| OPCD | olivopontocerebellar degeneration |
|---|---|
| OPCOS | oligomenorrheic polycystic ovary syndrome |
| OPD | Out-Patient Department; 외래 |
| OPD | obstetric prediabetic; optical path difference; otopalatodigital [syndrome]; outpatient department; outpatient dispensary; p-phenylenediamine |
| OpDent | operative dentistry |
| OPDG | ocular plethysmodynamography |
| OPG | ocular pneumoplethysmography; orthopantomogram; oxypolygelatin |
| opg | opening |
| OPH | obliterative pulmonary hypertension; ophthalmia |
| OPH, Oph | ophthalmology; ophthalmoscopy, ophthalmoscope |