Latanoprost Drops: Primary Uses and Indications
Latanoprost drops are primarily used to reduce elevated intraocular pressure (IOP) in patients with open-angle glaucoma or ocular hypertension. 1 As a prostaglandin F2 alpha analog, latanoprost works by increasing uveoscleral outflow rather than altering conventional aqueous outflow, making it particularly effective for IOP reduction.
Mechanism and Efficacy
Latanoprost functions through a unique mechanism:
- Increases uveoscleral outflow to reduce IOP
- Provides 22-39% reduction in diurnal IOP over 1-12 months of treatment 2
- Maintains efficacy during treatment periods of up to 2 years
- Provides IOP-lowering effect that lasts 20-24 hours after a single dose, allowing for once-daily dosing 3
Clinical Applications
Primary Open-Angle Glaucoma
- First-line treatment due to superior efficacy in lowering IOP (6-8 mmHg reduction) 4
- More effective than timolol 0.5% twice daily in multiple large studies 2
- Generally as effective as other prostaglandin analogs like bimatoprost or travoprost
- Significantly more effective than dorzolamide, brimonidine, or unoprostone 2
Ocular Hypertension
- Reduces IOP by approximately 35% in patients with ocular hypertension 5
- Maintains low IOP over at least a 2-year period
- Can be used as initial therapy when treatment is indicated 6
Normal Tension Glaucoma
- Once-daily application of 0.005% latanoprost results in 21.4% IOP reduction 7
- Improves ocular perfusion pressure more effectively than timolol in normal tension glaucoma 7
- Well-tolerated in normal pressure glaucoma patients with significant IOP reduction 8
Combination Therapy
- Shows significant additive effects when used with other glaucoma medications 2
- Fixed combination of latanoprost plus timolol is more effective than either component alone
- More effective than fixed combination of dorzolamide and timolol in a 3-month study 2
Dosing and Administration
- Standard concentration: 0.005% solution
- Dosing regimen: One drop once daily, typically in the evening 6, 4
- A reasonable target IOP based on the Ocular Hypertension Treatment Study would be 20% lower than baseline IOP measurements 6
Side Effects and Considerations
Common side effects include:
- Mild to moderate conjunctival hyperemia (3-15% of patients) 2
- Iris color change (2-9% of patients), which may be permanent 2
- Increased iris pigmentation occurs in at least 10% of patients with hazel-colored eyes 5
Important considerations:
- Unlike beta-blockers, latanoprost induces minimal systemic adverse events 2
- Isolated cases of cystoid macular edema have been reported 5
- Use during pregnancy carries a theoretical risk (Pregnancy Category C) 6
- May be considered for use in breastfeeding mothers 6
Clinical Decision Making
When deciding whether to initiate treatment:
- Evaluate if the patient has open-angle glaucoma or ocular hypertension
- Consider target IOP (typically 20% reduction from baseline)
- For normal tension glaucoma, aim for at least 30% reduction in IOP 4
- Monitor for structural changes in the optic disc and retina, and functional changes via visual field assessment
Latanoprost's once-daily dosing regimen, potent IOP-lowering effect, and favorable side effect profile make it an excellent first-line choice for treating open-angle glaucoma and ocular hypertension.