Columbia subject headings:
Retina--Diseases--Congresses.
Retina--Surgery--Congresses.
Vitreous body--Diseases--Congresses.
Vitreous body--Surgery--Congresses.
Harvard subject headings:
Retina--Diseases--Congresses.
Retina--Surgery--Congresses.
Surgical diseases.
Vitreous body--Diseases--Congresses.
Vitreous body--Surgery--Congresses.
Princeton subject headings: