Effects of Brinzolamide, a Topical Carbonic Anhydrase Inhibitor, on Corneal Endothelial Cells.

INTRODUCTION: This clinical study aimed to investigate the effect of brinzolamide, a topical carbonic anhydrase inhibitor, on corneal endothelial cells (CECs) in patients with glaucoma using a follow-up clinical study design. METHODS: Patients with primary open-angle glaucoma or ocular hypertension were administrated an ophthalmic solution of either latanoprost alone (LT) as a control (n = 18) or latanoprost plus brinzolamide (LT + BR; n = 16). CECs were examined at baseline and at 4, 12, 24, and 48 weeks in 18 and 16 eyes of the LT and LT + BR groups, respectively, using a non-contact specular microscope. CECs were evaluated by parameters, including cell density (CD), coefficient of variation (CV) in cell size, and percentage hexagonality (Hex). RESULTS: Compared with the baseline intraocular pressure (IOP), the mean IOP in the LT group was significantly reduced at 12 and 24 weeks, whereas that in the LT + BR group was significantly reduced at all time points (P < 0.01). The mean CD, CV, and Hex at baseline were not significantly different between the two groups. No significant time-course changes in CD, CV, or Hex were observed in either group. At 48 weeks, there was no significant difference in the mean CD, CV, or Hex between the two groups. CONCLUSION: Patients treated with LT + BR showed significant IOP reduction. However, the use of brinzolamide in addition to latanoprost had no influence on CECs during the one-year follow-up period.

Effect of topical unoprostone isopropyl on optic nerve head circulation in controls and in normal-tension glaucoma patients.

PURPOSE: To evaluate the effect of unoprostone isopropyl on microcirculation in the optic nerve head (ONH) of controls and patients with normal-tension glaucoma (NTG). METHODS: Thirty healthy volunteers were randomly placed in a placebo group or a control group. For ten NTG patients, one eye was selected to receive the placebo drops and the contralateral eye received the unoprostone in a masked fashion. In both studies, the intraocular pressure (IOP) and the parameters of the blood hemodynamics of the ONH were obtained before and at 1 and 2 h after the instillation. Blood flow measurements were made with a scanning laser Doppler flowmeter. RESULTS: In both control subjects and NTG patients, the changes in the IOPs after the instillation of either unoprostone or the placebo were not significant because almost all of the NTG patients had IOPs lower than 15 mmHg. Although the hemodynamic parameters were not significantly changed in the placebo-treated eyes of the controls, the eyes of the controls treated with unoprostone had mean blood velocity and flow values that were significantly higher than the baseline values 1 and 2 h after instillation (P < 0.01). The velocity values of the controls treated with unoprostone were significantly higher than in those controls receiving the placebo at 2 h postinstillation (P = 0.027). The values for the three circulation parameters (volume, velocity, flow) were significantly higher than the baseline values after instillation in the eyes of the NTG patients treated with unoprostone (P < 0.05). In contrast, none of these parameters was significantly different from the baseline in the eyes of NTG patients treated with placebo. CONCLUSIONS: These results showed that unoprostone significantly increased microcirculation in the ONH in control subjects and in NTG patients without reducing the IOP significantly.

Novel MYOC gene mutation, Phe369Leu, in Japanese patients with primary open-angle glaucoma detected by denaturing high-performance liquid chromatography.

PURPOSE: To screen for mutations in the MYOC gene in Japanese patients with primary open-angle glaucoma (POAG) using denaturing high-performance liquid chromatography (DHPLC). PATIENTS AND METHODS: Blood samples were collected from 171 patients with POAG and 100 controls from seven institutions in Japan. For high-throughput analysis, seven exonic regions were amplified by polymerase chain reaction using DNA pooled from three patients; each DNA pool was then analyzed chromatographically. For analysis of a small number of samples, 7 exonic regions were amplified separately but simultaneously with annealing at 58 degrees C in each patient and then chromatographed, using 7 wells of the same 96-well plate per sample. When chromatographic patterns were abnormal by either method, the PCR products of the individual samples were sequenced. RESULTS: Four glaucoma-causing mutations were identified in five POAG patients (2.9%). One missense mutation, Phe369Leu, is new; and three others, Ile360Asn, Ala363Thr, and Thr448Pro, have been reported in Japanese patients. Phe369Leu was associated with adult onset POAG. CONCLUSIONS: Mutations in the MYOC gene were demonstrated chromatographically in 2.9% of our Japanese POAG patients. The use of pooled DNAs with DHPLC analysis is a time- and labor-saving technique. All mutations detected appear to be specific to Japanese patients.

Variants in optineurin gene and their association with tumor necrosis factor-alpha polymorphisms in Japanese patients with glaucoma.

