Strabismus course : 17. Decision making

In a case like this the ophthalmologist should be aware of different causes of limitation of depression of one eye ( The above slide contains these causes )

and should be able to differentiate between restrictive causes from other causes . Mechanical causes that interfere with depression of the eye must be excluded. In spite of absence of history of previous orbital surgery or orbital trauma in the accident which may exclude restrictive causes , forced ductions must be done to rule out this . 

Double Depressor Palsy ( DDP )

This is one of the most rare oculomotor disorders may be seen by the strabismologist all over his life . This is my third case of DDP within 30 years of ocular motility examination . My first 2 cases were congenital , this case is acquired most probably due to central lesion following the sever head injury although MRI and CT brain could not localize the underlying pathology. Paralysis of both depressor muscles of one eye (inferior rectus and superior oblique) always occurs with obscure etiology because both depressor muscles are innervated from different nuclei ( 3rd and 4th ).

The characteristic ocular motility of DDP are : when the non-paretic eye is fixating, the paretic eye is hypertropic in primary position (Picture 5). . Ductions are limited in the entire lower field of gaze and normal in all other gaze positions.

Patients have double depressor palsy are rarely found in the literatures , I have been invited once to a session titled " a case of double depressor palsy " . I put photos of my case in comparative with the only case of  DDP of the great text " Binocular vision and Ocular motility " , I think they are the same with different colors

Binocular vision and ocular motility

Therapy