Buphthalmos : A Comprehensive Review

Introduction

Buphthalmos is a rare but severe ophthalmic condition, primarily affecting infants and young children, characterised by an abnormal enlargement of the eyeball due to increased intraocular pressure (IOP). The term “buphthalmos” is derived from the Greek words “bous” (ox) and “ophthalmos” (eye), alluding to the ox-like appearance of the enlarged eye. It is most commonly associated with congenital (primary) glaucoma, though it may also occur in secondary forms of childhood glaucoma.

The epidemiological incidence of buphthalmos varies globally, with higher prevalence in certain regions where consanguinity is common. Early identification and management are critical to prevent irreversible visual impairment or blindness, making buphthalmos a significant concern for paediatric ophthalmologists and general clinicians alike.

Definition and Overview

Buphthalmos refers to the abnormal, pathological enlargement of the globe (eyeball), typically presenting in children under the age of three years. It is most often a manifestation of increased intraocular pressure, commonly due to primary congenital glaucoma (PCG). The condition is defined by an increase in both the axial length and diameter of the cornea and sclera, resulting in a visibly enlarged eye. Unlike adult-onset glaucoma, where the sclera is rigid, the paediatric eye is more distensible, allowing for expansion in response to elevated intraocular pressure.

The significance of buphthalmos lies in its association with irreversible optic nerve damage if left untreated, leading to permanent visual disability. Hence, it is a paediatric ophthalmic emergency warranting prompt attention.

Etiology and Pathogenesis

Causes

The primary cause of buphthalmos is congenital glaucoma, specifically primary congenital glaucoma, which results from developmental anomalies of the anterior chamber angle structures. These anomalies hinder the normal outflow of aqueous humour, leading to increased intraocular pressure.

Secondary causes, though less common, include congenital rubella syndrome, Sturge-Weber syndrome, neurofibromatosis, trauma, uveitis, and other syndromic or acquired paediatric glaucomas. However, the overwhelming majority of cases are idiopathic and classified as primary congenital glaucoma.

Risk Factors

• Genetic Predisposition: Familial cases have been reported, and consanguinity increases risk.
• Ethnic and Geographic Factors: Higher prevalence in populations with higher rates of consanguinity, such as in parts of the Middle East, South Asia, and North Africa.
• Gender: Some studies suggest a slight male predominance.
• Associated Syndromes: Certain genetic syndromes and ocular anomalies may increase risk.

Genetic Aspects

Genetic mutations are increasingly recognised as central to the pathogenesis of primary congenital glaucoma and, by extension, buphthalmos. The most commonly implicated gene is CYP1B1, which encodes a member of the cytochrome P450 superfamily of enzymes. Mutations in CYP1B1 account for a significant proportion of familial and sporadic cases, particularly in populations with higher rates of consanguinity. Other genes, such as LTBP2 and MYOC, have also been linked, albeit less frequently.

The inheritance pattern is typically autosomal recessive, though variable penetrance and expressivity are observed. Genetic counselling is recommended for affected families.

Clinical Presentation

Signs and Symptoms

Buphthalmos typically presents in infancy or early childhood, often within the first year of life. The hallmark clinical features include:

• Enlarged Eye (Unilateral or Bilateral): Visible increase in the size of the affected eye(s), often noticed by parents or paediatricians.
• Corneal Enlargement and Clouding: The corneal diameter exceeds normal limits (usually >12 mm in infants), and corneal oedema may cause a hazy or cloudy appearance.
• Photophobia: Increased sensitivity to light, leading to eye closure or irritability in bright environments.
• Epiphora: Excessive tearing, often mistaken for nasolacrimal duct obstruction.
• Blepharospasm: Spasmodic closure of the eyelids due to discomfort.
• Haab’s Striae: Horizontal breaks in Descemet’s membrane of the cornea, pathognomonic for congenital glaucoma.
• Optic Disc Cupping: Detected on fundus examination, indicative of glaucomatous damage.
• Refractive Errors: Myopia and astigmatism are common due to globe elongation.

Symptoms may be subtle in early stages, leading to delayed diagnosis in some cases. The condition can be unilateral or bilateral, with bilateral involvement in approximately 70% of cases.

