Can optic disc vessel density help in cases of residual disc elevation after shunt surgery in cases of idiopathic intracranial hypertension?

AIM: To detect if we can use the reduction in the optic disc vessel density as an indicator to the reduction in intracranial tension in patients with residual optic disc elevation after shunt surgery as fundus examination in those cases is not conclusive. PATIENTS AND METHOD: 21 patients with papilledema due to idiopathic intracranial hypertension underwent shunt surgery. Full neurological and ophthalmological assessments were done. The optic disc vessel density was measured before and 3 months after surgery. Patients were then divided according to the resolution of papilledema into 2 groups: 1) Residual disc elevation group. 2) Completely resolved disc edema group. CSF pressure was measured via lumber puncture preoperative for all patients and 3 months post-operative only for patients with residual disc edema. A comparison between both groups was done. RESULTS: There was a highly statistically significant difference between the two groups as regard the papilledema grade (the residual disc elevation group had a higher grade of papilledema) with P-value=0.000. As regard the difference in the preoperative optic disc vessel density between the two groups, there were statistically significant differences (optic disc vessel density was more in the residual disc elevation group). As regard the postoperative optic disc vessel density, there were non-significant differences between the two groups in whole image, inside disc and peripapillary vessel density (either in macro or microvasculature). CONCLUSION: The optic disc vessel density decreased with normal postoperative CSF opening pressure in cases with residual disc elevation postoperatively. Thus, in cases of residual optic disc swelling after shunt surgery, we can detect the reduction of intracranial pressure by the reduction in the optic disc vessel density which is a safe non-invasive technique. That may help in cases of residual disc elevation.

Optic disc vessel density changes after shunt surgery in idiopathic intracranial hypertension.

AIM: To detect the change in optic disc vessel density in patients with idiopathic intracranial hypertension (IIH) after shunt surgery. PATIENTS AND METHOD: Twenty-one patients with IIH underwent shunt surgery. Patients were subjected to full ophthalmic and neurological examinations. Optic disc vessel density was measured using optical coherence tomography angiography (OCT-A) before and two months after surgery. RESULTS: The age of patients ranged from 27 to 48 years old, with a mean of (34.85 ± 6.87). Visual acuity ranged between 0.2 and 0.9 by log Mar, with a mean of (0.64±o.20). The mean deviation (MD) of the perimeter ranged from -22.9 to 0 dB, with a mean of (-9.77 ± 7.23 dB). With respect to the grade of papilledema, 15 eyes (35.7%) were of grade II, 21 eyes (50.0%) were of grade III, and 6 eyes (14.3%) were grade IV. Intracranial pressure measured by lumbar puncture (LP) prior to surgery ranged from 30 to 40 cm, with a mean of 35.43 cm. Except for right transverse sinus hypoplasia in 6 patients (28.6%), MRV was normal. In 15 patients (71.4%), lumboperitoneal shunt was performed, while ventriculoperitoneal shunt was performed in 6 patients (28.6%). After surgery, the optical disc vessel density was decreased in all patients. This decrease was highly significant for the whole image, the inner disc, the peripapillary, superior, and inferior hemispheres. Moreover, this reduction affected both optic disc microvasculature (referred to as capillary vessel density) and macro vasculature (also known as all vessel density). There were positive correlations between the CSF opening pressures and the preoperative optic disc vessel density of the whole image and inside disc with a P-value (0.002, 0.009), respectively. In addition, there was a positive correlation between the opening CSF pressures and the reduction in whole image vessel density after surgery with a P-value of 0.000. CONCLUSION: Optic disc vessel density decreased after shunt surgery in patients with IIH. Consequently, optic disc vessel density can be used as a biomarker for the reduction of CSF opening pressure.