Free previewYou're reading the free part of this topic. The rest is included with Clinical.See what's included
Presbyopia
Cataract & Refractive Surgery
Key Points
- •Presbyopia is a universal, age-related, physiological loss of accommodation affecting 100% of people by age 50 - it is NOT a disease
- •The primary cause is lens hardening (sclerosis) - the ciliary muscle actually hypertrophies with age but cannot deform the rigid lens (Helmholtz mechanism)
- •Symptoms begin when amplitude of accommodation falls below +3 D (typically age 40–45), which is the minimum needed for comfortable reading at 33 cm
- •Typical near additions: age 40–45 = +1.00 to +1.50 D; age 50 = +2.00 D; age 60+ = +3.00 D (maximum)
Free preview ends here
Keep reading Presbyopia
17 more sections are included with the Clinical plan.
- Definition
- Epidemiology
- Aetiology and causes
- Pathogenesis
- Classification
- Risk factors and associations