PURPOSE: To investigate sequence variations in the optineurin (OPTN) gene and their association with TNF-alpha polymorphisms in Japanese patients with glaucoma. METHODS: The OPTN gene was analyzed in blood samples from 629 Japanese subjects. There were 194 patients with primary open-angle glaucoma (POAG), 217 with normal-tension glaucoma (NTG), and 218 with no eye disease (control subjects). The gene was screened for mutations by denaturing high-performance liquid chromatography. Genotyping of three polymorphisms of -308G-->A, -857C-->T, and -863C-->A in the TNF-alpha promoter region was performed. The associations between the genotypes and age, intraocular pressure (IOP), and visual field defects at the time of diagnosis were examined. RESULTS: A possible glaucoma-causing mutation, His26Asp, was identified in 1 of the 411 Japanese patients with glaucoma. A c.412G-->A (Thr34Thr) polymorphism in the OPTN gene was significantly associated with POAG (genotype frequency, P = 0.011; allele frequency, P = 0.003). The frequency of TNF-alpha/-857T and optineurin/412A carriers was significantly higher (P = 0.006) in patients with POAG than in control subjects. Among the patients with POAG who were carriers of TNF-alpha/-857T, the optineurin/412A carriers had significantly worse (P = 0.020) visual field scores than the non-optineurin/412A ones. The frequency of TNF-alpha/-863A and optineurin/603A (or Lys98) carriers was significantly higher in patients with POAG (P = 0.008) or NTG (P = 0.027) than in control subjects. Among the patients with POAG who were carriers of TNF-alpha/-863A, the ones with optineurin/603A (or Lys98) had significantly worse (P = 0.026) visual field scores than did those with non-optineurin/603A (or Lys98). CONCLUSIONS: These findings demonstrated that the OPTN gene is associated with POAG rather than NTG in the Japanese. Statistical analysis showed a possible interaction between polymorphisms in the OPTN and the TNF-alpha genes that would increase the risk for glaucoma.

[Genetic diagnosis of retinoblastoma by a combination of fluorescence in situ hybridization and restriction fragment length polymorphism].

PURPOSE: It is important to exclude germ line mutation in cases of unilateral retinoblastoma(RB) to estimate hereditary or possible secondary cancer. We investigated whether genetic diagnosis is feasible in a health check screening program. METHODS: Five patients with RB had surgery for enucleation in Keio University Hospital. Tumor cells from enucleated eyes and lymphocytes representing systemic cells were collected and analyzed genetically by fluorescence in situ hybridization(FISH) and restriction fragment length polymorphism (RFLP). RESULTS: One out of three unilateral RB cases could be diagnosed as non-hereditary by the finding of no copies of the RB gene in the tumor cells using the FISH method and no signal in the RFLP method. A decrease of signal in tumor cells to less than 50% in the RFLP method was observed in another case of unilateral RB that seemed to be non-hereditary, but the case ultimately could not be diagnosed as non-hereditary because polycopies were found in the FISH method. No abnormality in tumor cells could be found in another unilateral case or in systemic cells of two bilateral cases. CONCLUSION: A combination of FISH and RFLP methods can be used to diagnose some cases of RB as non-hereditary.

[Long-term efficacy and safety of combined topical antiglaucoma therapy--timolol & unoprostone vs. betaxolol & unoprostone].

PURPOSE: To evaluate long-term efficacy and safety of treatment combining topical beta-blockers and isopropyl unoprostone in primary open-angle glaucoma and normal-tension glaucoma patients. METHODS: A prospective, open-label, parallel-group clinical comparison trial was performed to evaluate efficacy and safety of treatment combining 0.5% betaxolol and 0.12% isopropyl unoprostone (B&U) or 0.5% timolol and 0.12% isopropyl unoprostone (T&U). Forty eyes of 40 patients, which were matched in the aging and the stage of glaucomatous visual field defect, were studied. Twenty patients were treated with B&U and the other twenty patients with T&U twice daily for 24 months. Goldmann intraocular pressure(IOP), Humphrey automated perimetry, blood pressure, heart rate, and peak flow were done every six months in each group. RESULTS: In the B&U treatment group, mean IOP was 21.2 mmHg at baseline and 18.3 mmHg(p < 0.005) after 2 years, and in the T&U treatment group it was 21.1 mmHg at baseline and 17.9 mmHg (p < 0.001) after 2 years. The cases in which MD value decreased over 2 dB were one in the B&U treatment group and three in the T&U treatment group. The average MD value was significantly improved from -7.40 dB to -5.90 dB after 2 years with B&U treatment(p < 0.05), but there was no difference with the T&U treatment. None of the patients stopped combined therapy because of side effects, though heart rate was significantly reduced only in T&U treatment group. CONCLUSION: Both combined treatments were effective for IOP reduction in glaucoma patients, and the data from the B&U treatment group suggested that B&U was more effective in maintaining visual field than T&U.

Variants of the myocilin gene in Japanese patients with normal-tension glaucoma.

