Therapeutic limitations of argon laser trabeculoplasty.

Sixty-one patients (82 eyes) were studied after argon laser trabeculoplasty (ALT) to determine the lasting efficacy of such treatment. This investigation, now in its fourth year, was prospective, and the information derived was analysed with the aid of a computer. Success was defined as intraocular pressure (IOP) below baseline (22 mmHg). The mean follow-up time was 24.5 months, when the success rate was 74% compared with 75% at three months. Success declined to 45% at 42 months. No significant difference was noted when (a) first lasered eyes of all patients and those fellow eyes treated were analysed separately, (b) when right and left eyes were analysed separately, nor (c) when patients were divided into two treatment groups, (I) 100 burns at 1 W, and (II) 65 burns at 850 mW. Eight of 11 eyes showed progressive postlaser field loss despite below-baseline intraocular pressures. ALT is an alternative to carbonic anhydrase inhibitor therapy, with a success rate of 66.7% at two years. However, repeat ALT was successful in only 25% of patients seven months after treatment.

Laser trabeculoplasty and decay effects in glaucoma patients.

Forty patients (47 eyes) with open-angle glaucoma who had been treated by laser trabeculoplasty to help reduce intraocular pressure were reviewed. The majority of patients had been followed for at least one year. Eighty-nine percent responded satisfactorily, with an average pressure decrease of 5 mmHg. There was no evidence of decay (pressure reversal) after one year. Seventy-six percent of patients who had been on carbonic anhydrase inhibitor medication were able to discontinue this therapy after laser treatment. Blacks, aphakic and diabetic patients responded satisfactorily, but hypertensive patients and those with narrow-angle glaucoma less so. Re-lasering was successful in only one of 6 patients.

Argon laser trabecular surgery as an alternative to carbonic anhydrase therapy.

Thirty-four eyes (25 patients) with diagnosed chronic open angle glaucoma on maximal medical therapy were studied to determine whether argon laser trabecular surgery was a desirable alternative to carbonic anhydrase therapy. Ninety-four per cent of patients responded favourably to argon laser trabecular surgery as an alternative to carbonic anhydrase therapy. The average pressure drop was 9.9 mm Hg. Interestingly, there was a mean drop of 4.2 mm Hg in the contralateral eye. There was minimal, if any, iris response although there was a small but probably not clinically significant decrease in corneal endothelial cell count. Blanching of the trabecular wall was used as the endpoint to help minimize post-laser pressure rise. Blacks and aphakic patients responded satisfactorily. Laser surgery is best reserved for those patients with a pretreatment intraocular pressure no higher than the 30 to 35 mm Hg level. Trabeculectomy, in spite of its known complications, offers a better prognosis in those cases where the pretreatment pressure exceeds the 30 to 35 mm Hg level.

Use of the ocutome in anterior segment surgery.

9 patients are presented on whom anterior vitrectomy was performed. The indications included congenital rubella cataract with microphthalmos, traumatic cataract, persistent anterior and posterior hyperplastic primary vitreous, postcataract pupillary membranes, and postcataract vitreous prolapse with cystoid mascular edema. All patients to date have responded satisfactorily to the procedure. There has been no incidence of complicating retinal detachment.

Sicca complex and cholangiostatic jaundice in two members of a family probably caused by thiabendazole.

An entire family (father, mother, and three daughters) were given thiabendazole because one of the children had acquired pinworm infestation. The mother and one daughter (non-infected) developed a sicca complex (keratoconjunctivitis sicca and xerostomia) accompanied by cholangiostatic jaundice. Sjögren's syndrome is an autoimmune disease and presents many immune mechanism aberrancies. An association between autoimmune liver disease and sicca complex has been reported. Labeled mitochondrial antibodies bound to the parotid duct have been noted in patients with autoimmune cholangiostatic jaundice and such antibodies may be similar to the antibody against salivary duct found in Sjögren's syndrome. It is suggested that in these two patients, thiabendazole may have acted as a hapten and by binding to the body protein induced the production of autoantibodies which may have acted against the biliary epithelium, the salivary duct epithelium, and the lacrimal gland ducts.

The anatomic basis for glaucoma.

The greatest bulk of aqueous passes through a sieve-like trabecular wall to reach Schlemm's canal. The vacuoles of the endothelial lining of the trabecular wall are pressure-dependent one-way valves, adapted morphologically to provide for adequate aqueous transfer. Resistance to aqueous outflow seems to be most concentrated in the juxtacanalicular tissue which is also the site of the greatest mucopolysaccharide concentration and phagocytic activity. Normal intraocular pressure may be maintained through a balance between hydrophilic polymerized MPS and hydrophobic depolymerized MPS. It may be effected also by a phagocyte-induced, self-cleaning biologic filter mechanism of the trabecular wall. The use of electron microscopy and improved biochemical techniques have led recently to a greater understanding of the anatomy of the structures concerned with the outflow of aqueous from the anterior chamber. Despite these advances, no clear-cut differences between normal and glaucomatous eyes have emerged thus far. However, the future should bring more knolwedge as the stimulus of conflicting theories leads to progress.