Unusual macular thickness in Alport syndrome: case report

This case report describes the presence of bilateral macular atrophy in a patient with Alport syndrome and compares this finding with literature. At fundoscopy, there was a discrete circumscribed macular thinning showing intense retinal pigment epithelium color and the presence of whitish circular retinal lesions ("dots" and "flecks") at nasal mid periphery of both eyes. Optical coherence tomography showed bilateral partial atrophy of the neurosensory retina in the macula, with a greater extent in the temporal region. This case describes a rare ophthalmological finding in Alport syndrome and important to be recognized for a precise diagnosis as well as for determining visual prognosis.

New approaches and potential treatments for dry age-related macular degeneration

Emerging treatments for dry age-related macular degeneration (AMD) and geographi c atrophy focus on two strategies that target components involved in physiopathological pathways: prevention of photoreceptors and retinal pigment epithelium loss (neuroprotection induction, oxidative damage prevention, and visual cycle modification) and suppression of inflammation. Neuroprotective drugs, such as ciliary neurotrophic factor, brimonidine tartrate, tandospirone, and anti-amyloid β antibodies, aim to prevent apoptosis of retinal cells. Oxidative stress and depletion of essential micronutrients are targeted by the Age-Related Eye Disease Study (AREDS) formulation. Visual cycle modulators reduce the activity of the photoreceptors and retinal accumulation of toxic fluorophores and lipofuscin. Eyes with dry age-related macular degeneration present chronic inflammation and potential treatments include corticosteroid and complement inhibition. We review the current concepts and rationale of dry age-related macular degeneration treatment that will most likely include a combination of drugs targeting different pathways involved in the development and progression of age-related macular degeneration.

Plasma levels of complement proteins from the alternative pathway in patients with age-related macular degeneration are independent of Complement Factor H Tyr(402)His polymorphism

Purpose: To investigate the influence of the Factor H (CFH) Tyr(402)His polymorphism on the plasma levels of the alternative pathway proteins CFH, C3, Factor B (FB), Factor D (FD), and Factor I (FI) and the inflammatory marker C-reactive protein (CRP) in 119 patients with age-related macular degeneration (AMD) and 152 unrelated control individuals. Methods: Patients with AMD and the control group were separated according to CFH polymorphism, age, and gender. Plasma complement proteins and CRP concentrations were determined with enzyme-linked immunosorbent assay, immunodiffusion, or nephelometry. Results: Significant differences in the concentrations of FD and FI were observed between the patients with AMD and the control individuals. We observed significantly reduced FD plasma levels in patients with AMD. We also identified a significant decrease in CFH plasma levels in female patients with AMD in relation to female controls. Plasma FI levels were significantly increased in patients with AMD compared to the control group. Regarding gender, a significant increase in FI plasma levels was observed in male patients. Finally, we found no significant correlation between the CFH Tyr(402)His polymorphism and the CFH, C3, FB, FD, FI, and CRP plasma levels. Conclusions: Patients with AMD present altered levels of FD and FI in a manner independent of this CFH polymorphism, and gender apparently contributes to the plasma levels of these two proteins in patients with AMD and control individuals.

Signaling Events During Cyclic Guanosine Monophosphate-Regulated Pigment Aggregation in Freshwater Shrimp Chromatophores

Crustacean color change results partly from granule aggregation induced by red pigment concentrating hormone (RPCH). In shrimp chromatophores, both the cyclic GMP (3', 5'-guanosine monophosphate) and Ca2+ cascades mediate pigment aggregation. However, the signaling elements upstream and downstream from cGMP synthesis by GC-S (cytosolic guanylyl cyclase) remain obscure. We investigate post-RPCH binding events in perfused red ovarian chromatophores to disclose the steps modulating cGMP concentration, which regulates granule translocation. The inhibition of calcium/calmodulin complex (Ca2+/CaM) by N-(6-aminohexyl)-5-chloro-1-naphthalenesulphonamide (W7) induces spontaneous aggregation but inhibits RPCH-triggered aggregation, suggesting a role in pigment aggregation and dispersion. Nitric oxide synthase inhibition by N omega-nitro-L-arginine methyl ester hydrochloride (L-NAME) strongly diminishes RPCH-induced aggregation; protein kinase G inhibition (by rp-cGMPs-triethylamine) reduces RPCH-triggered aggregation and provokes spontaneous dispersion, disclosing NO/PKG participation in aggregation signaling. Myosin light chain phosphatase inhibition (by cantharidin) accelerates RPCH-triggered aggregation, whereas Rho-associated protein kinase inhibition (by Y-27632, H-11522) reduces RPCH-induced aggregation and accelerates dispersion. MLCP (myosin light chain kinase) and ROCK (Rho-associated protein kinase) may antagonistically regulate myosin light chain (MLC) dephosphorylation/phosphorylation during pigment dispersion/aggregation. We propose the following general hypothesis for the cGMP/Ca2+ cascades that regulate pigment aggregation in crustacean chromatophores: RPCH binding increases Ca2+ (int), activating the Ca2+/CaM complex, releasing NOS-produced nitric oxide, and causing GC-S to synthesize cGMP that activates PKG, which phosphorylates an MLC activation site. Myosin motor activity is initiated by phosphorylation of an MLC regulatory site by ROCK activity and terminated by MLCP-mediated dephosphorylation. Qualitative comparison reveals that this signaling pathway is conserved in vertebrate and invertebrate chromatophores alike.