Age of Onset and Progression

Buphthalmos is usually diagnosed before the age of three, with most cases presenting between birth and 12 months. The progression depends on the degree of intraocular pressure elevation and the timeliness of intervention. Without treatment, the disease progresses rapidly, leading to irreversible visual loss.

Diagnosis and Investigations

Clinical Examination

A thorough ophthalmic examination is crucial for diagnosis. Key components include:

• Measurement of Corneal Diameter: An enlarged cornea (>12 mm in infants) is suggestive.
• Assessment of Intraocular Pressure: Tonometry is performed, often under anaesthesia in infants.
• Slit-Lamp Examination: Evaluation of corneal clarity, Haab’s striae, and anterior chamber depth.
• Gonioscopy: Assessment of the anterior chamber angle structures, often revealing developmental anomalies.
• Fundus Examination: Evaluation for optic disc cupping and other glaucomatous changes.

Imaging and Ancillary Tests

• Ultrasound Biomicroscopy (UBM): Provides high-resolution images of anterior segment structures.
• Optical Coherence Tomography (OCT): Assesses retinal nerve fibre layer thickness and optic nerve head changes.
• Axial Length Measurement: Ocular biometry confirms globe enlargement.
• Pachymetry: Measures corneal thickness, important for interpreting IOP readings.

Differential Diagnosis

• Megalocornea: Enlarged cornea without raised IOP or optic nerve changes.
• Congenital Hereditary Endothelial Dystrophy (CHED): Corneal clouding without raised IOP.
• Anterior Segment Dysgenesis Syndromes: Including Axenfeld-Rieger anomaly and Peters anomaly.
• Ocular Tumours: Rarely, retinoblastoma may present with globe enlargement.

A careful exclusion of these conditions is essential for accurate diagnosis and appropriate management.

Treatment and Management

The primary goal in treating buphthalmos is to lower intraocular pressure to levels compatible with preservation of visual function and to prevent further optic nerve damage. Management strategies are tailored to the individual patient, considering age, severity, and response to initial therapy.

Medical Management

Medical therapy is primarily used as an adjunct to surgical intervention or as a temporising measure before surgery. Common agents include:

• Topical Beta-Blockers: Timolol is commonly used, though caution is warranted in infants due to risk of systemic side effects.
• Carbonic Anhydrase Inhibitors: Both topical (dorzolamide, brinzolamide) and oral (acetazolamide) forms are used to reduce aqueous production.
• Prostaglandin Analogues: Latanoprost and related agents, though less effective in infants.
• Alpha Agonists: Brimonidine is generally avoided in young children due to CNS side effects.

Systemic side effects and limited efficacy make long-term medical management less preferable. Medical therapy is rarely sufficient as monotherapy in congenital glaucoma.

Surgical Management

Surgery is the definitive treatment for buphthalmos and primary congenital glaucoma. The choice of procedure is influenced by the anatomy of the angle structures, corneal clarity, and surgeon expertise. Key surgical options include:

• Goniotomy: Incision of the trabecular meshwork via an ab interno approach. Indicated when the cornea is clear enough for visualisation.
• Trabeculotomy: Opening of Schlemm’s canal via an ab externo approach. Preferred when corneal clouding precludes goniotomy.
• Trabeculectomy: Creation of a guarded fistula to facilitate aqueous drainage. May be augmented with antimetabolites.
• Combined Trabeculotomy-Trabeculectomy: Used in severe or refractory cases.
• Glaucoma Drainage Devices: Ahmed or Baerveldt valves may be used in refractory cases or where conventional surgery fails.
• Cyclodestructive Procedures: Reserved for end-stage disease unresponsive to other interventions.

Success rates for angle surgeries are highest when performed early in the disease course. Multiple procedures may be required, and long-term follow-up is essential.

Supportive and Adjunctive Therapies

• Refractive Correction: Spectacles or contact lenses for myopia and astigmatism.
• Amblyopia Therapy: Occlusion therapy or penalisation for visual rehabilitation.
• Low Vision Aids: For patients with significant visual impairment.
• Family Counselling and Genetic Guidance: For affected families, particularly in consanguineous populations.

Prognosis and Complications

The visual prognosis in buphthalmos depends on the age at diagnosis, severity of disease, timeliness and efficacy of intervention, and the presence of complications. Early detection and prompt surgical management are associated with the best visual outcomes.

