What abnormality is present in this patient's visual field? (If you can not recall the picture, click here to view the picture again.)

Answer
Inferior nasal step in the right eye.

What are the early visual field changes in glaucoma?

Answer
The changes may be diffuse or localized.
In diffuse form, there is generalized depression of the
retina to stimuli in the absence of medium opacity such 
as cataract. 
Early localized changes in glaucoma include:
Nasal step
Temporal wedge
Paracentral nasal defect
Siedal's scotoma (extension of the blind spot)
 

Most patients find visual field tests tedious and time-consuming. One technique which overcomes this problem is SITA. What does it stand for and how does it work?

Answer
SITA stands for Swedish Interactive Threshold Algorithm. It increases
the speed of visual field test without compromising the accuracy. Two
types of SITA are available. SITA standard and SITA fast (for screening).
They takes on average 50% less time than conventional visual field tests. 
The tests allow the likely threshold values to be established more rapidly 
than conventional tests. This is achieved by repeatedly recalculating all the test points as the test progresses.

What is SWAP? What is the theory behind this test?

Answer
SWAP stands for short-wavelength automated perimetry. 
This is a blue/yellow perimetry based on the assumption
that blue-yellow ganglion cells are lost early in glaucoma.

What is frequency doubling perimetry? What is the theoretical advantage of this technique in detecting glaucoma?

Answer
This test uses low spatial frequency sinusoidal grating which undergoes 
high temporal frequency flicker. This test targets the magnocellular pathway which is believed to be lost early in glaucoma.