Add this one to your list of differential diagnoses. A 10 year old boy whose reading teacher refers him because he’s constantly rubbing his eyes. Though he may occasionally do it at other times, it’s quite striking when he’s reading. You examine him and note that he appears to have a touch of AI and CI. So you Rx a low power bifocal together with low power base-in prism, and ask to see him back in three months.
His mother casually mentions that he has some eczema mostly on his knees, for which his pediatrician gave him ointment that doesn’t really seem to be helping. The child develops pain in his feet so severe that he can barely walk. Mom takes him to consult with an orthopedist who takes a look at his knee and says: “That doesn’t look like eczema to me. Let’s do a blood workup, because I don’t see anything wrong with his feet”. The blood workup comes back positive for high levels of inflammation, so he’s referred to a pediatric rheumatologist who makes the formal diagnosis of psoriatic arthritis. In the office this evening he rolled up his pants leg to reveal this:
The rheumatologist has started him on Motrin twice daily. He’s still rubbing his eyes, so we switched gears and dispensed artificial tears even though conventional dry eye testing didn’t reveal much. Why was he rubbing his eyes particularly when reading? When you concentrate on the reading task, your blink rate goes down, exacerbating a marginally dry eye resulting in rubbing to generate reflex tearing. Might the AI/CI be impacted by the psoriatic arthritis? Omega 3s wouldn’t hurt.
This may be a classic case of the eye’s involvement as a specialized joint adapted for sight.