R. Linsy Farris

Tear Osmolarity — A New Gold Standard?

The purpose of this presentation is to propose tear osmolality measurement as a new gold standard for the diagnosis of keratoconjunctivitis sicca. Agreement on the diagnostic criteria is needed in order to permit meaningful comparisons of scientific results obtained from varying patient populations. The method employed is a review of previous studies of clinical symptoms, signs and diagnostic tests employed in making a diagnosis of keratoconjunctivitis sicca. Data from previous studies are reviewed and the results of individual and combinations tests are compared in regard to sensitivity, specificity and overall efficiency in establishing accurate diagnoses. The results are that the measurement of tear osmolality measurement provides the greatest sensitivity, specificity and overall efficiency of a single test. Adding either the Schirmer test without anesthetic or tear lactoferrin measured by the Lactoplate™ method in parallel to tear osmolality measurement did not increase the sensitivity of diagnotic testing beyond 90% which was obtained by using tear osmolality measurement alone. The specificity of such combination diagnostic testing was increased only from 95% to 100%. The simplicity of tear osmolarity measurement and its established reliability supports the conclusion that this test is a reasonable candidate for a new international gold standard in the diagnosis of keratoconjunctivitis sicca.

Keratoconjunctivitis Sicca in Male Patients Infected with Human Immunodeficiency Virus Type 1

Keratoconjunctivitis sicca (KCS) has not been reported as occurring as a single entity in the acquired immune deficiency syndrome (AIDS) population. In a survey of human immunodeficiency virus type 1 (HIV-1) infected male patients, the authors found that 21% (9/42) had signs and symptoms compatible with KCS with positive Schirmer test results. Tear osmolarity determinations were obtained from this group and from an age- and sex-matched group of HIV-infected patients without symptoms of KCS and with negative Schirmer test results. Eighty-nine percent of the suspect group had increased tear osmolarity, whereas none of the control patients had a hyperosmolar tear film (P less than 0.0001). Results strongly suggest that KCS occurs at a significantly greater rate in male individuals infected with HIV-1 than in the general population.

Ultrastructural variation in granular dystrophy of the cornea.

Corneal deposits of granular dystrophy were studied in six corneas from five patients. Two additional corneas from two patients with lattice dystrophy were used for comparison. The diagnoses were confirmed by light and electron microscopy. Three types of ultrastructural features were distinguished in the electron-dense rodshaped deposits of granular dystrophy, i.e., Type 1 with homogeneous structure, Type 2 with fibrillar constituents, and Type 3 with a moth-eaten or sponge-like appearance. In polarization microscopy of Congo-red stained sections, the Type 2 tended to show an increased birefringence without green dichroism, while the other types were less birefringent than the stroma. Three different components were found immediately around the deposits, i.e., 1. normal collagen fibrils, 2. finely filamentous substance, and 3. areas of thin fibrils (70–100 Å in diameter). While the second component appeared non-specific, the third component was found only in two corneas, superimposed on the lesions of granular dystrophy, and showed light and electron microscopic characteristics of the lesions of amyloid as well as of lattice dystrophy. Die Hornhautablagerungen bei der granulären Dystrophie konnten an Hand von 6 Präparaten von 5 Patienten untersucht werden. Zwei weitere Hornhäute von 2 Patienten mit gittriger Hornhautentartung wurden zum Vergleich untersucht. Die klinischen Diagnosen wurden durch licht- und elektronenmikroskopische Untersuchungen bestätigt. Unter den elektronen-dichten, stäbchen-artigen Ablagerungen der granulären Entartung konnten 3 Typen unterschieden werden: Typ 1 mit homogenem Bau; Typ 2 mit fibrillären Bestandteilen und Typ 3 mit einem schwamm-artigen Aussehen. Der Typ 2 zeigte im Kongorot gefärbten Schnitt unter dem Polarisationsmikroskop vermehrte Doppelbrechung, aber keinen grünen Dichroitismus. Die Ablagerungen vom Typ 1 und 3 drehten das polarisierte Licht weniger als das Hornhautparenchym. Um diese Ablagerungen herum fanden sich drei verschiedene Hornhautbestandteile: 1. normale Kollagen Fasern, 2. eine feine faserige Substanz, und 3. Gebiete von dünnen Fasern (70–100 Å im Durchmesser). Der zweite Bestandteil ist nicht spezifisch. Der dritte Bestandteil war nur in 2 Präparaten zu sehen. Es ist den Ablagerungen der granulären Entartung aufgepfropft und zeigt sowohl licht- als auch elektronenmikroskopische Eigenheiten, die für das Amyloid und die gittrige Entartung charakteristisch sind.

