Systematic review and risk factor analysis of post-vitrectomy silicone oil migration to the central nervous system

Table 1 Inclusion and exclusion criteria of this systematic review

Criteria
Inclusion criteria	Publications on silicone oil migration to central nervous system
	Publications from 1994 to June 1, 2024
	All types of publications, including case reports, case series, retrospective case control, cohort studies, randomized controlled trials
Exclusion criteria	Non-English language publications
	Studies without neuro-imaging of the cerebral ventricles

Table 2 Details comparison of eyes included in group 1 and group 2, n (%)

	Group 1 (n = 11)	Group 2 (n = 43)	Fisher's exact test	Mann-Whitney U tests	Binary logistic regression
Patient demographics
Male	6 (54.5)	25 (58.1)	P = 1.00		P = 0.152
Age (years) mean ± SD	55.8 ± 17.5	59.9 ± 16.1		P = 0.43	P = 0.664
Diabetes mellitus	2 (18.2)	23 (53.5)	P = 0.05		aP = 0.037
Visual acuity (logMAR)	2.74± 1.00	2.84± 0.42		P = 0.06	aP = 0.011
SiO-filled eyes' ocular characteristics
Congenital disc pit	0 (0.0)	1 (2.3)	P = 1.00		P = 0.424
Optic nerve atrophy/cupping	2 (18.2)	9 (21.0)	P = 1.00		P = 0.790
Scleral buckle	1 (9.1)	2 (4.7)	P = 0.50		P = 0.696
Glaucoma drainage device	0 (0.0)	3 (7.0)	P = 1.00		P = 0.242
Vitrectomy surgical details
Post-operative intraocular pressure (mmHg)	31.9± 16.2	49.1± 16.5		aP = 0.047	aP = 0.012
SiO emulsification	1 (9.1)	2 (4.7)	P = 0.50		P = 0.696
Endotamponade time (months)	10.3± 10.9	67.3± 64.8		aP = 0.002	P = 0.152
Presenting symptoms
Headache	3 (27.3)	17 (39.5)	P = 0.73		P = 0.869
Nausea	0 (0.0)	4 (9.3)	P = 0.57		P = 0.424
Dizziness	2 (18.2)	7 (16.3)	P = 1.00		P = 0.242
Loss of consciousness	1 (9.1)	9 (21.0)	P = 0.67		P = 0.242
Mental change	1 (9.1)	5 (11.6)	P = 1.00		P = 0.424
Painful eye	2 (18.2)	2 (4.7)	P = 0.18		P = 0.696
Visual field loss	1 (9.1)	0 (0.0)	P = 0.20		P = 0.182
Visual change	2 (18.2)	8 (18.6)	P = 1.00		P = 0.790

^aP < 0.05.

SiO: Silicone oil.