So would retinoic acid be of any use in those with .. proliferative ..
diabetic .. retinopathy .. ?

Indian J Ophthalmol. 2004 Jun;52(2):145-8.  Related Articles, Links  

Trace elements iron, copper and zinc in vitreous of patients with various
vitreoretinal diseases.

Konerirajapuram NS, Coral K, Punitham R, Sharma T, Kasinathan N,
Sivaramakrishnan R.

Biochemistry Research Department, Sankara Nethralaya, Chennai, India.

PURPOSE: To measure the concentrations of iron, copper and zinc in human
vitreous and to interpret their levels with various vitreoretinal diseases like
proliferative diabetic retinopathy, retinal detachment, intraocular foreign
body, Eales' disease and macular hole. METHODS: Undiluted vitreous fluid
collected during pars plana vitrectomy was used to measure trace elements using
an atomic absorption spectrophotometer. RESULTS: The level of vitreous iron
increased threefold in Eales' disease (1.85 +/- 0.36 pg/ml), 2.5-fold in
proliferative diabetic retinopathy (1.534 +/- 0.17 pg/ml) and 2.3-fold in eyes
with intraocular foreign body (1.341 +/- 0.25 pg/ml) when compared with macular
hole (0.588 +/- 0.16 pg/ml). This was statistically significant (P < 0.05).
Zinc was found to be low in Eales' disease (0.57 +/- 0.22 pg/ ml) when compared
with other groups, though the difference was not statistically significant.
CONCLUSION: The increased level of iron with decreased zinc content in Eales'
disease confirms the earlier reported oxidative stress mechanism for the
disease. In proliferative diabetic retinopathy and intraocular foreign body the
level of iron increases. This is undesirable as iron can augment glycoxidation,
which can lead to increased susceptibility to oxidative damage, in turn causing
vitreous liquefaction, posterior vitreous detachment and ultimately retinal
detachment and vision loss.

PMID: 15283220 [PubMed - in process]

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Ophthalmologe. 2004 Nov 10; [Epub ahead of print] Related Articles, Links  

 
[Reduction of lipid peroxidation and apoptosis in corneal endothelial cells by
vitamin A.]

[Article in German]

Serbecic N, Ehmann AK, Beutelspacher SC.

Augenklinik, SMZ-Ost des Donauspitals, Wien, Osterreich.

PURPOSE. The goal of this study was to determine the effects of lipid
peroxidation-mediated toxicity of iron ions on corneal endothelial cells
leading to apoptosis. METHODS. Murine corneal endothelial cells were maintained
in tissue culture medium supplemented with free iron ions, known to lead to
increased lipid peroxidation. Retinoic acid in the cell supernatant and
cytoplasm of these cells was determined using HPLC. The rate of apoptosis was
assessed by quantification of caspase-3-like activity. The lipid peroxidation
was measured using the malondialdehyde method. Supplementation of retinoic acid
was tested in the setting of apoptosis. RESULTS. Free iron ions led to a rapid
loss of retinoic acid in the supernatant and the corneal endothelial cells.
This was correlated with rising levels of malondialdehyde following oxidative
stress and increased apoptosis. Supplementation of retinoic acid alone
significantly reduced oxidative stress and apoptosis in the respective cells.
CONCLUSION. In this study the authors present a novel in vitro model to test
the direct influence of pro-oxidative species on corneal endothelial cells. The
authors also prove that supplementing corneal endothelial cells with retinoic
acid sufficiently prevents free radical injury and apoptosis.

PMID: 15549323 [PubMed - as supplied by publisher]

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