my personal edition > glaucoma > news


  E-Mail this DGDispatch to a colleague

DGDispatch

Prostaglandins Generally Safe for Patients With Ocular Inflammation but Caution Should Be Used: Presented at AAO

By Earl R. Nichols

NEW ORLEANS, LA -- November 13, 2007 -- Using prostaglandins to control glaucoma in patients with either uveitis or inflamed eyes appears to be safe with no increase in the number of new cases or recurrences of uveitis and apparently no reduction in the efficacy of the drug.

These conclusions were presented here November 10 in a Glaucoma Subspecialty Day presentation at the annual meeting of the American Academy of Ophthalmology (AAO). However, caution should still be exercised in prescribing these drugs and perhaps they should be reserved for patients who do not respond to other antiglaucoma medications, attendees were told.

According to presenter Simon Law, MD, Assistant Professor of Ophthalmology, Jules Stein Eye Institute, University of California at Los Angeles, Los Angeles, California, United States, prostaglandins are now the most widely used medications for treating glaucoma. However, there have been some questions as to whether they should be used in patients with various eye conditions that would affect the blood-aqueous barrier or the corneal surface. Some small case studies and retrospective studies have reported that prostaglandins could actually cause uveitis de novo. It's thought that prostaglandins could also cause a recurrence in uveitis or even lose their efficacy in patients who have ocular inflammation.

However, Dr. Law said larger studies now appear to show minimal negative reactions when prostaglandins are used in most patients. For example, a study of 527 patients using latanoprost reported that among 13 patients who had inactive uveitis, there were 3 recurrences over a 10-month period. These inflammations were described as "trace amounts" and were treated with topical steroids. The patients even able to keep using latanoprost.

A smaller case study reported that 4 out of 5 eyes among patients using latanoprost had uveitic flares but that all of these patients had multiple risk factors.

"The association between the use of prostaglandins and either a disruption of the blood-aqueous barrier or the onset of uveitis is weak," said Dr. Law. "However, these drugs should still be used cautiously in patients with active uveitis."

At the same time, he said, there are conflicting reports as to whether the use of prostaglandins will influence postoperative inflammation. Some studies have suggested that there is a disruption of the blood-aqueous barrier while other studies have been less clear. Nonetheless, he advised caution when treating such patients.

"It has been suggested that the disruption of the blood-aqueous barrier is not directly mediated by the prostaglandin use, but by the synthesis of endogenous prostaglandins and other substances triggered by the exogenous prostaglandins." The inflammation and flares could also be caused by the preservatives in the eye drops, he added, noting that benzalkonium chloride is well known to cause hyperaemia, itching, and irritation in the eyes of glaucoma patients.

There are two caveats to using prostaglandins in the eyes of glaucoma patients with any kind of inflammation. These drugs should not be used in patients who have herpetic simplex keratitis, multiple risk factors for uveitis, or who have had recent eye surgery. In the latter case, studies have suggested that the risk of complications can be fairly high.

Dr. Law added that physicians should be aware that prostaglandin use in patients with existing uveitis could have a deleterious impact on the drug's intraocular pressure (IOP)-lowering capabilities. In some cases, the drugs may become totally ineffective.

"The IOP dynamic in an inflamed eye may involve the interaction of a number of altered pressure regulatory mechanisms. Although prostaglandins are effective in controlling IOP in general, their efficacy in eyes with active uveitis may be unpredictable," he said.

Physicians may want to exercise caution in prescribing prostaglandins for most patients with inflamed eyes and perhaps prostaglandin use should be reserved for patients who do not respond to other topical ocular hypotensive drugs or those who are not good candidates for IOP-lowering surgery.


[Presentation title: Use of Prostaglandin Analogues in an Inflamed Eye]

E-Mail this DGDispatch to a colleague

To print, use this version