Akihiko Tamai

Management of posterior capsule rupture during phacoemulsification using the dry technique

&NA; To manage posterior capsule rupture during phacoemulsification, we use a dry technique in which all procedures are performed without an irrigation/aspiration system. The dry technique is characterized by (1) continuous viscoelastic injection instead of fluid irrigation to maintain anterior chamber depth with the posterior capsule and vitreous located posteriorly and (2) static removal of most residual lens material by viscoexpression and/or manual small incision extracapsular cataract extraction without aspiration and dynamic water flow. In 16 cases of posterior capsule rupture managed using the dry technique, the residual nucleus and cortex were readily removed with minimum extension of the ruptured area and new vitreous loss. Although large amounts of viscoelastic material (mean 5.8 mL) were required, rapid and stable visual recovery was comparable to that in patients having uneventful surgery. The dry system is a safe and reliable technique for managing posterior capsule rupture during phacoemulsification.

Role of Pseudomonas aeruginosa Culture Filtrates in the Association, Invasion, and Cytotoxicity Against Cloned Cells from Murine Corneal Epithelium and KB Cells

PURPOSE To clarify the effect of Pseudomonas aeruginosa culture filtrates on the association with, invasion into, and cytotoxicity against cloned cells from murine corneal epithelial cells and KB cells. METHODS Simian virus 40-transformed murine corneal epithelial (MCE) cells were established. Murine corneal epithelial cells and KB cells were infected with a protease-positive strain, IID1117 (Pa IID1117), and a protease-negative strain, IID1130 (Pa IID1130) of P. aeruginosa, and then tested for association and invasion of Pa IID1117. The cytotoxicity test was performed by incubating the cells with culture filtrate. RESULTS Association of Pa IID1117 with KB cells pretreated with Pa IID1130 was significantly promoted. After pretreatment with culture filtrate, invasion was more effective into MCE cells than into KB cells. When infecting bacteria (Pa IID1117) were pretreated with protease inhibitor, invasion of the bacteria into MCE cells and KB cells clearly decreased. The cellular damage induced by the culture filtrate of Pa IID1130 was greater than the damage by that of Pa IID1117. CONCLUSION These results suggest that association of P. aeruginosa with MCE cells and KB cells was influenced by the culture filtrates other than proteases, and that invasion of P. aeruginosa into MCE cells and KB cells was promoted by protease.

Expression of stress-response protein 60 in iritis associated with experimental autoimmune encephalomyelitis

PURPOSE To study the expression of stress-response proteins in the inflamed iris of rats with experimental autoimmune encephalomyelitis (EAE). METHODS EAE was induced in Lewis rats by immunization with homogenized spinal cord of the guinea pig emulsified in complete Freunds adjuvant (CFA) (group EAE). Control rats included those immunized with only CFA (group CFA) and those that were untreated (group Normal). Immunohistochemical study for the localization of stress-response protein (srp) 27, srp 60, srp 72, ubiquitin, and alphaB-crystallin was performed. RESULTS All rats in group EAE developed iritis, whereas none of the rats in group CFA and group Normal developed iritis. No expression of ubiquitin, alphaB-crystallin, srp 27, srp 60, or srp 72 was seen in the epithelium of the iris in group CFA rats. In the eyes of rats in group EAE, srp 60 was expressed in the epithelium of the iris in 20 of 22 (90.9%), ubiquitin in 4 of 22 (18.2%), and alphaB-crystallin in 3 of 22 (13.6%). In the group Normal rats, only ubiquitin was expressed in the epithelium of the iris in 1 of 6 (16.7%) eyes examined. CONCLUSIONS These results suggest that srp 60 may be a potential uveitogenic antigen in the iris in EAE.

Expression of stress-response protein 60 in lens epithelial cells in atopic cataract.

PURPOSE To clarify the pathogenesis of atopic cataract, especially to determine if there is any relationship between autoimmunity and atopic cataract. METHODS We investigated the lens epithelia obtained at surgery from 12 patients (12 eyes) with atopic cataract: from 8 patients (8 eyes) with nonatopic cataract (5 with senile cataract, 2 with juvenile cataract, and one with secondary cataract due to anterior uveitis); and from 4 autopsy eyes as controls. RESULTS Histopathological findings in the lens epithelial cells from atopic and nonatopic cataract patients were essentially the same: atrophy of the cells, presence of the superimposed cells, migration of cells into the lens cortex, cytoplasmic vacuolation, and loss of cells. In an immunohistochemical study, the expression of stress-response protein 60 (srp 60), srp 27, and srp 72 was examined in the lens epithelial cells. In atopic cataract specimens, 71%-87% of the lens epithelial cells were stained with the antibody against srp 60, but the cells in nonatopic cataract and control specimens were not stained. CONCLUSIONS Srp 27 and srp 72 were not expressed in any observed epithelial cells. The expression of srp 60 may reflect a protective mechanism of the epithelial cells against injury triggered by immunorelated agents. These findings suggest that the pathogenesis of degeneration of the lens epithelial cells in patients with atopic cataract may be related to autoimmunity.

Studies on the Early Receptor Potential in the Human Eye

The early receptor potential (ERP) was measured and examined in 41 fellow eyes of 41 patients under 60 years of age with unilateral, idiopathic retinal detachment, who were free from myopia over -8 diopters and myopic chorioretinal atrophy. Eighty-six eyes of 50 normal subjects, comparable in age and in refractometric findings, served as normal controls. Mean ERP amplitudes in the group of 19 fellow eyes with some degenerative changes in the peripheral retina of the patients were, statistically, greatly decreased at the 1% level of significance, as compared with the normal controls. Even in the group of 22 fellow eyes with no appreciable retinal abnormalities, the mean ERP amplitude was significantly decreased at the 5% level, as compared with normal.

Intraocular Pressure and Myopia: Circular Optical Coherence Tomographic Features of the Retinal Nerve Fiber Layer Thickness in Myopes

Circular optical coherence tomography (OCT) around the optic disc was performed i myopic or glaucomatous eyes. The retinal nerve fiber layer (RNFL) thinning was more rpatients with high myopia associated with primary open-angle glaucoma than in patients with hiWi myopia only. These results indicated that focal RNFL dropouts and diffuse RNFL atrophy or defect in high myopes might be accelerated by an elevated intraocular pressure.

Studies on the Early Receptor Potential in the Human Eye VIII. ERP in Behçet’s Disease

In 22 cases of Behcet’s disease (43 eyes, one eye with corneal staphyloma being excluded) manifesting ocular symptoms in the complete form, abnormal changes in the amplitude of the early receptor potential (ERP) were noted at the first consultation in 51.2% of the eyes examined as compared with 53.3% with abnormal areal indices (∑A) of the oscillatory potential and 39.5% with abnormal amplitudes of the b-wave in the ERG. Almost the same detection rate of abnormalities as in the ∑A of the oscillatory potential was obtained with respect to the ERP amplitude. The ERP and the b-wave were either reduced in their amplitude or absent in accordance with the grade and duration of this disease. Relatively early disappearance of the oscillatory potential was also noted.