Your eye is red, painful, and the vision is blurred, with haloes around lights, add nausea; then acute angle closure glaucoma is a fairly obvious diagnosis. That eye will be partly blinded by this attack. But one of the most difficult diagnoses in all of eye care is the common related condition – chronic angle closure glaucoma. The condition which may in fact precede an acute attack.
The doctor must place a mirrored contact lens on your ocular surface, while you cooperate as best you can to permit the doctor to study a circle of tissue 50 microns wide (0.050 millimeters!) that is inspected through the mirror. [The Barkan gonio lens was a direct technique for such inspection, eliminating the mirrors, but the patient must lay flat (a position normal to us only during sleep) and the doctor must hold a 15 pound microscope to see the fine details.]
Easy to imagine that subtle trouble with the observations will, and often do, happen. When the drainage angle for fluid closes in part, pressure in the eye will increase slightly. The goal of treatment is to remove the obstructing iris folds which roll up to and over the fine meshwork which percolates fluid through and out of the eye.
The treatment? Create a second opening in the iris other than the pupil, which will allow fluid to pass directly to the drains, and eliminate the pupil – blocking part of the fluid stream.
This was performed by surgery prior to the 1970s but the advent of laser technology improved surgery. Each generation of laser has proved effective at puncturing a hole in the iris, without surgically opening the eye. The surgeon’s job is to ascertain who will benefit from this procedure as to eliminate the folds which block fluid exiting the eye.
Patients come in for a routine eye exam, and they may have partly or completely blocked drains. If the eye pressure has – or has not – built up, should a laser treatment be recommended? How risky is it for the laser treatment, verses the risk of having low grade glaucoma, or even an acute attack – as decribed at this blog’s outset?
Even second opinion glaucoma patients arrive with the same dilemma – are they “open angle” or “closed angle” patients – and are the treatments correct?
A yearly “gonioscopy” by your eye doctor is an important part of maintenance for every glaucoma patient, and we will perform this exam in any patient with suspicious findings seen during the course of any eye examination.