A 61 year old male presenting with itching and mild allergic conjunctivitis had intra-ocular pressure of 17mmHg in the right eye and 21 mmHg in the left. Anterior segment and dilated fundus exams were normal except for disc asymmetry, with vertical cup disc ratio of 0.3 and 0.6 in the right and left eyes respectively.

RTA color image of the right and left discs showing asymmetry in the cupping.

Visual field testing was almost normal with a small inferior defect in the left eye.

Rim/Cup area maps show a disc with a small cup in the right eye and a large cup in the left eye.

The RNFL cross section graph displays a double hump pattern of the RNFL thickness thicker in the right eye and thinner in the left eye.

The retina thickness deviation maps show small deviations that may be insignificant or the first sign of a defect. The thickness map of the left eye displays a clear arcuate defect in the upper retina that correspond to the initial defect in the lower visual field. In addition a small defect appears in the lower retina of the left eye. There was no corresponding defect in the visual field but it may represent an early identification of glaucomatous damage. Longer follow-up is needed to clarify the nature of the lower defect.

RTA deviation map of the right eye shows small deviations while that of left eye displays a superior arcuate thinning and a smaller inferior one.