Effects of Selenium and Melatonin on Ocular Ischemic Syndrome
Condition: Anterior Segment Ischemia (Diagnosis)
MeSH terms: Ischemia
Study type: Interventional
Phase: Early Phase 1

Summary: 
      ABSTRACT:

      PURPOSE: To determine the effects of selenium, melatonin and selenium + melatonin
      administered for one month on anterior chamber (AC ) malondialdehyde (MDA) and AC glutathione
      (GSH) levels in patients with Ocular ischemic syndrome.

      MATERIAL AND METHODS: Thirtyfive patients were included in the study. Study groups were
      formed as follows: 1-Control group, 2-Ischemia group 3-Selenium Ischemia group, 4-Melatonin
      Ischemia group, 5-Selenium + Melatonin + Ischemia group. AC samples were obtained. MDA and
      GSH levels in AC samples were evaluated.

      RESULTS : MDA levels were significantly increased in ischemia groups. Selenium and melatonin
      supplementation resulted in reduction of MDA levels and significant increase in GSH values.

      DISCUSSION: Increased lipid peroxidation associated with ischemia of the anterior segment has
      been prevented by selenium and melatonin supplementation.

      KEYWORDS: Ocular ischemic syndrome, selenium, melatonin, MDA, GSH
    

Detailed description: 
      In this retroprospective study, patients who presented with the clinical features of OIS or
      who had a history of OIS and who had visited the Department of Ophthalmology or who were
      referred by the Department of Cardiology were considered for inclusion. The patients of OIS
      were included according to the following criteria (26-29) (1) when the stenosis of the
      ipsilateral (to the affected eye) internal carotid artery (ICA) was >50% and the ICA blood
      flow velocity was abnormal; (2) abnormal ocular symptoms and/or signs that could not be
      explained by other ocular diseases. The ocular symptoms included amaurosis fugax , visual
      loss ,floaters, metamorphopsia, phosphenes ,diplopia ,and ocular/periorbital pain . Most
      patients (88.10%) complained of constitutional symptoms, such as headache, syncope,
      palpitations, hemiplegia, and claudication.The patients who were suffered from other ocular
      diseases, including primary glaucoma, uveitis, age-related macular degeneration, symmetrical
      proliferative diabetic retinopathy, choroidal detachment, retinal detachment, hereditary eye
      diseases, ocular tumor, or ocular trauma, were excluded. Informed consent was acquired from
      all of the participants before the collection of clinical materials. The study adhered to the
      tenets of the Declaration of Helsinki.

      All of the OIS patients underwent carotid artery color Doppler imaging (CDI) and/or computed
      tomographic angiography (CTA) to identify the ICA stenosis. Detailed ophthalmic examinations,
      including best-corrected visual acuity (BCVA), intraocular pressure (IOP), slit-lamp exam,
      and funduscopy were performed at each follow-up visit. Constitutional and ocular symptoms,
      medical history (arterial hypertension, diabetes mellitus (DM), hyperlipidemia (HLP),
      coronary heart disease, cerebrovascular disease, and so on), the clinical department of the
      first visit, and treatments were also recorded. A statistical description was generated using
      SPSS for Windows, version 22.0.

      Twenty eight OIS patients were recruited in our study, including 20 males (%71,4) and 8
      females (%28,6). The age of onset ranged from 58 to 87 years (65.10 ± 10.95), with the
      majority of patients aged between 61 and 75 years (69.50%). No statistically significant
      difference was found for gender and age between groups (p <0,01) The study was conducted at
      Trabzon Numune Training and Research Hospital between May 2014 and September 2016. Approval
      from the Trabzon Numune Training and Research Hospital Ethics Committee was obtained. All
      procedures performed in studies involving human participants were in accordance with the
      ethical standards of the institutional and/or national research committee and with the 1964
      Helsinki declaration and its later amendments or comparable ethical standards.

      Patients were divided into five groups.

        1. Control group: Seven healty person were included in this group. After topical anesthesia
           approximately 0.1 cc samples were obtained from the anterior chamber.

        2. Ischemia group: Seven OIS patients were included in this group. Under topical
           anesthesia, 0.1 cc samples were obtained from the AC.

        3. Selenium + Ischemia group: Seven OIS patients were included in this group. The patients
           in this group were supplemented with oral selenium at 0.1mg/kg doses twice daily for one
           month. After selenium supplementation period was completed, AC sampling as described
           above.

        4. Melatonin + Ischemia group: Seven OIS patients were included in this group. The patients
           in this group were supplemented with oral melatonin 0.5 mg/kg/day doses twice daily for
           one month. After supplementation was completed 0.1 cc sampling from AC.

        5. Selenium + Melatonin + Ischemia group: Seven OIS patients were included in this group .
           The patients were supplemented with selenium and melatonin for one month as described
           above, subsequently 0.1 cc sampling from AC.

      In order to determine AC Malondialdehyde (MDA) levels, 2.5 ml of 10% TCA
      (tricholoroessigaurekrist.) was put in a test tube, 0.1 ml of AC sample from the patients was
      added. Tubes were vortexed and sealed. Incubation was applied for 15 minutes in 90ºC water
      bath. They were cooled in cold water and their absorbance values were read with reference to
      blank on spectrophotometer at 532 nm. Results were presented as nmol/ml. At the beginning of
      the testing, blank was prepared by placing the same amount of distilled water instead of
      plasma in the blank tube and performing the same procedures. In order to measure AC
      Glutathione (GSH) levels, AC samples placed in tubes containing EDTA were centrifuged at 3000
      rpm for 5 minutes. The samples were washed 3 times with 0.9% saline solution and 50μl of each
      sample was derived. Consecutively, 450μl of distilled water and 500μl of 10% sulfosalicylic
      acid were added. The mixture was cooled in ice for 1 hour and then centrifuged at 4000 rev
      for 3 minutes. Subsequently, 200μl of the supernatant was derived and consecutively 8 ml of
      phosphate buffer with pH of 6.8, 78 μl of 1 N NaOH and 100μl of Ellman solution were added.
      After waiting for 5 minutes, absorbance values in reagent tube were read with reference to
      distilled water on spectrophotometer at 412 nm.Ellman solution was prepared by dissolving 100
      mg of 5'-5'-dithiobis-2-nitrobenzoic acit (DTNB) in 100 ml of pH 7.8 phosphate buffer.
      Glutathione standard was prepared as 15.34mg/100 ml by dissolving 15.34 mg of reduced
      glutathione in 100 ml of 1 nm sodium EDTA. Results were presented as mg/dl.
    

Intervention name(s): SELENIUM; MELATONIN
Intervention type(s): Drug; Drug
Intervention description(s): Increased lipid peroxidation associated with ischemia of the anterior segment has been prevented by selenium supplementation.; Increased lipid peroxidation associated with ischemia of the anterior segment has been prevented by melatonin supplementation.
Other intervention name(s): MELATONIN; SELENIUM
Intervention MeSH terms: Selenium; Melatonin
Allocation: Randomized
Intervention model: Sequential Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: Ocular ischemic syndrome; selenium; melatonin; MDA; GSH