Macugen to Prevent Worsening of Macular Edema Following Cataract Surgery in Diabetics
Macugen to Prevent Worsening of Macular Edema Following Cataract Surgery in Diabetics
This research is being conducted to look at the effects of an intraocular drug (pegaptanib,
 also called Macugen) for the treatment of swelling in the retina (the light sensitive tissue
 in the back of the eye) that often occurs following cataract surgery in patients with
 diabetic eye disease. Swelling in the retina can lead to blurry vision, and Macugen may
 reduce this swelling. Eyedrops that decrease inflammation also may help to stop some of the
 swelling. We are testing this drug (pegaptanib) to see if it can decrease swelling in the
 retina and improve vision in patients with diabetes who are having cataract surgery.
Macular edema occurs as a complication of cataract surgery in approximately 2% of all
 surgeries. In this condition, cystic, fluid-filled spaces develop in the outer plexiform
 layer of the retina resulting in a loss of vision. This condition is termed "Cystoid Macular
 Edema (CME)." In non-diabetics, the majority of such cases resolve spontaneously.

 Diabetic macular edema (DME) is an important cause of visual disability among patients with
 diabetes. It is widely recognized that cataract surgery often triggers severe CME in patients
 with pre-existing DME. This exacerbation begins immediately following cataract surgery; and
 unlike in non-diabetics the edema is likely to be protracted and poorly responsive both to
 traditional treatments for CME (topical NSAIDS) and DME (laser photocoagulation). Fluorescein
 angiography, a photographic test that evaluates the blood circulation in the back of the eye,
 has demonstrated that both CME and DME are associated with increased permeability of retinal
 blood vessels.

 The high rates and severity of post-cataract surgery CME in diabetic patients with DME render
 this population ideal for the study of potential agents to reduce the rate and severity of
 this condition (i.e., post-cataract surgery CME). Recent studies have shown that vascular
 endothelial growth factor (VEGF) plays a major role in vessel permeability. Pegaptanib
 (Macugen) is an FDA-approved drug for wet AMD. Pegaptanib is a selective VEGF antagonist that
 blocks the effects of VEGF; therefore pegaptanib might decrease vessel permeability and
 possibly decrease the incidence and severity of CME. We plan to conduct a controlled pilot
 study to investigate the effects of pegaptanib (up to 3 treatments of pegaptanib given prior
 to cataract surgery and as often as every 6 weeks for up to 12 weeks after cataract surgery)
 in diabetic patients with pre-existing DME who are undergoing cataract surgery and who are,
 therefore, at very high risk for development of CME. Should the pilot study indicate a
 potential benefit of pegaptanib in this setting, a larger, fully powered clinical trial will
 be proposed. An effective treatment or preventive measure for post-cataract surgery macular
 edema in patients with diabetic retinopathy would offer benefit to a large patient population
 nationally that is at high risk of vision loss.
Inclusion Criteria:

 -  Adults (ages 18 years or older) with diabetes mellitus

 -  Best corrected visual acuity worse than 20/40 but no worse than 20/800 in the study
 eye

 -  Best corrected visual acuity better than or equal to 20/800 in the fellow eye

 -  DME in the study eye (eye scheduled to undergo cataract surgery) as documented on OCT
 as a center point thickness of at least 250 microns no more than 3 weeks prior to
 cataract surgery

 -  No prior laser photocoagulation in the study eye for at least 4 months prior to
 cataract surgery

 -  Women of child-bearing potential who are interested in participating in this study
 will use two effective forms of contraception prior to initiation of pegaptanib and
 then throughout the remainder of the study. For women of childbearing potential,
 results from a urine pregnancy test will be obtained prior to each injection with
 pegaptanib. Urine samples will be disposed of after the test is performed.

 Exclusion Criteria:

 -  History of intravitreal steroid (triamcinolone) injection into the study eye within 4
 months prior to cataract surgery

 -  Macular edema due to non-diabetic etiologies such as vein occlusion

 -  Retinal diseases that preclude evaluation of the macula for edema (e.g., macular hole)

 -  Media opacity will not be an exclusion criterion provided that the investigator can
 assess the presence or absence of DME on OCT