Glaucoma Drugs

I can be dense, but I have learned a few lessons in this life. One is the saying, "Where there is smoke, there is fire" is generally true.

The acetazolamide case study discusses a drug which was effective in RP with CME and traditionally used to treat glaucoma. I remembered the drug Dr. Nolan is using to treat retinal disease is also one which was used in the past to treat glaucoma.

I was curious to see if acetazolamide and the echothiophate, used by Dr. Nolan, were in the same category. I have read the drops used by Dr. Nolan are no longer manufactured. It would be beneficial if there was another drug which worked equally as well that is available.

Below is a link to an article on drugs used for glaucoma.

http://www.eyesurgeryeducation.com/Glaucoma_prescribed.html


The acetazolamide case study I link to discusses the positive results of a patient with macular edema and RP who used acetazolamide long term. Below is another study which was larger, double blind and focused on people with RP who did not have macular edema.

However, it was limited to eight weeks. The case study highlighted a patient treated for twenty four weeks, The dosing in the double blind study was also limited to 500 mg/ day. The patient in the case study who had impressive gains was taking 1000 mg/day. The results are not nearly as encouraging in the eight week study in which the patients only took 500 mg/ daily. However, for the three people who made "significant peripheral field" gains it does not matter.

I think three out of 13 people experiencing "significant gains in peripheral field" while none of the placebo group experienced gains IS worthy of further investigation, particularly in light of the success of the twenty four week case study.

The shorter term success of the three patients in the eight week double blind brings up some interesting questions: Were they all at a cetain level of degeneration? What other systemic issues did they have in common? Were there any similarities in lifestyle choices? Did they all have the same type of RP? Were they of the same gender? Now that Dr. Stone at the University of Iowa has a genetic testing lab, it would be interesting to see if these three individuals had the same genetic mutation.

The conclusion portion of this article the authors state: Given the results and the reports of side-effects, it is difficult to justify using acetazolamide to improve retinal function in RP patients who show no evidence of cystoid macular edema.

How can you make this conclusion when you did not follow the full protocol established in the case study? How about presenting information to patients along with full disclosure and let us decide? Retinal specialists did that with potentially toxic levels of Vitamin A Palmitate which never showed an increase in anyone's peripheral fields, only a slowing of the disease sometimes.

I also shudder to think the authors of the double blind were actually trying to replicate the excellent work done in the case study. Maybe they were unaware of the case study and did not do a thorough review of research prior to starting their study. Why do I criticize so harshly?

Because practicing physicians only have time to read abstracts, if that. Many people in the research community only read abstracts. We are talking about people's vision, not just lab rats. If the pressure to publish leads you to do less than your best, then go research something else, like the mating habits of the duck-billed platypus. I am sure there is funding for that.

http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_uids=8425835&dopt=AbstractPlus