein‐thiol repair enzyme, on in vivo UVR‐induced cataract. Further, to estimate the MTD(2.3:16) for Grx1+/+ and Grx1‐/‐ mice and to calculate the protection factor for the thioltransferase gene on UVR‐induced cataract. Methods 20 Grx1+/+ and 20 Grx1‐/‐ mice were unilaterally exposed in vivo to UVR‐300 nm for 15 min. Altogether, 5 groups of 4 animals received 0.0, 2.1, 2.9, 3.6 or 4.1 kJ/m2 each. At 48 h post UVR exposure, light scattering in the exposed and contralateral not exposed lens was measured quantitatively. Macroscopic lens changes were documented with dark field illumination photography. Results Subcapsular and cortical opacities were observed in both the Grx1+/+ and Grx1‐/‐ mice. Forward light scattering in the lenses from the Grx1+/+ group was lower than in the lenses from the Grx1‐/‐ group and increased with increasing radiant exposure. The MTD(2.3:16) was for the Grx1+/+ group 3.81 (CI(0.95) = [2.82;6.37]) and for the Grx1‐/‐ group 2.99 (CI(0.95)= [2.33;4.00]) resulting in a protection factor of 1.28. Conclusion Deficiency of the Grx1 gene makes the lens 28 % more sensitive to early onset UVR‐300 nm induced cataract, indicating the important role of the Grx1 gene in the oxidation defense of the lens.

Effects of Topical Application of Ibudilast for Seasonal Allergic Conjunctivitis in Patients Wearing Soft Contact Lenses

To assess the influence of topical application of ibudilast for seasonal allergic conjunctivitis in patients wearing soft contact lenses (SCLs). There were 16 SCL wearers (32 eyes) with allergic conjunctivitis due to cedar pollen, who were studied from February to April 2007. Before enrollment, informed consent to participation in this study was obtained from all subjects. A frequent replacement SCL (2 Week Pure) was worn for 2 weeks, and ibudilast was applied topically four times daily during this period. The severity of allergic symptoms and the severity of SCL-related symptoms were assessed by scoring using two questionnaires, and before and after topical application of ibudilast results were compared. The severity of objective ocular findings was also scored and compared in the same way. After the final examination, the SCLs were collected and immersed in physiologic saline. Then morphologic changes and drug adsorption were investigated. Among the allergic symptoms, itching and a dry sensation improved after topical application of ibudilast ophthalmic solution (both P<0.05). Phlyctenular conjunctivitis was noted in one eye after topical application, but there were no significant differences of SCL-related symptoms and objective ocular findings between before and after application. There were also no morphologic changes of the contact lenses, and the ibudilast concentration in the lenses was below the detection limit. These results suggest that topical application of ibudilast while using 2 Week Pure lenses can improve subjective symptoms without influencing drug adsorption or lens morphology.

Early cortical lens opacities: a short overview

Cataract is still the dominant cause of blindness worldwide. Cortical cataract is the most prevalent of the age-related changes in the human lenses that require surgical intervention to restore vision. The absence of adequate cataract surgery in most developing countries is the main cause of the high prevalence of cataract blindness worldwide. Lens ageing is accompanied by dramatic increases in stiffness, light scattering and coloration of the lens nucleus. These changes start to become manifest as early as the fourth or fifth decade of life and lead to nuclear cataract in old age. In the same period the equatorial deep lens cortex starts to show small opaque shades, which eventually grow out to segmental and annular opacities. These opaque shades are filled with small vesicles and contain abnormal amounts of cross-linked proteins, cholesterol and phospholipids. They are bordered by membranes that are rich in square arrays, have 'degenerate' gap junctions and have few intramembranous particles. It has been shown that the opaque shades represent cohorts of locally affected fibres segregated from unaffected neighbouring fibres by 'non-leaky' membranes. This segregation is an effective mechanism delaying the outgrowth of these opacities to cuneiform cataracts entering the pupillary space and thus leading to blinding cortical cataracts. Although cataract formation is mostly considered to be a multi-factorial disease, oxidative stress might be one of the leading causes for both nuclear and cortical cataract. In cortical cataracts shear stress between cortex and nucleus during accommodation may also play a significant role.