MACULAR phototoxicity and Macular Degeneration

http://www.womenfitness.net/beauty/eye/lutein_zeaxanthin_amd.htm

Lutein and Zeaxanthin and Age-related Macular Degeneration (AMD)

People with high amounts of lutein+zeaxanthin in their blood have lower risk for developing AMD.

 

Age-Related Macular Degeneration (AMD) is an acquired ocular disorder and a leading cause of legal blindness in persons over sixty. AMD affects the macula, the central part of the retina, which is responsible for providing clear, sharp vision needed for reading, writing, driving and other visually-demanding activities.

 

Earlier research had suggested that the development of AMD is linked to a depleted level of macular pigment. This retinal layer efficiently filters out harmful blue wavelengths of light, and also reduces the amount of free radicals, which are compounds found in high concentrations in the macular area and can cause oxidation of cell membranes. It is theorized that certain antioxidant compounds reduce the effect that these free radicals have on the macular pigment, and consequently may have an impact on the development of AMD.

 

According to a new study, people who ate more of these foods, which contain the nutrients lutein and zeaxanthin, were less likely to have advanced age-related macular degeneration (AMD) than people who ate fewer servings.

 

Researchers conducted the study using about 4,500 people ages 60 to 80, a group considered at high risk for the sight-robbing condition. Researchers photographed the study participants' retinas to find out if they had AMD and to identify which of four stages of the disease they were in if they did.

 

Then, the participants filled out questionnaires about eating habits, and the investigators divided them into five groups according to their consumption of several key nutrients, including lutein, zeaxanthin, beta-carotene, lycopene and vitamins C and E. Those in the highest lutein and zeaxanthin groups had the lowest risk for advanced AMD. The other nutrients didn't seem to affect the condition negatively or positively.

 

The researchers report the two nutrients may help prevent advanced AMD because they have the ability to filter short-wavelength light. That type of light has been implicated in the condition, which slowly erodes sharp central vision.

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OPTICAL COHERENCE TOMOGRAPHY AND MACULAR

PHOTOTOXICITY

OCT Y FOTOTOXICIDAD MACULAR

RODRÍGUEZ-MARCO NA

REBOLLO-AGUAYO A

1, ANDONEGUI-NAVARRO J1, COMPAINS-SILVA E2,1, ALISEDA-PÉREZ-DE-MADRID D3, ARANGUREN-LAFLIN M1

Received: Jan. 8, 2007. Accepted: March 3, 2008.

Ophthalmology Service. Navarra Hospital. Pamplona. Spain

1

Graduate in Medicine.

2

Graduate in Medicine. Virgen del Camino Hospital.

3

Correspondence:

Nelson Arturo Rodríguez Marco

Plaza Mar del Plata 5-0-2.ª

50012 Zaragoza

Spain

E-mail: Nelson5000@latinmail.com

Ph.D. in Medicine.

ABSTRACT

Case report:

coherence tomography (OCT) were performed in

three patients with retinal phototoxicity lesions.

Fluorescein angiography depicted a window defect.

OCT exhibited hyporeflectivity at the outer foveal

retina and fragmentation of the inner reflective

layers, corresponding to the junction between the

inner and outer photoreceptor segments.

Ocular examinations and optical

Discussion:

has a rapid onset and shows different patterns in

OCT examination. OCT findings suggest that

decreased visual acuity may be associated with fullthickness

photoreceptors and retinal pigment epithelium

(RPE) involvement. OCT is a useful tool for

objective assessment of retinal pathology in phototoxicity

cases where fundus changes may be minimal

or absent

267-272).

Retinal damage after light exposure(Arch Soc Esp Oftalmol 2008; 83:

Key words:

eclipse, foveomacular retinitis, Optical coherence

tomography, microscope light.

INTRODUCTION

Phototoxic maculopathy (PM) is a retinal alteration

which appears in patients whose fovea has been

exposed for a long time to an intense light source. It

generally affects patients after watching a solar

eclipse without protection. Many exhibit psychological

problems, consume drugs (LSD) or are involved

in mystic practices. In addition, similar injuries

have been described after watching welding arcs

without a protection mask, laser pointers or even

after ocular surgery due to a photochemical reaction

in light receptors. These patients may notice a pericentral

scotoma, metamorphopsia or slight/moderate

vision loss between 1 and 4 hours after exposure.

The ophthalmoscopy shows a small yellow foveal

lesion in the form of an exudate or edema, followed

about two weeks later by foveal reflex loss, formation

of pigment accumulation and thinning of the

fovea. The scotoma may diminish after a few

months and the patient usually recovers part of the

lost eyesight (1,2). At present, with Optical Coherence

Tomography (OCT) we are able to describe

the damages at the intra-retinal level because, in a

high number of cases, the retinal lesions cannot be

observed ophthalmoscopically.

CASE REPORT

Case 1

A 60 year-old woman who visited the service due

to blurred vision and feeling a central spot in both

eyes. She referred having observed a sun eclipse

two months earlier. Upon exploration, her visual

acuity (VA) was of 0.5 in both eyes, with the intraocular

pressure and anterior segment normal. Both

maculas showed rounded hypo- and hyper-pigmented

lesions (fig. 1 A and B). OCT exhibited a loss in

the retinal pigmentary epithelium layer (RPE). The

rest of retinal layers did not exhibit alterations (fig.

1 C and D). Fluorescein angiography (FA) showed

early hyper-fluorescent areas in the ring (fig. 1 E).
.................................
..........................Discussion...........

The visual prognosis for solar retinopathy is

generally positive, with spontaneous VA improvement.

Accordingly, the use of corticoids has been

questioned, although education of the general

public, prevention and prophylaxis in surgical acts

such as using the lowest possible light intensity,

placing opaque elements in the pupillar area, indirect

oblique lighting or use of filters in anterior segment

interventions are crucial for preventing said

damages.

By way of conclusion, OCT can be a useful tool

for verifying, characterizing and following up retinal

damages as described above, where sometimes the

eye fundus changes may be absent or negligible.

OCT findings suggest that vision reduction is associated

to the damages in photoreceptors and the RPE.Phototoxicity, solar retinopathy, solar

ARCH SOC ESP OFTALMOL 2008; 83: 267-272