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The term "buphthalmos" was derived from the Greek word "ox-eyed." Congenital enlargement of the eye was recognized as early as 400 BC by Hippocrates and later by Celsus and Galen in the 1st and 2nd centuries AD, respectively. However, the condition was not related to increased intraocular pressure (IOP) until after the 19th century, with the invention of the ophthalmoscope and tonometer and discoveries from more precise anatomical dissection. At present, the term "buphthalmos" is used to describe the visible enlargement of the eyeball detected at birth or soon after due to uncontrolled glaucoma in early childhood. Diagnosis involves comprehensive ophthalmic evaluation, including tonometry, gonioscopy, and imaging techniques like ultrasound biomicroscopy. Management primarily involves surgical intervention to reduce IOP, such as goniotomy or trabeculotomy. Medical therapies may provide temporary relief. Early and effective treatment improves prognosis, though visual impairment remains a concern due to optic nerve damage or amblyopia. Regular follow-up is critical to monitor IOP and preserve vision. This activity for healthcare professionals is designed to enhance learners' proficiency in evaluating and managing buphthalmos. Participants gain deeper insights into the condition's pathophysiology, presentation, and best diagnostic and therapeutic practices. Greater competence equips clinicians to collaborate effectively within an interprofessional team caring for patients with buphthalmos, improving outcomes. Objectives: Identify the signs, symptoms, and ocular examination findings suggestive of buphthalmos. Select the appropriate diagnostic modalities to evaluate suspected buphthalmos cases. Apply personalized, evidence-based management strategies for buphthalmos. Implement effective collaboration and communication among interprofessional team members to improve outcomes and treatment efficacy for patients with buphthalmos. Access free multiple choice questions on this topic.

The clinical term "buphthalmos" describes the visible enlargement of the eyeball, typically detected at birth or shortly after, due to uncontrolled glaucoma in early childhood. The name originates from the Greek word meaning "ox-eyed." Congenital eye enlargement was noted as early as 400 BC by Hippocrates and later by Celsus and Galen in the 1st and 2nd centuries AD. However, the condition was not initially associated with increased intraocular pressure (IOP). This connection was established after the 19th century with the advent of the ophthalmoscope and tonometer, as well as advancements in anatomical dissection. Buphthalmic eyes typically have corneal diameters exceeding 12 mm in newborns or 13 mm in children older than 1 year (see Image. Buphthalmos). The diameters sometimes exceed 16 mm, with the globe appearing noticeably enlarged. Normal corneal diameters are 9.5 to 10.5 mm at birth and 11 to 12 mm by age 1.[1]

IOP elevation stretches the cornea and sclera, causing buphthalmos. The condition arises most frequently from primary congenital glaucoma, where abnormal development of the anterior chamber angle leads to impairment of aqueous humor drainage.[2] Mutations in the CYP1B1 and PAX6 genes are also associated with IOP elevation.[3][4] Other secondary conditions that can raise IOP include Sturge-Weber syndrome, neurofibromatosis, and aniridia.[5][6][7]

The average prevalence of buphthalmos is around 1 in 30,000 births.[8] The Slovak Romani, South Indian, and Saudi Arabian populations show a significantly higher prevalence of primary congenital glaucoma than the rest of the world. In Saudi Arabia and the Romani population of Slovakia, primary congenital glaucoma is the most frequent cause of childhood blindness. The highest reported prevalence is in Slovakia, with 1 in 1,250 live births, followed by Saudi Arabia, with 1 in 2,500 live births.[9]

Extensive growth of the human eye occurs in the first 5 years of life, with the greatest increase in axial length seen in the first 4 years. High IOP increases axial length and corneal diameter. This increase in the size of the eyeball in congenital glaucoma occurs due to the extreme softness and elasticity of the infantile eyeball. Eyeball enlargement can cause axial myopia, while an increase in corneal diameter can cause corneal thinning and breaks in the Descemet membrane, called "Haab striae," a classical finding in patients with buphthalmos. The number of endothelial cells in the cornea is often reduced, leading to corneal haziness. The severity of corneal haze correlates with increases in the IOP, cup-to-disc ratio, and corneal diameter.[10]

The most common causes of buphthalmos are primary congenital glaucoma, which presents at birth, and primary infantile glaucoma, which develops after birth and up to the age of 3 years. Buphthalmos is typically absent in glaucoma that begins after the age of 3 years, making juvenile-onset glaucoma, occurring from 3 years to adolescence, unassociated with buphthalmos.[11] The classic symptoms of congenital and infantile glaucomas include tearing, photophobia, and irritability (see Image. Buphthalmos with Bilateral Tearing and Light Sensitivity). Parents may observe corneal haziness or enlargement. Clinicians may identify an increased corneal diameter, a deep anterior chamber, and an enlarged globe during examination. The corneal examination may reveal edema and Descemet membrane rupture (Haab striae). IOP elevation is a hallmark feature. Optic disc cupping may also be present. Several other conditions can lead to buphthalmos. Aniridia, an autosomal dominant disorder, is characterized by complete or partial iris hypoplasia. Glaucoma in aniridia is believed to result from angle closure. Neurofibromatosis type 1, another autosomal dominant condition, presents with multiple neurofibromas, café au lait spots, iris Lisch nodules, and axillary or inguinal freckling. Glaucoma in this condition is associated with developmental anomalies of the anterior chamber angle. Sturge-Weber syndrome, which includes nevus flammeus of the face and meningeal angiomas, is linked to glaucoma in approximately 60% of cases. The glaucoma in individuals with this condition is attributed to angle developmental anomalies and raised episcleral venous pressure.[12]

