Evaluation of tear production in juvenile opossum using three different methods / Avaliação da produção lacrimal em gambás filhotes por três diferentes métodos

The establishment of parameters for tear production in different species is important for better understanding eye´s health and is one of the components of the ophthalmic semiological technique. Particularities derived from the anatomophysiology of non-domestic species induce the search for more reliable methodologies. The aim was to evaluate and compare tear production of white-eared opossum (Didelphis albiventris) and Brazilian common opossum (Didelphis aurita) by three different methods. Fifteen individuals of each species, juveniles, healthy, of both sexes, with 60 to 90 days of life, were physically restrained. Phenol red thread test (PRTT), endodontic absorbent paper point tear test (EAPPTT) and modified -Schirmer tear test (mSTT) were performed. PRTT was the most difficult to perform because of the wire malleability, while EAPPTT was more feasible for both species. The median ± semi-quartile range for PRTT were 19.79±2.61mm/15 "and 5.22±2.92mm/15", for EAPPTT were 16.25±1.82mm/min and 10.9±3.04mm/min, and for STTm were 0±1.63mm/min and 0±1.63mm/min for white-eared opossum and Brazilian common opossum respectively. There was no difference between the right and left eye neither sex. A significant difference was obtained for the same test to different species. No significant correlation was found between the tests for both species. The description of tear production parameters for juvenile white-eared opossum and Brazilian common opossum may be used as a tool, which will allow the early diagnosis of ocular diseases.(AU)

O estabelecimento do parâmetro de produção lacrimal nas diferentes espécies é importante para o entendimento da saúde do olho e é um dos componentes da semiotécnica oftálmica. Particularidades derivadas da anatomofisiologia das espécies não domésticas induzem a busca de metodologias que sejam mais fidedignas aos parâmetros. Objetivou-se com este estudo avaliar e comparar a produção lacrimal de gambás-de-orelha-branca (Didelphis albiventris) e gambás-de-orelha-preta (Didelphis aurita) por três diferentes métodos. Quinze indivíduos de cada espécie, juvenis, hígidos, de ambos os sexos, com 60 a 90 dias de vida, foram contidos fisicamente para realização do teste lacrimal do vermelho de fenol (TLVF), da ponta de papel absorvente estéril e do teste lacrimal de Schirmer modificado (TLSm). O TLVF foi o mais difícil de ser executado devido à maleabilidade do fio, enquanto a TEPA se mostrou mais exequível para ambas as espécies. A mediana ± intervalo semi-interquartil para o TLVF foi de 19,79±2,61mm/15" e 5,22±2,92mm/15", para a TEPA foram de 16,25±1,82mm/min e 10,93±3,04mm/min, e para o TLSm foram de 0±1,63mm/min e 0±1,63mm/min, para gambás-de-orelha-branca e gambás-de-orelha-preta, respectivamente. Não houve diferença entre o olho direito e esquerdo e nem quanto ao sexo. Obteve-se diferença significativa para um mesmo teste entre as espécies. Não foi encontrada correlação significativa entre os testes para ambas as espécies. A quantificação da porção aquosa da lágrima poderá auxiliar no diagnóstico precoce de doenças oculares nas espécies estudadas.(AU)

Evaluating the effect of an aqueous extract of Pistia stratiotes Linn (Araceae) on tear secretion and tear film stability in ICR mice.

Management of allergic conjunctivitis with conventional anti-allergic drugs usually cause the discomfort of dry eyes. This study, therefore, sought to evaluate the effect of Pistia stratiotes, a herbal remedy with anti-allergic properties, on tear secretion and tear film stability. ICR mice were grouped and treated with 5 mg/kg cetirizine, 10 mg/kg prednisolone, 100 mg/ kg leaf extract of P. stratiotes (LEPS), or 2 ml/kg normal saline per os for 7 consecutive days. With the phenol red thread test and the determination of fluorescein tear film break-up time, tear secretion and tear film stability before and after drug interventions were determined. Results recorded indicated that tear secretion and tear film stability declined significantly with cetirizine treatment (1.188 ± 0.4369 mm; P ≤ 0.05, and 2.688 ± 0.6185 s; P ≤ 0.001 respectively), while only tear secretion reduced significantly (P ≤ 0.05) in mice treated with prednisolone (0.9380 ± 0.4422 mm). Treatment with LEPS showed no significant effect (P > 0.05) on tear secretion and tear film stability (0.7050 ± 0.4236 mm, and 0.9790 ± 0.6145 s respectively); comparable to normal saline treatment. Per the findings, Pistia stratiotes does not affect tear secretion and tear film stability and hence is not likely to exhibit the adverse effect of dry eyes, as conventional anti-allergic drugs do, in the management of allergic conjunctivitis.

Clinical Usefulness of the Phenol Red Thread Test as Diagnostic Tool in Dry Eye Patient

PURPOSE: To evaluate the clinical usefulness of the phenol red thread test as a diagnostic tool of dry eye by comparing the phenol red thread test, Schirmer's test and tear break-up time. METHODS: The present study included 30 dry eye patients belonging to dry eye workshop grade 1 or 2 and 25 normal subjects. Phenol red thread test, Schirmer's test, and tear break-up time were performed on each subject's right eye. The sensitivity, specificity and repeatability of each test were compared, and the correlations between the 3 tests were also analyzed. RESULTS: Tear break-up time was superior to the other tests in terms of sensitivity and repeatability. The phenol red thread test was better than Schirmer's test in terms of specificity and repeatability. In all 55 patients including dry eye patients and normal subjects, the phenol red thread test showed a greater correlation with tear break-up time than did Schirmer's test. In addition, in 25 dry eye patients, the correlation between the phenol red thread test and Schirmer's test increased significantly. CONCLUSIONS: The phenol red thread test is less irritating and requires a shorter testing time than Schirmer's test. Additionally, the phenol red thread test is superior to Schirmer's test in terms of specificity, repeatability, and relation to tear break-up time. In addition, the correlation between the phenol red thread test and Schirmer's test significantly increases in dry eye patients. Therefore, the phenol red thread test is a good substitute option for Schirmer's test in diagnosing dry eye.