Myocilin (MYOC) mutations are associated with juvenile- and adult-onset primary open-angle glaucoma (POAG). The purpose of this study was to determine whether MYOC gene mutations are associated with normal-tension glaucoma (NTG). The prevalence of MYOC mutations was determined in 80 Japanese NTG patients and 100 control subjects. In addition, the expression of mutant MYOC was determined by transforming COS-1 cells with five myocilin variants (R158Q, D208E, I360N, A363T, and I477S) and examining whether myocilin was present in the cultured cells and/or the culture medium by western blotting. Six different nucleotide sequence variants, R46Stop, R76K, R158Q, D208E, A488A, and one in the 3' non-coding region, were identified in 80 NTG patients. Variants in codon 46 (R46Stop), codon 158 (R158Q), and codon 488 (A488A) were not found in the 100 normal controls. The frequency of other sequence changes (R76K, D208E, and 3' non-coding) in NTG patients did not differ significantly from the frequencies in the control subjects. COS-1 cells transfected with the wild type, R158Q, or D208E variants secreted myocilin into the culture medium. On the other hand, the detected myocilin was significantly reduced in the medium of cells transfected with the I360N, A363T, or I477S variants that were previously identified as mutations for POAG. Definitive evidence of MYOC variants associated with NTG was not found.

[A comparison of visual field and optic disc appearance depending on the peak intraocular pressure in patients with normal-tension glaucoma].

PURPOSE: To investigate the clinical differences between the two groups depending on the peak intraocular pressure(IOP) in patients with normal-tension glaucoma(NTG). METHODS: We studied 96 eyes of 48 NTG patients who were hospitalized for diurnal IOP measurement. Then we selected the eye whose peak IOP was higher than the other, or the right eye if the peak IOP of both eyes was equal. We divided these eyes into a "high-teen" group (peak IOP > or = 16 mmHg) and a "low-teen" group(peak IOP < or = 15 mmHg). We compared these two groups by age, gender, refraction, IOP, visual field defect, optic disc appearance, and tomograph. We used a Humphrey C 30-2 program to estimate the visual field defect and classified the optic disc into four types according to Nicolela's criteria. 22 eyes were imaged with Heidelberg Retina Tomograph (HRT) to obtain topographic parameters of the optic disc. RESULTS: There were no significant differences in age, gender, refraction, optic disc appearance, or tomograph between two groups. The trough and variation range of diurnal IOP were significantly larger in the high-teen group(p < 0.01). The value of mean deviation(MD) given by STATPAC was statistically lower in the high-teen group(p < 0.01). CONCLUSIONS: In patients with NTG, the visual field damage tended to be greater in the high-teen group than in the low-teen group. We surmise that the IOP might influence the progression of visual field defect in NTG.

Optic disc excavation in the atrophic stage of Leber's hereditary optic neuropathy: comparison with normal tension glaucoma.

BACKGROUND: Abnormal optic disc excavations are reportedly seen in patients with Leber's hereditary optic neuropathy (LHON), a mitochondrial dysfunction disease. We examined the disc morphology in the eyes of patients with LHON at the atrophic stage and compared it to that in eyes with normal-tension glaucoma (NTG). METHODS: We studied 15 LHON patients with the 11778 mutation, 15 patients with NTG, and 25 normal subjects. The optic disc morphology was analyzed by Heidelberg retinal tomography (HRT). Ten parameters of the optic disc obtained by HRT were evaluated, including the diagnostic classification of glaucoma. RESULTS: Six of the nine morphological HRT parameters of the LHON patients, the exceptions being disc area, mean cup depth, and maximum cup depth, differed significantly from those of the normals. NTG patients had a significantly greater mean and maximum cup depth than LHON patients. The HRT glaucoma diagnostic software classified 22 (73%) of the 30 optic discs in LHON patients as glaucomatous. CONCLUSION: The optic discs at the atrophic stage of LHON eyes have glaucoma-like morphological changes. However, the cups were significantly deeper in NTG than LHON. The similarity in the optic disc findings in LHON and NTG suggests that alterations in mitochondrial function may be related to optic disc excavations.

[Two families with primary open-angle glaucoma associated with myocilin gene mutations].

BACKGROUND: Myocilin is a gene that causes primary open-angle glaucoma(POAG). We found a family with normal tension glaucoma(NTG) whose members had an Asp 208 Glu mutation, and a family with POAG whose members had an Ile 360 Asn mutation in myocilin. CASE: In the family with the Asp 208 Glu mutation, the proband, a 31-year-old male, was diagnosed as having NTG. His mother had the same mutation and was also diagnosed as having NTG, but a sister with the same mutation showed no glaucomatous changes. We also found this mutation in normal controls. In the family with the Ile 360 Asn mutation, the proband, a 67-year-old female, was diagnosed as having POAG. Four members of this family showed different phenotypes including POAG, ocular hypertension, and normal. We found no cases with the same mutation in the controls. CONCLUSION: Since the Asp 208 Glu mutation was found in NTG, the pathogenesis of glaucoma with myocilin mutation might be more complex and it may be related to weakness of the optic nerve head. On the other hand, the mutation may be a polymorphism. The Ile 360 Asn mutation was considered to be disease-causing. However, both late-onset glaucoma cases and non-glaucomatous cases were observed in this family. The implications of the mutation and other risk factors remain to be discussed.