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 Table of Contents  
CASE REPORT
Year : 2023  |  Volume : 3  |  Issue : 1  |  Page : 89-91

Nyctalopia in alcoholic liver disease–induced vitamin A deficiency: Can serum retinol levels be relied upon?


1 Shri Bhagwan Mahavir Vitreoretinal Services, Medical Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
2 Vision Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India

Date of Submission28-Jul-2022
Date of Acceptance07-Sep-2022
Date of Web Publication20-Jan-2023

Correspondence Address:
Rajiv Raman
Shri Bhagwan Mahavir Vitreoretinal Services, Medical Research Foundation, Sankara Nethralaya, 18 College Road, Chennai - 600 006, Tamil Nadu
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/ijo.IJO_1830_22

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  Abstract 


We report a case of a 52-year-old man with diminution of vision in both eyes at night for 15 days with mild retinal pigment epithelium changes at the macula and a tessellated background on fundus examination. Given his history of chronic alcohol consumption and jaundice two weeks back, vitamin A deficiency was contemplated. Electroretinogram (ERG) showed diminished responses. Serum retinol was 17 μg/dl. On supplementation with vitamin A, symptoms improved and ERG was normal; however, serum retinol levels were still low at 8.98 μg/dl. Thus, serum retinol does not necessarily indicate response to treatment, and ERG is necessitated in such cases.

Keywords: Electroretinogram, night blindness, serum retinol, vitamin A deficiency


How to cite this article:
Nadig RR, Kashyap H, Nagarajan R, Raman R. Nyctalopia in alcoholic liver disease–induced vitamin A deficiency: Can serum retinol levels be relied upon?. Indian J Ophthalmol Case Rep 2023;3:89-91

How to cite this URL:
Nadig RR, Kashyap H, Nagarajan R, Raman R. Nyctalopia in alcoholic liver disease–induced vitamin A deficiency: Can serum retinol levels be relied upon?. Indian J Ophthalmol Case Rep [serial online] 2023 [cited 2023 Feb 1];3:89-91. Available from: https://www.ijoreports.in/text.asp?2023/3/1/89/368180



Vitamin A (retinol) is a lipid-soluble compound that plays a key role in the visual cycle. The present knowledge on it was enriched by the work of Dowling and Wald[1] who elucidated on “capacity for sight under variable levels of light.” Their studies explicated the need for adequate functioning of “three integrative parts of the eye: the pupil, the rods and cones, and rhodopsin in the rods” for night vision.[1]

Rhodopsin is crucial for night vision. Various nutrients are required in the regeneration of rhodopsin, including proteins, vitamins, and minerals like zinc which significantly affect the metabolism of vitamin A. Although poor dietary intake is the cause in underdeveloped countries, in developed countries nyctalopia due to vitamin A deficiency occurs in cases of chronic alcoholism and cirrhosis that lead to impaired liver function.[2]

Deficiency causes varied ocular manifestations, the earliest being night blindness. Therefore, a high index of suspicion to detect the deficiency and start early treatment are essential. This can reverse ocular complications prior to permanent vision loss.

Monitoring the changes in ERG in a case of vitamin A deficiency (VAD)-associated night blindness aids in demonstrating functional recovery.[3]


  Case Report Top


A 52-year-old man presented with diminution of vision in both eyes at night for 15 days. Best-corrected visual acuity (BCVA) in the right eye was 6/7.5, N6 and in the left eye was 6/12, N8. Both eyes revealed mild retinal pigment epithelium changes at the macula and a tessellated background on fundus examination [Figure 1]a. Color vision was normal. Visual fields showed low reliability.
Figure 1: (a) Color Fundus photo of a 52-year-old patient at initial presentation. (b) Color fundus photo of the same patient at the subsequent visit

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Given his history of chronic alcohol consumption and jaundice two weeks back, vitamin A deficiency was contemplated. The patient was investigated for serum vitamin A levels and was found to be reduced at 17 μg/dl (normal being 30–80 μg/dl). A full-field ERG performed according to ISCEV Standards demonstrated absent scotopic responses to dim flash dark adapted (DA) 0.01, reduced A and B wave amplitudes for DA 3.0 and DA 10.0 tests, and significant reduction in oscillatory potential amplitudes. Reduced B wave amplitudes in light adapted (LA) 3.0 and 3.0 Hz flicker were also seen [Figure 2]a.
Figure 2: (a) Full-field ERG of a 52 year-old patient at initial presentation. (b) Full-field ERG of the same patient at the subsequent visit

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Thus, it was established that the patient had alcoholic liver disease–induced vitamin A deficiency which caused acquired night blindness. He was advised vitamin A supplementation of 25000 IU orally daily for a month.

On follow-up, patient was symptomatically better. BCVA in both eyes were 6/6, N6 with a fundus picture similar to the initial visit [Figure 1]b. A repeat full-field ERG showed normal responses [Figure 2]b. However, serum vitamin A levels were still low at 8.98 μg/dl.


