Questione giuridica chiave
Whether the conditions for revising the disability pension under changed circumstances were met
Decisione estratta
No material change in health or earning capacity was shown; the pension reduction to a quarter was unjustified.
Motivazione estratta
Revision under Art. 17 LPGA requires a notable change compared with the situation at the initial award. The cantonal findings that the health situation remained stationary were not manifestly incorrect, and the insured's part-time work did not itself justify a revision.