The saga of poor vision continues for me and has put a sizable crimp in my activities. About a year ago, I underwent a procedure called
pars plana vitrectomy, which was done on the left eye, the one giving me all the grief. I was told this was a preventative procedure to forestall more serious problems that might eventually developed. In other words, the surgery was intended to fix something that had not yet broken.
It didn't quite work out as expected. In less than a year, I went from okay vision in the left eye to incipient blindness, due to something called
cystoid macular edema. The cause is unknown, but could be related to the vitrectomy. The edema has virtually stopped me in my tracks, insofar as doing any electronic work is concerned. To give you an idea as to how bad this has gotten, two years ago I was 20/30 in the left eye without correction. It is now 20/200 uncorrected and continues to deteriorate. Compounding the problem, objects seen with the left eye are wavy and distorted in shape. For example, a utility pole appears to have several kinks in it. A ball looks elliptical and watching television has become an exercise in figuring out what it is I'm seeing. The distortion and lack of focus in the left eye is so great I have almost no close-up depth perception and can't read anything smaller than 14 point type without magnification.
Anyhow, thanks to some persistence on the part of my primary doctor, I am now in a clinical trial for a new drug that may be able to reverse this problem. There is currently a drug on the market called
bevacizumab that has been used off-label to treat macular edema.
¹ I was treated with it and after a three month period, showed no response, and treatment was discontinued.
Ergo my doctor suggested that I consider a clinical trial.
The drug being studied in the trial supposedly will be more likely to work in advances cases. However, that is an unknown at this time, as only the first phase of the trial has been completed. I will be in the second phase of the trial, which is the phase in which efficacy is determined, while carefully monitoring for side-effects. Test subjects will be randomly assigned to one of three groups, treated as follows:
- Treatment with the study drug at the middle of the dosing range.
- Treatment with the study drug at the highest safe dosage, "safe" having been determine in phase one of the trial.
- Treatment at standard dosage with an existing product called Lucentis, which is considered the "gold standard" for macular edema treatment at this point in time. The "gold" part is apt: a single injection of Lucentis costs 1500-1600 USD.
Injections are directly into the "study eye" and are spaced at 28 day intervals. In between injections, monitoring of the study eye and general health will be frequently conducted. A total of 210 test subjects in the USA (including me) will in this part of the trial. Studies are also being conducted in the UK and Switzerland, Switzerland being the home of the drug manufacturer. Only the manufacturer will know into which of the three groups test subjects are assigned, with an equal number in each group. Subjects who are treated with the study drug and fail to respond will be treated with Lucentis after the trial has concluded, using the standard treatment protocol. No placebo is used—everyone in the trial will receive an active agent. They just won't know what they are getting and how much.
The study runs six months, after which a two month followup period with no medication occurs. In the event an adverse effect that has been caused by the study drug occurs, the subject will receive as much medical care as necessary to treat the effect. Reported side-effects during the first phase of the trial were generally mild, so I'm not overly concerned at this time. I've already received the first treatment and so far, nothing whatsoever has happened. I was told that if I do respond it will become evident in about three months.
So, now that it really is broke we're going to try to fix it again. We'll see!
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¹There currently is a fierce battle going on in the UK and parts of the EU over the used of bevacizumab to treat macular edema. As it is an off-label use, national health care services are balking at paying for the drug, since no trials have been conducted on its use as an intravitreal medication. The manufacturer of the drug isn't willing to conduct a trial, since a newer drug (Lucentis) has been approved for treating macular edema. The catch is the huge cost difference between Lucentis and bevacizumab, on the order of 32 to 1 at current prices. Hence the national health care services are "rationing" use of these drugs, in a few cases, causing some patients with macular edema to lose their eyesight due to lack of treatment or delayed treatment.
In the USA, the use of bevacizumab or Lucentis is controlled if the patient is on Medicare (that would be me). Medicare generally requires the use of "step therapy" to determine if the less expensive drug will work well enough before authorizing the use of the more costly alternative. The problem is the injection process has some risk of causing serious eye infection or internal damage to the eye, resulting in irreversible blindness. Needless to say, there is a lot of resistance to step therapy where vision is involved. If the patient fails to respond to bevacizumab he or she then has to undergo the treatment regimen a second time with Lucentis, with a marked increase in risk exposure.