Authors: Amir R. Vosoughi, Edward Margolin, Jonathan A. Micieli.

Disclosure Block: A.R. Vosoughi: None. E. Margolin: None. J.A. Micieli: None.

Abstract Body:

Purpose: Patients with idiopathic intracranial hypertension (IIH) may seek medical care due to symptoms of raised intracranial pressure such as headache, pulsatile tinnitus or vision changes or papilledema may be incidentally discovered during an unrelated eye examination. We aimed to compare the clinical characteristics, disease course and visual outcomes between these two groups of patients.
Study Design: Retrospective chart review of consecutive patients (May 2012 to August 2020) conducted at tertiary neuro-ophthalmology clinics at the University of Toronto.
Methods: Patients were divided into Group-1 (incidentally discovered disease) and Group-2 (patients seeking medical care due to symptoms of intracranial hypertension such as headache, pulsatile tinnitus, vision loss or diplopia).
Results: A total of 186 patients were included in the study (Group-1 n=75; Group-2 n=111). There was no difference in the proportion of females (0.98 vs. 0.94), mean age (32.0+11.6 vs. 30.7+9.5) and BMI (34.0+6.3 vs. 35.0+7.58) between groups. Group-1 patients were significantly less likely to have experienced headache (p=0.001), transient visual obscurations (TVOs; p<0.001) or diplopia (p=0.026). Group-1 patients also had better LogMAR visual acuity (0.028+0.063 vs. 0.090+0.274; p=0.001), better Humphrey mean deviation (-2.78+3.89dB vs. -4.41+5.72dB; p<0.001), and less severe papilledema as indicated by the OCT-RNFL thickness (157.4+69.2μm vs. 192.3+107.1μm; p<0.001). There was no different in the presence of an empty or partially empty sella between groups (Group-1 89.3% vs Group-2 83.8%, p=0.41). Fewer patients in Group-1 required medical treatment (19 vs. 56; p<0.001) and no patient in Group-1 required surgical treatment (0 vs. 11; p=0.004). At final follow-up, there was no difference in the proportion of patients that lost weight, but Group-1 patients were still less likely to report pulsatile tinnitus (p=0.002) and TVOs (p=0.026), but there was no different in headache (p=0.207). At final follow-up, there was no significant difference in the OCT-RNFL thickness (123.2+37.2μm vs.120.2 +53.3μm; p0.58), but Group-1 patients continued to have better LogMAR visual acuity (0.029+0.072 vs. 0.081+0.206; p0.002) and Humphrey mean deviation (-2.22+2.87dB vs. -4.30+6.74dB; p<0.001).
Conclusions: Patients with incidentally discovered papilledema attributable to IIH have better visual function, milder papilledema and experience less symptoms compared to those seeking care due to symptomatic intracranial hypertension. Only a minority of incidentally discovered IIH patients required medical treatment and surgery was not required for any of these patients. The route to diagnosis (incidental discovery compared to symptomatic presentation) is an effective way to stratify IIH patients and can help determine prognosis and length of follow-up.