Yo Nakamura

Inflammatory cytokines in normal human tears

PURPOSE To elucidate inflammatory cytokine levels in normal human tears, we investigated the concentrations of interleukin-1alpha (IL-1alpha), interleukin-1beta (IL-1beta), interleukin-6 (IL-6), and interleukin-8 (IL-8) both in basal tears and reflex tears of normal healthy eyes. METHODS Tear samples were collected from 270 healthy, normal volunteers with no past history of ocular surface disease; the total number of eyes was 295. All tear samples were collected in graduated disposable microcapillaries from the conjunctival cul-de-sac. Reflex tear stimulation was carried out by inserting an applicator into each volunteers nose. Cytokine levels in basal tears and reflex tears were determined by ELISA. Tears were not diluted, and pooled samples were used for the cytokine assays. RESULTS In basal tears, the concentrations of IL-1alpha, -1beta, -6 and -8 were 10.9 +/- 1.2, 12.9 +/- 2.3, 226.2 +/- 29.6 and 731.4 +/- 116.2 pg/ml, respectively. In reflex tears, IL-1beta was not detectable, and the concentrations of IL-1alpha, -6 and -8 were 9.3 +/- 2.7, 11.6 +/- 1.6 and 276.1 +/- 47.5 pg/ml respectively. IL-1beta, -6 and -8 levels in reflex tears were significantly lower than those in basal tears, except for IL-1alpha. CONCLUSIONS In the present study, the normal concentration range of inflammatory cytokines in human basal tears was clarified, as a baseline for further studies to examine the levels of these cytokines in tears during disease states.

Gene expression of neurotrophins and their high-affinity Trk receptors in cultured human Muller cells

Purpose: To investigate the gene expression of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin 3 (NT-3) and their high-affinity receptors (TrkA, TrkB and TrkC) in cultured human Müller cells. Methods: The polymerase chain reaction was performed using specific primers for NGF, BDNF, NT-3, TrkA, TrkB and TrkC with complementary DNAs as the template, which were generated from poly-A+ RNA of cultured human Müller cells. Results: We detected the precursor mRNA transcripts for NGF, BDNF, NT-3, TrkB and TrkC, but not TrkA. Conclusion: Human Müller cells can direct mRNA expressions of a number of neurotrophins which may have a neurotrophic function in the retina. An autocrine mode of action is suggested, since Müller cells not only synthesize neurotrophic factors, but also express their specific receptors.

The Detection of Bacteria and Bacterial Biofilms in Punctal Plug Holes

Purpose. An investigation into bacterial biofilm formation on and in punctal plugs. Methods. The study involved 21 patients with severe dry eye whose puncta were occluded by the use of punctal plugs. Of these, 15 had Sjögrens syndrome, 3 had non–Sjögrens syndrome, 2 had Stevens–Johnson syndrome, and 1 had graft-versus-host disease. From 17 of the 21 subjects, 18 samples of material were extracted from the holes of the punctal plugs (16 unilateral and 1 bilateral) and were subjected to enrichment culture. Nineteen punctal plugs were removed and processed for electron microscopy: 15 by scanning electron microscopy, and 4 by transmission electron microscopy. Results. Positive cultures were found in 8 of 18 (44%) samples of the material extracted from the holes of punctal plugs. In six of these eight cases (75%) the cultured bacterial species was Staphylococcus epidermidis, whereas in the other two cases (25%) it was S. aureus. In 8 of the 15 punctal plugs examined by scanning electron microscopy and in the material extracted from 1 plug that was examined by transmission electron microscopy, there was clear evidence of bacterial colonization. Conclusion. Careful observation of patients with punctal plugs is important. If material accumulates in or on a punctal plug, it may contain bacteria and may form a bacterial biofilm. In these cases, replacement of the plug, clearing of the hole, or an alternative treatment should be considered.

Sialic Acid in Human Tear Fluid Decreases in Dry Eye

PurposeTo evaluate the association between tear mucin and dry eye, we compared tear fluid sialic acid concentration in dry eye patients with that in normal volunteers. We also compared the sialic acid concentration with the results of several different types of dry eye examinations.MethodsSubjects comprised 16 age-matched, normal healthy controls and 45 dry eye patients. Dry eye examinations included fluorescein staining, rose bengal staining, Schirmer I test, cotton thread test, and fluorescein breakup time. Tear samples were collected with a micropipette after the instillation of 50 µl saline. The sialic acid concentration was measured by high-performance liquid chromatography.ResultsThe sialic acid concentration was significantly lower in the dry eye group (5.3 ± 4.3 µg/ml) than in the control group (37.1 ± 28.3 µg/ml) (P < 0.001). Also, the sialic acid concentration correlated significantly with the results of dry eye examinations (P < 0.0002).ConclusionsThe different sialic acid levels in the control and dry eyes may imply differences in the quantity or quality of glycoprotein in tears between these two groups. Thus, sialic acid, a component of mucin, may play a key role in the dry eye condition. Jpn J Ophthalmol 2004;48:519–523

Surgical Reconstruction of the Tear Meniscus at the Lower Lid Margin for Treatment of Conjunctivochalasis

Conjunctivochalasis is an important cause of several types of ocular surface discomforts, including irritation, intermittent epiphora, dryness, and blurred vision, and is often associated with with dry eye. Since conjunctivochalasis most frequently protudes into the tear meniscus at the lower lid margin, the disease often interferes with the tear meniscus lacrimal pathway, and tear fluid reservoir functions. In addition, conjunctivochalasis-related redundant conjunctiva can irritate the ocular surface like a foreign body. Accordingly, conjuctivochalasis may explain patient complaints related to tear meniscus dysfunction or foreign body sensation. In this report, we propose that conjunctivochalasis causes tear meniscus dysfunction, and although several surgical procedures have been previously developed for treatment of this disease, we introduce a new surgical treatment for removal of redundant conjuctiva whilesimultaneously restoring the original tear meniscus at the lower lid margin.