• Favourable Prognosis: Achievable in cases diagnosed and treated early with good control of intraocular pressure and minimal optic nerve damage.
• Poor Prognosis: Associated with late presentation, severe optic nerve cupping, corneal opacification, or refractory glaucoma.

Long-term complications may include:

• Persistent corneal oedema or scarring
• Optic atrophy
• Refractive amblyopia
• Strabismus
• Phthisis bulbi (in rare, end-stage cases)

Quality of life can be significantly affected, especially in cases of bilateral involvement and severe visual impairment. Ongoing surveillance is necessary to monitor for disease progression, surgical failure, or late-onset complications.

Nursing Care of Patients with Buphthalmos

Assessment and Early Recognition

• Monitor for Symptoms: Observe for signs such as enlarged, cloudy cornea, excessive tearing, photophobia (light sensitivity), and frequent eye rubbing.
• History Taking: Gather detailed history regarding onset, family history of glaucoma or similar ocular conditions, and previous interventions.
• Physical Examination: Regularly assess the size and appearance of the eyes, noting any asymmetry or rapid changes.
• Monitor Intraocular Pressure: Assist in regular intraocular pressure measurements as advised by the ophthalmologist.

Preoperative Nursing Care

• Education and Counselling: Provide parents and caregivers with information about the condition, treatment options, and prognosis.
• Anxiety Reduction: Offer emotional support and reassurance to both the child and family. Explain all procedures in simple terms.
• Prepare for Surgery: Ensure the child is appropriately prepared for surgery, including fasting protocols and preoperative investigations.
• Infection Control: Maintain strict aseptic techniques to reduce the risk of postoperative infections.

Postoperative Nursing Care

• Pain Management: Administer prescribed analgesics and monitor for signs of discomfort.
• Monitor for Complications: Watch for indications of infection, bleeding, or sudden vision changes. Report any abnormalities promptly.
• Eye Care: Apply prescribed eye drops or ointments as per the ophthalmologist’s instructions. Ensure the child does not rub or press on the operated eye.
• Positioning: Advise appropriate positioning to reduce intraocular pressure, such as keeping the head elevated.
• Protective Measures: Use eye shields if recommended to prevent accidental trauma.

Ongoing Care and Education

• Follow-up Visits: Emphasise the importance of regular follow-up appointments for monitoring intraocular pressure and eye development.
• Medication Adherence: Educate caregivers on the correct method and timing of administering eye medications.
• Visual Rehabilitation: Encourage participation in visual rehabilitation programmes if indicated, including use of corrective lenses or low vision aids.
• Developmental Support: Monitor for any developmental delays or challenges related to vision impairment and refer to specialists as needed.

Family and Psychosocial Support

• Parental Support: Acknowledge parental concerns and provide resources for support groups and counselling services.
• Education: Teach parents how to recognise warning signs of increased intraocular pressure or complications at home.
• Community Resources: Guide families to local or national organisations for children with visual impairments for additional assistance.

REFERENCES

1. American Academy of Ophthalmology. Multiple pages were reviewed for this article. Retinoscopy 101. https://www.aao.org/young-ophthalmologists/yo-info/article/retinoscopy-101.
2. Feroze KB, Blair K, Patel BC. Buphthalmos. https://www.ncbi.nlm.nih.gov/books/NBK430887/. [Updated 2022 May 24]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-.
3. Mehner L, Jung J. Eye. In: Bunik M, Hay WW, Levin MJ, et al. eds. Current Diagnosis & Treatment: Pediatrics, 26e. McGraw Hill; 2022.
4. Khokhar, S., Kumar, S., Rani, D. (2023). Cataract Surgery in Buphthalmic Eyes. In: Gupta, S., Mahalingam, K., Gupta, V. (eds) Childhood Glaucoma. Springer, Singapore. https://doi.org/10.1007/978-981-19-7466-3_38
5. Feroze KB, Blair K, Patel BC. Buphthalmos. 2025 Jan 20. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan–. PMID: 28613637.

Stories are the threads that bind us; through them, we understand each other, grow, and heal.

JOHN NOORD

Connect with “Nurses Lab Editorial Team”

I hope you found this information helpful. Do you have any questions or comments? Kindly write in comments section. Subscribe the Blog with your email so you can stay updated on upcoming events and the latest articles.