Congenital Glaucoma Associated with An Arginase Deficit: A Case Report

PURPOSE

Argininemia is a rare congenital disease caused by deficiency. We present here a case in which argininemia and buphthalmos are associated.

CASE REPORT

This female patient, who died at eighteen, had intraocular pressure correlated with her blood levels or arginine. Hyperammoniemia causes a change in pH that could explain an increase in aqueous humor (from the ciliary body). Ammonium ions could also damage the matrix of the trabecular meshwork.

CONCLUSIONS

The association of argininemia and buphthalmos have never been described. This might be because of the different expressions of the disease, or because nobody has ever looked for ocular hypertension in these patients unless they had subjective symptoms.

Proteome alterations in primary open angle glaucoma aqueous humor

As the only nourishment and scavenging source for most of the anterior and posterior chamber tissues in the eye, the aqueous humor represents one of the target for glaucoma. The aim of this study is to investigate the yet unexplored relationship between aqueous humor protein content and open-angle glaucoma (POAG) pathogenesis. Aqueous humor was collected from 10 POAG patients (cases) and 14 senile cataract patients (controls), matched for age and gender, undergoing surgery for trabeculectomy and cataract, respectively. Protein samples were cyanine-labeled and hybridized with antibody microarrays. Microarray signals were revealed by laser scanner, quantified, and compared by statistical analyses. Total protein amounts were not significantly different in patients versus controls. Conversely, a proteome cluster significantly modified in patients as compared to controls was identified as highly predictive for disease status. Selected proteins underwent dramatic variation, which was correlated to pathogenetic events characterizing POAG, including oxidative damage, mitochondrial damage, neural degeneration, and apoptosis. The results obtained indicate that proteomic analysis of aqueous humor is a new tool for POAG diagnosis in the case of otherwise uncertain disease recognition. Furthermore, this study allows a better understanding of mechanisms involved in the pathogenesis of POAG, the main cause of irreversible blindness worldwide.

Glaucoma and Helicobacter pylori infection: correlations and controversies

A possible association between Helicobacter pylori infection and eye diseases, including Sjögren syndrome, blepharitis, central serous chorioretinopathy and uveitis, has been proposed. Glaucoma is the second leading cause of blindness in the world, after cataracts, and the leading cause of irreversible blindness, but many aspects of its pathogenesis remain unknown. H pylori infection may influence the pathophysiology of glaucoma by releasing various proinflammatory and vasoactive substances, as well as by influencing the apoptotic process, parameters that may also exert their own effects in the induction and/or progression of glaucomatous neuropathy. It is difficult to understand how H pylori infection can be linked to such varied pathologies. Systemic H pylori-induced oxidative damage may be the mechanism which links oxidative stress, H pylori infection and the damage to the trabecular meshwork and optical nerve head that results in glaucoma.

Antioxidant activity of timolol on endothelial cells and its relevance for glaucoma course

PURPOSE

A growing evidence in the scientific literature suggests that oxidative damage plays a pathogenic role in primary open-angle glaucoma. Therefore, it is of interest to test whether drugs effective against glaucoma display antioxidant activity. We test the hypothesis that the classic beta-blocker therapy for glaucoma with timolol involves the activation of antioxidant protective mechanisms towards endothelial cells.

METHODS

Oxidative stress was induced in cultured human endothelial cells by iron/ascorbate with or without timolol pretreatment. Analysed parameters included cell viability (neutral red uptake and tetrazolium salt tests), lipid peroxidation (thiobarbituric reactive substances), and occurrence of molecular oxidative damage to DNA (8-hydroxy-2'-deoxyguanosine).

RESULTS

Oxidative stress decreased 1.8-fold cell viability, increased 3.0-fold lipid peroxidation and 64-fold oxidative damage to DNA. In the presence of timolol, oxidative stress did not modify cell viability, whereas lipid peroxidation was increased 1.3-fold, and DNA oxidative damage 3.6-fold only.

CONCLUSIONS

The obtained results indicate that timolol exerts a direct antioxidant activity protecting human endothelial cells from oxidative stress. These cells employ mechanisms similar to those observed in the vascular endothelium. It is hypothesized that this antioxidant activity is involved in the therapeutic effect of this drug against glaucoma.

A human placental polydeoxyribonucleotide (PDRN) may promote the growth of human corneal fibroblasts and iris pigment epithelial cells in primary culture

The optimal concentration of a human placental polydeoxyribonucleotide (PDRN) preparation (100 microg/ml) enhances the growth of human corneal fibroblasts in primary culture depending upon the donor age. In particular, this effect is very consistently reproducible with donors over 60 years of age (p = 0.0028), suggesting a selective benefit of PDRN in the tissue culture of senescent cells. Moreover, this drug may promote the development of human iris pigment epithelium (IPE) cells with much lower concentrations of fetal bovine serum than those suitable for the culture of IPE. Lastly, the use of a 'gauze disk' on the pieces of the corneal explants improves the efficiency of growth of the control fibroblast primary cultures.

