Dysthyroid optic neuropathy: A preventable cause of blindness

Dysthyroid Optic Neuropathy (DON) is a treatable cause of visual loss in ~5% of pts w/ ted. Monitor closely those pts with risk factors (proptosis, tight orbit, restricted motility, strabismus, smoker, diabetic). Oral prednisone is often effective, but frequent relapses after tapering. Orbital xrt is controversial, but reported to be mod. Effective and generally safe. Orbital decompression surgery is highly effective, but does carry risk of new-onset or worsened strabismus and diplopia. A prospective, randomized trial would help to better define the role of each of these treatment modalities in DON.Orbit, RetinaDysthyroid Optic Neuropathy (DON)- 40 yo wf w/hyperthyroidism, Tapazole, then rai oct 1998 - Feb 1999- vision started declining - April 1999- orbital xrt 2000 cgy and low-dose prednisone - Vision briefly improved, then declined - July 1999- sent for orbital and neuro-ophth. Consult - Bcva od 20/60, os 20/30 - ¯ cv od > os - Rapd od - Dense inf. Vf defects od > os - Eom- full ou - Hertel- 20 ou (base 95) - Rtr- od 3/4, os 2/4 - Fundi- +/-trace disc pallor ou - Ct- markedly enlarged eoms w/ crowding of orbital apex ou - Dx = compressive optic neuropathy due to ted - Started prednisone 80 mg qd - 3 wks later, va od 20/40, os 20/25 - Va and vfs declined when prednisone ¯ to 60 qd - Prednisone dose increased, tapered more slowly - Va stable, but cv & vfs worsened - Very cushingoid appearance - Oct 1999- right transconj. Orbital decompression (2-wall) - 3 mos po, va 20/20, nl cv & vf od - However, va os 20/25 ® 20/40 and new rapd os as prednisone tapered down to 20 mg qd - Jan 2000- left transconj. Orbital decompression (2-wall) - 3 mos postop, va 20/25 od, 20/20 os, nl cv & vfs ou, no rapd - 2 yrs later, stablecurriculum_fellow; VBorbitalpathologythyroidorbitopath