Single intravitreal bevacizumab injection effects on contrast sensitivity in macular edema from branch retinal vein occlusion

Purpose: To evaluate the effect of a single intravitreal bevacizumab injection on visual acuity, contrast sensitivity and optical coherence tomography-measured central macular thickness in eyes with macular edema from branch retinal vein occlusion. Methods: Seventeen eyes of 17 patients with macular edema from unilateral branch retinal vein occlusion were treated with a single bevacizumab injection. Patients were submitted to a complete evaluation including best corrected visual acuity, contrast sensitivity and optical coherence tomography measurements before treatment and one and three months after injection. Visual acuity, contrast sensitivity and optical coherence tomography measurements were compared to baseline values. Results: Mean visual acuity measurement improved from 0.77 logMAR at baseline to 0.613 logMAR one month after injection (P=0.0001) but worsened to 0.75 logMAR after three months. Contrast sensitivity test demonstrated significant improvement at spatial frequencies of 3, 6, 12 and 18 cycles/degree one month after injection and at the spatial frequency of 12 cycles/degree three months after treatment. Mean +/- standard deviation baseline central macular thickness (552 +/- 150 mu m) reduced significantly one month (322 +/- 127 mu m, P=0.0001) and three months (439 perpendicular to 179 mu m, P=0.01) after treatment. Conclusions: Bevacizumab injection improves visual acuity and contrast sensitivity and reduces central macular thickness one month after treatment. Visual acuity returns to baseline levels at the 3-month follow-up, but some beneficial effect of the treatment is still present at that time, as evidenced by optical coherence tomography-measured central macular thickness and contrast sensitivity measurements.

INTRAVITREAL INJECTION OF RANIBIZUMAB DURING CATARACT SURGERY IN PATIENTS WITH DIABETIC MACULAR EDEMA

Purpose: To investigate macular thickness and visual acuity changes after 1 intravitreal injection of 0.5-mg ranibizumab during phacoemulsification cataract surgery in eyes with diabetic macular edema refractory to laser treatment. Methods: Eleven eyes of 11 patients with diabetic macular edema refractory to modified Early Treatment Diabetic Retinopathy Study laser therapy received intravitreal during phacoemulsification cataract surgery. Comprehensive ophthalmic evaluation was performed preoperatively and at 1, 4, 8 +/- 1, and 12 +/- 2 weeks postoperatively. Main outcome measures included central subfield thickness and best-corrected Early Treatment Diabetic Retinopathy Study visual acuity. Results: Eleven patients completed the 12-week study visit. Mean central subfield thickness (+/- SEM) was 399.82 +/- 29.50 mu m at baseline and did not change significantly at any postoperative study visit (P > 0.05). Mean (+/- SEM) best-corrected Early Treatment Diabetic Retinopathy Study visual acuity was 0.95 +/- 0.13 logarithm of the minimum angle of resolution (20/200) at baseline and was significantly improved at Weeks 1 (0.38 +/- 0.13), 4 (0.38 +/- 0.11), 8 (0.35 +/- 0.08), and 12 (0.46 +/- 0.12) after treatment (P < 0.05). Conclusion: In this case series of patients with diabetic macular edema refractory to laser therapy, intravitreal ranibizumab administered during cataract surgery was associated with no significant change in central subfield thickness postoperatively. Significant improvement in best-corrected Early Treatment Diabetic Retinopathy Study visual acuity was observed after treatment, likely because of cataract removal. RETINA 32:1799-1803, 2012

Seasonal changes in the pigment composition of natural population of Gracilaria domingensis (Gracilariales, Rhodophyta)

The concentrations of phycobiliproteins (phycoerythrin and phycocyanin), chlorophyll-a and total soluble proteins were determined monthly in three strains (red, green and brown) of Gracilaria domingensis (Kützing) Sonder ex Dickie, collected from natural populations on the coast of Rio Grande do Norte, Brazil. In all the strains, pigment and protein concentrations were higher in the months of less sunlight and greater nitrogen availability and decreased gradually with increased sunlight and decreased nutrient concentration. The red strain showed higher concentrations of phycoerythrin and total soluble proteins. The difference in the concentration of biochemical components over the course of the year indicates species acclimation to different environmental conditions.

Variability in light absorption and scattering of phytoplankton in Patagonian waters: Role of community size structure and pigment composition

Intense phytoplankton blooms were observed along the Patagonian shelf-break with satellite ocean color data, but few in situ optical observations were made in that region. We examine the variability of phytoplankton absorption and particulate scattering coefficients during such blooms on the basis of field data. The chlorophyll-a concentration, [Chla], ranged from 0.1 to 22.3 mg m−3 in surface waters. The size fractionation of [Chla] showed that 80% of samples were dominated by nanophytoplankton (N-group) and 20% by microphytoplankton (M-group). Chlorophyll-specific phytoplankton absorption coefficients at 440 and 676 nm, a*ph(440) and a*ph(676), and particulate scattering coefficient at 660 nm, b*p(660), ranged from 0.018 to 0.173, 0.009 to 0.046, and 0.031 to 2.37 m2 (mg Chla)−1, respectively. Both a*ph(440) and a*ph(676) were statistically higher for the N-group than M-group and also considerably higher than expected from global trends as a function of [Chla]. This result suggests that size of phytoplankton cells in Patagonian waters tends to be smaller than in other regions at similar [Chla]. The phytoplankton cell size parameter, Sf, derived from phytoplankton absorption spectra, proved to be useful for interpreting the variability in the data around the general inverse dependence of a*ph(440), a*ph(676), and b*p(660) on [Chla]. Sf also showed a pattern along the increasing trend of a*ph(440) and a*ph(676) as a function of the ratios of some accessory pigments to [Chla]. Our results suggest that the variability in phytoplankton absorption and scattering coefficients in Patagonian waters is caused primarily by changes in the dominant phytoplankton cell size accompanied by covariation in the concentrations of accessory pigments.