Presbyopia is when the eyes gradually lose the ability to see things up close. It is a normal part of ageing and starts getting noticeable around the age of 45.
The condition is caused by a gradual loss of amplitude of accommodation that is provided by the crystalline lens, and presbyopic individuals start holding reading material further away in order to see clearly. Due to an ageing population, presbyopia now represents one of the largest groups of patients suffering from a refractive error.
As it is not possible to restore accommodation, current treatments focus on compensating for the lack of accommodation by providing a different refractive power at distance and near. The challenge for such treatment options is to provide both distance and near vision while simultaneously maintaining optical quality with particular regards to contrast sensitivity and night vision preservation.
Presbyond LBV is an advanced and sophisticated method for treating patients who require reading glasses due to presbyopia. It is a relatively new, physiologically optimised laser treatment method which offers the opportunity to achieve freedom from glasses by combining the accuracy of corneal refractive surgery with the benefits of increased depth of field of vision and retention of visual quality.
In LBV, the dominant eye is corrected for distance vision to almost 0, whereas the non-dominant eye is corrected to be slightly short-sighted for near vision up to -1.50 Diopters. This so-called micro-monovision is further enhanced by a decisive factor: an increase in the depth of field of each eye using a wavefront-optimised corneal ablation profile to create a continuous power gradient for the whole optical zone of the cornea.
LBV is an individualised treatment plan based on pre-operative spherical aberrations and the functional age of the eye. This results in a customised fusion of the two images, providing clear vision at all distances; near, intermediate and far- the so-called Blend Zone.
Presbyond LBV is a proven and effective method for treating presbyopia in individuals who only require reading glasses as well as for simultaneously treating presbyopia in individuals who are short-sighted or long-sighted, including astigmastism. The upper limits of myopia and hypermetropia which can be simultaneously corrected with presbyopia are -8.50 Diopters and + 5.50 Diopters respectively.
Currently it seems that the best outcomes, lowest complication rates and least side effects are afforded by corneal refractive surgery by means of Laser Blended Vision. With the safety advantage of modern femtosecond LASIK, the rapid bilateral surgical procedure and the recovery time of a few hours, patient satisfaction is very high. LBV benefits from all the wow factors of LASIK surgery with the ability to offer easy enhancements of vision if necessary in the future.
LBV is proven to be tolerated by more than 95 per cent of patients and is effective for treating up to 97 per cent of all presbyopia-related forms of visual impairment. At present, Presbyond LBV represents the best modality to help restore the youthful functionality which presbyopia compromises.
Ivan Vella is a consultant ophthalmic and refractive surgeon.