What is Xerophthalmia? Learn about its Causes, Symptoms & Treatments

Xerophthalmia is a preventable form of vitamin A deficiency, which is an umbrella term for all less severe to severe forms. If your stage is still in the beginning of keratomalacia, you can manage symptoms and reverse them with timely treatment plans. Stay tuned for many such interesting facts and must-dos when your eyes are extremely dry due to a deficiency in nutrients. 

What is Xerophthalmia? 

Xerophthalmia is a clinical spectrum when vitamin A is deficient in our eyes. In the less severe spectrum, there is night blindness and Bitot spots; as severe as it gets, one experiences corneal xerosis and Keratomalacia. 

Xerophthalmia stands for dry eyes and is an aggregate of all problems caused by the ocular manifestation of vitamin A deficiency in our eyes. 

The joint committee of WHO and USAID committee, 1976, states, “Xerophthalmia is a reserved term for ocular manifestations of vitamin A deficiency, including structural changes affecting the conjunctiva, cornea, and occasionally retina. Not only this but the term also covers the biophysical disorders of retinal rods and cone functions. “

Types of Xerophthalmia 

As per WHO Classification (1982), it is classified in 

• XN Night Blindness
• X1A Conjunctival xerosis (mucin deficiency of eyes) 
• X1B Bitot’s spots 
• X2 Corneal xerosis 
• X3A Corneal ulceration/ Keratomalacia affects less than one-third of the corneal surface
• X3B  Keratomalacia affecting more than one-third of the corneal surface
• XS Corneal scar due to xerophthalmia 
• XF Xerophthalmic fundus 

Causes of Xerophthalmia

Vitamin A deficiency is the primary cause of Xerophthalmia. If your regular diet is low in vitamin-A foods, such as carrots, you are no exception. The time when you have issues like diarrhea, inflammatory bowel disease, or celiac disease is when your body absorbs less vitamin A than usual from the intestine. 

When you are pregnant and breastfeeding, your body demands more vitamin A than usual; that's where any sort of deficiency can be seen. Even if you have liver diseases, the vitamin A release is slowed or impaired. 

Effects of Vitamin A deficiency

Besides Xerophthalmia, the effect on the eyes, this vitamin A deficiency also results in growth retardation due to impairment in skeletal formation. Keratogenic papules (follicular papules of various sizes) occur on the skin when you have vitamin A deficiency in your body, known as phrynoderma in medical terms. 

In some cases of vitamin A deficiency, males experience issues with sterility for which the doctor cites the reason for degeneration of germinal epithelium. The effects of vitamin deficiency do not end here. 

Keratinization of epithelial cells of the gastrointestinal tract, urinary tract, respiratory tract, and urinary stones are also some other effects. In addition, the plasma level of retinol-binding protein is also decreased, and skin is usually more dry and rough. 

Vitamin A deficiency is also characterized by acne, breakouts, poor wound healing, and throat and chest infections. Many of us are unaware that people with vitamin A deficiency face issues regarding infertility and experience trouble conceiving. 

Night Blindness

Night (scotopic) vision is a function of rods and rhodopsin, and when it fails due to a lack of vitamin A, night blindness results. Most commonly, it affects children aged 2–6 years and adult women who are lactating. It is not immediately blinding but poses significant health risks.

Causes of Night blindness include, 

• Vitamin A deficiency
• Retinitis pigmentosa and other tapetoretinal 
• Degeneration 
• Congenital night blindness ( pathological myopia and peripheral cortical cataract)
• Congenital high myopia 
• Familial congenital night blindness 
• Oguchi’s disease

Symptoms

• Difficulty adapting to darkness.
• Increased fear or hesitation in dark environments.
• Behavioral changes in children, such as reduced activity after sunset.

Diagnosis

• Clinical Assessment: Observing symptoms and asking caregivers about changes in behavior related to light conditions.
• Serum Retinol Levels: Measuring vitamin A levels can help confirm deficiency.
• Dark Adaptometry: Tests may be conducted to evaluate the ability to see in low light

Conjunctival xerosis 

Conjunctival xerosis is a condition where one can note the dull and wrinkled appearance of the conjunctiva, as classified X1A by WHO in 1982. 

Diagnosis of Conjunctival xerosis

• Serum Vitamin A Levels: Low levels can confirm vitamin A deficiency.
• Impression Cytology: This test can assess changes in conjunctival cells

X1B Bitot’s spots 

Bitot's spots are whitish, opaque, and foamy in appearance, often developing in the temporal side of the conjunctiva. These white triangular plaques result from a combination of desquamated epithelial cells and bacteria, particularly Corynebacterium xerosis. This results in dry patches that accumulate keratin. They emerge like sand banks at the receding tide, wrestling mucin deficiency in the eyes. 

