A panel of international glaucoma experts has determined that age, life expectancy, intraocular pressure, central corneal thickness, cup-to-disc ratio, disc size and family history are the primary variables to consider when deciding whether to treat glaucoma suspects. This conclusion comes from a recent study designed to determine the appropriateness of treating a glaucoma suspect. The RAND/UCLA appropriateness method—a well-established procedure to synthesize scientific literature with expert opinion to resolve uncertainty on a health topic—was used to reach a consensus.

Using a systematic review of the literature on potentially important factors to consider when deciding to initiate treatment, the panel explored more than 1,800 scenarios involving glaucoma suspects. The panel formally rated the appropriateness of initiating treatment for glaucoma suspects through a two-round modified Delphi method, a technique that preserves the confidentiality of individual panelists' ratings while still allowing them to compare their own ratings with those of the entire panel. Scenarios were rated as appropriate, uncertain or inappropriate to treat according to typical prespecified statistical criteria previously used in projects using the RAND/UCLA appropriateness method. Tools were developed to help clinicians approximate the panel ratings of glaucoma suspects.

The panel rated 587 scenarios (33 percent) as appropriate, 585 (33 percent) as uncertain and 628 (35 percent) as inappropriate for treatment initiation. Analysis of variance de-termined that IOP had greater impact than any other variable on panel ratings. A point system was created with 96 percent sensitivity and 93 percent specificity for predicting panel ratings of appropriateness for a glaucoma suspect.

(Ophthalmology 2009;116:710-6)

Cheng EM, Giaconi JA, Coleman AL, Lee BL, et al.

 

PDE5 Inhibitors Safe on the Eyes

Phodiesterase type 5 (PDE5) inhibi-tors tadalafil and sildenafil that are prescribed for erectile dysfunction may not affect retinal function as once thought, suggests a recent study. The study tested tadalafil and sildenafil citrate to assess changes in electroretinography and other retinal function parameters. Subjects were randomized to use of a placebo (n=82), 5 mg of tadalafil (n=85) or 50 mg of sildenafil (n=77) daily for six months. Elec-troretinographs were recorded using the Int-ernational Society for Clinical Electro-physiology of Vision (ISCEV) protocol and standardized ERG equipment at all 15 study sites. Other tests of ocular anatomy and visual function were performed at each assessment.

The outcome was measured by observing average mean change for both eyes from baseline to endpoint in ERG b-wave amplitude using dark-adapted combined standard re-sponse to a bright ISCEV standard flash. The outcome was also measured by observing other ERG parameter changes, visual acuity, number of errors in color discrimination testing, mean deviation in automated visual field testing and intraocular pressure.

Results showed no significant differences between treatment and placebo groups for the primary outcome, most other ERG variables, visual function, IOP or anatomic assessments. The medications were well-tolerated over the prolonged time period.

(Arch Ophthalmol 2009;127:367-73)

Cordell WH, Maturi RK, Costigan TM, et al.