Anterior Subcapsular Opacities Research Articles

Cataract and Aqueous Flare Levels in Patients With Atopic Dermatitis

To determine whether cataract in patients with atopic dermatitis is associated with higher levels of aqueous flare or cells. In a prospective study, 35 consecutive patients examined during a 6-month period at the atopic dermatitis service in a university hospital underwent standardized ophthalmologic evaluations including the quantitative measurement of aqueous flare and cells by a laser flare-cell meter. Seven patients had bilateral cataract with anterior or posterior subcapsular opacities, or both; one patient had similar cataract in one eye and no cataract in the opposite eye; and 27 patients had no cataract in either eye. Fifteen eyes with cataract showed significantly higher levels of aqueous flare (2.1 to 33.9 photon counts per millisecond with a median of 18.0) compared with 55 eyes without cataract (2.4 to 16.0 photon counts per millisecond with a median of 9.2; Mann-Whitney U test, P = .0008). The association of cataract with higher levels of aqueous flare remained significant when only one eye (the right eye) of each patient was chosen for statistical analysis (P = .0024). Higher levels of aqueous flare caused by the breakdown of blood-aqueous barrier may contribute to the formation of cataract in patients with atopic dermatitis.

Effects of UV-B Radiation on a Hereditary Suture Cataract in Mice

UV-B (290–320 nm, λmax=305 nm) radiation and the Cat2ns(suture cataract) mutation in mice affect both the anterior lens epithelium and the formation of the suture. A low dose of UV-B radiation (2.2 Jcm−2) induces similar anterior subcapsular and cortical lens opacities in wild type as in heterozygous mutant mice. The UV-B treatment of the mutant lenses, however, leads to an increase in the number of epithelial cell layers in the anterior central part as compared to the wild type indicating a more severe form of the cataract formation in mutants. In addition, mutants demonstrate a predisposition for a rupture of the posterior lens capsule, because from 2.9 Jcm−2and higher, this phenomenon could always be observed in the UV-B treated mutants, but never in the treated wild type mice. The protein biochemical analyses were performed by gel electrophoresis and isoelectric focusing of extracts of total lenses or from defined areas of the lens (lens slice technique). These covered the patterns of those proteins already synthesized before irradiation, which in irradiated lenses in no case evidenced a difference to the untreated control, neither in the wild type nor in the mutants. In contrast, by analysing specifically those proteins, which are synthesized after irradiation, in both treated groups a protein with a molecular mass of about 31 kDa becomes discernable in both treated groups. In addition, the cataractous lenses demonstrate a significantly enhanced overall synthesis of water-soluble proteins after irradiation, which might promote the rupture of the posterior capsule at the posterior pole.The present study offers for the first time the possibility to discriminate between endogeneous (genetic) effects and exogeneous (environmental) effects in cataractogenesis and to study their interactive effects. The first set of experiments demonstrated a clear intensification of the hereditary cataract by the UV-B treatment. The study supports the hypothesis that environmental stress (like UV-B radiation) enhanced the severity of genetically triggered eye disease.

Prevalence of lenticular abnormalities in a population-based study: Oxford clinical cataract grading in the Melton Eye Study

Purpose To describe the distribution of the 11 features assessed by the Oxford Clinical Cataract Classification and Grading System (OCCCGS) in a population-based study.Methods The Melton Eye Study is an English community-based epidemiological study of the natural history of eye disease in people aged 55 to 74 years. Both lenses of 560 subjects were graded at the slit lamp using a decimalised version of the OCCCGS. Subject prevalences were estimated by logistic regression and the extent, when present, against normal errors regression.Results White nuclear scatter (WNS), brunescence, cortical spoke (cs), anterior subcapsular opacity (ASC), fibre folds (FF), waterclefts (WC) and perinuclear retro-dots all increased with age (p < 0.05). Posterior subcapsular opacity (PSC), vacuoles, focal dots (FD) and coronary flakes (CF) did not significantly increase with age. Subject prevalences of the features and the mean Oxford scores when present were: WNS (1.33), brunescence (0.88), CS 36% (0.34), PSC 11% (0.52), ASC 2% (0.53), FF 18% (0.53), WC 17% (0.29), retro-dots 11% (1.15), vacuoles 59% (0.43), FD 98% (1.79) and CF 39% (1.24). Significantly more common in women were both coronary flakes (p < 0.001) and waterclefts (p < 0.05).Conclusions These are the first data on the distribution of these minor lesions in a population-based study. Coronary flakes and waterclefts are more common in women.

