Cataract Surgery | Jan 2012

Lens Implantation After RK, LASIK, and Placement of Intrastromal Corneal Ring Segments

Surgeons provide take-home points and suggest several IOL options.

CASE NO. 5

Patient E is a 44-year-old man who underwent radial keratotomy (RK) with eight incisions in his right eye in 1994. Patient E then underwent LASIK in 2002 to treat hyperopia; his refraction before laser vision correction was +4.50 -1.00 X 67°. In 2008, keratectasia was observed and confirmed in the patient’s right eye using the Orbscan (Bausch + Lomb; Figure 1).The treating surgeon implanted two Intacs segments (Addition Technology Inc.) into the cornea.Under topical anesthesia, each RK incision was partially opened during creation of the tunnel for the Intacs segments at twothirds the depth of the cornea.Afterward, each incision was closed with 10-0 nylon suture for both Intacs segments.Over the next year, every suture was carefully removed (Figure 2), and after suture removal the patient’s BCVA was 20/25 with refraction of +2.50 -4.25 X 70°. What would you do for this patient?

– Case and images submitted by Erik L. Mertens, MD, FEBOphth

J.M. BOSC, MD

Despite the presence of keratectasia after RK and failed attempts at LASIK and intrastromal corneal ring segment (ICRS) implantation, Patient E has relatively good BCVA (20/25). Unfortunately, his pachymetry and topography results are not available, and the stability of his ectasia is unknown.

In my experience, four points are essential in this and similar cases:

(1) Perform a visual field test and careful optic disc examinations. These exams should signal the presence of any associated pathologies, especially glaucoma;
(2) Be cognizant of the probable evolution of ectasia, which will induce variability in the patient’s refraction and possibly require a future corneal graft;
(3) Consider the status of the contralateral eye; and
(4) Take the patient’s expectations into account. Due to the oblique and probably irregular astigmatism, glasses are not a good option.

for this patient, as these can provide good visual comfort and can be changed with the evolution of ectasia. Corneal surgery options should also be discussed, one of which is the exchange of ICRSs. Another technique, which is easier, is creation of relaxing incisions in the contralateral axis (160º). However, neither technique can guarantee good refractive results.

If the anterior chamber is deep enough and the endothelial cell density is normal, implantation of a toric iris-fixated phakic IOL is another option that could be discussed. Refractive predictability is good, but this surgery is invasive, can carry endothelial risk, and moreover is a transient solution. I would not perform clear lens surgery.

If Patient E’s keratectasia is progressive, the ultimate solution might be deep lamellar keratoplasty with the big-bubble technique, followed by femtosecond LASIK 4 to 6 months after the graft. I have performed one such case with good results and high patient satisfaction.

All therapeutic strategies must be explained to the patient and discussed before surgery.

JOSE L. GÜELL, MD

For a thorough and comprehensive response, I would also like to know the complete refractive and visual information for Patient E’s left eye and how satisfied Patient E is with his current situation. Without this information, however, I think the most important points are:

(1) The first step is to check stability, including visual, refractive, and topographic control during a 12- to 18- month follow-up period. In the interim, Patient E can use spectacles, toric contact lenses, or both;
(2) If the cornea is unstable, I would perform corneal collagen crosslinking (CXL) and consider proceeding with the following steps;
(3) If the cornea is stable and the patient is satisfied, I would continue with his current strategy (spectacles and/or contact lenses); and
(4) If the cornea is stable but he is unsatisfied with spectacles or contact lenses, I would consider toric phakic IOL implantation.

From my point of view, the best option for Patient E is a toric hyperopic IOL such as the Artisan phakic IOL (Ophtec BV). As he is a middle-aged patient with a myopic eye, I assume that his anterior chamber depth fulfills the minimum criteria for implantation and, on the other hand, crystalline lens surgery might increase the retinal risk. Crystalline lens surgery would have been my first choice if Patient E was 55 years of age or older.

ANTÓNIO A.P. MARINHO, MD, PhD

This 44-year-old man has been operated on three times, first RK for myopia, then LASIK for consecutive hyperopia, and then ICRS implantation for corneal ectasia. After all that, he still has good BCVA (20/25). This is a case in which my first inclination would be not to do more surgery. However, if Patient E insisted on getting rid of his astigmatism, I would advise the following steps:

(1) Perform corneal topography to assess the regularity of astigmatism;
(2) If the astigmatism is regular, a standard laser surface ablation could be done, but if the astigmatism is irregular (the most likely situation) topography-guided laser surface ablation would be called for; and
(3) Perform postoperative CXL, in either case outlined in No. 2, to further stabilize the cornea.

Another more invasive option would be to implant a toric Visian ICL (STAAR Surgical) if the anatomic configuration of the eye is suitable. If the cornea changes after ICL implantation, the phakic IOL would lose its desired effect.

In this case, I would not contemplate lens exchange, as the patient has a clear lens and still probably fairly good accommodation. This would contraindicate a toric monofocal IOL, and multifocals are out of the question in a patient who has already undergone three corneal surgeries.

ERIK L. MERTENS, MD, FEBOphth

Patient E was treated at my clinic. Here is how I proceeded: After the cornea and the refraction were stabilized, I decided to implant a hyperopic toric Visian ICL (VTICM 13.2). The refractive aim was -1.40 +4.50 X 157°, meaning that the toric ICL had to be rotated 3° clockwise after horizontal implantation to match the toric ICL astigmatism with the axis of the refractive astigmatism of the eye (Figure 3). Six months after toric ICL implantation, Patient E’s UCVA was 20/20.

J.M. Bosc, MD, practices at the Hopital Jean-Minjoz, Besancon, France. Dr. Bosc did not provide disclosure information. He may be reached at e-mail: jmbosc@aol.com.

Jose L. Güell, MD, is the Director of the Cornea and Refractive Surgery Unit at the Instituto de Microcirugia Ocular, Barcelona, Spain, and an Associate Professor of Ophthalmology at the Universitat Autónoma de Barcelona. He is also the President of the ESCRS. Dr. Güell states that he is a paid consultant to Ophtec BV. He may be reached at tel: +34 93 253 15 00; e-mail: guell@imo.es.

António A.P. Marinho, MD, PhD, is the Chairman of the Department of Ophthalmology, Hospital Arrábida, Porto, Portugal. Dr. Marinho states that he has no financial interest in the products or companies mentioned. He may be reached at tel: +35 1936093345; e-mail: marin@mail.telepac.pt.

Erik L. Mertens, MD, FEBOphth, is Medical Director of Medipolis, Antwerp, Belgium. Dr. Mertens is a Co-Chief Medical Editor of CRST Europe. He states that he has no financial interest in the material presented in this article. Dr. Mertens may be reached at tel: +32 3 828 29 49; e-mail: e.mertens@medipolis.be.

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