[Choroidal neovascularization complicating Best's vitelliform macular dystrophy in a child]

INTRODUCTION

Best's disease is a progressive macular dystrophy, beginning either in childhood or adolescence.

CASE STUDY

We report a rare case of choroidal neovascularization complicating vitelliform dystrophy in a child of 8 years with bilateral progressive loss of visual acuity. The ophthalmoscopic examination showed vitelliform lesions in both foveas. Fluorescein angiography confirmed a subretinal neovascular membrane in the left eye. Additional testing also confirmed the diagnosis of Best's disease associated with choroidal neovascularization.

DISCUSSION

Best's vitelliform macular dystrophy is often asymptomatic because visual acuity tends to remain stable for a long time. A sudden loss of vision suggests the occurrence of complications, such as choroidal neovascularization.

[Diagnostic use of macular layer analysis by SD-OCT in primary open angle glaucoma]

PURPOSE

The purpose of this study is to evaluate the diagnostic ability of segmentation of the various internal macular layers by spectral domain optical coherence tomography (Cirrus HD-OCT, Carl Zeiss Meditec (CZM), Dublin, CA, USA) and to compare it to that of the peripapillary retinal nerve fiber layer (cpRNFL) in primary open angle glaucoma (POAG).

MATERIALS AND METHODS

This study included 252 eyes diagnosed with primary open angle glaucoma (POAG) (164 early POAG, 44 moderate POAG and 44 advanced POAG) and 223 eyes of control subjects. All patients underwent visual field testing (Humphrey Field Analyser, SITA-Standard 24-2, CZM), and SD-OCT imaging (Cirrus HD-OCT) of the macular and optic nerve head regions (ganglion cell analysis (GCA), macular cube 200×200; optic disc cube 200×200). OCT macular scans were segmented into macular nerve fiber layer (mNFL), ganglion cell layer with inner plexiform layer (GCIPL), outer retinal layers, and ganglion cell complex (GCC) (mNFL+GCIPL). Glaucoma discriminating ability was assessed using the area under the receiver operator characteristic curve (AUC) for all macular parameters and mean circumpapillary retinal nerve fibre layer (cpRNFL).

RESULTS

For the entire POAG population of this study, the minimum GCIPL index provided greater diagnostic ability than the other parameters studied, with a statistically significant difference in their AUC (minimum GCIPL [0.887], mean GCIPL [0.865], GCC [0.863], cpRNFL [0.823], mean mNFL [0.786] and minimum mNFL [0.742]). The results were similar in the early POAG group but without any statistically significant difference with the cpRNFL parameter. In the moderate POAG group, the diagnostic ability was similar for all indices, whereas in the advanced POAG group, minimum GCIPL and GCC gave the largest AUC indices.

DISCUSSION AND CONCLUSION

The minimum macular GCIPL is a new index obtained with the GCA algorithm of the Cirrus HD-OCT. It appears to have an excellent ability to detect glaucoma at every stage and demonstrates performance comparable to that of the cpRNFL parameter, in combination with which it may provide important complementary information for clinical practice.

Nanoprecipitation technique for the encapsulation of agrochemical active ingredients

In 1997, a research programme was initiated to assess the ability of nanospheres (NS) to improve the biodelivery of a new insecticide to plants. Stable polymeric NS, with a size near 135 nm and an encapsulation rate in the range of 3.5%, have been obtained using a nanoprecipitation method with Eudragit S100 polymer. Biological studies have been performed on cotton plants infested with aphid, to estimate the direct contact efficacy of NS formulations on the insects and the systemicity of the encapsulated active ingredient and its level of penetration through the plant, compared to a classical suspension used as a reference. Results indicate that NS formulations are not so good as the reference in terms of speed of action and sustained release. Nevertheless, NS formulation performed better than the reference to enhance the systemicity of the AI and improve its penetration through the plant. It is concluded that the NS do not provide a controlled release of AI but, due to their small size, they enhance the penetration in the plant compared to the classical suspension.

Poly epsilon-caprolactone nanoparticles containing a poorly soluble pesticide: formulation and stability study

In 1997, a research program was initiated in the laboratories to assess the ability of nanosperes (NS) to improve the biodelivery of new active ingredients (AI) to plants. The goal was to obtain stable poly (epsilon-caprolactone) NS (PeC-NS) with the smallest size and the largest amount of encapsulated AI, using a nanoprecipitation method. The smallest particles obtained were in the range of 200-250 nm. The highest encapsulation is obtained with Montanox 80 as surfactant and is between 5-10% (expressed in per cent weight relative to the total weight of polymer), which corresponds to an encapsulation yield of 95%. There is no desorption of the AI with time. In contrast, the dilution of the NS suspension in water is followed by a large removal of the AI in the aqueous phase. This suggests that NS are complex dynamic systems in equilibrium with the external medium and disturbances of this system lead to a loss of AI.