K. M. Saari

EYE INJURIES IN AGRICULTURE

To study eye injuries in agriculture we reviewed the case records of 662 patients with eye injuries treated at the Department of Ophthalmology, Central Hospital of Tampere between the years 1972 and 1979. Of the whole material 96 (14.5%) were agricultural workers, 74 (77%) male and 22 (23%) female, with the mean age of 43 years. The mean annual incidence of eye injuries in agriculture was 3.46 per 10.000 people which was higher than in industry (1.9 per 10.000 people) but lower than in construction (5.28 per 10.000 people). The use of AIV solution was the most frequent cause of eye injury in farming (6/10) and was the most common cause of all chemical eye burns in agriculture (6/7). Cow butting with horn caused all eye injuries in dairying; 50% of these were perforating eye injuries. In lumbering, forest work or a flying piece of wood at chopping caused eye injuries in 29 cases including 19 cases with blunt ocular trauma and 8 cases with perforating eye injuries. Hammering was the most frequent cause of injury in repair work (7/16). Unilateral blindness was seen in 17 cases (17.7%). It was caused mostly by cow butting with horn (6 cases) or lumbering (5 cases). The importance of employment of protective eye screen or glasses also in agriculture is pointed out.

OPHTHALMOLOGICAL FINDINGS IN NEPHROPATHIA EPIDEMICA IN LAPLAND

We report ophthalmological findings in 15 cases of nephropathia epidemica. The patients, 13 men and 2 women, were 20 to 62 (mean 30) years of age. The onset of the disease was characterized by high fever, nausea, headache, abdominal pain, backache, somnolence, red throat, proteinuria, and oliguria. The symptoms subsided rapidly during the polyuria stage. Transitory myopia occurred in 8 patients (53%). Conjunctival injection and haemorrhages were seen in 3 patients (20%). One patient had acute glaucoma with oedema in the cornea and shallowing of the anterior chamber, with subsequent anterior uveitis and haemorrhages in the ocular fundus, and another patient had acute glaucoma. Three patients had photophobia which occurred in 2 patients without any glaucoma or anterior uveitis.

MANAGEMENT OF CHEMICAL EYE INJURIES WITH PROLONGED IRRIGATION

To study the effect of prolonged irrigation in the treatment of chemical eye injuries we reviewed the case records of 172 patients. Most of the patients were men in working age. The injury was caused by acid in 57 patients (33%). Of the acid burns, 28 were due to AIV solution commonly used in agriculture in Finland, and 27 were due to inorganic acids. Alkaline burns occurred in 64 (37%) patients including 33 cases with natrium hydroxide and 20 cases with mortar and cement burns. Other chemicals including organic solvents and surfactants caused the eye burn in 51 (30%) cases. Fifty three patients mostly with alkaline and acid burns were treated with prolonged irrigation with one liter of physiological saline using intravenous delivery system during 1–2 hours. The extent of damage was smaller, the visual outcome better, and the duration of treatment at the hospital and absence from work were shorter in patients treated with prolonged irrigation than without such treatment.

ENZYME-LINKED IMMUNOSORBENT ASSAY (ELISA) FOR SEROLOGICAL DIAGNOSIS OF TOXOPLASMIC CHORIORETINITIS

To make a definite serological diagnosis of ocular toxoplasmosis we determined the ratio of toxoplasma IgG antibody levels in the aqueous humour and serum by using a new four‐layer modification of ELISA, and the ratio of total IgG in serum and aqueous by using single redial immunodiffusion plates. We used the product of these ratios as a coefficient (C) to characterize the antibody activity in aqueous as compared with that of serum. The C value was close to 1 (below 3.5) in seropositive normal cataract patients. In patients with recurrent active focal chorioretinitis the C value was elevated indicating intraocular antibody production; in other forms of posterior uveitis the C value was normal. Parallel determination of mumps virus IgG antibody levels in aqueous and serum confirmed without IgG determination the intraocular toxoplasma antibody production. This test is valuable if the aetiology of the fundal lesion is in doubt.

