| OAK | Kjer optic atrophy |
|---|---|
| OCA | oculocutaneous albinism; olivopontocerebellar atrophy; oral contraceptive agent |
| OPCA | olivopontocerebellar atrophy |
| PMA | index of prevalence and severity of gingivitis, where P = papillary gingiva, M = marginal gingiva, a... |
| POA | pancreatic oncofetal antigen; phalangeal osteoarthritis; preoptic area; primary optic atrophy |