Pellucid Marginal Degeneration Ectasia: A Challenging Corneal Disorder

Keratoconus is a well-known non-inflammatory, bilateral corneal ectasia characterized by gradual thinning and protrusion of the cornea. However, pellucid marginal degeneration (PMD) ectasia is another type of advanced corneal ectasia that poses significant challenges for corneal surgeons. PMD is a condition where the peripheral area of the cornea becomes thinned, leading to bulging and distortion of the cornea.

The management of early corneal ectasias is well established in literature, but the management of advanced corneal ectasias (ACEs) such as PMD remains challenging due to the lack of definitive guidelines. The aim of treatment for these cases includes improving visual acuity (VA) and providing tectonic support to the cornea.

PMD typically affects individuals in their 30s and 40s, although it can occur at any age. The condition is characterized by a gradual thinning of the peripheral cornea, leading to bulging and distortion of the cornea. PMD can cause significant visual impairment, including blurred vision, ghosting, and glare.

Surgical intervention is often necessary for PMD ectasia, as contact lenses may not be sufficient to correct the condition. Penetrating keratoplasty (PKP) was once a commonly performed surgical procedure for advanced corneal ectasias, but it has been associated with a higher risk of complications such as corneal neovascularization, graft rejection, induced astigmatism, and glaucoma.

Newer generation contact lenses may be useful in some cases of PMD ectasia, but the majority of patients require surgical intervention. Corneal surgeons must carefully evaluate each case to determine the best course of treatment for patients with PMD ectasia.

The development of newer surgical techniques over the last decade has minimized many of the limitations associated with PKP. However, PMD ectasia remains a challenging condition that requires careful consideration and expertise in its management. By providing tectonic support to the cornea and improving visual acuity, surgeons can help patients with PMD ectasia achieve improved vision and better quality of life.

Pellucid marginal degeneration ectasia