Paediatric Keratoconus

Paediatric conditions often possess distinct clinical characteristics that differentiate them from their adult variants. Keratoconus is one such condition, and its initial diagnosis can be difficult for clinicians.

“Paediatric keratoconus is often a more advanced disease at diagnosis, often with a higher frequency of acute corneal oedema, [which] may lead to the risk of amblyopia. This type of patient frequently requires a multidisciplinary approach to treatment due to a strong association with other atopic allergic conditions,” said David Alves Berhanu MD, PhD.

“Between 7% and 10% of these patients require penetrating keratoplasty (PK) or deep anterior lamellar keratoplasty for treatment. This entails surgical challenges, both intraoperatively [due to] a less rigid sclera and the difficulty of trepanation and suturing, and postoperatively due to difficulty in follow-up and suture management.”

Dr Berhanu wanted to examine the efficacy of using PK for paediatric keratoconus patients, so he set up a retrospective observational study on a group of paediatric patients undergoing PK treatment for keratoconus. The study sought to determine the best-corrected visual acuity (BCVA) outcomes and assess changes in tomography data and surgical outcomes over a minimum follow-up of 12 months.

Twenty eyes of 17 patients affected by paediatric keratoconus were surveyed in the study, with only one patient having undergone previous ocular surgery. The review covered 21 PK procedures, including 15 due to advanced or severe disease, 5 due to acute corneal hydrops, and 1 due to previous graft failure.

“Sixty per cent of the eyes were classified as stage 4 using the severity classification, and a quarter of the patients had experienced prior episodes of acute corneal oedema. Regarding surgical technique, the donor corneal spiral graft was oversized by about 0.25 mm, and the most frequently trephine size used was 7.00 mm,” Dr Berhanu said.

He reported that BCVA improved significantly across the studied cohort, from 1.1 to 0.1 logMAR. Regarding the tomographic data and visual and surgical outcomes, there was a marked preoperative corneal thinning, with a mean thinnest pachymetry of 332 μm that significantly increased to 521 μm postoperatively.

Overall, the results showed PK as a highly effective treatment, Dr Berhanu said, with a clear reduction and flattening of the corneal curvature. With improved anterior and posterior curvature parameters, and a decrease in anterior astigmatism, this technique can be used effectively to treat paediatric patients, he believes.

“We can say that paediatric keratoconus requiring PK presents normally at advanced stages with severe ectasia and, in some cases, episodes of acute corneal hydrops. PK provides both favourable anatomical and functional outcomes in the short and medium term,” Dr Berhanu said.

“PK appears to be a safe and effective measure, with minimal complication rates and favourable graft survival in the mid-term, especially to the five-year mark. In our cohort of patients, only one required repeated keratoplasty.”

Dr Berhanu presented at the EuCornea annual congress in Porto, Portugal.

David Alves Berhanu MD, PhD is a neuroradiology specialist at North Lisbon University Hospital Centre/Hospital de Santa Maria in Portugal.