Immunoassay of human tear lysozyme.

We used a single radial immunodiffusion technique to determine the lysozyme content of human tears. The level in healthy subjects with this method was 1.3 mg/ml of tears. In patients with trachoma, the level was low, 0.9 mg/ml of tears. Detecting the reduction in lysozyme level in patients with trachoma proved the utility of this method.

Biological variations of lysozyme concentration in the tear fluids of healthy persons.

Concentration of tear lysozyme was measured in healthy Indian subjects of the same racial group aged 2 to 78 years by a single radial immunodiffusion technique. Variations in its concentration between the two eyes, during the day, over a period of time, in both sexes, and in different age groups were studied. The diurnal and age-related changes in the concentration of tear lysozyme were found to vary to an appreciable extent. The mean lysozyme concentration in tears was lower in the morning and higher in the evening. It tended to be low in children under 16, rose and attained a plateau in the age group 16-45 years and fell in later life, though still remaining higher than in the children.

Serum complement component depression during acute adenovirus conjunctivitis.

Serum C1q, C3, C4, and C5 components of complement levels were measured in 35 healthy subjects and 29 patients with acute conjunctivitis due to adenovirus type 2, 7, and 8 infections. Serum C1q and C3 levels were found to be significantly low, and there was no change in serum C4 and C5 levels. A progressive decline in the serum complement level with the severity of disease was observed. The change in the complement levels in serum showed a tendency to reach normal levels with clinical improvement.

Immunoassay of serum alpha-1 antitrypsin level in uveitis.

The serum alpha-1 antitrypsin level was measured in 60 patients with endogenous uveitis, 27 patients with phacoallergic endophthalmitis, 12 patients with phacolytic glaucoma, and 58 healthy subjects. Thirty-four patients with endogenous uveitis were also followed up for 6 months after treatment, and the serum alpha-1 antitrypsin level was measured again. There was a significant rise in the serum alpha-1 antitrypsin level in cases of endogenous uveitis and phacoallergic endophthalmitis but no alteration in cases of phacolytic glaucoma. Among the patients with endogenous uveitis the level was significantly raised in cases of anterior uveitis, but there was no change in cases of posterior uveitis. A significant rise was seen only in cases of acute anterior uveitis but not in chronic anterior uveitis. The serum alpha-1 antitrypsin level was unaltered in endogenous uveitis despite clinical improvement.

Immunoassay of tear lysozyme in conjunctival diseases.

The tear lysozyme content in 111 normal subjects and in 159 patients with various conjunctival diseases was determined by a single radial immunodiffusion technique. Tear lysozyme level in normal people was 1.33/mg/ml. (SI conversion: mg/ml = g/l.) The mean tear lysozyme levels in patients with chronic irritative conjunctivitis (0.97 mg/ml) and nutritional deficiency with epithelial xerosis (0.76 mg/ml) were significantly lower than in the normal controls. The mean tear lysozyme levels in tears from patients with vernal conjuctivitis (1.20 mg/ml), phlyctenular conjunctivitis (1.10 mg/ml), and acute bacterial conjunctivitis (1.48 mg/ml) were not significantly different from those in the normal controls. Superimposition of acute bacterial conjunctivitis on trachoma did not alter the low tear lysozyme level that existed before in these patients.

Serum and tear immunoglobulin levels in acute adenovirus conjunctivitis.

Tear and serum IgG, IgA, and IgM levels were measured in 35 healthy subjects and 31 patients with acute conjunctivitis due to adenovirus 2, 7, and 8 infections. Serum IgG and IgM levels were found to be significantly low and there was no change in the serum IgA level. There was a significant rise in the tear IgG level. A progressive decline in the serum immunoglobulin level with the severity of the disease was observed. The changes in the immunoglobulin levels in serum and tears showed a tendency to reach normal levels with clinical improvement.

Tear glucose levels in normal people and in diabetic patients.

Fifty normal people and 50 diabetic patients were studied by means of an enzymatic method for the glucose content in the blood, tears, and urine before and after the peroral glucose load. In normal subjects the fasting glucose levels in the tears averaged 3.6 mg/100 ml (0.2 mmol/l) and in the diabetic patients it averaged 16.6 mg/100 ml (0.92 mmol/l). As in blood and urine, tear glucose levels are significantly higher in diabetic patients than normal persons both at fasting and after the peroral glucose load test. The fasting tear glucose level did not appear to be a satisfactory index for classifying a person as a diabetic or normal. It was found that after the peroral glucose load test a tear glucose level at 11 mg/100 ml (0.61 mmol/l) resulted in only 4.6% of the diabetics being missed, while 5.8% of the normal persons were misclassified as diabetics.

Immunoglobulin concentrations in human tears in ocular diseases.

