Phakic lenses – qualification for the procedure

The phakic lens implantation procedure is used for refractive defects from -18.00 to +10.00 diopters, even with astigmatism up to -6.0 diopters. Phakic lenses – special artificial flexible intraocular lenses – are implanted between the iris and the natural lens.

Since the natural lens is preserved, the accommodative abilities of the eye are also preserved. Collamer, a biocompatible material created from collagen, is used to manufacture phakic lenses. It is very well tolerated by the eye.

Who qualifies for phakic lens doppler surgery

If all test results and the patient’s current visual defect do not allow to undergo laser vision correction , usually the patient can undergo phakic lens implantation (grafting). This is a reversible procedure.

Phakic lens implantation is a solution aimed primarily at patients with high myopia, hyperopia or astigmatism, or even presbyopia. In the latter case, multifocal/EDOF lenses are available.

The patient no longer needs to wear corrective glasses or contact lenses after phakic lens implantation. Phakic lenses are often referred to as implantable contact lenses.

The treatment is dedicated to people who:

  • are between the ages of 18 and 55
  • have myopia from – 0.5 to -18 diopters
  • have farsightedness from +0.5 to +10 dioptersi
  • have astigmatism up to +6D
  • suffer from presbyopia
  • have a stable visual defect – although phakic lenses can be replaced if the visual defect worsens.

For higher vision defects, the decision on the possibility of the procedure is made by an ophthalmologist at a qualifying visit.

https://www.youtube.com/watch?v=xenunjE6w1o

Contraindications to phakic lens implantation

  • Anatomical parameters of the eye, such as the depth of the anterior chamber and the width of the cornea
  • Unstabilized autoimmune (autoimmune) diseases
  • connective tissue diseases
  • Eye diseases (e.g., glaucoma, retinal detachment)
  • cancers
  • infections
  • pregnancy and breastfeeding period

The following tests and procedures are performed as part of the qualification for phakic lens implantation:

  • Patient Interview
  • Computerized eye examination (autorefractometry)
  • Keratometry (measurement of corneal curvature)
  • Pachymetry (measurement of corneal thickness)
  • Corneal topography

The following tests and procedures are performed as part of the preoperative examination for phakic lens implantation:

  • Patient Interview
  • Computerized eye examination (autorefractometry)
  • Keratometry (measurement of corneal curvature)
  • Tonometry (measurement of intraocular pressure)
  • Optometric examination
  • Visual acuity without correction (vis sc)
  • Eye dominance
  • Subjective refraction
  • In the case of astigmatism – Determining the power and axis of the cylinder
  • Visual acuity under correction (vis cc)
  • Checking the parameters of binocular vision (fusion, stereopsis, presence of foria/tropia)
  • In the case of presbyopia, determination of addition (nearsightedness addition)
  • In case of presbyopia, simulation of monovision (monovision tolerance test)
  • Pachymetry (measurement of corneal thickness)
  • Corneal topography
  • Dynamic pupilography
  • BUT – tear film interruption test (tear film quality)
  • Eye biometry (measurement of eyeball length), anterior chamber depth (ANTERION®)
  • Cycloplegia (paralysis of accommodation and pupil dilation)
  • Autorefraction
  • Anterior and posterior ocular biomicroscopy
  • Tomography (OCT – optical coherence tomography of the eye)
  • fundus photography (fundus camera image)

The examination of the anterior segment of the eye is performed at SwissLaser through the ANTERION® platform. The device combines corneal topography and tomography, measurement of the anterior segment of the eye, measurement of axial length, and IOL ( Intraocular lens power calculation) calculation to facilitate the routine surgical procedure.

Visual confirmation of all measurements with high-resolution swept source OCT images ensures diagnostic confidence. One of the ANTERIONA® modules (the Barret module) includes calculation formulas for calculating toric lenses.

https://www.youtube.com/watch?v=fiMyufGZORc

OCT examination of the posterior segment of the eye and cornea is performed at SwissLaser with the Retina Scan Duo ™. It’s a high-resolution OCT and funduscamera (imaging the fundus of the eye through the pupil) in one.

NOTE: During the diagnosis before phakic lens implantation, drops are used to dilate the pupils. After their use, the eyes are sensitive to light (the pupil does not constrict) which results in worse vision, so it’s a good idea to come to the tests with someone who will be there to help us when we get home.

NOTE: If you wear soft contact lenses, you should give them up 2 weeks before the test, and 4 weeks if you use hard lenses. During this time, the cornea will return to its physiological shape (wearing lenses causes, a temporary change in the shape of the cornea, which affects the accuracy of important measurements taken during the qualifying examination).

author image

Author:

Dr. Victor Derhartunian

Dr Victor Derhartunian od 2012 roku z sukcesem prowadzi własną klinikę EyeLaser we Wiedniu (Austria), zaś od 2016 roku – Centrum Chirurgii Laserowej w Zurychu (Szwajcaria). Obie te placówki należą do wysoko ocenianych przez Pacjentów klinik w tej części Europy, a wszystko to dzięki umiejętnemu wykorzystaniu innowacyjnych technologii i zastosowaniu absolutnie wysokich standardów w pracy z Pacjentami.