Diurnal variation of macular oedema in CRVO: prospective study.

INTRODUCTION: Patients with central retinal vein occlusion (CRVO) may experience reduced vision in the morning. This may be due to increased cystoid macular oedema (CMO), which can be measured on optical coherence tomography (OCT). METHODS: A prospective study was performed on ten patients. Retinal thickness measurements were made with the Topcon 3D OCT-1000: at 9 A.M., 11 A.M., 1 P.M., 3 P.M., 5 P.M. In addition, at 9 A.M. and 5 P.M. visual acuity was recorded using ETDRS LogMAR. RESULTS: There were seven males and three females with average age of 59.4 years (range 40-80 years). The average duration of symptoms was 5.4 months (range 3-9 months). In eyes with CRVO, median central macular thickness (CMT) significantly reduced from 571 microm at 9 A.M. to 475 microm at 5 P.M. (p < 0.05). Comparison of CMT at 9 A.M. to each of the subsequent time intervals found that there was a significant reduction in the central macula thickness late in the day (p < 0.05). There was no statistical difference in the visual acuity and change in macular thickness did not correlate with change in visual acuity in eyes affected by CRVO. DISCUSSION: Patients with CRVO demonstrate increase in CMO in morning compared with late morning and afternoon. Possible causes are diurnal variation in blood pressure, retinal metabolism and erect posture. Interventions designed to influence these factors could be used to try to reduce CMO severity.

A novel imaging approach to periocular basal cell carcinoma: in vivo optical coherence tomography and histological correlates.

PURPOSE: Optical coherence tomography (OCT) is a non-invasive imaging method widely used in ophthalmology. Recent developments have produced OCT devices for imaging the skin. The purpose of this study was to investigate Fourier Domain OCT morphological features of periocular basal cell carcinoma (BCC) in correlation with conventional histopathology. METHODS: Consecutive patients with periocular nodular BCC were prospectively examined with VivoSight OCT (Michelson Ltd) prior to surgical excision. OCT slice mode images were analysed using criteria defined for conventional and HD-OCT; the images were correlated to haematoxylin and eosin stained histology sections. RESULTS: A total of 15 patients with periocular BCC were recruited. Three categories of BCC morphological features were identified from slice mode OCT images: (1) Epidermal changes included epidermal thinning (15/15; 100%), ulceration and crusting (5/15, 33.3%) and decreased density of hair follicles (8/15; 53.3%); (2) Intralesional features included hyporeflective nodules (15/15; 100%), hyper-reflective edges (15/15; 100%) and hyporeflective central necrosis (3/15; 20%) (3) Perilesional features included hyporeflective borders (11/15; 73%), hypereflective margins (15/15; 100%) and dilated blood vessels (5/15; 33%). CONCLUSIONS: This study demonstrated that Fourier Domain OCT imaging offers additional information in the identification of morphological features of nodular BCC compared to conventional OCT diagnostic criteria. VivoSight produced fast, non-invasive imaging of skin lesions in the periocular region and high correlation with histology. Further studies are necessary to investigate OCT features of different histological subtypes of BCC.