Yoshinao Majima

Comparison of diclofenac and fluorometholone in preventing cystoid macular edema after small incision cataract surgery : A multicentered prospective trial

PURPOSE To compare a nonsteroidal topical solution (0.1% diclofenac) to a steroidal topical solution (0.1% fluorometholone) in preventing cystoid macular edema (CME) and disruption of the blood-aqueous barrier. METHODS A multicentered, prospective clinical trial was performed on eyes undergoing phacoemulsification followed by implantation of a foldable acrylic intraocular lens by the envelope technique. The presence and degree of cystoid macula edema (CME) was determined by fluorescein angiography. A breakdown of the blood-aqueous barrier was determined by laser flare-cell photometry. RESULTS Five weeks after surgery, CME was present in 3 of 53 eyes (5.7%) receiving diclofenac and in 29 of 53 eyes (54.7%) receiving fluorometholone. This difference was statistically significant (P < .001). The amount of flare in the anterior chamber at 3 days, 1, 2, 5, and 8 weeks after surgery was also significantly lower (P < .01-P < .001) in the diclofenac group. The degree of flare at 3 days, 1, 2, 5, and 8 weeks after surgery was significantly higher in eyes with CME (P < .001). CONCLUSIONS These findings suggest that diclofenac effectively prevents CME following cataract surgery and that CME is closely related to the breakdown of the blood-aqueous barrier.

Current Trends in Cataract and Refractive Surgery in Japan: 1996 Survey

A fifth annual survey was carried out by mail in February 1997 to investigate the current trends in cataract and refractive surgery in Japan. A questionnaire was sent to 867 ophthalmologist members of the Japanese Society of Cataract and Refractive Surgery. Data received from 440 (50.7%) of the recipients were cross-analyzed and compared with those from the previous surveys. For cataract surgery, there have been trends toward more surgical procedures performed by a surgeon, shorter period of hospitalization, and increased number of outpatient surgery. Ninety percent of respondents preferred phacoemulsification, 42% employed the self-sealing wound closure technique, and 26% used topical anesthesia for phacoemulsification. As for refractive surgery, surgeons remained rather conservative, with 26% and 6% of surgeons doing astigmatic keratotomy and refractive keratotomy, respectively.

Detection of cytotoxic anti-LEDGF autoantibodies in atopic dermatitis

In the last two decades, atopic dermatitis (AD) has been of increasing clinical significance in Japan. Eight-20% of patients with AD developed progressive cataracts (cataract-AD) and lens epithelial cells (LECs) were severely damaged. Lens epithelium-derived growth factor (LEDGF) is a newly isolated survival factor. In the presence of LEDGF, LECs survive well and in the absence of LEDGF, they become highly susceptible to stress. We investigated (1) whether auto-antibody (auto-Ab) to LEDGF is present in sera of AD patients and (2) whether depletion of LEDGF by the auto-Ab kills LECs. In sera from 26 patients with AD using ELISA, we found significantly higher levels of auto-Ab to LEDGF than that in a normal control group. Affinity purified auto-Ab to LEDGF from these sera killed LECs without complement activation. Levels of histamine in the AD group were significantly higher and levels of prostaglandin E2 were significantly lower than in the normal group. However, statistically there are no differences between sera from AD and cataract-AD in levels of Ab to LEDGF, histamine, prostaglandin E2 (PGE2), immunoglobulin E (IgE) and eosinophiles. We speculate that cataract-AD may be induced, in part, by a combination of high levels of serum histamine and eye rubbing which could break the blood-aqueous barrier to allow the entry of Ab to LEDGF into the privileged compartment, thus, reducing LEDGF levels, resulting in damage to LECs, and cataract formation.

Cataract Development in 12-Month-Old Rats Fed a 25% Galactose Diet and Its Relation to Osmotic Stress and Oxidative Damage

We attempted to clarify the pattern of cataract development in 12-month-old rats fed a 25% galactose diet and to assess the relation of cataract development with osmotic stress and oxidative damage. In lenses of 12-month-old male Wistar rats fed a 25% galactose diet over an 8-month period, suture accentuation appeared at 6 months of galactose feeding and then opacities developed from the anterior subcapsular cortex toward the posterior subcapsular cortex, reaching the nuclear region at 8 months of galactose feeding. Increases in lens galactitol and lipid peroxide contents and a decrease in lens reduced glutathione content occurred at 4, 6 and 8 months of galactose feeding. The increase in lens lipid peroxide content and the decrease in lens reduced gluthatione content were accelerated with an increase in feeding period, while the increase in lens galactitol content was decelerated. An increase in lens water content and a decrease in lens protein content occurred at 6 and 8 months of galactose feeding. The lens vitamin E content increased at 6 months of galactose feeding and this increase was concomitant with increases in serum vitamin E and total cholesterol concentrations. The serum lipid peroxide concentration increased at 4 and 6 months of galactose feeding. The present results indicate that in lenses of 12-month-old rats fed a 25% galactose diet, suture accentuation appears initially and then opacities develop from the anterior subcapsular cortex toward the posterior subcapsular cortex, finally reaching the nuclear region. These results also suggest that in the galactosemic aged rats, osmotic stress would mainly contribute to cataract formation, while oxidative damage could be linked to both cataract formation and progression, although an increase in lens vitamin E content occurs during the cataract development.

