Comanaging non-corneal refractive surgery

Last time we discussed the benefits of phakic intraocular lenses (IOLs), including patient selection criteria for both anterior chamber and posterior chamber lenses. Now, let’s discuss the comanagement of phakic IOLs including outcomes, perioperative care, and complication management.

Visual outcomes

Visian ICL (Implantable Collamer Lens) induces fewer high-order aberrations compared to LASIK in high myopia, resulting in better quality of vision in low luminance.¹ U.S. military studies show that Visian ICL provides 98 percent uncorrected visual acuity (UCVA) at 20/20, resulting in a 99 percent patient satisfaction rate.² Thirty-four percent of soldiers gained at least one line of best-corrected visual acuity (BCVA).³ One hundred percent of more than 200 U.S. soldiers report that Visian ICL provided better vision than their previous spectacles, enabling them to function and perform better.²

Effectively comanaging femtosecond laser-assisted cataract surgery

Next: Perioperative care

Perioperative care

Perioperative care for phakic IOL patients is very similar to that of patients who undergo cataract surgery. Because toric phakic IOLs are not currently available in the U.S., a plan to correct significant residual astigmatism (spectacles, LASIK, PRK, LRI [limbal relaxing incisions]) should be in place prior to surgery.

Preoperative evaluation is also similar to cataract surgery. Soft contact lenses should be removed one to two weeks prior to pre-op evaluation and one day prior to actual surgery. Hard or rigid gas permeable contact lenses must be removed four to six weeks prior to pre-op evaluation. These patients can be transitioned to soft contact lenses during this period if they cannot tolerate vision with spectacles.

Preoperative medications typically include topical antibiotic prophylaxis (qid x five to seven days). After surgery, continue the topical antibiotic for one week, add a topical steroid (two to four weeks) and a topical NSAI (two to four weeks). After surgery, patients should be instructed to refrain from eye makeup, heavy lifting, and swimming for one week and to wear clear plastic shields at bedtime for three to five days.

If your patient is having a Visian ICL implanted, laser peripheral iridotomy is performed one to two weeks prior to ICL implantation. One or two holes are created in the superior iris near the superior limbus to allow unimpeded flow of aqueous fluid after ICL implantation. Patients are usually given a topical steroid for one week after surgery. You should monitor the patient for intraocular pressure (IOP) spike and inflammation within 24 hours of iridotomy. 

Figure 1. After phakic IOL surgery, post-operative care includes examination two to four hours after surgery, then one day, one week, one month, and three months after surgery (Table 1). The first examination at two to four hours includes UCVA, biomicroscopy, and IOP check. You must ensure that the IOL is centered, attached (Verisyse), and properly vaulting crystalline lens (Visian) (Figure 1), as well as look for anterior chamber inflammation. Early IOP elevation is most often caused by retained viscoelastic or non-patent iridotomy. Retained viscoelastic material can often be resolved by “burping” the wound at the slit lamp, while a non-patent iridotomy requires return to YAG laser to enlarge opening(s).

Biomicroscopy is essential to rule out infection or endophthalmitis and ensure IOL centration and ICL vaulting. Proper vaulting of the Visian ICL is between 0.5 to 1.5 times the thickness of the cornea. Inadequate vault can result in crystalline lens opacification, while excessive vaulting can result in elevated IOP. Dilated retinal exam can wait until one or three months post-op, provided BCVA is unchanged, no excessive inflammation noted, and no symptoms of photopsia or floaters arise.

Next: Complications

Complications

Many studies show excellent safety profile of the phakic IOLs currently available in the United States.⁴ All intraocular surgeries have the potential for serious vision-threatening complications. One U.S. military study in Ft. Hood, TX, of 141 eyes reported zero percent complications in a young myopic population. In 2011, Staar Surgical reported Visian post-market safety data with complication rates below one percent (Table 2).

Anterior chamber lenses can potentially increase the risk of corneal decompensation and pigment dispersion. Posterior chamber ICLs can increase the risk of glaucoma and anterior subcapsular cataract. All phakic IOLs also can cause retinal detachment or endophthalmitis. A long-term study of 617 consecutive myopes who underwent ICL implantation demonstrated a rate of retinal detachment of 0.32 percent.⁵ A literature review of 2,592 eyes with Visian ICL implantation showed the most common complication was cataract in 5.2 percent, often due to improper ICL sizing resulting in insufficient lens vaulting of the crystalline lens.⁶

More from Dr. Tullo: Is your patient healthy enough for LASIK surgery?

Coming soon

Patients in the U.S. will likely see new phakic IOL options available in the near future. In addition to a toric version of Visian ICL, under investigation is a fenestrated version of the ICL that will eliminate the need for peripheral iridotomy prior to lens implantation.ODT

References

1. Parkhurst GD, Psolka M, Kerzirian GM. Phakic intraocular lens implantation in United States military warfighters: a retrospective analysis of early clinical outcomes of the Visian ICL. J Refract Surg. 2011 Jul:27(7):473-81.

2. Barnes S. Is the ICL Ready for Service in the US Army. Kauai, HI: Hawaiian Eye Meeting; February 2010.

3. Parkhurst GD, Psolka M. A Retrospective Analysis of Outcomes in Consecutive Eyes Undergoing Implantable Collamer Lens Refractive Surgery for the Correction of Myopia. San Antonio, TX: Fourth Annual International Military Refractive Surgery Symposium; January 11-13, 2010.

4. Igarashi A, Shimizu K, Kamiva K. Eight year follow up of posterior chamber phakic intraocular lens implantation for moderate to high myopia. Am J Ophthalmol. 2014 Mar:157(3);532-9.

5. Bamashmus MA, Al-Salahim SA, Tarish NA, Saleh MF, et al. Posterior vitreous detachment and retinal detachment after implantation of the Visian phakic implantable collamer lens. Middle East Afr J Ophthalmol. 2013 Oct-Dec;20(4):327-31.

6. Fernandes P, Gonzalez-Meijome JM, Madrid-Costa D, Ferrer-Blasco T, et al. Implantable collamer posterior chamber intraocular lenses: a review of potential complications. J Refract Surg. 2011 Oct;27(10):765-76.