Alan N. Carlson, M.D. from the Duke Eye Center reminds us that Drs. Donald Korb and Anthony Bron have very astutely pointed out that anterior and posterior blepharitis, over time become less distinguishable from each other. What may be more important is our ability to recognize that they are seldom isolated and instead give us a mixed pattern or combination contributing to a “dry eye” with MGD leading to a significant “evaporative” component of the resulting dryness.
With respect to chronicity, the patient’s eyelid thickness, contour, vasculature, lash loss, foamy tear film are all findings that I associate with the combination of severity and chronicity.
Also, reprinting the following commentary on evaluating patients for chronic vs acute blepharitis:
Blepharitis can present as either chronic or acute. Chronic cases often are managed with oral tetracyclines and anti-inflammatory agents, while acute blepharitis typically is treated with antibiotics.
Here are several identifying characteristics that will help you differentiate between chronic or acute blepharitis:
· Look for the presence of eyelid margin thickening. Typically, significant eyelid thickening occurs over a lenghty period of time, and is indicative of chronic blepharitis.
· Telangiectasia (prominant blood vessels on the eyelids) and posteriorly located meibomian glands are suggestive of chronic blepharitis. Furthermore, atrophy of the meibomian glands would be another indicator of chronic disease.
Finally, the location of the debris and collatettes indicate disease duration in cases of anterior blepharitis. For example, it takes approximately 12 weeks for lashes to grow, and can take as long as nine months for complete growth in some cases. So, if the debris and collatettes are located at the tip of the lashes as well as at the base, the condition likely has persisted for a while. If, however, the debris or collarettes are located only at the base, the patient likely has acute blepharitis