The transepithelial riboflavin solution should contain no dextran, but it should include 0.01% BAC and 0.44% NaCl to promote the permeability of riboflavin through the epithelium, resulting in a sufficient concentration of riboflavin in the corneal stroma.

We appreciate having another chance to point out that corneal CXL is a clinical procedure with complications and failures, and we are grateful that Kymionis et al. drew attention to more infrequent complications that were not mentioned in our discussion.We fully agree that an impact on the cornea such as CXL may initiate a recurrence of herpes keratitis and in cases with an ocular herpes history, systemic antimetabolite therapy is clearly indicated. Stimulation of an inflammatory reaction such as diffuse lamellar keratitis after LASIK by CXL is also not a surprising side effect, and we agree that topical steroids should precede CXL in cases of iatrogenic keratectasia.Please keep in mind: CXL is a technically easy procedure but represents a significant impact on the eye treated.dTobias Koller, MD, Theo Seiler, MD, PhD LETTERS

No abstract

No abstract

Which pathogenic mechanisms underlie age-related macular degeneration (AMD)? Are they different for dry and wet variants, or do they stem from common metabolic alterations? Where shall we look for altered metabolism? Is it the inner choroid, or is it rather the choroid–retinal border? Again, since cell-clearing pathways are crucial to degrade altered proteins, which metabolic system is likely to be the most implicated, and in which cell type? Here we describe the unique clearing activity of the retinal pigment epithelium (RPE) and the relevant role of its autophagy machinery in removing altered debris, thus centering the RPE in the pathogenesis of AMD. The cell-clearing systems within the RPE may act as a kernel to regulate the redox homeostasis and the traffic of multiple proteins and organelles toward either the choroid border or the outer segments of photoreceptors. This is expected to cope with the polarity of various domains within RPE cells, with each one owning a specific metabolic activity. A defective clearance machinery may trigger unconventional solutions to avoid intracellular substrates’ accumulation through unconventional secretions. These components may be deposited between the RPE and Bruch’s membrane, thus generating the drusen, which remains the classic hallmark of AMD. These deposits may rather represent a witness of an abnormal RPE metabolism than a real pathogenic component. The empowerment of cell clearance, antioxidant, anti-inflammatory, and anti-angiogenic activity of the RPE by specific phytochemicals is here discussed.