KAMRA implant

The KAMRA implant , also known as the KAMRA inlay, is an ophthalmological aid for the surgical correction of presbyopia . It is only used on one eye and consists of a circular, 5-10µ thin black plastic lens with a diameter of 3.2-3.8 millimeters and a central opening 1.6-1.8 millimeters in diameter. The implant is placed under the cornea , centrally above the pupil and acts like a pinhole to increase the depth of field . The goal of its application to completely replace optical media such as glasses or contact lenses as a correction for presbyopia has not yet been achieved. The inlay has been clinically available since 2009 and has been scientifically supported from a wide variety of sources since then. Long-term studies on the benefits, risks and side effects are not yet available. Short-term studies show an improvement in near vision acuity in central areas, but this leads to other functional losses.

Procedure and mode of action

The KAMRA inlay is implanted on an outpatient basis under local anesthesia and takes about 10-20 minutes. A so-called femtosecond laser is used to create a pocket in the cornea of ​​the non-dominant eye , into which the surgeon inserts the implant and aligns it over the pupil. The procedure is preferable for people over 50 who do not have any other ametropia, i.e. are emmetropic . Nonetheless, the implant can also be carried out in ametropic , i.e. ametropic people, with simultaneous Femto Lasik .

The mode of action is based on the principle of the Stenopean gap . Disturbing marginal rays are eliminated and the depth of field increased. The result is a significant increase in reading ability in the medium close range without additional aids. In individual cases and generally for longer reading times, however, it is usually not possible to completely do without reading glasses. In addition, the unilateral use process brings about what is known as monovision , in which only the treated eye can see in the vicinity and the other in the distance.

The current data situation is not yet sufficient for the binding definition of specific areas of application. Presbyopia in emmetropes, otherwise in ametropes with an additional treatment with Femto-LASIK, is specified as the borderline area. According to the current state of knowledge, the process is easy to carry out and highly reversible. In the event of complaints, complications or intolerance, the implant can be removed at any time with little effort.

A sensible use without further eyeglass correction is seen at a medium distance up to a minimum close distance of 50 cm and generally relates to the so-called everyday area, such as reading the wristwatch or price tags, short sections of text in the newspaper, etc. with longer reading time, pronounced screen activity or even Operating machines, the need for additional reading or proximity glasses is recognized.

Risks, side effects and interactions

Patients with chronically progressive corneal diseases such as keratoconus , retinal diseases such as age-related macular degeneration or only one normally seeing eye are just as unsuitable for the use of the KAMRA implant as are people under the age of 18, those with symptomatic cataracts or glaucoma with pronounced visual field damage .

As an undesirable side effect, weak halos around light sources and diminished vision in twilight can occur in the dark . Problems such as dry eyes can occur, which requires treatment with tear substitutes. As a result, the visual acuity of the treated eye can temporarily drop below the preoperative visual acuity. In addition, the change in the optical conditions, which is normal in presbyopia, can lead to the need for a revision in which the implant must be removed again.

There is a possibility that patients with the treated eye will see slightly darker than the eye without the KAMRA implant. Corneal opacities, massive scarring, infections and significant visual impairment due to melting of the cornea are also given as extreme, but rare, side effects. Furthermore, in a series of tests on 17 patients, central and peripheral corneal iron deposits were found after Kamra implants, which, however, had no demonstrable influence on visual acuity. Another possible impairment is of a cosmetic nature and relates to the clear visibility of the implant under the cornea.

An aspect that has not been considered so far is the massive impact on binocular vision and the lack of spatial perception due to the monovision brought about by the implant. However, a high-quality stereopsis is required especially in the vicinity , so that the KAMRA implant with the relative advantage of improved monocular visual acuity in the medium close range can cause a complete loss of spatial vision, for example, concentrated work in the vicinity or high visual stress at a computer workstation . At least the fulfillment of the legal requirements of the VDU work regulation is called into question.

costs

Even if the eye implant has been approved in Germany since 2009, the costs of the procedure are not covered by either the health insurance or private health insurance companies. This also applies to the pre- and post-operative examinations to be carried out in connection with the operation. In Germany, with a pure implantation of the KAMRA inlay and after billing in line with the fee schedule for doctors (GOÄ), they amount to between 3,600 and 3,900 euros (as of 08/2013). With a simultaneous surgical correction of a farsightedness or myopia using Femto-LASIK, additional costs are added.

Sources and web links

• Evaluation and quality assurance of refractive surgical interventions by the DOG and the BVA , page 12, as of January 2014 ( Link )

Individual evidence

1. ↑ ^{a b c d} G. Grabner, W. Riha, A. Dexl, T. Rückl, M. Rasp, M. Hohensinn: The KAMRA intracorneal inlay for correcting presbyopia  ( page no longer available , search in web archives )  Info: Der Link was automatically marked as broken. Please check the link according to the instructions and then remove this notice. (PDF; 17 kB)  
2. ^ Daniel S. Durrie: Clarity for KAMRA . In: EyeWorld , 2/2012.
3. ↑ ^{a b c} Vance Thompson et al .: Corneal correction for presbyopes. Near and intermediate vision improvement with corneal implant .  ( Page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. In: Ophthalmology Times Europe Volume , 7/2011, pp. 2-4.  
4. ^ Walter Bethke: The Corneal Route for Treating Presbyopia. Corneal inlays may give patients a removeable option for dealing with their presbyopic eyes . In: Review of Ophthalmology , 2011, Volume 11, Number 33, pp. 72-73.
5. ↑ Plastic implant replaces reading glasses . Doctors newspaper , accessed January 23, 2013
6. ↑ ^{a b c d} Opinion of the Refractive Surgery Commission of the DOG and the BVA , May 2011 ( Memento of the original from January 24, 2013 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 170 kB) 
7. ^ ^{A b} Thomas Kohnen: Refractive Surgery. Google eBook, Springer DE, page 200 ff.
8. ↑ ^{a b} Information from the University Eye Clinic Frankfurt am Main
9. ^ George O. Waring: Correction of Presbyopia With a Small Aperture Corneal Inlay . In: The Journal of Refractive Surgery , 2011, 27 (11), pp. 842-845, PMID 22045576 .
10. ^ Dean Corbett: Lessons from a Surgeon Patient . In: Cataract & Refractive Surgery Today Europe 3/2012, pp. 1–2.
11. ↑ Ömer F. Yilmaz: Intracorneal inlay to correct presbyopia: Long-term results . In: Journal of Cataract and Refractive Surgery , 2011, 37 (7), pp. 1275-1281, PMID 21570249 .
12. ↑ J. Ruckhofer, G. Nix, W. Nix, M. Hohensinn, G. Grabner, E. Messmer: Central and peripheral corneal iron deposition according to Kamra Intracorneal Inlay  ( page no longer available , search in web archives )  Info: The link became automatic marked as defective. Please check the link according to the instructions and then remove this notice. (PDF; 81 kB)  
13. ↑ FreeVis LASIK Centers - The KAMRA lens or KAMRA mini diaphragm ( memento of the original from August 25, 2013 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.  
14. ↑ ARTEMIS Eye and Laser Clinic - KAMRA Inlay costs ( Memento of the original from December 11, 2013 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  

This article is about a health issue. It is not used for self-diagnosis and does not replace a diagnosis by a doctor. Please note the information on health issues !