Sjogren's syndrome and keratoconjunctivitis sicca.

Keratoconjunctivitis sicca patients diagnosed on the basis of a history, dry-eye symptoms, and definite clinical signs of keratoconjunctivitis sicca, with the associated symptoms of dry mouth and/or arthritis, had measurements of tear osmolarity, Schirmer tear test without anesthetic, stimulated parotid salivary flow, and serum analysis for the presence of autoantibodies associated with Sjogrens Syndrome. In contrast to previous studies, a lower incidence of SS-A or SS-B (1-3%), ANA (41-47%), DNA (11-16%), and RF (9-12%) serum antibodies was detected. Salivary-stimulated parotid flow was abnormally decreased in 59% of the patients. Sjogrens syndrome, as indicated by the presence of serum antibodies, appears to have a lower incidence in keratoconjunctivitis sicca than considered previously.

Tear lactoferrin levels and ocular bacterial flora in HIV positive patients.

Keratoconjunctivitis Sicca(4) has recently been reported to occur at a greater rate in HIV-positive symptomatic patients. We looked at HIV positive asymptomatic patients, compared to age matched HIV negative patients to study external ocular resistant factors, namely lactoferrin levels in tears, bacterial flora in lid margins, conjunctiva and tears, and evidence of dry eyes using a Schirmer test and tear osmolarity. Eighteen eyes of nine HIV positive patients and eighteen eyes of HIV negative controls were studied. Results showed markedly decreased lactoferrin levels in HIV positive asymptomatic patients with a mean of 85.8 mgs/dcl compared to HIV negative patients with a mean 156 mgs/dcl (P < 0.01). There were increased numbers of colonies of bacterial flora on the lids of HIV positive asymptomatic patients with an average colony count 4.1 colonies/patient compared to 1.5 colonies/patients in the control group (P < 0.025). Seventy eight percent of the study group had bacterial growth compared to 33% in the control group. The tear osmolarity in both groups had no significant difference; mean in HIV positive being 312 mosml/litre; mean in control 306 mosml/litre. The Schirmer test also showed no significant difference, with the mean in HIV positive patients being 11 mm wetting, and in control patients being 12.7 mm wetting. Therefore, despite no symptomatic or clinical evidence of dry eyes, asymptomatic HIV-positive patients had markedly decreased levels of lactoferrin in tears and increased colony counts of bacterial flora in the lids.

Complications Associated with Aphakic Contact Lenses

Complications associated with rigid contact lenses are more frequent in aphakia. The limited dexterity of older patients not only may prove an insurmountable barrier to the mastery of daily contact lens insertion and removal, but also may produce significant direct eye trauma, its seriousness determined by the integrity of the cataract wound. Since prolonged wear of aphakic contact lenses is the rule rather than the exception, the risk of irreversible corneal changes such as vascularization and erosions is greater. A poorly fitted aphakic contact lens that does not permit adequate oxygenation of all corneal areas makes such complications even more likely to occur. Decreased corneal sensitivity associated with cataract surgery permits continued wear of a poorly fitted lens, which does not allow the cornea to recover between wearing periods. Detection of keratoconjunctivitis sicca, more prevalent in the older age group, may prevent the associated complications of corneal erosion, iritis, and infection. Complications of aphakic contact lenses can be controlled by patient instruction, appropriate contact lens adjustments, and regularly scheduled follow-up examinations.

Keratoconjunctivitis sicca in HIV-1 infected female patients.

AIDS is caused by infection with the human immunodeficiency virus type-1 (HIV-1) presently affecting over 1.5 million people in the United States. While affecting less than 1% of the general population, keratoconjunctivitis sicca (KCS) occurs in greater than 20% of males infected with HIV.1 In our preliminary survey of HIV infected females, we found 17% had clinical signs and symptoms compatible with KCS.2

Current Concepts in Ophthalmology.

Thanks to the editorship of Drs. Becker and Burde, the current thoughts and practices of the present and former ophthalmology staff of Washington University are compiled again in a concise volume. The subspecialties of cornea, retina, and muscle are well represented with several chapters each, and there are also chapters on ophthalmic pathology, thyroid disease, gonioscopy, plastic surgery, and dyslexia. We are given practical information regarding corneal transplant techniques and the treatment of herpes simplex keratitis. The retina also gets fair treatment with chapters about utilization of contact lenses in biomicroscopy and the use of cryotherapy in retinal surgery. The cryosurgical removal of cataracts is discussed in a 39-page chapter which describes with numerous illustrations most of the cryo instruments now available. The chapter on gonioscopy outlines the reasons for utilizing a set of 13 gonioprisms to compensate for varying corneal curvatures. A review of lens induced inflammation with discussion