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Purpose: To examine patients with persistent watery epiphora following patent external dacryocystorhinostomy (DCR) with magnetic resonance imaging dacryocystography (MR-DCG). Methods: Patients with unobstructed nasolacrimal irrigation following external DCR were included. Five patients with watery epiphora constituted the study group (SG). Five patients without epiphora constituted the control group (CG). All patients underwent MR-DCG following the instillation of artificial tears in the conjunctival fornix. The osteotomy site was identified in T1-weighted coronal images. Lacrimal flow was assessed with modified T2-weighted (True Fast Imaging Steady State Pulse, 'TrueFISP') coronal images before and 10 min after repeated blinking. Signal intensities at three regions of interest (ROIs), corresponding to the eyeball (ROI-1), conjunctival sac (ROI-2), and anastomotic site (ROI-3) were measured. Results: Differences in the diameter of both osseous and soft tissue ostia between SG and CG were statistically not significant. A post-blink increase in signal intensity at ROI-3 was noted in both groups, whereas differences in signal intensity for ROI-1 and ROI-2 were statistically not significant. The post-blink signal intensity increase in ROI-3 was significantly more pronounced in the CG, compared with the SG. Conclusions: The fact that signal intensity increase at ROI-3 was less pronounced in the SG, compared with CG, implies a compromised 'lacrimal pump' mechanism in the former group. The methodology presented may be used for the evaluation of post-DCR epiphora. [ABSTRACT FROM AUTHOR]

Purpose: Previous studies have examined factors affecting the position of the eyeball to the orbit. This study examined the role of effective orbital volume (EOV), defined as the difference between orbital and eyeball volume, as a determinant of eyeball position, using MRI scans. Methods: Forty-six patients were recruited from the Department of Ophthalmology of the University Hospital of Heraklion, Crete Greece. Patients with a history of orbital disease were excluded. Distances between eyeball poles and orbital landmarks were measured in T1 weighted transverse, sagittal and coronal orbital images. The protrusion of the eyeball in the sagittal and transverse planes was recorded. The volume of the eyeball and bony orbit, the EOV, the volume of the extraocular muscles as well as clinical information (age, gender, Hertel exophthalmometry) were also recorded. Results: EOV was significantly associated with orbital volume but not with eyeball volume. EOV was also significantly associated with transverse and sagittal globe ptotrusions. Females displayed significantly lower orbital and eyeball volumes as well as EOV than males but higher transverse globe protrusion than males. Conclusions: Variations in EOV are associated with orbital volume rather than with eyeball volume. EOV is associated with globe protrusion and may be taken into account in the planning of various procedures, including orbital decompression, treatment of enophthalmos or the size of orbital implants following enucleation. [ABSTRACT FROM AUTHOR]