Associations between lens features assessed in the Oxford Clinical Cataract Classification and Grading System

PURPOSE To study the associations between eleven lens features graded according to the Oxford Clinical Cataract Classification and Grading System (OCCCGS).METHOD 560 subjects taking part in the Melton Eye Study had their lenses graded according to the OCCCGS by one of two examiners. Associations between features were examined using log-linear models for categorised grades. Adjustment was made for age, sex and grader.RESULTS Within subjects, the two nuclear features, white nuclear scatter and brunescence, are closely related with one another, as are coronary flakes and focal-dots, but these two groupings are negatively associated. Cortical spoke, fibrefolds and waterclefts are all associated with one another and this group is positively associated with coronary flakes and focal-dots. Posterior subcapsular and anterior subcapsular opacity are associated with one another and with cortical spokes. A within-eye analysis gives similar results.CONCLUSION These associations may be important in defining cataract subtypes and in identifying minor features that indicate early cataract development.

UV-b-induced cataract model in brown-Norway rat eyes combined with preadministration of buthionine sulfoximine.

In order to develop a more adequate ultraviolet (UV)-induced cataract model, a combination of l-buthionine sulfoximine (BSO) treatment was applied to experimental animals. A single administration of BSO 4 mmol/kg caused reduced glutathione concentration until experimental day 8. In the 0.067-J/cm2 UV-B irradiation experiment, the light-scattering intensity of the anterior lens cortex of the combination group was significantly higher than that of the other groups during the second week after irradiation commenced. After the fourth experimental week, however, there was no significant difference between the group treated by UV-B alone and the combination group. In the 0.2-J/cm2 UV-B irradiation experiment, anterior polar cataract was seen in the group receiving UV-B alone, as already reported, 6 weeks after starting UV irradiation. Meanwhile, in the combination group, shallow cortical opacity was seen at 26 weeks after the start of experiment in the deeper lenticular layer which was separated from the anterior subcapsular opacity. This anterior shallow cortical opacity seemed to move towards the nuclear region during the time course of the experiment. The results of this experiment suggested that the BSO treatment accelerated cataractogenesis through additional UV-B irradiation. Although more experiments are needed, this model is useful in investigating the connection between UV-B and other cocataractogenic factors in age-related cataract in humans.

Progression of amiodarone induced cataracts.

Amiodarone hydrochloride is a potent antiarrhythmic agent recently approved for use by the Food and Drug Administration. Anterior subcapsular lens opacities were observed in seven of fourteen patients treated with moderate to high doses of amiodarone at the Veterans Administration Medical Center in San Francisco in 1982. The present report summarizes the present status of these same fourteen patients ten years later. Anterior subcapsular lens opacities developed or progressed in all patients continuing treatment with this antiarrhythmic agent during the following ten year interval. Although Snellen visual acuities are not decreased, subtle visual impairment is present as measured by contrast sensitivity measurements with and without glare. This decrease in visual acuity is not a contraindication for therapy with this potentially life saving drug.

Amiodarone-Induced Lens Opacities: An 8-Year Follow-up Study

To the Editor. —Amiodarone hydrochloride is a benzofurane derivative used for cardiac abnormalities. It has recently been approved by the Food and Drug Administration for use in cardiac arrythmias (Cordarone; Wyeth, Philadelphia, Pa). Eight years ago, visually insignificant anterior subcapsular (ASC) lens opacities were reported in seven of 14 patients using moderate to high doses of amiodarone who were treated at the Veterans Affairs Medical Center in San Francisco, Calif. 1 A summary of the present ocular status of these 14 patients 8 years later is provided in the Table. The first report of lens opacities in patients receiving amiodarone describes them as anterior, subcapsular, white-yellow, loosely packed, and covering an area greater than 2 mm in a loosely distributed fashion, with clear spaces between deposits. 1 They are clearly distinguished from axial punctate opacities, which are found in the general population and are pigmented, tightly packed, and cover an

Cataracts induced by microwave and ionizing radiation

Microwaves most commonly cause anterior and/or posterior subcapsular lenticular opacities in experimental animals and, as shown in epidemiologic studies and case reports, in human subjects. The formation of cataracts seems to be related directly to the power of the microwave and the duration of exposure. The mechanism of cataractogenesis includes deformation of heat-labile enzymes, such as glutathione peroxide, that ordinarily protect lens cell proteins and membrane lipids from oxidative damage. Oxidation of protein sulfhydryl groups and the formation of high-molecular-weight aggregates cause local variations in the orderly structure of the lens cells. An alternative mechanisms is thermoelastic expansion through which pressure waves in the aqueous humor cause direct physical damage to the lens cells. Cataracts induced by ionizing radiation (e.g., X-rays and gamma rays) usually are observed in the posterior region of the lens, often in the form of a posterior subcapsular cataract. Increasing the dose of ionizing radiation causes increasing opacification of the lens, which appears after a decreasing latency period. Like cataract formation by microwaves, cataractogenesis induced by ionizing radiation is associated with damage to the lens cell membrane. Another possible mechanism is damage to lens cell DNA, with decreases in the production of protective enzymes and in sulfur-sulfur bond formation, and with altered protein concentrations. Until further definitive conclusions about the mechanisms of microwaves and ionizing radiation induced cataracts are reached, and alternative protective measures are found, one can only recommend mechanical shielding from these radiations to minimize the possibility of development of radiation-induced cataracts.

