Primary Angle Closure Disease - Cause, Symptoms, Diagnosis, and Management

What Is Primary Angle Closure Disease?

Primary angle closure disease is a condition that affects around half of the irreversible blindness cases of glaucoma. During this condition, intraocular pressure increases due to partial or complete obstruction of fluid inside the eyes. Especially the angle closure is the result of appositional approximation between the iris and trabecular meshwork in the anterior chamber of the eye. Due to increased intraocular pressure, the glaucomatous optic nerve is damaged, which results in many health-related complications. Usually, this condition affects females more than males. Moreover, it is documented that the condition is usually seen in elderly patients with a family history. There are diagnostic methods such as gonioscopy, optical coherence tomography, or ultrasound biomicroscopy that are used to evaluate the condition.

What Are the Types of Primary Angle Closure Disease?

There are the following types of primary angle closure disease:

1. Primary Angle Closure Suspect: Patients with this type have primary and narrow angular widths of the anterior chamber. Moreover, the posterior trabecular chamber does not touch the iris periphery.

2. Primary Angle Closure and Primary Angle Closure Glaucoma:

• Acute Primary Angle Closure: During this type, the entire circumference of the anterior chamber angle is obstructed, which leads to a sudden increase in intraocular pressure. This can further lead to nausea, vomiting, headache, vascular congestion, and pain in the eyes. If this condition is not treated on time, this can lead to permanent blindness in patients.

• Chronic Primary Angle Closure: During this type of angle closure, the portion of the angle closes with peripheral anterior synechiae. However, this type does not affect intraocular pressure much. During this type, the patient might have mild to severe visual field loss.

What Are the Causes of Primary Angle Closure Disease?

The following are the etiological factors associated with primary angle closure disease:

• Hyperopia: Refractive error such as hyperopia has more risk of developing this condition.

• Family History Related to Glaucoma: Although the study supporting this cause is still under research, there is some relevance of family history seen associated with primary angle closure disease.

• Increasing Age: With increased age, the structures of the eye undergo many changes, and pupillary block and partial angle closure are a few of them. The depth of the interior chamber and its volume reduces with age. Moreover, these changes affect the thickness of the lens too.

• Gender: Females are three times more at risk than males due to their anatomical difference in the body and structure of the organs. For instance, the study shows that the females have a much narrower angle width and lower axial length of the anterior chamber.

• Ethnicity: Primary angle closure disease is mostly seen among Asians. The cases of blindness related to bilaterally glaucoma are mostly seen among Chinese people.

What Are the Signs and Symptoms of Primary Angle Closure Disease?

The following are the signs and symptoms associated with primary angle closure disease:

• Corneal edema (a condition where there is swelling seen in the cornea due to fluid buildup).

• Halos light vision (a symptom associated with conditions such as cataracts or glaucoma, where a person sees halo-like light in the vision).

• Mild-dilated pupil (a symptom associated with many conditions such as medication side effects, fear, substance abuse, dark room, or sleep.

• Vascular congestion (a condition where the swelling is caused by increased vascular blood flow and blood pressure).

• Pain in the eyes.

• Blurred vision.

• Nausea.

• Headache.

How to Diagnose Primary Angle Closure Disease?

There are the following diagnostic methods used for primary angle closure disease:

1. History: If the condition is induced by any systemic medication, the diagnostic method can reveal the cause.

2. Physical Examination:

Refractive Status Assessment: This diagnostic method is important for examining narrow anterior chambers, especially in aged patients.

• Pupil: During the examination, the size and the reactivity of the pupil are checked.

• External Examination: This diagnostic option examines corneal clarity and conjunctival hyperemia.

• Slit-Lamp Biomicroscopy: This diagnostic method is used to check for anterior chamber depth, edema, or iris atrophy.

• Gonioscopy: This is the essential diagnostic method used to examine angle closure. There are different lenses used in this diagnosis, such as Zeiss, Sussman, and Posner's lenses. These lenses are used to indent the cornea, which further provides clear and adequate visualization of angle structures.

What Are the Differential Diagnosis Associated With Primary Angle Closure Disease?

The following are the differential diagnosis associated with primary angle closure disease:

• Neovascular Glaucoma: It is a severe form of glaucoma caused by increased fibrovascular tissue in the anterior chamber of the eye.

• Aqueous Misdirection: It is a form of secondary angle closure glaucoma where there is increased intraocular pressure seen.

• Anterior Suprachoroidal Effusion: The condition is caused by fluid accumulation in the suprachoroidal space.

How to Manage Primary Angle Closure Disease?

Primary angle closure disease can be treated or managed with the following methods:

1. Treatment Options for Acute Primary Angle Closure: There are four stages of treatment that an ophthalmologist usually follows:

• During this treatment stage, the primary concern is to stop the attack by reducing the damage to the optic nerve and lens.

• The fellow eye is protected from further progress of the condition.

• Definitive treatment iridotomy.

• Management of angle closure attack to clear corneal edema and pain.

2. Treatment for Chronic Primary Angle Closure: Patients with chronic primary angle closure have obstructed aqueous flow due to damage or angle closure. Moreover, during iridocorneal apposition, damage to trabeculae or synechiae formation is seen.

• Iridotomy: This treatment option is suggested to relieve the pupillary block and stop the progression of synechiae closure. Furthermore, if the iridotomy has a recurrent pupillary block, the doctor may further suggest a re-operation.

• Lensectomy: This treatment is used to widen the anterior chamber angles in narrow-angle closure glaucoma. As compared to iridotomy, this treatment option requires less post-operative care and has fewer post-operative complications.

• Nd-YAG Iridotomy: This treatment is safer and has more efficient results as compared to iridectomy. There are many conditions that are suggested for this treatment option, such as nanophthalmos, malignant glaucoma, and combined mechanism glaucoma.

What Are the Complications Associated With Primary Angle Closure Disease?

The following are the complications associated with primary angle closure disease:

• Blurred vision.

• Diplopia.

• Corneal damage.

• Anterior uveitis.

• Posterior synechiae.

• Pupillary abnormalities.

• Lens opacity.

• Retinal damage.

• Zonular damage.

Conclusion:

Primary angle closure disease is associated with many eye-related complications. This condition needs to be diagnosed on time. If the patients have any of the symptoms affecting the eye's vision, they should directly contact their ophthalmologist for further management of the condition. Moreover, after surgical treatment, patients should regularly go for follow-ups suggested by the healthcare provider.