Long-term changes in the outer part of the eye in welders. Prevalence of spheroid degeneration, pinguecula, pterygium, and corneal cicatrices.

Biomicroscopical examination of possible cumulative changes in the outer part of the eye in 217 male welders with variable welding exposure time showed conjunctival spheroid degeneration in 24% of the welders. The prevalence of changes was significantly increased in welders with the higher exposure time in an age-matched reduced material (98 x 2 eyes; respectively, over and under 40 h.y (number of daily hours of welding multiplied by number of years of welding), welders with stays abroad over one year being withdrawn. The prevalence was also increased in the latter group (41%, N = 40, against 21%, N = 177). Pinguecula was present in 57% of the welders, with a tendency towards larger area with increasing welding exposure. The frequency was increased as compared with that in a control material examined on a previous occasion (41%). Pterygium proper was found in only one subject, pseudopterygium in 5%. Corneal cicatrices were present in about one half of the subjects. The prevalence increased with increasing welding exposure (24% in subjects with short, 42% in those with long exposure; 98 x 2 eyes). Acute welding light keratopathy was experienced by 73%. The mean number of attacks in the 217 welders was 6.4. The frequency was highest in subjects with long welding exposure. The risk of chronic impairment of sight owing to cumulative welding light injuries is very little in the present material, since only 2% had spheroid degeneration on the cornea (only discrete, peripherally located); there was no preponderance of pterygium. On the other hand, the many foreign bodies on the cornea (cicatrices) constitute a risk that apparently does not decrease with increasing welding experience nor repeated attacks of welding light keratopathy.