Intraocular peaks

An oximine (i.e., a substituted oxime) analogue of alprenoxime was examined in an attempt to overcome the problem of low stability in aqueous solution. To this end, the methoxime analogue of alprenolol (11.74, R = Me) was prepared and evaluated [109]. Stability in solution was greatly improved at neutral pH. Topical administration to rabbits produced a decrease in intraocular pressure that had the same onset and intensity as that produced by alprenolol, but that lasted longer. Alprenolol was, indeed, formed in eye tissues as a metabolite, with the peak concentration reached 30 min after topical administration of the methoxime. 

Administration of succinylcholine may be associated with the rapid onset of an increase in intraocular pressure (< 60 seconds), peaking at 2-4 minutes, and declining after 5 minutes. The mechanism may involve tonic contraction of myofibrils or transient dilation of ocular choroidal blood vessels. Despite the increase in intraocular pressure, the use of succinylcholine for ophthalmologic operations is not contraindicated unless the anterior chamber is open ("open globe") due to trauma. 

Administration of succinylcholine is followed by a transient increase in intraocular pressure that is manifested less than 60 seconds after intravenous injection, peaks at 2-4 minutes, and declines after... 

Figure 10-10 (A) Efficacy at peak (2 hours after morning dose) showing mean intraocular pressure in patients administered brimonidine Purite 0.15% or brimonidine 0.2% at baseline and follow-up visits.The difference in mean lOP between the two groups was less than 0.2 mm Hg at all visits. (B) Efficacy at trough (before morning dose) showing mean intraocular pressure in patients administered brimonidine Purite 0.15% or brimonidine 0.2% at baseline and follow-up visits.The difference in mean lOP between the two groups was less than 0.3 mm Hg at all visits. (Adapted from MundorfT, Williams R.Whitcup S, et al.J Ocul PharmacolTher 2003 19 37-44.)...

Figure 10-11 Effect of brimonidine 0.2% and timolol 0.5% at peak 2 hours after morning drug instillation. Asterisks indicate statistically lower intraocular pressure with brimonidine at week 1, week 2, month 3, and month 12. (Adapted from Katz LJ. Brimomdine tartrate 0.2% twice daily versus timolol 0.5% twice daily 1-year results in glaucoma patients.Am J Ophthalmol 1999 127 20-26.)...

Figure 10-16 Mean intraocular pressure GOP) at hour 2 (morning peak) for dorzolamide, timolol, and the combination product (Cosopt).The combination provided a greater decrease in lOP at all time points than did either single product. (Adapted from Boyle JE, Ghosh K, Gieser DK, et al.A randomized trial comparing the dorzolamide-timolol combination given twice daily to monotherapy with timolol and dorzolamide. Ophthalmology 1998 105 1945-1951.)...

Shortly after the introduction of suxamethonium it was noted that it can increase intraocular pressure (99), an observation that has subsequently been confirmed in several other studies (100-114). The increase in intraocular pressure occurs promptly after intravenous injection of suxamethonium, peaks at 1-2 minutes, and returns to basehne after 6-10 minutes (102,109). The mean increase is about 4—8 mmHg, with a range of 5-15 mmHg. 

The pharmacokinetics and ocular bioavailability of topical NSAIDs in the horse are unknown. In other species, topical NSAIDs readily penetrate and disseminate within the eye, reaching peak intraocular levels within 2 h. In general, the levels achieved by topical administration exceed those... 

As treatment for postoperative pressure peaks, acetazolamide (Lewen 8c Insler, 1985), as well as diverse beta-blockers (Duperre et al., 1994 Fry, 1992 Kanellopoulos et al., 1997a and b Percival, 1982 Pfeiffer, 1993) and parasypathomimetics (e.g., pilocarpine) have been shown to lower intraocular pressure to varying extents. 

In a trial performed by Wedrich Menapace (1992), the removal of viscoelastic from behind the lOL lowered the incidence of early postop intraocular pressure peaks (Fig. 109). To mobilize OVD from behind the IOL,the irrigation/aspiration handle is generally lightly pressed onto the lOL optic. Moving the handle behind the lOL directly should be avoided so as not to aspirate the posterior capsule which would increase the danger of capsular damage (Wesendahl et al., 1994). 

Both patients had clear anatomical causes for blindness, and unilateral (rather than bilateral) blindness suggested a limited role for systemic arsenic toxicity. Nevertheless, a weak contribution of ocular arsenic toxicity should not be ruled out. Both arsenic trioxide and all-trans retinoic acid can increase intracranial pressure, resulting in pseudotumor cerebri and a secondary increase in intraocular pressure, which may augment retinal injury. Also, arsenic trioxide can cause vasoconstriction and worsen retinal artery occlusion. Finally, elemental arsenic was detected in the eyes at 30-50% of the plasma concentration, a ratio comparable to that in cerebrospinal fluid. This may have direct retinal toxicity, especially with the high peak concentrations associated with intravenous arsenic trioxide. Full ophthalmic evaluation is recommended in patients receiving longterm or intravenous arsenic trioxide. 

Inflammatory bowel disease (Crohn s disease and ulcerative colitis) occurs among all age groups but has peaks of incidence in the second and fourth decade of life. Currently, corticosteroid therapy is the most effective treatment for moderate to severe cases of IBD. Ocular pathology in the setting of IBD may be related to inflammation of the gastrointestinal tract or secondary to corticosteroid treatment. The two major ocular side effects of systemic corticosteroid therapy are posterior subcapsular cataract (PSC) and raised intraocular pressure (lOP). Recently, we reported that PSC was detected in 12 of 58 (20.7%) corticosteroid-treated pediatric IBD patients and that 21 patients of the same population (36.2%) had raised lOP. Because pediatric IBD patients continue corticosteroid therapy into adulthood, we analyzed the prevalence of PSC and raised lOP in a series of adult IBD patients. 

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