Involvement of oxidative stress in D-xylose-induced cataractogenesis in cultured rat lenses

In order to clarify the involvement of oxidative stress in in vitro sugar-induced cataractogenesis, we examined changes in lipid peroxide, reduced glutathione, vitamin E, and water contents following cataractogenesis in rat lenses cultured with 20 mM D-xylose over a period of 24 h. In D-xylose-treated lenses, an apparent opacity appeared at the equator after 6 h of D-xylose treatment, increases in lipid peroxide and water contents and decreases in reduced glutathione and vitamin E contents occurred with the appearance of opacity. We further examined the effect of the treatment of vitamin E in a liposomal form on cataractogenesis and the changes of lipid peroxide, reduced glutathione, vitamin E, water, and xylitol contents in rat lenses cultured with 20 mM D-xylose for 24 h. This vitamin E treatment significantly prevented not only cataractogenesis, but also an increase in lipid peroxide content and a decrease in vitamin E content in the D-xylose-treated lenses. However, the vitamin E treatment had no effect not only on a decrease in reduced glutathione content, but also on increases in water and xylitol contents, which are known to be induced via aldose reductase, in the D-xylose-treated lenses. These results indicate that not only osmotic stress but also oxidative stress should be involved in cataractogenesis in rat lenses cultured with D-xylose and support the involvement of oxidative stress in in vitro sugar-induced cataractogenesis.

Anticataract Action of Vitamin E: Its Estimation Using an in vitro Steroid Cataract Model

The aim of this study was to estimate the anticataract action of vitamin E using an in vitro methylprednisolone (MP)-induced cataract model. The same severity of early cortical cataract was induced in lenses isolated from male Wistar rats aged 6 weeks by incubation with MP (1.5 mg/ml) in TC-199 medium. The cataractous lenses showed slight increases in lipid peroxide (LPO) content and Na+/K+ ratio and slight decreases in reduced glutathione (GSH) content and glyceraldehyde-3-phosphate dehydrogenase (GAP-DH), a sensitive index of oxidative stress, and Na+,K(+)-ATPase activities. When the cataractous lenses were further incubated in TC-199 medium with and without vitamin E (250 micrograms/ml) for 48 h, the progression of cataract was prevented in the vitamin E-treated lenses, but not in the vitamin E-untreated lenses. The vitamin E-untreated lenses showed a decrease in vitamin E content and an increase in water content in addition to further increases in LPO content and Na+/K+ ratio and further decreases in GSH content and GAP-DH and Na+,K(+)-ATPase activities. In contrast, the changes of these components and enzymes except for GSH were attenuated in the vitamin E-treated lenses. From these results, it can be estimated that vitamin E prevents in vitro cataractogenesis in rat lenses treated with MP by protecting the lenses against oxidative damage and loss of membrane function.

The utilization of a biological adhesive for wound treatment: comparison of suture, self-sealing sutureless and cyanoacrylate closure in the tensile strength test.

We produced a measurement apparatus for testing the tensile strength of wounds during cataract surgery, and tested the tensile strength of treated wounds including wounds sutured with various methods, non-sutured and wounds treated with various bio-tissue adhesives. Methods. In cataract surgery on white rabbits eyes, a corneoscleral incision 5 mm in length was made 2.5 mm from the limbus corneae, and entry into the anterior chamber was obtained 0.5 mm to the clear cornea. After treatment for closure, the corneoscleral piece was subjected to the tensile strength test. Results. The tensile strengths just after surgery were (1) 0 gf/mm2 after self-sealing sutureless closure; (2) 114 gf/mm2 after vertical suture closure (one stitch with 10-0 nylon); (3) 125 gf/mm2 after horizontal suture closure (one stitch with 10-0 nylon); (4) 143 gf/mm2 after infinity suture closure (with 10-0 nylon); (5) 112 gf/mm2 after fibrin glue (Beriplast®P) application (instilled on the surface of scleral incision); (6) 121 gf/mm2 after fibrin glue application (glued on corneoscleral wound); (7) 131 gf/mm2 after cyanoacrylate closure (instilled on the surface of scleral incision); (8) 139 gf/mm2 after cyanoacrylate closure (glued on corneoscleral wound). The respective strengths at four days after surgery were: (1) 86; (2) 131; (3) 137; (4) 175; (5) 109; (6) 43; (7) 138; and (8) 108 gf/mm2. At 28 days after surgery, the respective strengths were (1) 164; (2) 167; (3) 184; (4) 209; (5) 322; (6) 195; (7) 251; and (8) 175 gf/mm2. Conclusion. The use of fibrin glue in treatment of a wound in cataract surgery is beneficial in assisting this treatment.

