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COL4A1 may be a candidate gene in unexplained familial syndromes with autosomal dominant hematuria, cystic kidney disease, intracranial aneurysms, and muscle cramps.

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Aim: To describe the types and location of choroidal neovascularisation (CNV) in exudative age-related macular degeneration (AMD), including vascularised pigment epithelial detatchments (PED), and most recently described subtypes, such as retinal choroidal anasmostosis, also termed ''retinal angiomatous proliferation'' (RAP). Methods: Prospective multicentre consecutive descriptive case series. A total of 207 consecutive cases of newly diagnosed exudative AMD undergoing fluorescein angiography (FA) were recruited by 7 French referral hospital-based or private centres. Indocyanine green angiography (ICG) also was performed, when judged necessary by investigators. Types and location of CNV were classified by two independent experts and adjudicated by a third when discordant. Results: All patients had FA, while ICG was performed in 50% of subjects. A total of 17.6% had classic CNV only, 5.4% and 8.3% had predominantly and minimally classic CNV, respectively. Occult CNV could be classified in occult CNV without PED (32.7%) and occult CNV with PED, ie, vascularised PED (23.9%). RAP was observed in 15.1% of cases, and accounted for 30% of vascularised PED. In 5.8% of the cases there was haemorrhagic AMD and 4.8% had fibrovascular scars. Lesions were mainly subfoveal (80%). Agreement between the centre's ophthalmologist and the final validated expert classification was moderate (k = 0.52 for location and 0.59 for type of lesion). Conclusion: This study confirms that newly diagnosed cases of exudative AMD are mainly occult and subfoveal. RAP appeared as a common lesion in patients with newly diagnosed exudative AMD.A ged-related macular degeneration (AMD) is the leading cause of blindness in industrialised countries, representing 50% of all blindness cases.1 It is currently the third most common cause of blindness worldwide, behind cataract and glaucoma.1 More than 80% of severe visual loss in AMD is due to choroidal neovascularisation (CNV) and its consequences: exudation, bleeding and disciform scarring.2 At the time of completion of the present study, the only approved treatments for exudative AMD in France were laser photocoagulation and verteporfin photodynamic therapy (PDT). The choice of treatment with these laser-based therapies depended on the location, composition and size of the lesion. Fluorescein angiography has been used to define lesion size and composition. It allows distinction between well demarcated classic CNV, and ill-defined occult CNV. This angiographic distinction is of major importance for the choice of treatment; laser photocoagulation being preferred in cases of extrafoveal or juxtafoveal classic CNV, while PDT was preferred in cases of subfoveal predominantly classic and occult only CNV.3-5 The location and exact boundaries of occult CNV often are difficult to determine precisely on fluorescein angiography due to obscuration of the neovascular membrane by overlying turbid exudates, blood and/or pigment, and rapid fluorescein pooling beneath a serous PED. As the vast majority of CNV at diagnos...

Age-related macular degeneration (AMD) is a major cause of visual impairment in people older than 50 years in Western countries, affecting essential tasks such as reading and face recognition. Here we investigated the mechanisms underlying the deficit in recognition of facial expressions in an AMD population with low vision. Pictures of faces displaying different emotions with the mouth open or closed were centrally displayed for 300 ms. Participants with AMD with low acuity (mean 20/200) and normally sighted age-matched controls performed one of two emotion tasks: detecting whether a face had an expression or not (expressive/non expressive (EXNEX) task) or categorizing the facial emotion as happy, angry, or neutral (categorization of expression (CATEX) task). Previous research has shown that healthy observers are mainly using high spatial frequencies in an EXNEX task while performance at a CATEX task was preferentially based on low spatial frequencies. Due to impaired processing of high spatial frequencies in central vision, we expected and observed that AMD participants failed at deciding whether a face was expressive or not but categorized normally the emotion of the face (e.g., happy, angry, neutral). Moreover, we observed that AMD participants mostly identified emotions using the lower part of the face (mouth). Accuracy did not differ between the two tasks for normally sighted observers. The results indicate that AMD participants are able to identify facial emotion but must base their decision mainly on the low spatial frequencies, as they lack the perception of finer details.

Most studies on people with age-related macular degeneration (AMD) have been focused on investigations of low-level processes with simple stimuli like gratings, letters, and in perception of isolated faces or objects. We investigated the ability of people with low vision to analyze more complex stimuli like photographs of natural scenes. Fifteen participants with AMD and low vision (acuity on the better eye <20/200) and 11 normally sighted age-matched controls took part in the study. They were presented with photographs of either colored or achromatic gray level scenes in one condition and with photographs of natural scenes versus isolated objects extracted from these scenes in another condition. The photographs were centrally displayed for 300 ms. In both conditions, observers were instructed to press a key when they saw a predefined target (a face or an animal). The target was present in half of the trials. Color facilitated performance in people with low vision, while equivalent performance was found for colored and achromatic pictures in normally sighted participants. Isolated objects were categorized more accurately than objects in scenes in people with low vision. No difference was found for normally sighted observers. The results suggest that spatial properties that facilitate image segmentation (e.g., color and reduced crowding) help object perception in people with low vision.

Indocyanine green (ICG) is a fluorescent dye largely used as functional indicator, fluorescent imaging contrast agent and recently as enhancer during diode laser photocoagulation. In this study, indocyanine green was incorporated in an emulsion to increase its residence time in blood. In vitro results to show that indocyanine green absorption peak is shifted towards longer wavelength (from 778 nm to 794 nm) close to the peak emission wavelength of the near infrared diode laser (805 nm) used during laser-induced photocoagulation. Plasmatic clearance is slower (in the 15-60 min time interval) compared to the plasmatic clearance of ICG administered as an aqueous solution. The absorbing capacity of ICG at 805 nm shows a two- to threefold increase when indocyanine green is incorporated in this emulsion.

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