ABSTRACT
PURPOSE: To investigate the physics associated with the retention and removal of subretinal perfluorocarbon liquid (PFCL), as inspired by a series of anecdotal cases of spontaneous 'disappearance' of subretinal PFCL. METHODS: The profiles of subretinal PFCL in situ from published OCT images were studied and compared with that of PFCL droplets resting on a hydrophilic surface in vitro. A mathematical model based on Sampson's and Poiseuille's formula was developed to explain how evacuation of subretinal PFCL without aspiration could occur. RESULTS: The mathematical model suggested that in vivo subretinal PFCL can completely evacuate in less than a second via a 41-guage retinal hole. Perfluorocarbon liquid (PFCL) droplets in situ subretinally substantially varied in their aspect ratios (from 0.28 to 2.71) and their contact angles with the retinal pigment epithelium (from 98° to 155°). Conversely, PFCL in vitro had aspect ratios and contact angles close to 1 and 150° respectively. CONCLUSION: This study showed evidence that stretching of the retina to accommodate subretinal PFCL occurs, which might be responsible for the varied profile of the droplets and resultant forces that can cause retinal holes, and spontaneous evacuation of large PFCL droplets. By filling the vitreous cavity with PFCL, a small retinotomy alone might allow spontaneous evacuation without the need for aspiration.
Subject(s)
Endotamponade/adverse effects , Fluorocarbons/adverse effects , Postoperative Complications/etiology , Retinal Diseases/surgery , Subretinal Fluid/diagnostic imaging , Tomography, Optical Coherence/methods , Vitrectomy/adverse effects , Humans , Postoperative Complications/diagnosisABSTRACT
A 65-year old woman presented with 3-year history of painless, gradual swelling of the right upper eyelid associated with proptosis. Computed tomography (CT) and magnetic resonance imaging (MRI) of the orbit showed a well circumscribed soft tissue mass in the supero-lateral orbit. An excision biopsy of the lesion was performed via lateral orbitotomy. Histopathology examination and immunochemistry staining confirmed the diagnosis of cavernous angioleiomyoma. The tumour was excised completely. Orbital angioleiomyoma is a rare benign tumour and the lesion can cause visual morbidity, particularly when intraconal. Despite sophisticated imaging modalities, histopathological analysis is essential for diagnosis. Angioleiomyoma should be included in the differential diagnosis of well-defined orbital lesions. Complete surgical excision carries a low risk of recurrence.
