Corneal NV and lipid deposition may recur after ceasing the subconjunctival bevacizumab injections for lipid keratopathy. Some patients respond at least partially to repeated injections.

Purpose: To summarize the Integrated Stress Response (ISR) in the context of ophthalmology, with special interest on the cornea and anterior segment. Results: The ISR is a powerful and conserved signaling pathway that allows for cells to respond to a diverse array of both intracellular and extracellular stressors. The pathway is classically responsible for coordination of the cellular response to amino acid starvation, ultraviolet light, heme dysregulation, viral infection, and unfolded protein. Under normal circumstances, it is considered pro-survival and a necessary mechanism through which protein translation is controlled. However, in cases of severe or prolonged stress the pathway can promote apoptosis, and loss of normal cellular phenotype. The activation of this pathway culminates in the global inhibition of cap-dependent protein translation and the canonical expression of the activating transcription factor 4 (ATF4). Conclusion:The eye is uniquely exposed to ISR responsive stressors due to its environmental exposure and relative isolation from the circulatory system which are necessary for its function. We will discuss how this pathway is critical for the proper function of the tissue, its role in development, as well as how targeting of the pathway could alleviate key aspects of diverse ophthalmic diseases.

Background/aimsTo evaluate the utility rate, indication, outcome, and cost of refrigeration and glycerol cryopreservation for storing anterior corneal buttons during endothelial keratoplasty for subsequent use in tectonic lamellar patch grafting.MethodAnterior corneal buttons collected after precutting or prestripping during endothelial keratoplasty from January 2014 to December 2019 were preserved using the following protocol: (1) refrigeration for up to 4 weeks at 4°C in Optisol-GS and (2) glycerol cryopreservation for up to 2 years. The utility rate, outcome and cost of these cryopreserved anterior corneal buttons were retrospectively examined.ResultsDuring the 6-year study period, 26 anterior corneal buttons were refrigerated and 49 were cryopreserved for extended use. The utility rates for the refrigerated and cryopreserved anterior corneal buttons were 69.2% and 73.5%, respectively. Their average preservation periods were 0.53±0.05 and 12.76±0.94 months, respectively. Noninfection-related perforation was the leading indication for using the extendedly preserved anterior corneal buttons. The average postoperative follow-up periods were 10.03±2.91 and 14.35±2.17 months for refrigerated and cryopreserved anterior corneal buttons. Secondary keratoplasty was required by 7 of 18 (38.9%) and 6 of 36 (16.7%) patients receiving refrigerated and cryopreserved anterior corneal buttons, respectively. None of our patients developed graft infection from donor tissues.ConclusionCryopreservation can safely extend the utility of anterior corneal buttons. This method not only reduced the wastage of the limited donor tissue but also was cost-effective.