Keratoplasty in children

[caption id="attachment_11722" align="alignleft" width="1024"] Figure 1a: Failed graft following rejection in a child with congenital hereditary endothelial dystrophy;
Figure 1b: One year following DSAEK, the cornea is clear with a well apposed lenticule and compact clear overlying donor cornea[/caption] The overall success rate of keratoplasty in children ranges widely, from 40% to 90% in different studies. The numbers are influenced by many pathological variables, and the influence of new procedures remains unclear, according to Merle Fernandes MD, Director, LV Prasad Eye Institute (LVPEI), Visakhapatnam, India. Dr Fernandes discussed the outcomes of paediatric keratoplasty in a session of the World Congress of Paediatric Ophthalmology and Strabismus 2017 in Hyderabad, India. The wide variety of outcomes of paediatric keratoplasty can be attributed to the fact that the child’s eye and the pathology that affects it are both different from that in adults. Indications for transplantation in a child are many and range from congenital causes to acquired, such as those secondary to trauma, infection or keratoconus. Depending on the pathology, some of these cases require endothelial keratoplasty, others require deep anterior lamellar keratoplasty and yet others, penetrating keratoplasty. Advantages of anterior lamellar keratoplasty such as operating as a closed chamber procedure, lesser risk of rejection, retention of the precious host endothelial cells and greater graft survival that adult patients enjoy are also applicable in case of children, she said. Advantages of endothelial keratoplasty include the transplantation of lesser volumes of antigenic tissue, less risk of rejection, the use of softer steroids, lesser astigmatism and lesser surface- and suture-related problems. “Though changing trends reflecting the general changes seen in adult keratoplasties are also being seen in paediatric keratoplasties, paediatric data is not yet as clear as the adult data. Surgery requires greater skills, and problems such as management of amblyopia and difficulty in examination still persist after surgery,” Dr Fernandes cautioned. Citing results from an LVPEI Hyderabad study, she reported that more than 62% patients had greater than 20/80 vision following deep anterior lamellar corneal surgery. Common indications for anterior lamellar keratoplasty in children included keratoconus and trauma with scarring. Complications included Descemet’s membrane detachments, graft-host junction dehiscence and infections. She also showed an example of how epikeratoplasty could be done by tucking in a donor corneo-scleral rim 360 degrees into a scleral pocket following alcohol epitheliectomy, for a case of keratoglobus with pachymetry of 90 microns in the thinnest area. One of the indications for endothelial keratoplasty is a failed graft, especially following therapeutic keratoplasty, which often tend to be larger grafts. Poor visibility is a challenge in these cases and an endoilluminator helps in improving visualisation. Sharing her experience with Descemet’s stripping endothelial keratoplasty with the push-through technique in these cases, Dr Fernandes said that it was important to ascertain absence of interface fluid. Either good tamponade with a tight air bubble for 10 minutes or a longer tamponade followed by burping some air after one hour were choices. The latter though, had the disadvantage of requiring much longer anaesthesia. Merle Fernandes: merle@lvpei.org

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