Optometrists are invited to submit their case studies and colleagues are invited to have a go at making the diagnosis, by answering a few questions. The answers will be published in the next issue of Vision Online. This is not a CPD exercise, the emphasis is on the learning experience. There will be no record kept of your answers. The questions are posed to give you an opportunity to test yourself.
Case report 1 – Dirk Booysen
This 57 year old African female, presented with a history of vision loss more pronounced in her right eye. She was previously seen at Charlotte Maxeke Hospital and the clinical notes available show the following:
Poor vision, especially at night and headaches. Vision was measured in September 2012 as unaided right 6/18 and left 6/24. A note was made of temporal field loss in the right eye, but other than that, the clinical examination was normal. She was sent for a CT scan of her brain and orbits. The radiological report indicated normal orbits, globes, lenses, extraocular muscles (EOM’s), optic nerves, and lacrimal glands. The CT of the brain showed no intracranial mass lesions or shift of the midline, no calcification or other abnormalities. She was seen again in November 2012 and the unaided vision recorded as 6/24 in both eyes. No treatment was prescribed and a recommendation for further evaluation was made, which it seems the patient did not attend.
My evaluation during September 2017 showed the following.
R. +2.00/-0.75×95 6/7.5
L. +2.25/-0.75×85 Hand movement, no improvement with pin hole
Goldman applanation tonometry (GAT) IOP was right 10 and left 11mm Hg. There were early lens changes in both eyes, but the corneas and anterior segments were normal. Mydriatic examination revealed no retinal pathology.
OCT of the ganglion cell layer (GCC) and retinal nerve fibre layer (RNFL) as well as fundus photographs (and fundus autofluorescence (FAF)) and threshold fields are attached. Interestingly the right eye showed marked GCC and RNFL loss with C/D of 0.70, while the left eye showed relatively normal GCC and RNFL. However the threshold field was abnormal in both eyes showing a temporal defect in both eyes, much denser in the right eye than the left eye, which still had some macular sparing.
- This patient has normal tension glaucoma (NTG)?
- This patient probably has a lesion affecting the chiasma?
- Treatment includes
(a) Prostaglandin drops
(b) Referral for MRI and neurological consult
(c) Spectacle prescription
(d) Regular follow up
(e) All of the above