Patient right profile
Mr. U.N is a 42-year-old male with Down Syndrome, but no known family history of keratoconus. He complained of a progressive decrease in visual acuity in both eyes.
His refraction at the first visit at the Rothschild Foundation (on 06/08th/2017) was : Right Eye (RE) 20/80 with -6.0 (-4.5 x 80 °) and Left Eye (LE) 20/80 with -7 (-4.75 x 125 °).
Clinical examination with the slit lamp suggested thin and irregular corneas with Fleischer rings in both eyes. Fleischer rings are pigmented rings in the peripheral cornea, resulting from iron deposition in basal epithelial cells, in the form of hemosiderin. Blepharitis and an unstable tear film were noted bilaterally, with a tear film breakup time (TFBUT) of < 8 secs.
Corneal topography performed at our institution showed the presence of bilateral keratoconus.
He was accompanied by his mother at the first consultation. When asked about the possibility of frequent eye rubbing, the patient admitted to rubbing his eyes when he awoke in the mornings and when working in front of the computer. Eye rubbing gave him a sense of calm and relief. His mom told us that that she would often find his glasses malpositioned on his face as he would push the glasses aside to rub his eyes. They had to replace the glasses frequently as the spectacle frame was often found to be distorted and damaged from the motions involved in eye rubbing (see pictures below).
He is right handed and sleeps on his stomach.
We explained to the patient and his mom that since vigorous rubbing had preceded the drop in visual acuity, this habit may have caused the cornea to deform, leading to the classic clinical presentation of keratoconus in his case.
At the subsequent visits, his mother informed us that despite being warned of the dangers of eye rubbing, the patient had difficulty abstaining, as he derived a certain pleasure from rubbing his eyes.
We once again reiterated the dangers of eye rubbing and strongly encouraged this patient to consciously stop rubbing his eyes.
Here are pictures of the patient rubbing his eyes and his profiles
Fortunately, we were able to capture a few difference maps at the subsequent visits. Some of them may be difficult to interpret as the patient was unco-operative at times.
Unfortunately, progression of the keratoconus was observed as the patient had great difficulty refraining from rubbing his eyes.
Certain eye diseases are more frequently associated with Down syndrome (trisomy 21) than the rest of the population. Recently a study conducted in the United Kingdom showed that 70% of children with Down Syndrome have astigmatism, and 50% have blepharitis responsible for ocular pruritus and eye rubbing, which in turn induces keratoconus.
Keratoconus affects 2-3 persons per 1000 in the general population but 5 to 15% of individuals with trisomy 21. Unfortunately in Down Syndrome patients, keratoconus is often discovered during childhood or teenagehood at an advanced stage. Communication with these patients is sometimes difficult, and it is often assumed by the attending optometrist or ophthalmologist that a documented poor best corrected visual acuity is due to diminished patient co-operation, when in reality it is an underlying ocular pathology like keratoconus that is causing the visual blurring.
Keratoconus Awareness among the Down Syndrome population and their families needs to be increased and supported by the medical community and its affiliations, so that screening is implemented more systematically. Apart from early detection, it is also very important to treat other associated ocular surface pathologies like blepharitis and allergic conjunctivitis, both of which are responsible for eye rubbing and therefore the evolution of keratoconus.
This interesting case illustrates that the progression of keratoconus is directly related to the persistence of eye rubbing. Unlike the other cases in this website where the patients are able to refrain from rubbing their eyes, it is difficult to enforce this in individuals with behavioural disorders (eg trisomy 21, autism). Stabilization of keratoconus is therefore most challenging in these cases.
Corneal collagen cross-linking in such cases would be associated with a higher risk of post-operative infection, and as long as the patient continues to rub his eyes, it is highly unlikely to arrest the progression of keratoconus.
Visual rehabilitation is also difficult. Patients with Down Syndrome are poor candidates for rigid gas permeable or scleral lens adaptation. If corneal transplantation is indicated, a partial thickness graft (deep lamellar keratoplasty) would be preferred, as they would be at high risk of wound dehiscence, suture loosening and other issues if an intraocular procedure like a full-thickness graft (penetrating keratoplasty) is performed.
Other cases :
- Date 14 janvier 2018
- Tags Bilateral keratoconus, Computer screen, Down's Syndrome, Dry eyes, Enjoyed eye rubbing, Eye rubbing, Inferior keratoconus, Male, Offset glasses, Progression, Witness, Work rubbing