Presbyopia occurs as the lens becomes stiffer with age, with a consequent decrease in the range of focusing or accommodation.
When the nearest point at which an object can be brought into focus is beyond the normal reading range then presbyopia has become apparent. This normally occurs at about the age of 45 years.
Presbyopia can be compensated by the use of weak convex reading spectacles. As the degenerative stiffening of the lens gradually increases with age so there will be a need for gradual strengthening of the spectacles over the years.
The changes associated with presbyopia are generally complete by the age of 60 years.
Management:
- standard treatment for presbyopia is corrective spectacles or contact lenses
- surgery
- (monovision or blended-vision laser in situ keratomileusis [LASIK], or refractive lens exchange or replacement) may be considered in some patients
- corneal inlay implantation
- aims to improve near visual acuity and increase depth of focus. It may particularly benefit people who find it difficult to use spectacles or contact lenses, for instance, those with limited dexterity
- laser or microkeratome techniques are used to create either a lamellar corneal flap or a pocket within the corneal stroma
- the flap or pocket is separated with a spatula and a special tool is used to position the inlay within it, at the marked centre of the axis
- the flap or pocket self-seals, holding the inlay in place. Patients are normally prescribed corticosteroids and antibiotic eye drops in the short term and artificial tears for as long as needed
- the inlay can be removed or replaced if needed
- NICE state that "..evidence for corneal inlay implantation for correction of presbyopia is limited....there is some evidence of efficacy in the short term. In addition, there are reports that adverse effects occur frequently..."
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