The evaluation of buphthalmos typically involves an examination under anesthesia. Key assessments include refraction using streak retinoscopy and a detailed evaluation of the cornea. Measurement of the corneal diameter using calipers is an essential step, as a diameter greater than 12 mm is considered abnormal. Corneal edema, often resulting from elevated IOP, may also be observed. Haab striae, which are horizontal or parallel to the limbus, may be identified during the examination.[13] The anterior segment should be examined for other potential underlying causes of buphthalmos, such as aniridia and Lisch nodules associated with neurofibromatosis. IOP should be measured promptly within the first few minutes of anesthesia to avoid falsely low readings. Gonioscopy using a direct gonioscope may demonstrate significant findings, including anterior iris insertion onto the trabecular meshwork, vascular loops in the angle known as the "Loch Ness monster" phenomenon, and "Lister’s morning mist," characterized by fine, fluffy tissue on the peripheral iris. Ophthalmoscopy may demonstrate optic disc cupping, which is notable for its potential reversibility with appropriate treatment in cases of primary congenital glaucoma. Ultrasound biomicroscopy is recommended when the cornea is opaque to evaluate anterior segment structures effectively. Consultation with clinical genetics may also be advised to assess for hereditary factors and guide further management.

The primary goal of buphthalmos treatment is to lower IOP to prevent progressive corneal opacification and glaucomatous optic atrophy, thus preserving existing vision.[14] The most definitive approach to treating buphthalmos is surgical, while medical management is used to control IOP and facilitate clearer visualization of the cornea during surgery.[15] Medical Treatment Pharmacological options for buphthalmos include topical β-blockers, carbonic anhydrase inhibitors, and prostaglandin analogs. As mentioned, these medications help manage IOP and can be essential in preparing the patient for surgical intervention.[16] Surgical Treatment Several surgical options are available for treating buphthalmos. Goniotomy involves creating openings in the trabecular meshwork to reduce resistance to aqueous outflow.[17] Trabeculotomy entails incising the trabecular meshwork by cannulating the Schlemm canal with a probe. Trabeculectomy is performed by removing a section of the trabecular meshwork and Schlemm canal under a partial thickness scleral flap, creating a fistula that drains aqueous humor into the subconjunctival space.[18] A combined trabeculotomy and trabeculectomy procedure involves the removal of a block of sclera after completing trabeculectomy.[19] Other options include glaucoma drainage implants and cyclodestructive procedures, which may be used in more complex cases.[20][21][20] Correcting refractive errors and managing amblyopia are important components of postoperative care. Lifelong IOP monitoring is necessary to ensure ongoing management and prevent future complications.

The following conditions can cause an abnormal appearance of the eye that may be mistaken for buphthalmos. A thorough eye examination is essential to rule out these other diseases. Aniridia Coat disease Dysplasia of retina Endophthalmitis Inflammatory cyclitic membrane Neurofibromatosis type 1 Persistent hyperplastic primary vitreous Retinoblastoma Sturge-Weber syndrome Toxocariasis The presence of these conditions does not exclude the possibility that the patient may have buphthalmos. Additionally, some of these conditions, such as aniridia, neurofibromatosis type 1, and Sturge-Weber syndrome, are associated with buphthalmos.

The staging of congenital glaucoma is based on the severity of the disease and clinical findings. In stage 1 (mild), IOP is slightly elevated, with minimal corneal edema and slight corneal enlargement. Stage 2 (moderate) is characterized by noticeable optic nerve cupping, moderate corneal edema with Haab striae, and a corneal diameter measuring 13 to 14 mm. Stage 3 (severe) involves advanced optic nerve damage with significant visual impairment, severe corneal edema and opacification, and a corneal diameter greater than 14 mm.[22]

The visual prognosis for a patient with buphthalmos due to congenital glaucoma that goes undiagnosed for many years is generally very poor. Vision loss due to congenital glaucoma is irreversible and severe. Early surgical intervention for these patients is associated with better visual outcomes.[23] If treated early, glaucomatous progression typically does not occur in the majority of cases within the 1st year of treatment. Many patients who receive early treatment maintain useful vision and remain visually unimpaired throughout their lives. However, nearly half of patients experience further progression later in life, emphasizing the importance of regular lifelong ophthalmic monitoring (see Image. Buphthalmos in an Adult).[24]

IOP elevation presents as buphthalmos in pediatric patients, with complications stemming from high IOP. The sequelae include glaucomatous optic neuropathy, corneal damage, amblyopia, and refractive errors. Early IOP reduction can help prevent these complications. However, amblyopia and refractive errors must be treated separately if they occur.[25] Corneal damage may be irreversible, potentially requiring surgical intervention in the future.[26]

Educating providers and parents about buphthalmos being a sign of congenital glaucoma is vital to preventing irreversible vision loss. One study found that 97% of the time, parents were the first to identify the signs of congenital glaucoma and refer the patient to a healthcare provider.[27] This finding highlights the importance of educating parents about ocular abnormalities. Parents should be educated that large eyes may be a sign of a serious ocular condition and that the child should be seen by an eye care specialist as soon as possible. Proper education for parents and providers covering early signs and symptoms of congenital glaucoma can prevent blindness from this disease.

An interprofessional approach is often required to manage buphthalmos. The interprofessional team may include ophthalmologists, optometrists, pediatricians, and other healthcare providers. The main treatment goal is to reduce IOP to prevent progressive corneal opacification and glaucomatous optic atrophy, thus preserving vision. The most definitive treatment of buphthalmos is surgical. Medical management is necessary to control IOP and clear the cornea for surgery. The prognosis of buphthalmos has slightly improved over the years. Many children require low-vision aids and visual rehabilitation despite treatment.[28] Once considered a condition with a bleak prognosis, buphthalmos may now be managed reasonably well with modern surgical procedures. Early treatment and quality care coordination among different healthcare professionals can improve lifelong visual prognosis in patients with this disease.[29]