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Definition
A cataract is a disorder that causes the eye’s lens to become opaque or clouded, impairing vision. This cloudiness makes it difficult for light to reach the retina, which causes vision to become dim or hazy. Cataracts can occur in one or both eyes and usually grow slowly. Although they can be brought on by damage, heredity, or specific medical problems, they are most frequently linked to ageing.
As cataracts develop, individuals may experience several changes in their vision. The severity and progression of the symptoms can vary, but they generally worsen over time if left untreated (Liu et al, 2017).
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Symptoms
Common symptoms of cataracts in adults are listed in Table 1.
| Table 1. Common symptoms of cataracts in adults | |
| Blurry or clouded vision | One of the most common and noticeable symptoms of cataracts is blurry vision. The cloudy lens causes light to scatter as it enters the eye, which can result in the perception of blurred, hazy, or distorted images. In early stages, the clouding may be mild, and individuals might only notice blurriness in specific situations, such as when reading or driving. |
| Fading or yellowing of colours | Cataracts can cause colours to appear duller, faded, or yellowed. The cloudy lens filters out some of the light that enters the eye, affecting the way colours are perceived. |
| Increased sensitivity to light and glare | Glare becomes more problematic for people with cataracts. They may experience discomfort when exposed to bright lights, such as sunlight or headlights while driving at night. Individuals with cataracts often report that |
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Aetiology
The development of cataracts involves the progressive clouding of the eye’s natural lens due to structural and biochemical changes in its proteins and fibres. The lens, which is normally transparent, becomes increasingly opaque, impairing the transmission and the focusing of light onto the retina. A normal lens is composed of on average two‑thirds water and one‑third protein, with lens proteins amounting to 33% of its wet weight; over 90% of these proteins are crystallins, which maintain transparency and refractive properties (Michael and Bron, 2011). Lens fibres lack nuclei and organelles to reduce the scattering of light, and the lens has a unique system to maintain homeostasis and clarity over time (Nartey, 2017).
The key pathophysiological processes in cataract formation are:
- Protein aggregation: with age or damage, lens proteins (crystallins) undergo oxidation, glycation, and denaturation, leading to the formation of insoluble aggregates. These aggregates scatter light, causing lens opacification.
- Oxidative stress:
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Diagnosis
Cataracts are diagnosed through a comprehensive eye examination performed by an ophthalmologist or optician. The diagnostic process typically involves several steps to assess the health of the eyes and determine the presence, type, and severity of cataracts (Cicinelli et al, 2023):
- Medical history: the doctor will begin by taking a thorough medical history, asking questions about vision changes, symptoms, overall health, family history of cataracts, and any existing medical conditions (such as diabetes or previous eye injuries) that might contribute to cataract formation. The doctor will also inquire about any medications the individual is taking, as some medications can increase the risk of developing cataracts.
- Visual acuity test: this is one of the first tests performed during an eye exam. The visual acuity test measures how well you can see at various distances.
- Slit-lamp examination: the slit-lamp examination is a pivotal test in diagnosing cataracts. A slit lamp is a microscope that provides a magnified
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Management
Non-surgical management (early stages)
In the early stages of cataract development, when symptoms are mild and vision changes are not significantly impairing daily life, the management focuses on symptom relief and improving vision without surgery. This can involve the following strategies:
- Updated prescription glasses or contact lenses
- Magnifying lenses
- Anti-glare coating on glasses
- Using sunglasses.
Surgical treatment (advanced stages)
Surgery is the only definitive treatment for cataracts and is considered when cataracts significantly impair vision and affect daily activities, such as driving, reading, or working. Cataract surgery is considered one of the most common and safe procedures performed worldwide (McGhee et al, 2020).
Phacoemulsification
Phacoemulsification (phaco) is the most widely used technique for cataract surgery. It involves making a small incision in the cornea, through which an ultrasonic probe is inserted. This probe breaks up (emulsifies) the cloudy lens into tiny fragments, which are then suctioned out. The empty lens
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NMC proficiencies
Nursing and Midwifery Council: standards of proficiency for registered nurses
Part 4: Providing and evaluating care
4.5. Demonstrate the knowledge and skills required to support people with commonly encountered physical health conditions, their medication usage and treatments, and act as a role model for others in providing high quality nursing interventions when meeting people’s needs.
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Resources
Cicinelli MV, Buchan JC, Nicholson M, Varadaraj V, Khanna RC. Cataracts. Lancet. 2023;401(10374):377-389. Doi: 10.1016/S0140-6736(22)01839-6.
Delbarre M, Froussart-Maille F. Sémiologie et formes cliniques de la cataracte chez l’adulte [Signs, symptoms, and clinical forms of cataract in adults]. J Fr Ophtalmol. 2020;43(7):653-659. French. Doi: 10.1016/j.jfo.2019.11.009.
Liu YC, Wilkins M, Kim T, Malyugin B, Mehta JS. Cataracts. Lancet. 2017;390(10094):600-612. Doi: 10.1016/S0140-6736(17)30544-5.
McGhee CNJ, Zhang J, Patel DV. A perspective of contemporary cataract surgery: the most common surgical procedure in the world. Journal of the Royal Society of New Zealand. 2020;50(2), 245–262. Doi: 10.1080/03036758.2020.1714673.
Michael R, Bron AJ. The ageing lens and cataract: A model of normal and pathological ageing. Philosophical Transactions of the Royal Society B: Biological Sciences. 2011;366(1568):1278–1292. Doi:10.1098/rstb.2010.0300.
Nartey A. The Pathophysiology of Cataract and Major Interventions to Retarding Its Progression: A Mini Review. Adv Ophthalmol Vis Syst. 2017;6(3): 00178. Doi: 10.15406/aovs.2017.06.00178.
National Institute for Health and Care Excellence. Overview:
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