Sialic Acid in Normal and Dry Eye Tear Fluid

Mucin is a particularly important component in the pathogenesis of dry eye, because it is the main constituent of the mucus layer and contributes to tear film stability and viscosity.1 Although several methods can detect mucin in tear film, mucin measurement is difficult because of its high molecular weight. Based on the fact that mucin is composed of many glycoproteins,2 the periodic acid-Schiff (PAS) method has been used to measure it in the stomach and small intestine.

Canaliculitis caused by Actinomyces in a case of dry eye with punctal plug occlusion

BACKGROUND We report a case of canaliculitis caused by Actinomyces odontolyticus in a case of dry eye with punctal plugs. CASE A 64-year-old female with Sjögrens syndrome type of dry eye developed lacrimation, congestion in the lower palpebral conjunctiva and corneal epithelial damage in her right eye 30 months after punctal plug occlusion. After removal of the plug from lower punctum in her right eye, white material exuded from the punctum. However, even after the removal of a plug, corneal epithelial keratopathy did not get worse, implying that the granulation tissue formed by the plug completely occluded the canaliculus. Actinomices odontolyticus was cultured from the white material. One week after topical antibiotic treatment, conjunctival congestion and irritation were resolved. CONCLUSION This report indicates the possibility of canaliculitis as a complication of punctal plug occlusion. Careful observation is necessary after punctal occlusion with punctal plugs.

Outcome of punctal plug occlusion therapy for severe dry eye syndrome

PURPOSE Punctal occlusion using a silicone plug is one way of treating tear-deficient dry eye and it has been reported to be effective. We studied the outcome of punctal plug occlusion therapy for severe dry eye syndrome at our dry eye clinic. SUBJECTS AND METHODS Subjects were 76 eyes of 51 patients [6 eyes of 5 males, 70 eyes of 46 females, mean age: 58.6 +/- 13.4 (mean +/- standard deviation), 49 eyes of 30 patients with Sjögrens syndrome, 27 eyes of 21 patients without Sjögrens syndrome] with severe tear-deficient dry eye who underwent punctal occlusion using a silicone plug (Punctal plug, FCI Co. Ltd, France) during the period of Nov. 1996 to Mar. 2000 at our dry eye clinic. They were under observation for 632 +/- 405 days (mean +/- standard deviation). We studied if there is difference in tolerance between the sizes of punctal plug, compared epithelial damage before and after plug insertion, and studied relief in symptoms using self-assessment. RESULTS In tolerance of punctal plugs, 55.9% of all plugs were lost during our follow up, but there was no difference in time to loss between the sizes. Epithelial damage was reduced (p < 0.001). Dryness was the most reduced symptom: 26 patients (79%) got better, and only epiphora was increased, with 12 patients (36%) complaining slightly. CONCLUSION Punctal plug occlusion therapy for tear-deficient dry eye is conclusively very effective.

Sialic acid in normal human tear fluid

PURPOSE We measured the concentration of sialic acid, the terminal component of mucin, in normal diluted human tears. METHODS Twenty-microliter tear samples were collected from 31 healthy volunteers (average age = 50.7 years) using micropipette after 50 microL instillation of saline. We investigated the correlation of concentration between glycoprotein and sialic acid and the difference between the right and the left eyes, as well as the reproducibility of the sampling procedure. RESULTS There was significant correlation of the concentration between glycoprotein and sialic acid (right eye: r = 0.952, P <.0001; left eye: r = 0.976, P <.001). There was no significant difference in concentration between the right and the left eyes. Also, the reproducibility was considered acceptable in three measurements of sialic acid using the present procedure. The sialic acid concentration in normal diluted tears was 37.1 microg/mL on average. CONCLUSION Our data indicates that sialic acid concentration is an indicator for the concentration of glycoprotein and that this method of measurement is applicable to the analysis of mucin-deficient disorders.

Sialic Acid in Normal Human Tears

PURPOSE We measured the concentration of sialic acid, the terminal component of mucin, in normal human tears. SUBJECTS AND METHODS Tear samples were collected from 31 healthy volunteers(50.7 years old on average) using micropipett after instillation of saline. We investigated the correlation of concentration between glycoprotein and sialic acid, the difference between these in the right eye and left eye, and the reproducibility of the sampling procedure. RESULTS There was significant correlation of concentration between glycoprotein and sialic acid(right eye: r = 0.989, p < 0.0001; left eye: r = 0.988, p < 0.0001). There was no significant difference between these in the right and left eye. Also, the reproducibility was considered acceptable in three measurements of sialic acid with the present procedure. The concentration of sialic acid in normal diluted tears was 37.1 micrograms/ml on average. CONCLUSION Our data indicates that concentration of sialic acid reflects that of glycoprotein and this method of measurement is applicable to the analysis of disorders with mucin deficiency.