What is the treatment for high intraocular pressure (IOP)?

Treatment for High Intraocular Pressure (IOP)

Prostaglandin analogs should be considered as first-line medical therapy for high intraocular pressure unless contraindicated due to cost, side effects, intolerance, or patient refusal. 1

Medical Therapy Options

First-Line Treatment

• Prostaglandin analogs (e.g., latanoprost, travoprost)
  • Most effective at lowering IOP (4.5-5.5 mmHg reduction)
  • Once-daily dosing (typically evening)
  • Mechanism: Increase uveoscleral outflow
  • Common side effects: Conjunctival hyperemia, eyelash changes, iris pigmentation 2, 3

Alternative/Additional Agents (if target IOP not achieved)

1. Beta-adrenergic antagonists (e.g., timolol)

   • Mechanism: Decrease aqueous production
   • Contraindications: Asthma, COPD, bradycardia, heart block
   • Avoid nighttime dosing due to potential nocturnal hypotension

2. Alpha-2 adrenergic agonists (e.g., brimonidine)

   • Mechanism: Decrease aqueous production and increase uveoscleral outflow
   • Side effects: Allergic reactions, dry mouth, fatigue

3. Topical carbonic anhydrase inhibitors (e.g., dorzolamide, brinzolamide)

   • Mechanism: Decrease aqueous production
   • Side effects: Stinging, metallic taste

4. Oral carbonic anhydrase inhibitors (e.g., acetazolamide)

   • Reserved for short-term use or when topical therapy insufficient
   • Side effects: Paresthesias, fatigue, kidney stones, metabolic acidosis

5. Rho kinase inhibitors (e.g., netarsudil)

   • Mechanism: Increase trabecular outflow, decrease episcleral venous pressure
   • Side effects: Conjunctival hyperemia, corneal verticillata

Setting Target IOP

• Target should be approximately 20% lower than baseline IOP 1
• For patients at high risk of progression, a lower target may be necessary
• Target may need adjustment during clinical course based on response
• Regular monitoring is essential to determine if target IOP is achieved and maintained

Non-Medical Treatment Options

If medical therapy is insufficient or not tolerated:

1. Laser Trabeculoplasty

   • Can be considered as primary therapy for ocular hypertension
   • Alternative to medications or as adjunctive therapy

2. Surgical Options (for refractory cases)

   • Trabeculectomy
   • Tube shunt procedures
   • Minimally invasive glaucoma surgery (MIGS)

3. Cataract Extraction

   • May lead to substantial IOP lowering in some patients, particularly those with angle closure components 1

Monitoring and Follow-up

• Regular IOP measurements to assess treatment efficacy
• Periodic gonioscopy to evaluate angle status
• Optic nerve examination and imaging
• Visual field testing to detect functional changes
• Assessment of medication adherence and side effects

Special Considerations

• Acute Angle Closure Crisis: Requires immediate medical intervention with combinations of beta-blockers, alpha-2 agonists, carbonic anhydrase inhibitors, and possibly hyperosmotic agents, followed by laser peripheral iridotomy when feasible 1

• Normal Tension Glaucoma: Prostaglandin analogs have shown effectiveness with once-daily 0.005% latanoprost resulting in 21.4% IOP reduction 4

• Combination Therapy: If monotherapy is insufficient, fixed-combination medications may improve adherence and reduce preservative exposure 5

• Treatment Resistance: Consider factors such as poor adherence, incorrect diagnosis, or inadequate treatment before labeling as true resistant glaucoma 6

The management of high IOP requires careful consideration of efficacy, side effects, adherence, and cost. Regular monitoring is essential to ensure that target IOP is achieved and maintained to prevent glaucomatous damage and preserve vision.