Peripapillary fundus perimetry in eyes with glaucoma.

AIMS: To evaluate, with fundus perimetry, the peripapillary differential light threshold (DLT) in eyes with glaucoma and ocular hypertension (OHT), and compare it with peripapillary retinal nerve fibre layer (RNFL) thickness. METHODS: 35 glaucomatous, 29 OHT and 24 control eyes were included. Peripapillary DLT at 1 degrees from the optic nerve head was quantified with fundus perimetry; peripapillary RNFL thickness was measured over the same area by optical coherence tomography. RESULTS: Mean (SD) peripapillary DLT was 19.2 (1.7), 17.6 (4.2) and 10.1 (6.9) dB in control, OHT and glaucomatous eyes, respectively (p<0.001). Mean (SD) RNFL thickness was 98.4 (35.3), 83.9 (35.1) and 55.8 (28.2) microm, respectively (p<0.001). Mean peripapillary DLT showed higher sensitivity and specificity in differentiating the three groups compared with RNFL thickness. CONCLUSION: Progressive, significant reduction of peripapillary DLT was documented in OHT and glaucomatous eyes compared with controls (p<0.001). DLT reduction parallels RNFL reduction.

Collagen shields delivery of netilmicin: a study of ocular pharmacokinetics.

Collagen shields have been used as therapeutic contact lenses to promote corneal epithelial healing and to deliver hydrosoluble drugs. In albino rabbits, we studied the ocular pharmacokinetics of netilmicin, an aminoglycoside antibiotic, released by a 24-hour collagen shield immersed for 10 min in commercially available eye solution of netilmicin, at the standard concentration of 3 mg/ml. The animals were sacrificed after 0.5, 1, 6 and 18 h. The antibiotic concentrations were measured by the microbiological method. The drug levels remained above the MIC for the usual pathogens for 18 h in the cornea and for 6 h in the aqueous humor. In the iris and ciliary body the peak concentration was reached 1 h after shield application, netilmicin concentration decreased thereafter rapidly. The lens and the vitreous did not appear to be permeated by the drug. In the conjunctiva, drug concentrations were low, showing a negligible lateral diffusion of netilmicin released by shields. In conclusion, our findings show, that if the collagen shields are used as delivery systems, a very concentrated drug solution is not required to obtain high and persistent levels of netilmicin in cornea.

Influence of carteolol and timolol on IOP an visual fields in glaucoma: a multi-center, double-masked, prospective study.

The influences of Carteolol and Timolol eye drops on intraocular pressure (IOP) and visual fields were compared in a multi-center, double-masked, prospective study. Two-hundred and forty eyes of 120 patients were initially included in the study, and 142 eyes of 72 patients fulfilled all the criteria for final statistical analysis. Both drugs significantly reduced IOP. The visual fields in both treatment groups did not change during one year of treatment. In both groups some patients improved slightly, and others deteriorated slightly. This indicates that locally applied beta-blockers may efficiently stop further progression of visual field defects in cases with increased IOP and early visual field damage. There was no difference between Carteolol and Timolol in this regard. The side effects were minimal, and there were no differences in their frequency or intensity in the two treatment groups.

Cardiovascular effects of befunolol, betaxolol and timolol eye drops.

A double-blind cross-over study was carried out on 15 glaucoma patients so as to verify the effects of three the beta blockers, beta-1 selective betaxolol, non-selective timolol and befunolol an agent with intrinsic sympathomimetic activity on the heart rate, monitored by a Holter apparatus, and with the blood pressure measured in standing and supine positions before and after eight days of topical therapy. The results showed that timolol induced a significant decrease in minimum heart rate (-4.2 +/- 2.9) (p less than 0.001) and in diastolic blood pressure in standing position (-8.0 +/- 12.5 mmHg) (p less than 0.05), betaxolol decreased systolic pressure in orthostatism (-7.5 +/- 12.3 mmHg) and in clinostatism (-12.1 +/- 16.2 mmHg) and diastolic pressure in orthostatism (-6.25 +/- 9.4 mmHg) (p less than 0.05). Befunolol alone did not alter the heart rate or blood pressure.

