Defining dysfunctional lens syndrome
Clinical entity of DLS has been overlooked, inadequately characterised
Rose is a rose is a rose is a rose--a line written (1913) by Gertrude Stein and its variations in a famous quotation are often interpreted as meaning “things are what they are--makes a statement of the law of identity, and in the post-factum age is ever more meaningful.
An ophthalmologist could as well write: “Cataract is a cataract is a cataract is a cataract,” ICD-10 Code H25.0 for the diagnosis “Cataracta senilis incipiens” in its earliest stage and notably with a surgical history of more than 2,500 years.
Couching was already known to the Babylonian civilisation. In spite of progress to surgical techniques in many countries during the past decade, cataract remains the leading cause of visual impairment (47.9%, according to WHO) in the world, except for developed countries.
Usually, the medical procedures phacoemulsification and IOL implantation are covered by private or public health insurances when visual acuity drops below 20/40 (0,5). Patients have funded upgrading options themselves if refractive optimisation of pseudophakic presbyopia is the goal.
What is dysfunctional lens syndrome (DLS) all about then? In refractive surgery, presbyopia correction remains the holy grail. The demand is increasing along with the aging of the population. Procedures that target the cornea or sclera have failed to turn into blockbusters, such as LASIK. The refractive surgeon is reluctant to propose LASIK in an individual older than 45 to 55 years for many reasons: insufficient presbyopia correction with monovision; increased dry eye problems; and most commonly, instability of refraction and increasing visual symptoms due to the aging of the crystalline lens.
DLS characterises a spectrum of changes that occur with age, including presbyopia, opacification, loss of image quality, and higher-order aberrations. Actually, reduction of quality of vision is coded as well (ICD-10 H53.8 other visual disturbances).