Correspondence (reply): In Reply

We thank everyone for their valuable feedback to our CME article, which—for editorial reasons—understandably explained the expansive topic only generically (1). Accordingly, we are delighted to take up our correspondents‘ suggestions and wish to add the following:

To display corneal defects, the ocular surface is stained by using 1 drop of sterile fluorescein (1 µL, 0.2%), which should be stored away from light and (if the preparation is preservative-free) in the fridge. Corneal defects appear under „room light“ in a greenish-yellow color, and if a cobalt blue filter is used, they appear green. Applying a drop into the lower conjunctival sac (ask the patient to blink) can provide valuable indications of corneal epithelial defects. Before the dye is applied, contact lenses will have to be removed; these should be replaced only after the eye surface has been rinsed thoroughly (for example, using NaCl 0.9%, 5 mL) and only after about an hour in order to prevent staining the lenses.

In patients with epiphora in the context of the dry eye syndrome, eyelid malposition of the lower lid with eversion of the lacrimal punctum or manifest ectropium should be excluded. We also always flush the lacrimal passages, for the differential diagnostic exclusion of (relative) stenosis of the tear ducts. The point about the local (and systemic) ocular side effects of steroids was well made and important. In such so called steroid responders, the pathologically raised intraocular pressure often remains undetected for a long time and can lead to blindness, owing to secondary glaucoma (2). We therefore recommend that every patient who uses local and systemic steroids for longer than two weeks should present to an ophthalmologist (independently of the dose) for an opinion.

When using topical antiglaucoma medications—especially those that contain the active substances brimonidine or latanoprost—red eye often develops „iatrogenically.“ This is important because patients often stop their treatment prematurely because they develop red eye. Preservative-free eyedrops (free from benzalkonium chloride) are certainly the better choice, independently of their effective substance. A burning red eye often develops after application of eyedrops containing ciclosporin-A; these are used in the context of therapy for severe keratoconjunctivitis sicca. As a rule, this is a self-limiting finding, which in most patients is better tolerated after the initial two weeks if additionally, overlapping treatment is given of non-preserved dexamethasone eyedrops. As with all steroid containing eyedrops, the treatment should be tapered out (for example, 4 × daily in the first week, and reducing by one drop every subsequent week).

The diagnostic evaluation and therapy of arteriovenous malformations are certainly the preserve of the ophthalmologist and neurosurgeon and should always receive attention as differential diagnoses of red eye.