In an era when patients spend hours on end with their eyes bathed in blue light, reading the news on handheld screens and binge-watching streaming videos from their laptops, are optometrists doing enough to monitor for convergence insufficiency? That’s what one group of researchers out of Wills Eye Hospital in Philadelphia is asking. According to a recently published piece in Current Opinion in Ophthalmology, the reason they’re asking this now is twofold: (1) as we’re so frequently engaged in near vision activities, conditions that adversely affect it now have a profound impact on quality of life; and (2) the use of electronic devices themselves may have an impact on the conditions’ development.
While optometrists may have little say in how patients use devices, they can evaluate whether their screening techniques are up to date. Take, for instance, convergence insufficiency. While up to 17.6% of school-aged children may have some form of it, not all optometrists routinely screen for it, according to the authors.
“One of the problems in the recognition and diagnosis of convergence insufficiency is that the criteria for the diagnosis and the methods of examination vary in the literature and in practice,” the report reads, “As a result, some patients may be misdiagnosed, receive a delayed diagnosis or not be diagnosed at all and continue to suffer with their symptoms.” Patients with conditions such as traumatic brain injuries have an even higher likelihood (49%) of convergence insufficiencies.
Even if practitioners do screen for convergence insufficiency, the most sensitive methods are not always employed. In fact, since near-point convergence (NPC) measurements are not even standardized, practitioners often use “different targets, accept different measurements, perform it under different conditions and some repeat it multiple times,” the report says. The authors advocate for NPC testing to be performed on all patients, even those without any reported symptoms, and for the measurements to be standardized. It should be performed “with an accommodative target, the smallest letter or picture that the patient can focus on. If the break is more than 5 cm or recovery is more than 7 cm, then additional testing for convergence insufficiency is warranted,” the writers explain.
The report was less enthusiastic about the use of another screening tool, the 15-question Convergence Insufficiency Symptom Survey (CISS). The authors point to research showing that “in a prospective randomized trial, the CISS was found to be nonspecific for convergence insufficiency and another study found that the scores varied based on the type of near visual activity.”
|Trieu L, Lavrich J. Current concepts in convergence insufficiency. Curr Opin Ophthalmol. 2018;29(5):401-6.|