silver is a naturally occurring element with various physical properties , such as high thermal and electrical conductivity , ductility , hardness , malleability , and even antimicrobial ability .
silver was known and used by ancient people as early as 4000 bc , along with gold and copper.1 silver now has a wide variety of applications , including in photography , soldering , metallurgy , medicine and dentistry , water sanitation , jewelry , coins , silverware , and mirrors.2,3 silver nitrate ( agno3 ) is a soluble silver salt used in medications to treat intestinal and oral ulcers as well as to control gingival bleeding . another relatively common use of silver nitrate is water purification , as in the case reported here .
silver - containing compounds should be used with caution , given the risk of toxicity.3 generalized argyria is a rare dermatological disorder caused by silver granule deposits in the skin and mucous membranes , due to chronic exposure of patients to silver - containing compounds.4 persistent respiratory , topical , or oral exposure can lead to deposition of silver in the eye and periocular tissue , and a condition known as ocular argyrosis.5 this pathology has been described previously.58 the clinical presentation includes gray - blue discoloration of the periorbital skin , bulbar and palpebral conjunctiva , and lacrimal sac , as well as cornea opacities and cataracts.58 the latter are the main causes of specialist referrals.8 findings at the posterior pole include a leopard spot pattern of the macula and a dark choroid , observed by means of red - monochromatic fundus pictures and fluorescein angiography , respectively.9 although there are no visual symptoms in most reported cases , there are a few case reports in which patients complained of nyctalopia.5 however , patients undergoing electrophysiologic testing did not demonstrate functional deficits in scotopic or photopic electroretinography , nor were there any abnormalities on color vision testing.5 in the following case report , we describe a patient who developed ocular argyrosis after chronic ingestion of silver nitrate in his personal water supply . in order to expand the available data regarding this condition
an 86-year - old caucasian male with a previous medical history remarkable for normal pressure hydrocephalus after ventricular shunt placement , early dementia , and skin argyria ( 2 years ) was seen at the ophthalmology clinic , complaining of slowly decreasing visual acuity and nyctalopia in both eyes ( ou ) . according to the primary caretaker
, the patient had been drinking water from a well and purifying it with silver nitrate compounds for a period of at least 13 years , on the basis of advice from an alternative medicine professional , who recommended their use as antimicrobial agents and as a water purification method .
the patient was subsequently advised by dermatology to suspend his silver nitrate intake 2 years prior to presentation to us . during the initial consultation ,
the patient s appearance was remarkable for a generalized gray - bluish hue of the skin and fingernails , more pronounced on the face , periorbital area , and forearms ( figure 1 ) .
best corrected visual acuity was right eye ( od ) 20/40 and left eye ( os ) 20/50 .
there was no afferent pupillary defect and confrontational vision fields were full in both eyes .
conjunctiva had a purple - blue hue , but were normally vascularized and showed no epithelial defect .
the palpebral portion of the main lacrimal gland also had a purple - bluish hue .
fundus examination was remarkable for retinal pigment epithelium ( rpe ) changes and drusen formation on macula ou , consistent with age - related macular degeneration ( figure 2 ) .
fluorescein angiography showed choroidal blockage with completely dark choroid in later phases in both eyes .
areas of dot hyperfluorescence in the macula were present , corresponding to the drusenoid deposits .
spectralis domain optical coherence tomography showed multiple excrescences of rpe in both eyes , most likely representing drusen from age - related macular degeneration ( figure 3 ) .
an electroretinogram was obtained because of the patient s symptoms of nyctalopia , and revealed normal scotopic and photopic amplitudes and latency , as well as normal oscillatory potentials and 30 hz flicker testing ( data not shown ) .
in this case report , we describe the clinical and ancillary test findings in a patient with ocular argyrosis .
it is important to mention that , although there are previous reports and clinical descriptions of the anterior segment alterations and periocular skin deposits , there are relatively few descriptions of involvement of the posterior pole .
the interesting finding of dark choroid , which occurs when the normal choroidal background fluorescence is blocked , was made in our patient on fluorescein angiography .
silent  choroid is most commonly associated with stargardt s disease and other posterior retinal dystrophies.9 the pathophysiology in patients with silver accumulation which leads to this angiographic finding is not understood as yet .
wislocki and ladman conducted an experiment in albino rats involving giving them water containing silver nitrate for a period of 6 months to a year and trying to demonstrate the blood - ocular barrier .
they reported histopathologic data showing that silver accumulated in two regions of the eye , ie , the ciliary processes and bruch s membrane.10 they also noted that the longer silver nitrate was administered , the greater the amount that accumulated .
spencer et al performed a histopathologic examination in a patient with systemic argyrosis and found that brown - black silver pigment was present in three locations of the eye , ie , bruch s membrane , bowman s membrane , and descemet s membrane , with the majority of deposition occurring in bruch s membrane.11 therefore , the question arises as to how systemic argyrosis causes findings of dark choroid on fluorescein angiography , as in our patient .
one of the mechanisms proposed is that accumulation of silver pigment deposits in large amounts in bruch s membrane causes absorption of short - wavelength light during fluorescein angiography , which could be responsible for the phenomenon of dark choroid.911 furthermore , in the same study series , red light monochromatic pictures were taken , which utilize a long wavelength to bypass rpe and visualize the choroidal vasculature in normal subjects .
however , the choroidal vasculature could not be visualized in any of the six cases from that study utilizing red light pictures , meaning that the long wavelengths were blocked as well .
thus , it has been proposed that silver deposits block all light , from short to long wavelengths.911 given the results above , it is reasonable to question whether silver might accumulate not only in bruch s membrane but also in rpe cells . however , a previous histopathologic study in albino rats did not show any accumulation of silver deposits in rpe cells,10 and furthermore , the fundus autofluorescence images from our patient did not show any signs of rpe damage . to our knowledge
, there is only one previous report describing choroidal and retinal changes in patients with ocular argyrosis by means of fundus photographs and fluorescein angiography.9 in this case report , we expand the available information regarding changes in the retina and rpe .
our patient underwent noninvasive evaluation for retinal pigment abnormalities with fundus autofluorescence , which uses a confocal scanning laser ophthalmoscope to detect accumulations , typically of lipofuscin granules , in rpe cells .
. ophthalmologist and retinal specialists should be aware that conditions other than stargardt s disease can cause findings of dark choroid on fluorescein angiography .
 this case report describes the clinical , autofluorescence , and optical coherent tomography findings in a patient with panocular argyrosis secondary to chronic intake of diluted silver nitrate salts in his water supply . 
 an 86-year - old caucasian male with a distinctive gray - bluish hue of the skin presented to our clinic , having developed a slow decrease in visual acuity in both eyes and nyctalopia for the past 2 years . 
 based on the patient s history of chronic intake of silver nitrate salts and a positive skin biopsy ( performed by the dermatology department , data not shown ) , a diagnosis of panocular argyrosis was made . 
 fluorescein angiography showed choroidal blockage with a completely dark choroid . 
 fundus autofluorescence was within normal limits . 
 optical coherent tomography showed multiple excrescences of retinal pigment epithelium in both eyes . 
 although the drusen - like changes on fundus examination and retinal pigment epithelium changes may account for the diminished vision , the presence of concomitant nyctalopia suggests underlying damage of the photoreceptors . 
Introduction
Case report
Discussion