Basal precorneal tear turnover in the human eye.

We studied 51 normal subjects with a simple method that permits measurement of the rate of fluorescein loss from the central precorneal tear film. In 15 (29%), no measurable dye remained 30 minutes after application of 1 microliter of a 10% solution of sodium fluorescein into the lower culde-sac. In 31 (61%) of the subjects, an exponential decay of the dye was observed between 15 and 30 minutes after application. In 5 (10%) of the subjects, a prolonged increase in dye concentration was observed, followed by a steady decrease that began 30 to 45 minutes after application. One eye of one subject had a steady increase in dye concentration for over an hour, and this eye was excluded from the analysis. The mean value for the tear elimination coefficient in all subjects analyzed was 15%/min. The logarithm of the tear elimination coefficient appeared to be normally distributed within the population sample. Analysis of the frequency distribution permitted an estimate that the 95% confidence limits for the tear elimination coefficient, as measured by this method, was 5 to 30%/min. No statistically significant correlations were found between tear elimination coefficient and sex, eye color, or contact lens use.

Nasolacrimal duct obstruction following transantral-ethmoidal orbital decompression.

Of 200 patients undergoing bilateral transantral-ethmoidal orbital decompression for Graves' ophthalmopathy, nine suffered symptomatic postoperative obstruction of the lower nasolacrimal excretory system. Five of the nine patients had persistent symptoms of epiphora or repeated episodes of dacryocystitis that necessitated dacryocystorhinostomy. Dacryocystorhinostomy relieved symptoms and objective evidence of obstruction in these five patients. We believe that nasolacrimal duct obstruction occurred in these patients as a complication of nasoantral window construction.

En bloc removal of intrinsic neoplasms of the lacrimal gland.

The management of intrinsic neoplasms primary in the lacrimal gland is of serious concern because some of the most malignant primary tumors of the orbit occur in this glandular structure and present surgical techniques may easily disseminate the neoplasm and contribute to death or recurrences. We propose a surgical approach in which the tumor and adjacent adnexa are removed in a one-stage procedure, that is, an en bloc resection of the neoplasm, its periorbital base, and surrounding bone. This technique will minimize seeding of the tumor, provide a more complete eradication of the neoplasm without loss of the eye, and assure either a cure or a longer interval free of local recurrences or metastasis than is presently attainable.

The corneal penetration of 6-aminohexanoic acid.

6-Aminohexanoic acid is a potent antifibrinolytic agent with the ability to retard dissolution of fibrin clots. The corneal penetration of 6-aminohexanoic acid was measured to determine if therapeutic levels of the drug could be maintained in the anterior chamber by topical administration. The conjunctival sac to anterior chamber transfer coefficient was found to be 1.51 X 10-4 +/- 0.20 X 10-4 per minute and the corneal permeability found to be 3.46 X 10-7 +/- 0.46 X 10-7 cm. per second in the rhesus monkey eye. The results indicate that, to establish a therapeutic level in the aqueous humor, a high concentration of drug would have to be used with topical drop administration or a zero order delivery system must be used.

The use of the cryoprobe in the removal of posterior orbital tumors.

Experience with a cryoprobe for the surgical removal of encapsulated and circumscribed tumors, cysts, and neoplasms in the posterior orbit indicates that the instrument is a useful and efficient adjunct to the surgical management of orbital tumors.

En bloc removal of intrinsic neoplasms of the lacrimal gland.

The management of intrinsic neoplasms primary in the lacrimal gland is of serious concern because (1) some of the most malignant primary tumors of the orbit occur in this glandular structure and (2) present surgical techniques may easily disseminate the neoplasm and contribute to death or recurrences. We propose a surgical approach in which the tumor and adjacent adnexa are removed in a one-stage procedure, that is, an en bloc resection of the neoplasm, its periorbital base, and surrounding bone. This technique will minimize seeding of the tumor, provide a more complete eradication of the neoplasm without loss of the eye, and hopefully, assure either a cure or a longer interval free of local recurrences or metastasis than is presently attainable.