Fluctuations of intraocular pressure during the day in open-angle glaucoma, normal-tension glaucoma and normal subjects

PURPOSE

The aim of the present paper is to describe the variations in intraocular pressure (IOP) during the day in normals, in patients with primary open-angle glaucoma (POAG) and in patients with normal-tension glaucoma (NTG). IOP represents one of the most important risk factors for glaucoma. However the IOP value is not constant during the day and IOP fluctuation could influence the diagnostic and prognostic evaluation of the glaucomatous disease.

METHODS

For this purpose IOP was evaluated every 2 h from 8 a.m. to 8 p.m. in one randomized eye of 33 normal subjects, 95 POAG and 50 NTG patients.

RESULTS

The results show that the highest IOP values were detectable in the morning in all three groups. The lowest values were found in the early afternoon hours. These variations were most evident in POAG patients. The daily IOP fluctuations were directly proportional to IOP level.

CONCLUSION

The study evidents that a single tonometric evaluation, especially if done in the first hours of the afternoon, is not sufficient to correctly evaluate the IOP-related risk in glaucoma patients. If the pressure peaks are important in determining the extent of glaucomatous damage in NTG patients IOP should not have an important role in optic nerve head damage. The use of diurnal curves seems to be mandatory for the assessment of IOP-related risk and of efficiency of the therapeutic approach.

Echobiometric evaluation of the axial length of the eye and intraocular lens calculation in pseudophakic eyes: our experience

Intraocular lens (IOL) power calculation in 46 pseudophakic eyes (extracapsular cataract extraction with IOL in posterior chamber), utilizing a Javal keratometer, a Sonomed A 2000 echobiometer (probe 10 MHz, velocity=1,548 m/s) and the SRK2 formula, although there was a statistically significant reduction of the axial length, both in normal and hyperopic eyes, demonstrated no statistically significant differences of IOL power, when compared to the power previously calculated in the phakic eye.

Effect of betaxolol on primary open-angle glaucoma and normal-tension glaucoma patients

This study is aimed at establishing the efficacy of the therapeutic agent, betaxolol, in diurnal control of IOP (intraocular pressure). Therapy was performed on 32 eyes affected by POAG (primary open-angle glaucoma) and 16 eyes affected by NTG (normal-tension glaucoma). Two preparations of betaxolol were utilized: betaxolol hydrochloride 0.50% (Betoptic) was administered to 15 POAG and 7 NTG eyes; betaxolol hydrochloride 0.25% ophthalmic suspension (Betoptic S) was administered to 17 POAG and 9 NTG eyes. IOP measurements were taken every two hours from 8 a.m. to 8 p.m. IOP was measured before therapy and at 12 hours, 30 days, and 3 months of therapy. Betaxolol hydrochloride 0.50% was more effective at lowering IOP during the day. Diurnal pressure peaks, which are a risk factor concerning the maintenance of visual field in glaucoma patients, were also reduced using 0.50% betaxolol hydrochloride.

Role of impression cytology during hypovitaminosis A

AIMS

Evaluation of the morphological damage to the ocular surface of patients operated for biliopancreatic diversion for pathological obesity and the correlation of impression cytology with vitamin A plasma levels, adaptometry, and other general variables.

METHODS

48 patients (15 males, 33 females, age range 21-73) and 34 normal subjects were examined with fluorescein and rose bengal, a plasma dose of vitamin A, and adaptometry. The results of the various tests were subdivided into three levels (0 = normal, 1 = moderately altered, 2 = seriously altered). The impression cytology and adaptometry results were correlated with vitamin A levels and other patient data (age, nutritional condition, time since operation, percentage weight loss). All the examinations were repeated after intramuscular therapy with vitamin A.

RESULTS

Corneoconjunctival alterations visible with fluorescein and rose bengal staining were present in 67.7% of cases, impression cytology alterations in 93.7%, adaptometric alterations in 82.2%; vitamin A plasma levels were below normal in 95.8% of cases. After the therapy with vitamin A a significant reduction was found for every examination. The correlation between impression cytology and adaptometry and vitamin A plasma levels and between corneoconjunctival alterations and vitamin A plasma levels was significant. There was no significant correlation between impression cytology and nutritional condition, age time since operation, and percentage weight loss.

CONCLUSION

These results show impression cytology is a specific indicator for hypovitaminosis A because it is not influenced by other factors related to the general condition of the patient. Many patients with hypovitaminosis A not demonstrating ocular symptoms of changes visible with fluorescein and rose bengal showed alterations with impression cytology.

The mixed leukocyte reaction may promote the growth of human pericorneal fibroblasts in primary culture

Keratitis of the cornea is believed to be the leading cause of loss of vision due to external eye disease in the United States and in Europe. At present, primary and secondary cell cultures obtained from corneal explants are the most suitable system to study the role of drug-resistant viruses in severe recurrences of infections leading to irreversible corneal scarring. In this work, the growth of human pericorneal fibroblasts in primary and secondary cultures has been obtained by cocultivation with a mixed leukocyte reaction.