Intrastromal Correction of Ametropia by a Femtosecond Laser

Recruitment & Eligibility

Status: Complete

Sex: All

Target Recruitment: 86

Inclusion Criteria

age: > 18 years
- stable distance refraction for at least one year (i.e. a maximum change of 0.5 D)
- in the case of presbyopia: minimum near add +2D to + 4D
- in the case of myopia or hyperopia (without astigmatism): minimal 1D and maximum 3D
- in the case of myopia or hyperopia (with astigmatism):
spherical equivalent of minimal 1D and maximum 3D
- BSCVA of the eye to be treated >= 0.63
- patients are willing and in such conditions to come to the follow-up exams
- no further ocular pathologies

Exclusion Criteria

- age: < 18 years
- refraction less than +/- 1 D or higher than +/- 3 D (not valid for persbyopia patients)
- minimal pachymetry of < 500µm
- K-mean < 37 D or > 60 D
- Difference (K-max minus K-min) > 5D
- Difference cycloplegic refraction to subjective refrection more than 1 D (valid only for hyperopia correction)
- patients with previous intraocular or corneal surgeries (e.g. post-LASIK or PRK patients). Examption: standard cataract surgery.
- patients with one or more of the following ocular pathologies:
> keratokonus
> corneal scars
> transplanted cornea
> disorders of wound healing
> trauma
> glaucoma
> epilepsia
> nystygmus
> lack of concentration
> other complicated illnesses
> diabetis mellitus
> instable K-readings as a sign of instable cornea
> weakness of connective tissue
> sensitivity against the drugs used in the study
> continous wearing of contact lenses before the pre-exam, and before the surgery. At least 14 days before these dates patients must abstain from wearing CL.
> patients in pregnancy or during lactation
> patients who take part in an other clinical trial

Study & Design

Study Type: interventional

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Primary end point for each study arm: 3 months, because latest after this period of time a stable visus is expected. At this point the safety and efficacy of the procedure shall be assessed.<br>Diagnostic exams are carried out. The results are collected in Case Report Forms. E.g. data for near and distance visual acuity, read velocity, cycloplegical refrection, aberrometry, topography, pachymetry, pupilometry, intraocular pressure. Furthermore each patient has to fill in a questionnaire which shall reflect the subjective feelings.

Secondary Outcome Measures

Name	Time	Method
Secundary end point for each study arm: 6 months, serves for the validation of the 3 months results.<br>Simlar to the 3-months Follow-up diagnostic exams are carried aout after 6 months. The results are collected in Case Report Forms. E.g. data for near and distance visual acuity, read velocity, cycloplegical refrection, aberrometry, topography, pachymetry, pupilometry, intraocular pressure. Furthermore each patient has to fill in a questionnaire which shall reflect the subjective feelings. \|\| Final end point: 12 months, as at this point further data are available for the detailed observed, identical patient cohort. These are used in order to assess which influance the natural physiological ageing- and morphological processes have on the visual acuity.<br>Even after 12 months similar diagnostic exams are carried out as after 3 or 6 months. The results are also collected in Case Report Forms and each patient has to fill in the subjective questionnaire.

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