by Christina Twardowski , OD, FAAO
Pediatric keratoconus exhibits several unique characteristics that can make an otherwise difficult situation even more complex.
Children who develop keratoconus tend to start the corneal ectasia process at an early age, with faster progression compared to adult patients. The frequent eye rubbing in children is exacerbated by inflammatory conditions such as vernal keratoconjunctivitis, leading to a higher rate of rubbing and progression. In addition, when children are confirmed as having keratoconus they tend to be in a more advanced stage of the disease, which may, in part, be due to the difficulty of initially diagnosing this patient population.
Difficulties in confirming the presence of childhood keratoconus are often due to the inability of obtaining subjective data. Cooperation in this age group can be challenging at times, but looking at the overall clinical picture is crucial. Although verbal vision can be helpful, it is only one piece of the puzzle.
Working in a children’s hospital, I have many patients who come to the clinic for second opinions. Whenever keratoconus is suspected the first tool I reach for is my retinoscope. Retinoscopy is easy to do, can be performed at a comfortable distance to alleviate potential patient anxiety and is quite reliable in its diagnostic capabilities.
A recent study in Cornea compared the results of retinoscopy and Pentacam (Oculus) examinations on patients referred for questionable keratoconus diagnosis (Al-Mahrouqi et al.). The authors concluded that the retinoscopy results showed great specificity and sensitivity in confirming the diagnosis of keratoconus when compared to positive keratoconus identification with Pentacam imaging.
A simple case example to show the importance of interpreting a patient’s global clinical findings is a 10-year-old boy who came to my clinic for a second opinion due to a failed vision screening. The three tests I attempt on all suspected keratoconus patients are retinoscopy, slit lamp examination and topography. For this patient the retinoscopy reflex was abnormal, and the slit lamp exam confirmed the presence of a Fleischer ring in both corneas.