Contribution of manual and computerized perimetry to the differential diagnosis of optic neuropathies.

The contribution given by manual perimetry to differential diagnosis of optic neuropathies is described. The advantages and the disadvantages of automated perimetry in respect to manual perimetry are examined. The programs to use for a more precise diagnosis and according to different pathology are also examined. The problems connected to perimetric interpretation are discussed. The value of global indices in evaluating the visual field as well as the importance of statistical program in comparing more than one test performed are reported. The review stresses the usefulness of automated perimetry in early diagnosis and in the follow up of optic nerve diseases.

Optic neuropathies: therapeutic approach.

The review deals with therapeutic aspects of optic nerve diseases. Attention is given to the lack of established guidelines for treatment of different optic neuropathies. In fact, there are no sure protocols in the literature for infective, inflammatory and vascular disorders. The authors present some new drugs and discuss the efficacy of related therapy, in particular for vascular disorders. The differentiated therapy for arteritic and non-arteritic AION is discussed. Treatment of vascular occlusion in the acute phase, in the post-occlusive state and prophylaxis is reported. The usefulness of anticoagulants is examined. In the conclusion, the authors stress the necessity to carry out properly controlled multicenter trials to obtain valid knowledge that allows rational and effective therapy protocols.

Aging and drug-induced optic nerve side effects.

In this review the authors attempt to explain how aging can determine optic nerve neuropathy and modify the pharmacodynamics and pharmacokinetics of a drug. The major causes of increased drug toxicity in the elderly are discussed. The most frequently used drugs that can cause optic nerve side effects are reported. The authors stress problems related to drug administration in the elderly and push towards the study of this aspect of geriatric ophthalmology.

Antibiotic levels in aqueous and vitreous humor after intraocular administration.

Antibiotics poorly penetrate the vitreous humor after periocular or systemic administration. Sometimes a direct intravitreal injection is necessary for the treatment of bacterial endophthalmitis. The kinetics of the intravitreally injected antibiotics, netilmicin (500 micrograms/0.1 ml), piperacillin (2,000 micrograms/0.1 ml), ampicillin (2,000 micrograms/0.1 ml) and aztreonam (2,000 micrograms/0.1 ml), were examined in rabbits. Aqueous and vitreous antibiotic concentrations were assayed by microbiological methods. The results show that active levels of all drugs studied are present in the vitreous body for 48 h. In aqueous humor beta-lactam antibiotics are present in very small concentrations, whereas the aminoglycoside netilmicin (vitreous/aqueous ratio) have higher levels (%) than other drugs.

Aqueous prostaglandin E2 and intraocular pressure after argon laser trabeculoplasty in glaucoma patients pretreated with topical piroxicam.

Intracameral injection of prostaglandin E2 causes an increase in intraocular pressure (IOP) in rabbits, cats, and monkeys. Arachidonic acid administered topically in rabbits and monkeys also increases IOP. The effect of prostaglandin E2 on IOP in human eyes is unclear. We performed paracentesis of the anterior chamber one hour after 180 degrees argon laser trabeculoplasty in cases of primary open-angle glaucoma. This laser treatment may increase IOP, but no correlation was found between post-operative IOP changes and PGE2 levels. PGE2 was significantly lower in ten eyes pretreated with topical piroxicam, a prostaglandin biosynthesis inhibitor (7 +/- 6 pg/ml), than in ten untreated eyes (443 +/- 232 pg/ml) and five controls. No significant difference was found between post-operative IOP in eyes pretreated and untreated with piroxicam. The low levels of PGE2 in the aqueous humour of eyes pretreated with piroxicam indirectly demonstrated the transcorneal penetration of the topically-administered drug, and the effectiveness of piroxicam in inhibiting the ocular synthesis of PGE2.