Answers

1. Describe what you see.
The appearance on the slit lamp shows a red eye with partially opaque cornea, a mid sized pupil and a slightly eccentricly placed pupil. There is no evidence of hyphaema or hypoyon on this image (though further confirmation would be needed).

2. What is the diagnosis?
These findings are typical of acute closed angle glaucoma.

3. Is the time of day significant?
Yes, the angle is more likely to "close" when the pupil is dilated in low light, or for example if dilating drops are used.

4. What other precipitants of this condition do you know?
Use of mydriatics is probably the most worrying for us. Patients at risk have shallow anterior chambers which makes the iris conical in shape. If you are concerned that a patient is at risk you can roughly assess chamber depth by shining a light perpendicular to the visual axis at the cornea-scleral margin. If the chamber is shallow the light will appear to illuminate only half the iris.

5. How would you confirm the diagnosis?
By testing the intraocular pressure with a tonometer. You may get an impression of the pressure by feel, the eyeball often feels rock hard. Comparison with the other eye is often helpful if (like me) you do not make a habit of poking people in the globe!

6. How would you treat this?
They need urgent referral to an Ophthalmologist who would initially treat this with Diamox.

Further reading

http://www.emedicine.com/emerg/topic752.htm