- Summary
- Secondary cataract
- Cataract secondary to medication
- Traumatic cataract
- Aetiology
- Radiology in Focus
- Ultrasound biomicroscopy (UBM)
- Optical Coherence Tomography (OCT)
- B-scan ultrasound
- References
- Author(s)
Summary
A secondary (or complicated) cataract is one that develops as a consequence of pre-existing ocular disease, such as chronic anterior uveitis or acute angle closure glaucoma. Trauma to the eye, either blunt or penetrating, may also result in cataract formation. Ocular trauma is the leading cause of unilateral cataract in young patients.
Secondary cataract
A secondary cataract develops as a complication of a primary ocular pathology, importantly:
- Chronic anterior uveitis
- Acute angle closure glaucoma
- High myopia
- Hereditary fundus dystrophies
The table below summarises the key learning points concerning these ocular diseases and their association with cataract.
Condition | Notes |
Chronic anterior uveitis | - Commonest cause of secondary cataract
- Chronicity and severity of inflammation related to likelihood of cataract formation
- Steroids (topical/systemic) used in management can also cause cataracts
- The first finding is typically a polychromatic lustre on the posterior lens, followed by opacities on the posterior and/or anterior lens |
Acute angle closure glaucoma | -Ā Ā Ā Ā Ā Ā Ā āGlaukomfleckenā (small white-grey anterior subcapsular/capsular opacities) form in the pupillary area, signifying infarcts of the lens epithelium |
High myopia (aka pathological myopia) | -Ā Ā Ā Ā Ā Ā Ā Associated with posterior subcapsular lens opacity and early-onset nuclear sclerosis (which ironically can worsen the myopia) |
Hereditary fundus dystrophies (e.g. retinitis pigmentosa, Leber congenital amaurosis, gyrate atrophy, Stickler syndrome) | - Usually associated with posterior subcapsular lens opacity
- Cataract surgery is undertaken early, which can improve vision despite the presence of severe retinal changes |
Cataract secondary to medication
Cataract formation can also be caused by medication, such as:
- Topical and systemic steroids may cause cataracts, usually of the posterior subcapsular class. Predominant symptoms are severe glare and reduced near vision (see our āAge-related cataractā notes)
- Prolonged chlorpromazine use
Traumatic cataract
Trauma is the most common cause of unilateral cataract in young patients. This causes clouding of the lens at the site of injury (which can develop quickly after the incident), which can extend to the whole lens.
Traumatic cataracts are stellate or flower-shaped.
Aetiology
Traumatic cataracts may be caused by:
- Blunt injury to the eye ā causes a characteristic flower-shaped opacity
- Penetrating injury to the eye
- Radiation exposure
- Chemical burns
- Electric shock (rare) ā causes diffuse white opacification and multiple snowflake-like opacities
Radiology in Focus
Imaging plays a crucial role in the evaluation of secondary and traumatic cataracts. While the clinical examination is essential for diagnosis, radiological techniques can provide valuable insights into the underlying causes, associated ocular injuries, and the specific characteristics of these cataracts.
Ultrasound biomicroscopy (UBM)
UBM is particularly useful for visualising the anterior segment of the eye, allowing for detailed assessment of cataract morphology and any associated anterior segment abnormalities. It can help identify the presence of lens fragments or other pathologies.
Optical Coherence Tomography (OCT)
OCT provides high-resolution cross-sectional images of the lens and can help identify specific features of secondary cataracts, such as posterior capsule opacification (PCO) and changes in the lens structure.
B-scan ultrasound
B-scan ultrasound is useful for assessing the posterior segment of the eye, particularly in cases where cataracts obscure the view of the fundus. It can help identify any associated retinal or vitreous pathology, such as retinal detachment or hemorrhage.
References
- Salmon, John F., and Jack J. Kanski.Ā Kanskiās Clinical Ophthalmology: A Systematic Approach.Ā Ninth Edition, Elsevier, 2020.
- Basic Clinical Science Course (BCSC) of the American Academy of Ophthalmology. Section 11. 2006 - 2007.
- Kaur, Savleen, et al. āTraumatic Glaucoma in Childrenā.Ā Journal of Current Glaucoma Practice, vol. 8, no. 2, 2014, pp. 58ā62.Ā PubMed Central, https://doi.org/10.5005/jp-journals-10008-1162.
Author(s)
Jessica Mendall
Jessica is a final year medical student studying in London. She previously studied preclinical medicine in Oxford, intercalating in Systems Neuroscience and Molecular Pathology. She is particularly interested in Ophthalmology, medical education and clinical research.
Dr Abhiyan Bhandari
Abhiyan is the Co-Founder and Radiology & Imaging Lead of Ophtnotes. He is a doctor who graduated from UCL Medical School in London. He scored in theĀ top 10% of candidatesĀ who sat the Duke Elder examination and runs ophthalmology and Duke Elder revision sessions aimed at medical students. He also runs aĀ YouTube channelĀ aimed at medical students, covering topics ranging from study tips, productivity and vlogs of his journey through medical school.
Published: 23/8/22
Last updated: 29/1/25