Study of experimental cataract produced by sugar alcohols in the organ-cultured mammalian ocular lens.

Freshly isolated rabbit lenses were cultured in isosmolar TC-199 medium or hyperosmolar medium containing 180 mM sorbitol or mannitol. These experiments were performed to investigate the probable effects of hyperosmolar media on lens clarity and the ability of lens fiber cells to synthesize membrane intrinsic protein, MP-26. The data from these experiments show that incubation in hyperosmolar medium causes depressed MP-26 synthesis, whereas the presence of sugar alcohols in the culture medium induced anterior and posterior subcapsular opacities. The cation levels of lenses incubated in iso- and hyperosmolar medium were also measured. Data from these experiments revealed that although the experimental lenses display prominent opacities, their cation levels are generally similar to those of control lenses. It is proposed that the observed lens opacities are due to the presence of sugar alcohols in the culture medium and not to hyperosmolar shock.

Electric Cataract

Bilateral crystalline lens opacities developed in a 39-year-old black male who had been involved in an electrical accident approximately 1 yr before our examination. The anterior subcapsular opacities had feathered edges and a slightly raised center. The typical appearance and progressive course of the opacities, as well as the history, led to the diagnosis of electric cataract.

Amiodarone-induced lens opacities.

Amiodarone hydrochloride is a benzofurane derivative used for cardiac abnormalities. Its use is commonly associated with an asymptomatic keratopathy. Although lipid deposits have been observed with the electron microscope in the lens epithelium of one patient with a history of amiodarone therapy, lens opacities have not been reported in patients using this drug. Visually inconsequential, anterior subcapsular lens opacities in seven of 14 patients using moderate to high doses of amiodarone who were examined at the Veterans Administration Hospital in San Francisco are reviewed.

Echothiophate iodide cataracts in monkeys. Occurrence despite loss of accommodation induced by retrodisplacement of ciliary muscle.

Five cynomolgi underwent unilateral 360 degrees ciliary muscle retrodisplacement. Beginning several months later, they received 150 to 210 micrograms of echothiophate iodine topically once daily in both eyes for five months. In all eyes anterior and posterior subcapsular lens opacities developed that were characteristic of those caused by echothiophate. There were no apparent differences in biomicroscopic appearance or time course of the cataracts between eyes with or without retrodisplaced ciliary muscles. Since eyes with retrodisplaced ciliary muscles accommodate only minimally in response to echothiophate, possible mechanical stress on the lens due to sustained, intense accommodation cannot explain echothiophate cataractogenesis.

Human senile cataract. Light- and electron-microscopic studies of the morphology of the anterior lens structures, with special reference of anterior capsular/subcapsular opacity.

Light- and electron-microscopic studies of human senile cataractous lenses with and without biomicroscopically detectable anterior capsular/subcapsular opacity (ACSCO) revealed the main difference between the two types of cataract to be in the subepithelial cortex, where ACSCO lenses showed disintegrating cortex fibres, fibres of the deep cortical type and even in some cases collapsed fibres. These findings were considered to be associated with the decomposition and disappearance of the superficial cortex in ACSCO lenses. Numerous mitochondria in the epithelium of ACSCO lenses point towards a high oxidative metabolism, which may facilitate active transport across the epithelium. No difference in capsular surface morphology between cataractous lenses with and without ACSCO was found by scanning electron microscopy. Transmission electron microscopy showed in both categories of lenses granular inclusions in the capsules, most pronounced in totally opaque lenses. Large intercellular vacuoles were seen in the anterior part of the epithelium, both light- and electron-microscopically in both categories. Consequently, these ultrastructural changes do not seem to form part of the biomicroscopical picture of ACSCO. Based on our study, we prefer the term: ASCO (anterior subcapsular opacity) in place of ACSCO, the latter term having been used by us previously.

Philly mouse: A new model of hereditary cataract

Philly mouse is a new strain of mice derived from the Swiss-Webster strain which develops hereditary cataracts visible to the naked eye ca. 5–6 weeks after birth. Slit lamp examinations of the apparently clear lenses of 15 day mice indicate the presence of faint anterior opacities which progress, involving the suture area, by day 25. By 30 days a nuclear opacity develops which surrounds the nucleus by day 35. At the same time the anterior subcapsular opacity becomes diffuse and pronounced as the cataract becomes obvious to the naked eye. Biochemical studies indicate that an osmotic cataract is formed in the Philly mouse. By ca. 20 days of age there is an increase in lens water along with an alteration in electrolyte levels. Lenticular sodium rapidly increases while potassium levels decrease. Concomitant with cataract formation is an increase in total lenticular calcium and a decrease in lens dry weight, reduced GSH and ATP. In transport studies, no significant difference between the Philly and control lens was seen in the accumulation of AIB. When rubidium was substituted for potassium a decreased accumulation in the Philly lens older than 20 days was correlated with increased rubidium leak-out. This decreased accumulation due to increased leak-out appears to be the key biochemical change that accounts for osmotic cataract formation and it suggests the possibility of a defect in membrane permeability.