Epidemiology

Bitot's spots typically occur in children aged 3 to 6 years and are associated with longstanding vitamin A deficiency

X2 Corneal xerosis 

The cornea appears dull and hazy, often with superficial, punctate epithelial lesions that can progress to more severe forms of damage, including corneal melting (keratomalacia).

Age Group: Most commonly observed in children aged 1 to 4 years, 

The early signs and symptoms of corneal xerosis are, 

• Dryness and hazy appearance 
• Bilateral punctate epithelial erosions 
• Photophobia or sensitivity to light
• Blurred vision or fluctuations in visual acuity in low-light 
• Burning sensation and irritation in the eyes 
• Discomfort and grittiness in eyes due to dryness and irritation 
• If untreated, corneal xerosis can lead to ulceration and potentially result in blindness.

Corneal ulceration/ Keratomalacia 

Keratomalacia has a permanent liaison in the body, and bitot spots can be present on the sclera. This can be either more or less than 1/3rd of the corneal surface, as classified as X3A and X3B by WHO. The corneal necrosis has no inflammatory reaction. 

Symptoms of Keratomalacia include

• Softness of cornea 
• Opacity develops 
• Corneal infection 
• Delayed dark adaptation 

Corneal scar due to xerophthalmia 

Corneal scar results when the cornea becomes necrotic and can melt away. There is a rapid occurrence of symptoms after corneal ulceration, it progresses to result in corneal damage. These results in bilateral and symmetric scars on the cornea. 

There are surgical options like corneal transplantation to restore vision. The at-risk population needs regular screening to prevent the ultimate scarring, which may or may not cover the pupillary area. 

XF Xerophthalmic fundus 

Xerophthalmic fundus is characterized by typical seed-like raised, white liaisons, scattered uniformly at or over the part of the optic disc. It usually disappears after 2-4 months of regular vitamin A therapy. 

Walds Visual Cycle and Vitamin A Deficiency:

The Walds visual cycle, as described above, is crucial for normal vision. Vitamin A deficiency can disrupt this cycle, leading to night blindness.

The synthesis of visual pigment requires vitamin A. It is present in the cytoplasm of rods and the pigment layer of the retina as all-trans-retinol. If there is excess retinal it is converted back to vitamin A. 

1. Reduced Retinol 

Retinol is a form of vitamin A, and if there is reduced retinol there is difficulty in regeneration of visual pigments, its conversion, and transportation. This is a drawback of xerophthalmia in that you have an accumulation of toxic intermediates and long-term ocular health risks. 

2. Insufficient 11-cis Retinal 

11-cis retinal cell as a chromophore binds to opsins and responds to light, in case there is insufficient 11-cis retinal, the visual perception is not achieved. 

3. Impaired Vision

You see that the decrease in rhodopsin molecules is due to xerophthalmia. It results in an altered visual cycle and compromises your ability to see at night.

Treatment of Xerophthalmia 

Till X3A keratomalacia, when the corneal ulcer is less than 1/3rd of the corneal surface, it can be treated or reversed. We understand how it is done. 

1. Prophylaxis 

In the short-term approach, supplement to babies and lactating mothers but given in normal dose. Coming to the middle term, there is food fortification with vitamin A and the long-term goal is to have food rich in vitamin A and incorporate it into a regular diet. There can be adverse ocular effects of vitamin A supplements and drugs like, 

• Papilloedema 
• Retinal hemorrhages 
• Loss of eyebrows and lashes 
• Nystagmus 
• Diplopia and blurring of vision

2. To treat deficiency (till X3B)

Local Ocular therapy can be done in the stage of conjunctival xerosis.  For dryness, you give artificial tears but for keratomalacia, you have to give treatment for bacterial corneal ulcers with antibiotics.

Oral vitamin A intake and intramuscular injections are suitable for any person more than 1 year. This is repeated the following day and after 4 weeks to show the result. Consult a nearby eye doctor for the required dosage for such treatments. 

Conclusion 

Having trouble with your eyes? If your eyes feel gritty or you're worried about any eye issues, don't wait. Book an eye check-up with the Vision Concern clinic today. Eye care experts and surgeons help you figure out what's going on and get your eyes back to feeling great once again, with real-time diagnosis, possible reversible changes, treatment, and care plan.