  Discussion Top


Chronic liver diseases are mostly coupled with vitamin A deficiency. The vitamin A status can be assessed by measuring the serum retinol concentration. A study on “The vitamin A spectrum” stated that concentration of serum retinol below 0.5 μmol/L (14 μg/dL) could point toward deficiency, whereas levels more than 1.4 μmol/l (39.2 μg/dl) were suggestive of normal dark adaptation and therefore normal vitamin-A-dependent retinal function.[4] On analyzing the results of a patient, Wachtmeister et al.[5] discovered that “a serum retinol level above 0.7 μmol/L (19.6 μg/dL) predicts a normal or close to normal dark-adapted rod threshold.”

In our case, we observed abnormal ERG at 17 μg/dl when the patient had an acute episode of jaundice and thus compromised liver stores.

The serum retinol concentration is maintained by the circulating retinol from hepatic stores; therefore the levels of serum retinol may be normal even when the total body stores are low.[6] Thus, the total vitamin A status is not reflected appropriately by the serum retinol levels.

Abbott-Johnson et al.[7] showed “no significant correlation between DA thresholds and biochemical parameters (vitamin A, RBP, vitamin A/RBP ratio and zinc)”. The authors also stated that in spite of no demonstrable changes in retinol levels, there was considerable improvement in DA and it may have been due to storage of retinyl ester in the retina. The retinal pigment epithelium-choroid complex has the maximum concentration of vitamin A next only to liver, and this could effectively act as a buffer for the retina against hypovitaminosis.[7]

It was found that daily oral vitamin A supplements of 3300 μg was associated with significant (P < 0.05–0.005) improvement in dark adaptation and retinol-binding protein. Thus, the authors implied that supplementation of vitamin A stimulates retinol binding protein release from the liver which in turn enhances the transport and delivery of retinol to peripheral tissues like the retina. This may act as a significant factor in the improvement of vitamin A status and associated night blindness in patients with cirrhosis.[8]

In our patient, liver function was impaired at initial visit which led to decrease in serum retinol levels. However, the improvement in the ERG with decrease in vitamin A levels post supplementation led us to hypothesize that with the improvement in liver function, the protein component (like retinol-binding protein) improved which caused more binding of vitamin A and an acute phase of probable decrease in the free serum retinol level.

A WHO report states that ERG has high relevance, credibility, comparability, time sensitivity and information in assessing night blindness.[9] Thus, ERG monitoring is most reliable and indicative of response to supplementation.


  Conclusion Top


Thus, it can be concluded that in a case of nyctalopia due to alcoholic liver disease–induced vitamin A deficiency, ERG monitoring is of utmost importance as serum retinol monitoring does not necessarily indicate response to treatment.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

1.
Dowling JE, Wald G. Vitamin A deficiency and night blindness. Biochemistry 1958;44:648-61.  Back to cited text no. 1
    
2.
Halsted CH. Nutrition and alcoholic liver disease. Semin Liver Dis 2004;24:289-304.  Back to cited text no. 2
    
3.
Poornachandra B, Jayadev C, Sharief S, Shetty R. Serial ERG monitoring of response to therapy in vitamin A deficiency related night blindness. BMJ Case Rep 2022;15:e247856. doi: 10.1136/bcr-2021-247856.  Back to cited text no. 3
    
4.
Russell RM. The vitamin A spectrum: From deficiency to toxicity. J Clin Nutr 2000;71:878-84.  Back to cited text no. 4
    
5.
Wachtmeister L, Björkhem I, Diczfalusy U, Emami A. Attempts to define the minimal serum level of vitamin A required for normal visual function in a patient with severe fat malabsorption. Acta Ophthalmol (Copenh) 1988;66:341-8.  Back to cited text no. 5
    
6.
Tanumihardjo SA. Vitamin A: Biomarkers of nutrition for development. Am J Clin Nutr 2011;94:658S-65S.  Back to cited text no. 6
    
7.
Abbott-Johnson WJ, Kerlin P, Abiad G, Clague AE, Cuneo RC. Dark adaptation in vitamin A-deficient adults awaiting liver transplantation: Improvement with intramuscular vitamin A treatment. Br J Ophthalmol 2011;95:544-8.  Back to cited text no. 7
    
8.
Russell RM, Morrison AS, Smith FR, Oaks EV, Carney EA. Vitamin-A reversal of abnormal dark adaptation in cirrhosis: Study of effects on the plasma retinol transport system. Ann Intern Med 1978;88:622-6.  Back to cited text no. 8
    
9.
Taren D. Historical and practical uses of assessing night blindness as an indicator for vitamin A deficiency. World Health Organization. Report: Priorities in the Assessment of Vitamin A and Iron Status in Populations, Panama City, Panama, 15–17 September 2010. Geneva: World Health Organization; 2012.  Back to cited text no. 9
    


    Figures

  [Figure 1], [Figure 2]



 

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