Atropine Inhibition of Echothiophate Cataractogenesis in Monkeys

One cynomolgus and three vervet monkeys were treated topicall twice daily in one eye with 63 microgram of echothiophate iodide and 750 microgram of atropine sulfate. The opposite eyes were treated with echothiophate alone. The eyes treated with echothiophate alone all developed posterior and/or anterior subcapsular cataracts within 26 to 66 days. The echothiophate plus atropine-treated cynomolgus eye developed a cataracts of much delayed onset and lesser severity compared to its echothiophate-only-treated fellow. None of the echothiophate plus atropine-treated vervet eyes developed cataracts during the 121 (two eyes) or 231 (one eye) days of treatment. After 121 days of echothiophate plus atropine treatment, two vervet eyes were switched to echothiophate alone. Both eyes developed unequivocal posterior and anterior subcapsular lens opacities, one within 51 and one within 71 days after the switch. We conclude that atropine inhibits echothiophate cataracto-genesis in vervet and cynomolgus monkeys.

Induction of mitosis in ocular tissue by chemotoxic agents

Ocular inflammation has been induced in a number of species by a variety of chemical agents, including methylene blue. Initial cell destruction and subsequent repopulation by mitogenesis in lens epithelium and corneal endothelium were observed using techniques for living and fixed tissue. During the course of the chemical inflammation response, the lens displayed a prominent, anterior pole subcapsular opacity underlying the area of maximal epithelial destruction. Near-normal transparency returned with recovery of the lens tissue cytoarchitecture. Elevated protein concentrations in aqueous humor were found throughout the course of the experiments. Similar alterations in aqueous humor were observed in the course of immunogenic uveitis although lenticular or corneal endothelial destruction and subsequent proliferation were not detected.

Electric cataracts. II. Ultrastructural lens changes.

This is the first reported electron-microscopic evaluation of lens changes in electric cataracts. The anterior subcapsular opacity of these cataracts was composed of elongating and proliferating epithelial cells. Each elongating cell was surrounded by its own capsule. The posterior cortex of the lens was diffusely opaque and fibers in this region contained many small dense circular bodies. The anterior lens changes appear to be due to an electrically induced proliferation and abnormal differentiation of epithelial cells while the posterior changes involve faulty formation of lens fibers.

Cataract extraction in glaucomatous patients.

CATARACT formation with resultant reduction of vision is a frequent occurrence in patients receiving miotic therapy for glaucoma. This is especially true when using cholinesterase inhibitors which produce such intense miosis that the visual impairment from even minimal lens changes is greatly magnified. The development of proliferations of the pigment epithelium of the iris may cause further reduction of the pupillary opening in patients using these agents. In addition, individuals subjected to prolonged use of anticholinesterase drugs may develop central anterior subcapsular vacuoles and opacities. The necessity for cataract surgery, therefore, often arises in the long-term follow-up of glaucoma patients. Since the glaucoma patient will often require miotics postoperatively, it is advisable to create a permanent large pupillary opening at the time of cataract surgery. The advantages of the larger opening are twofold. First, during the operative procedure, the delivery of the lens is facilitated. Second, postoperatively, the fundus can

A case series of bilateral electric cataract in high-voltage electrical injury

A 39 year-old female presented with progressive diminution of vision in the right eye for six months after sustaining an injury from a high-voltage electric current to the right side of her forehead, face, around the right eye and to the scalp. On examination with the slit lamp, the right eye showed a mature cataract and anterior subcapsular opacities, with early lental opacity in left eye. She suffered from lagophthalmos and slight conjunctival congestion in the right eye. Vision in the right eye was only perception of light and in the left eye accurate projection of rays and 6/24. From the history, the type of injury (wound of entry and exit), and slit-lamp examination confirmed a case of bilateral electric cataract. We performed manual smallincision cataract surgery with posterior chamber intraocular lens implantation in right eye and in the left eye, using local anesthesia. Postoperative visual acuity was only 3/20 in the right eye and 6/6 in the left eye. In this case we have seen three circumscribed retinal lesions in the right eye; the left eye it was normal. This has been documented.The second case was a 20-year-old male, who was admitted to our center with bilateral electric cataract. He was treated the same way as the first case. He regained normal BCVA after cataract surgery with posterior chamber intraocular lens implantation.