Ans. A: Corneal dystrophyEpithelial and subepithelial corneal dystrophies may present with bouts of recurrent corneal erosions Bowman layer corneal dystrophy usually presents with recurrent corneal erosionsRecurrent corneal erosionIt is characterized by the failure of the cornea's outermost layer of epithelial cells to attach to the underlying basement membrane (Bowman's layer).The condition is excruciatingly painful because the loss of these cells results in the exposure of sensitive corneal nerves.There is often a history of previous corneal injury (corneal abrasion or ulcer), but also may be due to corneal dystrophy or corneal disease.In other words, one may suffer from corneal erosions as a result of another disorder, such as map dot fingerprint diseasePresentationSymptom include recurring attacks of severe acute ocular pain, foreign-body sensation, photophobia (i.e. sensitivity to bright lights), and tearing often at the time of awakening or during sleep when the eyelids are rubbed or opened.Signs of the condition include corneal abrasion or localized roughening of the corneal epithelium, sometimes with map-like lines, epithelial dots or microcyts, or fingerprint patternsInvestigationThe erosion may be seen by using the magnification of an ophthalmoscope, although usually fluorescein stain must be applied first and a blue-light used.Use of slit lamp microscopes allow for more thorough evaluation under the higher magnification.ManagementWith the eye generally profusely watering, the type of tears being produced have little adhesive propey.Water or saline eye drops tend therefore to be ineffective.Rather a 'better quality' of tear is required with higher 'wetting ability' (i.e. greater amount of glycoproteins) and so aificial tears (e.g. viscotears) are applied frequently.Where episodes frequently occur, or there is an underlying disorder, one medical, or three types of surgical curative procedures may be attempted:Use of therapeutic contact lens, controlled puncturing of the surface layer of the eye (Anterior Stromal Puncture) and laser phototherapeutic keratectomy (PTK).These all essentially try to allow the surface epithelium to reestablish with normal binding to the underlying basement membraneMedicalPatients with recalcitrant recurrent corneal erosions often show increased levels of matrix metalloproteinase (MMP) enzymes.These enzymes dissolve the basement membrane and fibrils of the hemidesmosomes, which can lead to the separation of the epithelial layer.Treatment with oral tetracycline antibiotics (such as doxycycline or oxytetracycline) together with a topical coicosteroid (such as prednisolone), reduce MMP activity and may rapidly resolve and prevent fuher episodes in cases unresponsive to conventional therapies.