Sir,
Night blindness is the earliest sign and milder form of vitamin A deficiency (VAD), in which an individual has difficulty seeing in low-light conditions. VAD follows a spectrum from night blindness to necrosis of the cornea, so the identification of early signs of VAD is very important. The national vitamin A prophylaxis programme against preventable blindness was introduced in the fourth five-year plan in 1969 on the recommendation of the Indian Council of Medical Research (ICMR) National Institute of Nutrition, Hyderabad. However, the problem of VAD still exists in the country.[1] There is known evidence that VAD contributes to maternal mortality and poor outcomes during pregnancy and lactation. Pregnant women are susceptible to VAD, especially during the third trimester because of rapid foetal development and physiological increase in blood volume. Vitamin A supplementation has been found to decrease the risk of maternal anaemia, maternal infection, and maternal night blindness.[2] Vitamin A doses are very important in preventing childhood mortality and morbidity, especially in children aged six months to five years.[3]
VAD is detected by the serum retinol method, which is costly and requires laboratory support and skilled manpower, thus making it irrelevant for screening. The team came across an appropriate technology named EmTech A metre which is a black adaptometre that measures the intensity of light to visualise the object and indirectly predicts VAD and other allied conditions.[4,5] The light intensity is measured in 0–999 absolute units, where a picture visible between 1–250 units indicates no VAD, 251–500 probably no VAD, 501–900 VAD, and 901–999 severe VAD or other problem that requires a specialist opinion. The team has used the instrument to see the effectiveness of the Vit-A prophylaxis programme and its feasibility on the ground. The national vitamin A prophylaxis activity is conducted twice a year by the government. The current study took this opportunity to study the efficacy of the EmTech A metre. The children aged 3–6 years who are attending Anganwadi were recruited for the study. In the pre-study period, baseline sociodemographic data were collected. The study was conducted with the permission of the Institutional Ethical Committee and Vadodara Municipal Corporation authorities.
There were 80 children whose reading and other details were collected pre Vit-A supply and after a week of Vit-A supplement. The results are presented in Table 1 in brief. The first row of the table shows that the mean absolute light unit required before Vit-A supply was 496.97 ± 244.2 standard deviation (SD). It was reduced to 344.66 ± 166.92 SD. This reduction was statistically highly significant. The light requirements were found to reduce all different variables in pre and post Vit-A supplementation like gender, age group, background, socio-economic status and anthropometric evaluation.
Table 1.
Distribution of mean and SD light unit requirements with EmTech A metre during pre and post Vit-A with various variables
| Variables and relation | Pre vitamin A supplement Mean±SD | Post vitamin-A supplement Mean±SD | Paired t-test | P |
|---|---|---|---|---|
| Children (n=80) | 496.975±244.20 | 344.66±166.92 | 8.68 | 0.00001 |
| Gender | ||||
| Male (40) | 479.875±246.32 | 344.825±168.68 | 5.32 | 0.000005 |
| Female (40) | 514.075±244.20 | 344.5±166.94 | 7.62 | 0.00 |
| Age | ||||
| 36–47 (28) | 510.75±247.54 | 346.89±163.27 | 5.4936 | 0.000008 |
| 48–59 (30) | 480.1±240.22 | 320.6±164.69 | 5.2117 | 0.000014 |
| 60–72 (22) | 502.45±244.79 | 374.63±167.57 | 4.153 | 0.00045 |
| Previous history of disease | ||||
| Yes (38) | 477.92±247.86 | 332.57±167.05 | 5.930 | 0.000001 |
| No (42) | 514.214±244.20 | 355.59±166.94 | 6.289 | 0.00 |
| Socioeconomic class | ||||
| Upper (6) | 457.5±241.33 | 307.16±159.25 | 1.914 | 0.11 |
| Middle (23) | 524.52±244.88 | 366.30±167.74 | 4.577 | 0.00014 |
| Lower (51) | 485.32±245.62 | 336.62±167.86 | 7.049 | 0.00 |
| Exclusive breastfeeding | ||||
| Yes (68) | 488.33±244.20 | 340.98±166.94 | 7.647 | 0.00 |
| No (12) | 545.91±247.92 | 365.5±168.30 | 4.22 | 0.0014 |
| Mid-upper arm circumference | ||||
| <13.5 cm (20) | 491.35±244.21 | 345.45±166.94 | 3.89 | 0.0009 |
| >13.5 cm (60) | 498.85±245.37 | 344.4±167.97 | 7.738 | 0.00 |
| Weight | ||||
| Male (33) | ||||
| < −2SD (11) | 438.27±213.18 | 283.72±142.38 | 3.70 | 0.004 |
| > −2SD (22) | 510.86±210.24 | 369.5±140.09 | 3.82 | 0.0009 |
| Female (35) | ||||
| < −2SD (10) | 472.7±206.37 | 334.7±144.00 | 2.234 | 0.052 |
| > −2SD (25) | 527.88±209.34 | 338.96±149.54 | 7.30 | 0.00 |
| Height | ||||
| Male (33) | ||||
| < −2SD (9) | 478.33±210.24 | 322.11±140.09 | 2.72 | 0.026 |
| > −2SD (24) | 489.79±211.30 | 348.04±141.77 | 4.35 | 0.00023 |
| Female (35) | ||||
| < −2SD (7) | 426.28±201.74 | 273±145.94 | 2.34 | 0.05 |
| > −2SD (28) | 533.5±207.75 | 353.92±145.03 | 6.484 | 0.000001 |
| Head circumference and chest circumference | ||||
| CC >HC (75) | 493.81±244.20 | 349.50±166.94 | 8.20 | 0.00 |
| CC ≤HC (5) | 481.8±240.40 | 248.8±158.21 | 2.90 | 0.04 |
| Vaccination status | ||||
| Fully immunized (16) | 489±246.82 | 361.93±168.63 | 3.120 | 0.007 |
| Completed (57) | 492.64±245.04 | 334.31±162.73 | 7.321 | 0.00 |
| Due (7) | 550.42±239.9 | 389.42±172.14 | 5.238 | 0.0019 |
The observation has revealed that Vit-A deficiency is still prevalent in the community. The light requirements reduced post Vit-A supplement in the study group. This shows the effectiveness of the programme and the instrument. This is the first study, though it was not standardised but conducted using the EmTech A metre. The major limitation of the study was that the study did not compare the EmTech A metre reading with the serum retinol level. The second one is that the study was conducted among children three to six years of age group. To overcome these limitations, it is recommended to conduct a control study among the adult population and compare it with serum retinol levels to determine the standard sensitivity and specificity of the instrument.
Thus, the researcher and innovator are requesting the scientific community to plan a larger study and use such appropriate technology with programme to reduce Vit-A toxicity among children.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
References
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