Immunoglobulin concentrations in human tears were determined in 165 patients with different eye diseases by a standard radial immunodiffusion method. IgA was present in all the samples in measurable quantity. The mean IgA values were significantly higher than the controls in patients with acute bacterial conjunctivitis, keratomalacia, corneal graft reaction, blepharoconjunctivitis, and acute keratoconjunctivitis. The values in the patients with vernal conjunctivitis, phlyctenular conjunctivitis, acute bacterial corneal ulcer, and acute endogenous uveitis were not significantly different from those in the controls. IgG could be detected in the majority of the samples but it was in measurable quantity in 18 samples. IgM could be detected in fewer samples. IgD was not detected in any of them. The study indicates that, whenever the immunoglobulin levels in tears are altered in diseased eyes, it is the IgA level that is predominantly altered and not the IgG level.

Immunoglobulins in human aqueous humour.

The immunoglobulin concentrations in human aqueous humour from 44 patients aged 35 to 85 years with cataracts were measured by a standard immunodiffusion method. IgG was found in all the samples (mean level 7-0 mg/100 ml. IgD, IgA or IgM could not be detected. There was no significant difference in IgG levels in aqueous humour between the two sexes, in different age groups, and in the different types of cataracts.

Immunoglobulins in tear in trachoma patients.

Tear immunoglobulin concentrations have been measured in 100 healthy people and 62 patients in different stages of trachoma. In healthy people the average IgA level was 27-8 mg/100 ml. There was no significant difference in the IgA level in various age groups and between the sexes. IgG was detected in 92 samples, and it was less than 1 mg/100 ml. IgM in tears was detected in only one sample. IgD was not detected in any specimen. In tracoma cases, the mean IgA level was found to be significantly lower (22-0 mg/100 ml) than in healthy people. There was no significant difference in IgA level between different stages of trachoma, IgG, IgD, and IgM could not be detected in any sample from the trachoma cases.

Serum complement components in patients with trachoma.

Serum C1q, C3, C4, and C5 components of complement levels were measured in 56 healthy subjects and 98 patients with trachoma. Serum C1q and C3 levels were found to be significantly low in stages II and III. There was no change in serum C4 and C5 levels in any of the stages. The levels of C1q and C3 complement components in serum in stages II and III returned to normal as the disease resolved following the medical treatment.

Alpha 1-antitrypsin and serum albumin in tear fluids in acute adenovirus conjunctivitis.

The alpha 1-antitrypsin and serum albumin levels in tear fluids were measured by electroimmunodiffusion in 76 healthy subjects and 63 patients with acute adenovirus conjunctivitis. They were found to be significantly increased during the acute phase of the disease. There was a correlation between increased severity of disease and increased levels of both the proteins. There was no significant difference in the tear alpha 1-antitrypsin and serum albumin levels in viral isolation-positive and isolation-negative patients. The raised levels of the two proteins in tears may reflect conjunctival inflammation rather than infection, since both isolation-positive and isolation-negative patients had the raised levels. The levels of the two proteins returned to normal with clinical improvement.

Immunoglobulins in tears of normal Indian people.

Immunoglobulin concentrations in tears from 50 healthy Indians aged from 14 to 50 years were measured by a standard immunodiffusion method. The levels of IgA were substantial; those of IgG were very low; and IgD and IgM were not present. The mean IgA level was 24-6 mg/100 ml.

Immunoassay of tear lysozyme in acute adenovirus conjunctivitis.

The tear lysozyme levels were measured by immunoassay in 92 healthy subjects and 98 patients with acute adenovirus conjunctivitis. They were found to be significantly decreased during the acute phase of the disease. The extent of this decline in the tear lysozyme level was correlated with increased severity of disease. There was no significant difference in the tear lysozyme level in viral isolation-positive and isolation-negative patients. The tear lysozyme level showed return to normal levels with clinical improvement.

Lactic acid in human aqueous humour.

We wished to assess the contribution of the lens to the maintenance of the high level of lactic acid found in human aqueous humour. The lactic acid in aqueous humour was estimated by Pryce's modification of the Barker-Summerson method in 41 subjects who were divided into four groups: those with early cataract, those with advanced nuclear cataract, those with mature cataract and those with hypermature (morgagnian type) cataract. Statistical evaluation of the results showed that there was no significant difference in the lactic acid level between the four groups. We assume that the lens does not contribute significantly to the high concentration of lactate found in human aqueous humour.

Immunoassay of serum muramidase (lysozyme) in ocular diseases.

Serum levels of muramidase activity were measured in 162 patients with different ocular diseases and 84 healthy subjects by electro-immuno-diffusion technique. We demonstrated for the first time that electro-immuno-diffusion technique could be successfully applied for the estimation of serum muramidase concentrations. Serum muramidase was found to be high in significant number of cases with granulomatous uveitis, tuberculous keratitis, central serous retinopathy and Eales' disease. Tuberculosis was presumed to be the cause in them by the process of exlusion. Patients with high serum muramidase activity were subjected to anti-tubercular treatment with a marked clinical improvement. It is suggested that high serum muramidase could be an useful parameter in deciding the line of treatment in patients with ocular diseases of uncertain etiology. Serum muramidase concentrations showed return to normal levels with the clinical improvement of the diseases with treatment. It increased again with the re-appearance of the activity of the diseases.