Intraocular pressure control with echothiophate iodide in children's eyes with glaucoma after cataract extraction.

PURPOSE: To report the intraocular pressure (IOP)-lowering ability and side-effect profile of echothiophate iodide (EI) in the control of glaucoma in aphakic and pseudophakic eyes of children. METHODS: The medical records of all aphakic and pseudophakic children treated with EI for IOP lowering after developing glaucoma were retrospectively reviewed. RESULTS: A total of 32 eyes of 21 children were included. Mean age at cataract removal was 3.9 months (range, 5 days-2.7 years). Mean age of glaucoma diagnosis was 3.2 years (range, 40 days-12 years). Mean duration from cataract removal and diagnosis of glaucoma was 2.9 years (range, 16 days-12 years). EI reduced IOP in 31 of 32 eyes. Mean baseline IOP (29.1 ± 5.3 mm Hg) dropped to 19.6 ± 6.7 mm Hg. Six eyes had IOP spikes that could not be controlled with other medications when commercial unavailability led to discontinuation of EI. Average duration of use was 3.5 years. Mean final IOP on an average of 2.2 medications was 16.9 ± 5.1 mm Hg 7.9 years following initial glaucoma diagnosis. Four eyes required surgery for uncontrolled IOP. Side-effects included transient redness (3/32 eyes), not necessitating discontinuation of EI. CONCLUSIONS: EI lowered IOP to within an acceptable range with no significant adverse events. In several patients it was the only pharmacologic agent that was successful.

Echothiophate iodide induced transient hyper- and hypothyroidism.

A case of hyper- and hypothyroidism induced by echothiophate iodide eye drops is presented. The thyroid dysfunction was due to excessive iodide intake from the eye drops.

Cholinergic toxicity resulting from ocular instillation of echothiophate iodide eye drops.

A patient developed a severe cholinergic syndrome from the use of echothiophate iodide ophthalmic drops, presented with profound muscle weakness and was initially given the diagnosis of myasthenia gravis. Red blood cell and serum cholinesterase levels were severely depressed and symptoms resolved spontaneously following discontinuation of the eye drops.

Cystoid macular edema associated with topical echothiophate iodide.

We report the case of a patient with visual loss and cystoid macular edema that was associated with the topical use of echothiophate iodide. After cessation of the drops, the cystoid macular edema nearly disappeared, and vision returned to normal.

Intraocular pressure response to the replacement of pilocarpine or carbachol with echothiophate.

In 20 patients with open-angle glaucoma in aphakia or pseudophakia whose intraocular pressure had remained uncontrolled on their current medical therapy, the medication was changed from pilocarpine or carbachol to echothiophate iodide. In all, 12 patients (60%) showed a statistically significant improvement in pressure control, 7 (35%) showed no change, and 1 had higher pressure. One-third of the patients with improved intraocular-pressure control eventually required laser or incisional surgery after a mean of 23 months, whereas the remaining subjects were controlled for the duration of the follow-up, which averaged 26 months. Side effects encountered during echothiophate iodide treatment included ocular irritation, decreased vision, and one retinal detachment.

How safe are ocular drugs in pediatrics?

In comparison with that of adults, the smaller body mass of children raises questions of dosage. In addition, manifestations of ocular drug toxicity are different in some respects. The ocular drugs causing serious adverse ocular or systemic side effects in children include glaucoma medications, corticosteroids, phenylephrine, and the anticholinergic cycloplegics. The reported complications from using these medications in children will be briefly reviewed, and strategies for minimizing the risk of their adverse effects will be suggested, including a discussion of dosages and techniques of administration.

Echothiophate iodide cataracts in monkeys. Occurrence despite loss of accommodation induced by retrodisplacement of ciliary muscle.

Five cynomolgi underwent unilateral 360 degrees ciliary muscle retrodisplacement. Beginning several months later, they received 150 to 210 micrograms of echothiophate iodine topically once daily in both eyes for five months. In all eyes anterior and posterior subcapsular lens opacities developed that were characteristic of those caused by echothiophate. There were no apparent differences in biomicroscopic appearance or time course of the cataracts between eyes with or without retrodisplaced ciliary muscles. Since eyes with retrodisplaced ciliary muscles accommodate only minimally in response to echothiophate, possible mechanical stress on the lens due to sustained, intense accommodation cannot explain echothiophate cataractogenesis.

Phospholine iodide toxicity and Jones' tubes.

A 72-year-old man with epiphora secondary to bilateral canalicular stenosis resulting from long-term treatment with 0.125% to 0.25% echothiophate iodide (phospholine iodide) drops for glaucoma underwent bilateral conjunctivodacryocystorhinostomies with Jones' tubes. Within days after undergoing this surgery, he experienced severe unexplained diarrhea, fatigue, weight loss, and prostration. He cancelled his postoperative ophthalmic appointment because of "medical illness." He required admission to his local hospital where extensive studies were done in an attempt to establish the cause of this life-threatening condition. After stopping the echothiophate iodide drops, all symptoms disappeared within two days. Drug toxicity is a previously unreported complication of conjunctivodacryocystorhinostomy, and this case demonstrates that topical medications have enhanced systemic absorption after lacrimal surgery with placement of fistulizing prosthetic devices. One must be aware of this possible complication, not only with long-acting anticholinesterases, but with topical sympathomimetic drugs (especially in cardiac patients) as well as cycloplegic agents in children.

Early lens changes in Macaca fascicularis monkeys under topical treatment with echothiophate or carbachol studied by slit-image photography.

Cynomolgus monkeys were given topical treatment with echothiophate or carbachol, and the lens changes were followed by slit-image photography. Both drugs caused an early retrodisplacement of the anterior zone of disjunction due to swelling of the most superficial lens cortex. Deeper layers of the cortex did not swell. The exact cause of the swelling is not known, but there must be a true cholinergic link. Accommodation as such is not the cause, since (1) the effect was seen also in a monkey eye which had its ciliary muscle disinserted from the scleral spur and therefore had little accommodation left and (2) acute accommodation produced by systemic pilocarpine did not cause the effect. Anterior subcapsular opacities were quantified and appeared very early in the echothiophate-treated eyes but were not seen with the doses of carbachol used.