α1-antitrypsin in acute anterior uveitis and rheumatic diseases

Abstract To test the pathogenetic role of the phenotype MZ of α1‐antitrypsin/α1‐protease inhibitor (PI) in acute anterior uveitis (AAU) and in different rheumatic diseases we examined 360 unrelated patients including 93 with AAU alone, 24 patients with AAU and ankylosing spondylitis (AS), 21 patients with AAU and Reiters disease (RD), 26 patients with AAU, AS, and RD 54 patients with AS alone, 16 patients with RD alone, 115 patients with rheumatoid arthritis (RA) alone, and 11 patients with psoriatic arthritis (PA) alone. Of the 164 AAU patients, 80 had a single attack, and 84 had repeated episodes. There were neither significant differences between different groups of the patients and 120 healthy controls nor between patients with AAU alone and patients with AAU and AS or RD in the frequencies of the PI phenotypes tested. The results indicate that the PI MZ type is not closely associated with AAU, AS, RD, RA and PA and that it does not play any role in determining whether AAU shows a pattern of a single attack or repeated episodes, and whether AAU occurs alone or together with AS or RD.

THE RELATIVE RISK

A relative risk (RR) indicates how many times more frequent the disease is in individuals carrying the factor (HLA antigen) relative those who lack it. RR values are calculated by the formula RR=ad:bc where a and b are the numbers of patients carrying and lacking the factor (antigen), respectively, and c and d the corresponding numbers of controls. Associations between HLA and disease may be much stronger (e.g. RR=90 in ankylosing spondylitis and RR=5.2 to 53 in acute anterior uveitis) than the classical association between blood group O and duodenal ulcer (RR=1.33) indicating a more important involvement of HLA in many diseases than of ABO in duodenal ulcer.

Wearing of Spectacles and Occurrence of Ocular Symptoms in Close Work in Different Occupations

To study the wearing of spectacles in different occupations we sent a questionnaire to all 26- and 46-year-old people (altogether 3 337 subjects) in the Jyväskylä district. 69% in the older age group and 42% in the younger age group had spectacles. Women wore spectacles more often than men. There was a correlation between the use of spectacles and accurate occupational close work. The proportion of those wearing spectacles was highest in subjects working, at least partly, with Visual Display Units (VDU). Farmers, industrial workers and service personnel wore spectacles less often than those in other occupations. In the older age group 70% and in the younger age group 11% of the subjects considered that they do not have good near vision without spectacles. Of those who used spectacles, 90% in the older and 52% in the younger age group reported that their near vision is better with spectacles than without them. In both age groups there was a positive correlation between the use of spectacles and the duration of daily close work. Subjective ocular symptoms occurred equally in different close work categories in the younger age group. In the older age group, those doing VDU work and reading and writing work had less symptoms of eye problems than those in other job categories.

NO ASSOCIATION OF CATARACT WITH THE HLA SYSTEM

The frequency of HLA antigens has been determined in patients with different types of cataract. No association was found between the development of senile cataract and HLA. Although HLA antigens are associated with susceptibility to acute anterior uveitis and juvenile‐onset diabetes, and these diseases may be complicated by cataract, it is obvious that the development of cataract is only secondary to these diseases and not itself associated with HLA antigens. We can conclude that there is no association between HLA and the development of cataract.

HLA SYSTEM AND SERONEGATIVE RHEUMATIC DISEASES

Reactive conjunctivitis and acute anterior uveitis may occur in association with ankylosing spondylitis, sarcoiliitis, reactive arthritis, and Reiters disease. These diseases showed a very close association with HLA‐B27 but not with any of the HLA‐Dw/DR antigens.

HLA SYSTEM AND MULTIPLE SCLEROSIS

Multiple sclerosis (MS) occurs most frequently in northern and central Europe, the north of the United States, and Canada; it is more rare in China and Japan. Population studies showed association between HLA‐A3, B7, Dw2, and DR2 with MS. There was a close association of MS with HLA‐Dw2 and DR2, and the increased frequencies of A3 and B7 were secondary to linkage disequilibrium of B7 with Dw2, and of A3 with B7 in Caucasians. Black American MS patients showed a slight association with Dw2. In Japan, there was an association between MS and Dw6.