Roenne nasal step

Roenne,

Henning K.T., Danish ophthalmologist, 1878-1947.
Roenne nasal step - a visual field defect seen in glaucoma.
Medical Eponyms © Farlex 2012

Roenne nasal step 

When scotomata occur above and below the fixation point they meet in the nasal field and form a horizontal step-like defect. It is one of the signs of glaucoma. See Bjerrum's scotoma.
Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann