ACTA 0 P zyxwvutsrqpo H TH A zyxwvutsrqpon L M 0 LOG I CA zyxwvutsr 69 (1991) 530-532 S H zyxwvuts 0 RT C 0 M M U N I C AT I 0 N Tear lysozyme levels in bacterial, fungal and viral corneal ulcers H. Lal', B. K. Ahluwalia2, A. K. Khurana2, S. K. Sharma2 and S. Gupta2 Departments of Biochemistry' (Head: A. S. Saini) and Ophthalmology-ll' (Head: B. K. Ahluwalia), Medical College,Rohtak, India Abstract. Low levels of tear lysozyme were observed in patients with infective corneal ulcers, when compared with controls. Lowest levels were seen in patients with bacterial corneal ulcers. The levels of tear lysozyme showed a corresponding decrease with the increase in Schirmer test values; meaning thereby, that in ocular conditions associatedwith increased rate of tear flow, the lysozyme content in tears tends to be low. Key words: tears - lysozyme - corneal ulcers. zyxwvut Lysozyme, also termed as muramidase, is a muco- lytic enzyme, first discovered by Fleming (1922). Tear lysozyme concentration is highest amongst all the body fluids (Fleming 1922), forming nearly 20 to 40% of the tear proteins, and is produced by aci- nar cells of the lacrimal gland (Klockars & Reitamo 1975; Gillettee et al. 1981). In tears, it acts as a pro- tective agent against bacterial infections (Hill & Porter 1974).It causes lysis of cells by hydrolysis of the polymer-N-acetyl-glucosamine-N-acetyl mu- ramic acid in the bacterial cell wall (Ronen et al. 1975).Although a bulk of literature is available on tear lysozyme studies, there exists paucity of com- parative studies on tear lysozyme levels in cases of bacterial, viral and fungal corneal ulcers. There- fore, the present study was planned to estimate tear lysozyme levels in patients with such corneal ulcers. Forty-five bacterial, 530 Material and Methods patients with corneal ulcers (15 each of fungal and viral type) and 15 healthy controls were studied. Their detailed clinical and laboratory data have already been described in a separate communicationon serum and tear immu- noglobulins (Lal et al. 1990). Schirmer-Itest was performed as described else- where (Khuranaet al. 1987). Tear lysozyme concen- tration was determined turbidometrically, by spec- trophotometer using Micrococus lysodeikticus as the substrate (Ronen et al. 1975). The concentra- tion of lysozyme in tear samples was calculated from a standard curve which was prepared by using Hen Egg Lysozyme (HEL). Results between the control and the different study groups were statistically analysed by Student's t-test, while the relationship between tear lysozyme and Schirmer test values was calculated by correlationcoefficient (r). Results Age and sex The mean age of patients with bacterial, fungal and viral corneal ulcers was 32.05 zy f 3.42 (4 females and 11males),37.80 f 3.15 (3females and 12 males) and 30.00 f 2.89 (6 females and 9 males) years, re- spectively. The mean age of control subjects was 45.90 f 7.84 years (7 females and 8 males).Male pa- tients outnumbered females in each group. Schirmer test Table 1 depicts the range and mean values of Schirmer test in patients with bacterial, fungal and viral corneal ulcers and controls. When compared