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28 June 2020 | Issue #2
Cornea and Ocular Surface in Children
The Rough with the Smooth by Sam McCommon
O
ne of the subspecialty symposia on day two of the 37th World Ophthalmology Congress (WOC2020 Virtual®) focused on the cornea and ocular surface in children. Treating children comes with a unique set of circumstances that must be considered in addition to the normal treatment of a condition. Below are two highlights from the discussion.
Allergic conjunctivitis The first topic tackled was allergic conjunctivitis (AC), covered in a presentation by Prof. Yair Morad of the Sackler Faculty of Medicine at Tel Aviv University in Israel. Prof. Morad discussed a range of treatment options, from managing common to extreme conditions. The condition leads to itchy, red eyes that many are unfortunately familiar with. AC is quite common, affecting 15% to 40% of the population affected. It’s seasonally exacerbated by things like pollen, though some 25% of sufferers are affected year round. It’s more common in children with an atopic background and is also more common in males. Primary treatments can be simple: avoiding allergens like pets, carpets, or pollinating trees, for example. Cold compresses and water-based lubricants can also help reduce symptoms. But,
as Prof. Morad noted, these ‘solutions’ often fail. He humorously compared treatments like topical antihistamines, mast cell stabilizing agents like cromolyn sodium, and non-steroidal anti-inflammatory drugs (NSAIDs) like ketorolac to lousy cars, with doctors offering them to patients before offering the comparative shiny Mercedes: multiple action drugs. Why not simply offer the higher quality product to begin with? Prof. Morad instead recommended multiple action drugs like nedocromil (Tilavist), azelastine (Optilast) or olopatadine (Patanol). In acute cases, he suggested using as mild a topical steroid as possible, like metholone — not prednisolone or dexamethasone. Another safe option is loteprednol, which is relatively safe for prolonged use. However, he stressed that steroids should only be used in the case of exacerbations. Steroids cannot be used forever and even they sometimes fail — so, Dr. Morad turned to what he dubbed “wonder drugs”. He therefore recommended 1% topical cyclosporine or tacrolimus — which he said has greater immunosuppression than cyclosporine, less stinging sensation, and no side effects. In the event these drugs aren’t tolerated, systemic steroids like prednisone at 1mg/kg can be used for
Seeing their smile when they see is all worth it.
alternate day treatment. Another option is a supra-tarsal injection of equal parts triamcinolone and tacrolimus, while continuing cyclosporine or tacrolimus treatment. He noted that patients experienced dramatic relief of symptoms within 1-5 days, with little need for repeated treatments. And if the case is truly difficult? Prof. Morad advised to turn to systemic cyclosporine.
Managing keratoplasty in children Prof. Nikolas Ziakas of the Aristotle University of Thessaloniki in Greece. discussed keratoplasty surgery in children — and all the special considerations one must take into account. These considerations include pre-, intra-, and postoperative complications as well as physiological differences between children and adults. Unsurprisingly, children are less cooperative and communicative than adults, which can lead to inaccurate visual acuity measurements and imprecise examinations. Physiologically, children have low scleral rigidity, thinner and more pliable corneas, smaller anterior segment dimensions, and a higher posterior vitreous pressure. Because of the lower scleral and corneal rigidity, Prof. Ziakas recommended oversizing the graft by 0.5-1 mm, particularly in the aphakic eye. This is in conjunction with choosing a corneal diameter of 5.5-7.0 mm. He noted that it’s especially important to oversize the graft when working with thin tissue, since compression of the tissue can compromise the wound. He also highlighted using the Price graftover-host technique to maintain positive pressure during penetrating keratoplasty. Postoperatively, children and infants require more control than adults. For example, the infant cornea heals much faster than the adult one, and sutures should be removed as soon as possible. Any microabscesses or neovascularization can indicate inflammation, which can lead to graft rejection.
