Acute effects of caffeine and glucose intake on retinal vessel calibres in healthy volunteers.

PURPOSE: To evaluate the acute effects of caffeine and glucose intake on retinal vascular calibre of healthy adults. METHODS: This prospective crossover study was conducted at the Centre for Eye Research Australia (Melbourne, Australia). Standardized doses of 300 mg caffeine (approximately 3 cups coffee), 30 g glucose or 300 ml of water, were each given to 19 healthy subjects on separate days. Retinal photographs and blood pressure measurements were taken at baseline, 30-, 60- and 120-min after ingestion of each solution. Central retinal artery and vein equivalents (CRAE, CRVE) and the arterio-venule ratio were measured using computer-assisted software. The mean retinal vascular calibre measurements were compared between pre- and post-ingestion images. RESULTS: After caffeine intake, significant reductions were observed in mean CRAE of - 9.3 µm, - 10.4 µm and - 8.5 µm and CRVE of - 16.9 µm, - 18.7 µm and - 16.1 µm at 30-, 60- and 120-min after intake when compared with baseline (p ≤ 0.002 for all; paired t test). No significant changes were observed in mean retinal vascular calibre measurements after intake of either glucose or water when compared to baseline (p ≥ 0.072 for all). When controlling for baseline characteristics and blood pressure measurements, only caffeine intake had a significant effect on reducing both CRAE and CRVE at all time points post ingestion (p ≤ 0.003 for all, multiple linear regression model). CONCLUSION: Caffeine is associated with an acute vasoconstrictive effect on retinal arterioles and venules in healthy subjects. Factors other than blood pressure-induced autoregulation play a significant role in caffeine-associated retinal vasoconstriction.

Paracentral acute middle maculopathy associated with eosinophilic granulomatosis with polyangiitis.

PURPOSE: To present a case of paracentral acute middle maculopathy (PAMM) associated with transient loss of vision from eosinophilic granulomatosis with polyangiitis (EGPA)-associated ischaemic vasculitis. METHODS: Case report and review of literature. RESULTS: A 52 year-old man presented with recurrent episodes of amaurosis of the right eye. A diagnosis of EGPA was established with the combination of late-onset asthma, peripheral eosinophilia, patchy parenchymal consolidation and diffuse pansinusitis. Fundus examination displayed cotton wool spots in the right eye. Optical coherence tomography (OCT) of the macula showed features of paracentral focal inner nuclear layer/outer plexiform layer hyperreflectivity consistent with PAMM. He was treated with corticosteroids and cyclophosphamide. At 2-months following treatment his EGPA was in remission, the patient reported no recurrence of visual symptoms. Dilated fundoscopy revealed resolution of the cotton wool spots. A repeat OCT macula showed resolution of PAMM. CONCLUSION: Our case supports sublethal hypoxia of the middle retinal layers as the underlying mechanism for PAMM. Ophthalmologists should be cognizant to look for PAMM on OCT in patients presenting with transient visual loss and be aware of EGPA-associated ischaemic vasculitis as a rare cause of amaurosis.

Quantitative Analysis of the Ellipsoid Zone Intensity in Phenotypic Variations of Intermediate Age-Related Macular Degeneration.

Purpose: Reduction of the ellipsoid zone (EZ) intensity has been reported in eyes with age-related macular degeneration (AMD). This study determined whether overall EZ intensity, in retinal locations undisturbed by pathologic features, is associated with the presence of clinical features, which are known important phenotypic risk factors for disease progression, large drusen, reticular pseudodrusen (RPD), and pigmentary abnormalities. Methods: A horizontal B-scan through the foveola on spectral-domain optical coherence tomography (SD-OCT) was performed in both eyes of 75 participants with bilateral intermediate AMD and 10 age-similar control participants. Eyes with AMD were classified as per the presence of large drusen, RPD, and hyperpigmentary changes. The relative EZ intensity profile, up to an eccentricity of 3400 µm, was averaged over seven 1000-µm retinal segments. The association between relative EZ intensity profile over seven retinal segments and AMD pathologic features was analyzed. Results: The average relative EZ intensities were significantly reduced in eyes with intermediate AMD compared to normal eyes (P ≤ 0.025) and with increasing age (P ≤ 0.020). On multivariate analyses, only the presence of hyperpigmentary changes and increasing age were significantly associated with reduced overall relative intensities (P ≤ 0.024), but not the presence of large drusen or RPD (P ≥ 0.115). Conclusions: The presence of hyperpigmentary change in the macula in association with large drusen, not large drusen alone, nor large drusen with RPD, was significantly associated with a generalised reduction in EZ intensity. Quantitative assessment of the relative EZ intensity may serve as an effective biomarker of disease severity and progression.

Spontaneous cutaneous endometriosis of the umbilicus.

Cutaneous endometriosis that arises de novo, without a prior history of surgery, is a rare phenomenon. The clinical diagnosis of cutaneous endometriosis remains challenging due to the variable clinical appearance and symptoms of the condition, and therefore must be considered in the differential diagnosis of any umbilical lesion. We report a 31-year-old woman who presented with spontaneous cutaneous endometriosis of the umbilicus.

Central retinal function as measured by the multifocal electroretinogram and flicker perimetry in early age-related macular degeneration.

PURPOSE: To determine the retinal function in early age-related macular degeneration (AMD) assessed by the multifocal electroretinogram (mfERG) and flicker perimetry and to seek a relationship between local objective mfERG parameters and subjective flicker perimetry thresholds. METHODS: mfERG and flicker perimetry were performed in 15 patients (15 eyes) with early AMD and 14 controls (14 eyes) of similar age. The mfERG P1 response amplitude density (nV/deg²) and P1 implicit time of the first-order kernel and the flicker thresholds of each concentric ring were analyzed. The relationship between individual mfERG responses and the corresponding individual flicker sensitivity outcomes was determined. RESULTS: The mfERG response amplitude of the central ring (ring 1) was significantly reduced in early AMD eyes compared with the controls (P = 0.009). No significant difference in mfERG amplitude between early AMD and control eyes was detected in the other rings. The mfERG implicit time was significantly increased in the early AMD eyes but only within the central four rings of 12°. A significant reduction in flicker sensitivity was also detected in early AMD eyes but only within the central 6°. There was a significant, moderate correlation (r = -0.477; P < 0.001) between local mfERG latency and flicker sensitivity from the same tested locations within the central 6°. There was a weak correlation (r = 0.200; P = 0.014) between mfERG amplitude and flicker sensitivity. CONCLUSIONS: Both mfERG and flicker perimetry show abnormal retinal function, but only in the very central macula, in early AMD. A novel relationship between mfERG and flicker sensitivity should enhance the clinical monitoring of disease progression.