Eye care in the community: Part 5

Patients attend practice complaining of having had double vision which cannot be borne out during the assessment of binocular vision. This may be due to a diurnal variation where an anomaly emerges at the end of the day but, with overnight rest, is no longer found the next morning. It is important to be aware of such an anomaly. It is, however, possible to time how long it takes for the diplopia (and/or a ptosis) to appear after working the muscles in different directions of gaze. This is helpful when assessing patients with either Parkinson’s or myasthenia gravis.

Case 1
A 76-year-old female patient came in for an eye examination complaining of having a ‘drooping right eyelid’ for the past two weeks. She was also experiencing some dull headaches and a more general ‘heavy lid feeling’.

Ocular examination

• No change in her myopic prescription, with visual acuity of 6/9 each eye and N5 unaided.
• Ocular muscle balance showed no signs of phoria or tropia and no double vision.
• Hess plot showed no signs of incomitancy.
• Pupils were symmetrical and reflexes were normal.
• Fundus revealed no abnormalities.
• Grade 2 right eyelid ptosis, but with no anhydrosis or lack of sweating seen.
• Right eyelid ptosis increased on looking up for a period of twenty seconds (figure 1).