Ocular Hypertension: Initial Assessment and First-Line Therapy
Direct Recommendation
For adults with ocular hypertension (IOP >21 mmHg) without optic nerve damage, perform comprehensive baseline assessment including gonioscopy, pachymetry, optic nerve evaluation, and visual field testing, then stratify risk using validated calculators—treat only high-risk patients (>13% 5-year conversion risk) with a 20% IOP reduction target using prostaglandin analogs or laser trabeculoplasty as first-line options. 1, 2
Initial Assessment Protocol
Mandatory Baseline Examinations
The American Academy of Ophthalmology requires the following comprehensive workup to establish the diagnosis and exclude glaucoma 1, 2:
- Gonioscopy to confirm open angles and exclude angle-closure mechanisms, pseudoexfoliation syndrome, pigment dispersion syndrome, and traumatic angle recession 1, 3
- Central corneal pachymetry to assess IOP measurement accuracy and independent risk (thinner corneas underestimate true IOP and independently increase glaucoma risk) 1, 2, 3
- Goldmann applanation tonometry as the gold standard for IOP measurement, with time of day recorded to assess diurnal variation 2
- Optic nerve head examination documenting cup-to-disc ratio, rim thickness, and presence of disc hemorrhages using imaging, photography, or detailed drawings 1, 2, 3
- Retinal nerve fiber layer (RNFL) assessment using clinical examination and OCT imaging for complementary structural information 1, 2, 3
- Visual field testing (30-2 or 24-2 automated perimetry) to establish baseline and exclude early glaucomatous damage 1, 2, 3
- Slit-lamp biomicroscopy and pupil examination for relative afferent pupillary defect 2
Critical Risk Factor Documentation
Document all established risk factors that predict conversion from ocular hypertension to primary open-angle glaucoma 1, 3:
- Age (risk increases progressively after age 40) 1, 3
- Race/ethnicity (African or Latino/Hispanic ancestry carries higher risk) 1, 2
- Family history of glaucoma (9.2-fold increased odds) 1, 3
- Central corneal thickness (CCT ≤555 μm significantly increases risk) 1, 2
- Baseline IOP level (≥26 mmHg versus <24 mmHg) 1
- Vertical cup-to-disc ratio (larger ratios indicate higher risk) 1, 3
- Pattern standard deviation on visual field testing 1
- Type 2 diabetes mellitus (40-140% higher odds of POAG) 1, 3
- Myopia 1
- Low ocular perfusion pressure 1, 2
- Disc hemorrhages 1, 3
Treatment Decision Algorithm
Risk Stratification is Mandatory
Use validated risk calculators based on the Ocular Hypertension Treatment Study (OHTS) and European Glaucoma Prevention Study (EGPS) to determine 5-year conversion risk. 1, 3, 4
The OHTS demonstrated that untreated patients with baseline IOP ≥26 mmHg and CCT ≤555 μm had a 36% chance of developing optic nerve damage during long-term follow-up, compared with only 2% risk for patients with baseline IOP <24 mmHg and CCT >588 μm 1
Treatment Thresholds
High-risk patients (>13% 5-year conversion risk): Initiate IOP-lowering treatment immediately 4
- Treatment reduced 5-year progression from 9.5% to 4.4% in OHTS 3
- The absolute benefit justifies exposure to treatment risks and costs 1, 4
Intermediate or low-risk patients (<13% 5-year conversion risk): Watchful waiting with regular monitoring 4
- More than 90% of untreated ocular hypertension patients did not progress to glaucoma over 5 years in OHTS 1, 2
- Potential side effects (local and systemic) outweigh possible benefits in this population 4
Very high IOP (>32 mmHg): Consider treatment regardless of other risk factors due to high likelihood of optic nerve damage 4
First-Line Therapy Options
Prostaglandin Analogs (Preferred Medical Therapy)
Prostaglandin analogs, specifically latanoprost once daily in the evening, are effective first-line medical therapy for ocular hypertension. 5
- Latanoprost achieved mean IOP reductions of 28-34% in treatment-naive patients with baseline IOP 20-27 mmHg 5
- Target IOP ≤18 mmHg was achieved in ≥70% of patients regardless of baseline IOP level 5
- Well-tolerated with established safety profile 5
Laser Trabeculoplasty (Alternative First-Line)
Selective laser trabeculoplasty should be considered as primary therapy, particularly when medication adherence, cost, convenience, or side effects are concerns. 2
Target IOP Reduction
A reasonable target for IOP reduction is 20% from baseline, based on OHTS data. 1
Monitoring Protocol
For Untreated Patients (Low-Risk)
- IOP measurements at intervals determined by risk level, with time of day recorded 2
- Optic nerve head evaluation at least yearly with documentation by imaging or photography 2
- Visual field testing at least yearly 2
- Reassess risk factors periodically as patient ages and other factors evolve 1
For Treated Patients
- More frequent visual field testing (three visual fields per year) during the first 2 years to detect rapid progression 2
- Regular IOP monitoring to ensure target reduction is maintained 2
- Annual optic nerve imaging to detect structural changes 2
Critical Pitfalls to Avoid
Never diagnose or screen for glaucoma based on IOP measurement alone—the 21 mmHg cutoff has only 47.1% sensitivity, missing more than half of glaucoma cases, and approximately 50% of glaucoma patients have IOP in the "normal" range 6
Never ignore central corneal thickness—failure to account for CCT leads to inaccurate IOP assessment and inappropriate treatment decisions 2, 3
Never treat all ocular hypertension patients—only 10% of untreated patients developed glaucoma over 5 years in OHTS, so indiscriminate treatment exposes 90% of patients to unnecessary risks, side effects, and costs 1, 4
Never assume elevated IOP equals glaucoma—population studies show only 13-71% of patients with IOP >21 mmHg actually have glaucomatous optic nerve damage, depending on the population studied 6
Always perform gonioscopy—this is mandatory to exclude angle-closure mechanisms and secondary causes that would completely change management 1, 2, 3