There are several circumstances when eye drops will be prescribed.
- Strongest: Pred Forte and Maxidex
- Mid/high strength: Lotemax
- Mid strength: Predsol and Betnesol
- Weakest: Vexol
- Preservative free drops: Minims
These drops are used to stop the inflammation. When there is a lot of inflammation, the drops are used every two hours to begin with, sometimes even more frequently. As the inflammation subsides, the drops are reduced (tapered) to six a day, then four a day, then three, two and one.
How long we stay on each stage of the tapering schedule varies, and for some patients, the taper from eight drops to no drops may be quite lengthy in order to prevent inflammation starting all over again as the steroid is reduced.
Predsol and Vexol drops tend to be used either when inflammation is not so severe, or the stronger drops have raised ocular pressure. Lotemax drops are less likely to raise ocular pressure than Pred Forte and Maxidex.
Beyond a slight stinging sensation there should be few, if any, side effects from using these drops in the short term. Pressing the lids together at the inner corner of the eye (next to the nose) will reduce the chance of steroid getting into the bloodstream and causing side effects beyond the eye. This punctal occlusion will also ensure the eye receives the full dose of steroid and less of it drains away.
The long-term use of steroid eye drops will cause cataracts and may cause glaucoma. Systemic side effects may also be experienced.
One of the problems of anterior uveitis is the potential for the pupil to become fixed and stop changing size in different light conditions. If this happens, there is also a danger of raised ocular pressure. You may be prescribed a dilating drop to keep the pupil open. The drops also help with the pain that many people experience and the eye feels more comfortable. It is not uncommon to experience blurry vision.
- Strongest: Atropine
- Weaker: Cyclopentolate
Atropine produces huge pupils, almost to the rim of the iris, and it is difficult to focus with this dilation. It can take up to five days for the pupil to return to a normal size and for vision to settle.
Cyclophentolate generally makes the pupil slightly larger and its effect wears off within five hours or so.
Regardless of potency, children’s pupils tend to dilate wider and for a longer period of time compared to most adults. Wearing sunglasses, especially those with Polaroid lenses, will help with problems of glare and photosensitivity.
Being given these drops does not mean we have glaucoma. Glaucoma is damage to the optic nerve and this happens if pressure remains high for some time. Uveitis patients have their eye pressures checked at every appointment so that these pressure-lowering drops can be used to prevent persistent high pressure turning into glaucoma.
Children’s eyes tend to be able to tolerate a longer period of high ocular pressure before the optic nerve is damaged.
Some types of uveitis cause a rise in ocular pressure, for example inflammation caused by the herpes virus (the one that gives you a cold sore). It is also common for steroid eye drops to cause a rise in pressure. This is why our pressures are checked at every clinic visit.
There are a number of glaucoma drops, and the treating doctor will ask questions about general health before selecting the best drop for the patient. Glaucoma drops can cause side effects and if the doctor is told about these, it’s often possible to change the drop.
Occasionally, eye pressure may need to be lowered using Diamox pills.
If the steroid itself has caused the high pressure, the pressure should return to normal eventually once the steroid treatment is stopped, and then the glaucoma drops will also be stopped.
When steroid eye drops cause high pressure, if it’s safe to reduce the number of drops, this will be recommended, and sometimes the mid strength and weaker steroid drops will be prescribed to replace Maxidex or Pred Forte.
For some patients, glaucoma surgery may be offered, and for those with chronic uveitis, a decision may be taken to begin second line treatment, or to increase the dose of an existing second line treatment in order to reduce dependence on steroid drops.
Sight lost to glaucoma cannot be recovered.