Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0086543 (cataract)
 29,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The aim of this study was the development of a capillary electrophoretic method for the determination of the levels of the selective alpha(2)-adrenergic receptor agonist brimonidine in aqueous humor of the eye and blood sera and their relation to its efficacy in reducing the intraocular pressure (IOP). Analysis of brimonidine was performed by capillary zone electrophoresis using 20 mM borate, pH 9.3, as operating buffer and detection at 255 nm. Brimonidine levels were determined in aqueous humor and blood sera from seven patients admitted for cataract extraction following ocular administration of the ophthalmic Alphagantrade mark solution. Levels of brimonidine and IOP values were recorded for a 24 h period. Alphagantrade mark administration resulted in a significant reduction of IOP, from within 30 min up to 4-5 h, whereafter a stepwise increase was recorded until 24 h, where mean IOP value returned to that before administration. The IOP reduction was related to the levels of brimonidine in aqueous humor, where maximal levels (80-100%) were obtained within 1-3 h. A 50% amount of the solution was determined after 4-5 h, whereas it reached the minimum level after 12 h. Serum levels reached maximum within 3-4 h, a 50% reduction was recorded in 12 h and minimum level in 24 h. It is concluded that brimonidine administration may significantly reduce IOP in patients when its level is maintained >/=50% of the maximum present in aqueous humor, i.e within a 4-6 h period. Since at this time the level of brimonidine in blood serum has reached maximum value, administration of brimonidine every 6 h may be used to obtain adequate brimonidine levels to maintain a constantly lowered IOP.
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PMID:Capillary electrophoretic analysis of brimonidine in aqueous humor of the eye and blood sera and relation of its levels with intraocular pressure. 1096 Aug 28

A 72-year-old man with long-standing bilateral glaucoma became refractory to levobunolol ophthalmic solution therapy after many years. Brimonidine was prescribed, but the patient developed a hypersensitivity several months later that was treated with loteprednol ophthalmic suspension. Bimatoprost was initiated 2 weeks later. Within an hour of the first dose of bimatoprost, the patient reported eye pain and photophobia that remained unresolved the following day. Examination revealed acute bilateral nongranulomatous anterior uveitis that was effectively treated with loteprednol. While observations in human and animal models suggest an association between certain prostaglandin-like agents and intraocular inflammation, this report is one of the first to suggest a link between bimatoprost and intraocular inflammatory reaction.
J Cataract Refract Surg 2003 Nov
PMID:Bilateral nongranulomatous anterior uveitis associated with bimatoprost. 1467 Apr 42

Glaucoma is the second most common cause of world blindness (following cataract) with estimated cases reaching 79.6 million by 2020. Although the etiology of glaucoma is multi-factorial, intraocular pressure (IOP) is the only modifiable factor in glaucoma management proven to alter the natural course of the disease. Among various classes of IOP-lowering medications currently available, alpha-adrenergic receptor agonists are used either as monotherapy, as second-line therapy, or in fixed combination with beta-blockers. Non-selective adrenergic agonists such as epinephrine and dipivefrin are infrequently used today for the treatment of glaucoma or ocular hypertension, and have been replaced by the alpha-2-selective agonists. The use of apraclonidine for IOP reduction in glaucoma or OHT is limited due to a high rate of follicular conjunctivitis. The alpha-2-selective agonist in use today is brimonidine. The brimonidine-purite formulations are preferred to brimonidine-benzalkonium chloride (BAC) formulations due better tolerability while maintaining similar efficacy. Brimonidine is also effective when used in combination with a beta-blocker. Using brimonidine-timolol fixed combination (BTFC) as first-line therapy has an added potential for neuroprotection. This would be a valuable strategy for glaucoma treatment, for patients who are intolerant of prostaglandin analogs, or for patients where prostaglandin analogues are contraindicated as first-line therapy, such as in patients with inflammatory glaucoma.
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PMID:Update on the role of alpha-agonists in glaucoma management. 2152 49