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OPD: Implant Center

The aberrometrique review to quantify the optical effect of a surgical complication of the cataract surgery as the occurrence of a dislocation of the artificial lens implant (implant pseudophake). A patient, cataract surgery, complains of severe discomfort in night vision, glare, halos, bright streaks, impossibility of driving at night. Visual acuity is measured at 10/10 with a slight correction astigmatism, but without this correction reduces the Visual symptoms, which are mitigated the day; the patient however noted a split on the side vision. This variation is consistent with the possibility that a high rate of optical aberration of high degree can be the cause of these symptoms.

(Biomicroscope) slit lamp inspection reveals the presence of a shift of the implant.

biased cataract implant

Biomicroscopique (slit lamp) on examination, there is a lateral shift of the intra ocular implant. This displacement is objectified by the OCT of the anterior segment examination.

The measure by the topographer aberrrometre OPD SCAN 3 reveals the increase in the rate of the high degree of internal origin aberrations (implant).

Wavefront aberration biased implant

Statement of the optical aberrations of high degree; the Wavefront eye total (left), corneal (in the middle) and internal (right) is represented at the top. Downstairs, appear the cumulative rate of high degree aberrations that are grouped by category. Observed that the total eye aberrations rate is high, and linked to a rise in internal optical aberrations.

The statement of the Wavefront accredits the internal origin of the aberrations of high degree, caused by the shift of the intra ocular implant.  The maps that explore the optical quality of the eye allow to appreciate the effect of these aberrations on the quality of the retinal image:

optical quality implant biased MTF

The optical quality of the eye survey objective a horizontal deformation of the PSF (upper-left), which corroborates the appearance of horizontal doubling of the perceived images (hates right). It is interesting to note that the orientation of these disturbances is identical to the direction of the shift of the implant. It is related to the induction of a high rate of optical aberrations of high degree of type coma and trefoil.

Aberrometrique review, faced with clinical data, allows to incriminate the decentering of the implant with Visual symptoms. A reconstructive surgery to refocus the implant to the pupil is then performed:

Re-centering implant surgery

After the operation, which is to refocus the lens through wires (10-0 Prolene) placed to spout the intraocular lens in order to refocus its approach with respect to the pupil.

This procedure, performed under local anesthesia, results in the disappearance of the Visual symptoms (duplication, halos, etc.). Review by OPD confirms the improvement of the optical quality of the eye:

optical quality implant refocused MTF

After narrowing of the implant, there is an improvement of the stigma (the PSF, in the upper left is more compact), contrasts (MTF curve), as well as the image retinal convoluee (disappearance of the side split). This improvement is objectified by the reduction in the rate of the aberrations of high degree.

This case illustrates the value of the OPD in the "complicated" cataract surgery case (in this case, the implant was not been positioned properly because of the occurrence of a breach of the cristallinienne capsule during the initial response). The parallelism between subjective symptoms and objective elements (the shift management and direction of the double vision, optical aberrations of high degree of coma guy) helped confirm the responsibility of the shift in the genesis of Visual annoyance.

2 Responses to "Aberrometry: Decentric Implant"

  1. CONSTANT Claude says:

    After a cataract operation, I found a perfect vision without glasses, but only for 2 days. Then the vision of the operated eye is once again very imperfect, as well nearly as far, and more very unstable, a month after the operation.
    Can it be: a move of the implant?
    Or a problem of instability of the volume of the capsular bag which, thus would no longer be at the proper
    Distance from the retina.
    For now, my surgeon, who finds that everything is normal, did not provide me with an answer.
    To read and thank you, for the advice you will be willing to give me.

  2. Dr. Damien Gatinel says:

    It is very difficult if not impossible to determine the causes of this decline in vision. A displacement of the implant guess the occurrence of an intraoperative complication. The capsular bag contraction does not in 2 days in principle. An eye exam eventually complemented objective measures (OPD) is expected to understand the reasons for your Visual annoyance.

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