Register / Log In

Signs of pellucid marginal degeneration should rule out refractive surgery


Pellucid marginal degeneration is a subtle condition that could lead to corneal ectasia following laser eye surgery. Although it is atypical and rare, clinicians should learn how to identify pellucid and screen patients for it preoperatively, said Yaron S. Rabinowitz, MD, director of ophthalmology research, Cedars Sinai Medical Center, Los Angeles.

.

In pellucid marginal degeneration, corneal thinning typically occurs from the 4 to the 8 o'clock position approximately 1 mm from the inferior limbus. Another difference between pellucid marginal degeneration and keratoconus is that the onset of pellucid tends to be in the 30s, rather than around the time of puberty.

The key to recognizing early cases of pellucid is topography, Dr. Rabinowitz said. Patients may appear clinically normal and have normal pachymetry, if it is performed centrally or paracentrally. However, since the cornea typically gets thicker from the center to the periphery, clinicians should be suspicious if there is little difference between the central and inferior pachymetry.

The presence of "crab claw" topography will indicate pellucid, but in early cases what will more likely be seen is inferior flattening characterized by an isolated inferior blue spot. Patients with either sign should be considered pellucid suspects and poor candidates for refractive surgery, Dr. Rabinowitz said.

Short-term results show that bevacizumab (Avastin, Genentech) seems to be safe and effective for neovascular age-related macular degeneration (AMD), reported Philip Rosenfeld, MD, PhD, during Retina Subspecialty Day.

Ranibizumab (Lucentis, Genentech) for treatment of neovascular age-related macular degeneration (AMD) was shown to prevent moderate vision loss over 24 months and to result in improved vision in some patients in the MARINA Study, according to Joan Miller, MD, who reported the results during Retina Subspecialty Day.

Welcome to Ophthalmology Times E-News, which will provide daily coverage of the 2006 joint meeting of the American Academy of Ophthalmology (AAO) with the Asia-Pacific Academy of Ophthalmology (APAO), Nov. 11 to 14 in Las Vegas at the Sands Expo/Venetian Hotel.

In 1962, James D. Watson, PhD, along with Francis Crick, PhD, won the Nobel Prize in Physiology or Medicine for scientific research that led to the proposal of the complementary double-helical configuration. Their research efforts meant solving the structure of DNA.

Although almost half of all patients who undergo LASIK report dry eye symptoms, there is no real evidence that the refractive procedure causes chronic dry eye, according to James P. McCulley, MD, FACS, UT Southwestern Medical Center, Fort Worth.


peds cover april.jpg
 
Stay Connected