Role of Catalase in Retinal Antioxidant Defence System: Its Comparative Study among Rabbits, Guinea Pigs, and Rats

The role of catalase in the retinal antioxidant defence system was examined in rabbits, guinea pigs, and rats with and without prolonged administration of a diet containing 0.4% 3-aminotriazole (3-AT), a catalase inhibitor. When weanling rabbits, guinea pigs, and rats we administered 3-AT for 8, 7, and 10 weeks, respectively, retinal catalase activity was reduced by approximately 50% in all these animals. In the retina of rabbits with 3-AT administration, a decrease in superoxide dismutase (SOD) activity and an increase in lipid peroxide (LPO) concentration occurred. while glutathione peroxidase (GSH-px) activity did not change. In the retina of guinea pigs with 3-AT administration, an increase in LPO concentration occurred, while SOD and GSH-px activities did not change. In the retina of rats with 3-AT administration, a decrease in GSH-px activity and an increase in LPO concentration occurred, while SOD activity did not change. An increase in serum LPO concentration was found in rats with 3-AT administration, while the concentration did not change in rabbits and guinea pigs. These results indicate that catalase plays an important role in the retinal antioxidant defence system, but that the way catalase contributes to the maintenance of the retinal antioxidant defence system is different among these animals. The present results suggest that under the prolonged inhibition of catalase, the retina of rats, but not of rabbits and guinea pigs, may suffer from the influence of systemic oxidative stress.

Histopathological and cell biological analyses of the formation mechanism of anterior polar cataract.

Anterior polar cataract, defined as an opacification limited to the anterior polar region of the crystalline lens, results in a significant decline of vision even though the area of opacification is generally small. Having performed histopathological and cell biological studies in an attempt to identify the formation mechanism of anterior polar cataract, we found that lens epithelial cells (LECs) in contact with the opacified region were arranged in a monolayer and contained vacuoles. Furthermore, compared to LECs obtained from cortical and nuclear cataractous lenses and cultured for the study, these LECs revealed a significantly diminished proliferation, suggesting that their physiological activity had been reduced. On the other hand, LECs existing within the opacified region were multi-layered, and there were structureless deposits including remnants of organelles among the cells. Based on these findings, we have concluded that the formation mechanism of anterior polar cataract is as follows: LECs contacting the opacified region initially undergo significant mitosis; rather than migrating towards the equator, these proliferating cells accumulate and form a multilayer in the anterior polar region. Since multi-layered cells are surrounded by the anterior lens capsule and the lens cortex, there is a limit as to how many layers the cells can continue to form; when this limit is reached, these cells next undergo endocytosis and exocytosis. Because the physiological activity has been reduced as a result of having undergone significant proliferation, the cells contacting the opacified area are no longer able to force the proliferating cells towards the anterior polar region; hence multi-layering of the cells and the entire cellular movement are terminated at this point and result in cells with vacuoles and diminished physiological activity. While further studies are required to confirm our hypothesis, we believe this is the first study to suggest a possible mechanism of formation of anterior polar cataract.

Cell-Biological Analysis of Atopic Cataractous Lenses

The number of people suffering from atopic dermatitis, a recent social problem believed to have arisen from environmental pollution and changes, continues to increase today, and these patients often encounter complications such as cataract and retinal detachment. In this study, I have conducted (1) a comparative study on the rate of cell proliferation between lens epithelial cells (LECs) obtained from 7 atopic cataractous lenses and from 1 normal lens, (2) a comparative study on cell density and alignment between LECs obtained from 5 nonatopic cataractous lenses and from 5 atopic cataractous lenses and (3) transmission electron microscopy of LECs obtained from 3 atopic cataractous lenses. My findings were as follows: (1) except for 1 case disclosing increased proliferative activity of the cells to become multilayered, LECs of atopic cataractous lenses showed diminished proliferative activity; (2) LECs of atopic cataractous lenses had decreased in cell density and revealed irregular cell alignment; (3) transmission electron microscopy of LECs of atopic cataractous lenses demonstrated multilayered cells, increased intercellular spaces, and degeneration and disappearance of some cells. A longer follow-up period and further studies using cells from additional atopic cataractous lenses are necessary before any conclusions can be drawn. However, obtaining human LECs especially of atopic cataract patients is not easy, and I do feel that my present study, although its number of patients may not be large enough, provides significant findings for further studies on the mechanism of atopic cataract formation.