April 2019

CATARACT

Presentation Spotlight
IOL preferences in long eyes and their complications


by Stefanie Petrou Binder, MD EyeWorld Contributing Writer


Pseudophakic macula-off retinal detachment

B-scan ultrasound showing a posterior vitreous detachment before clear lens exchange
Source (all): Oliver Findl, MD

 

Highly myopic, long eyes have a special set of challenges for refractive surgeons. Lending his expertise at a symposium at the 36th Congress of the European Society of Cataract and Refractive Surgeons, Oliver Findl, MD, shared today’s best options for the correction of vision in the “long eye.”

Phakic IOLs

Viable IOL options for individuals with long eyes include phakic IOLs and refractive lens exchange (RLE). Phakic IOLs consist of iris-fixated and posterior chamber devices. The outcomes from a wealth of studies allow the surgeon to not only choose the right device for the patient but also understand the risks and benefits involved with each type of IOL and anticipate complications. While the visual outcomes tend to be good with phakic IOLs, the potential complications can overshadow them.
Many studies have investigated the Artisan phakic IOL (Ophtec). Lines of Snellen are typically gained in long eyes with the Artisan IOL, although the refractive outcomes are not quite as good. Typically, more lines are gained in the more highly myopic eyes. Complications with the Artisan lens include poor intraoperative centration (seen in almost 9%), intraoperative IOL corneal touch, hemorrhage, late decentrations, and de-enclavations, which are all quite rare and some of which can happen years later with or without trauma.1
“The greatest challenge, of course, is the endothelium and the endothelial cell loss,” Dr. Findl said. “We should not forget that while the endothelial cell count can be reduced years after surgery, there is also natural loss of endothelial cells with age, without surgery.”
Chronic endothelial cell loss from 6 months to 5 years postoperatively was seen to be 10.5% in myopic and 10.2% in toric Artisan IOL eyes, with endothelial cell loss higher in foldable versus rigid versions of the Artisan lens. Explantations were carried out, owing to significant endothelial cell loss, in about 3% of all eyes studied.2 A more recent publication from the same study group revealed a continued decline in the endothelial cell count at 10 years after surgery, demonstrating a significant linear chronic endothelial cell loss. Patients with a smaller anterior chamber experienced a steeper decline in endothelial cell count.3
“The indications for phakic intraocular lens explantations in patients implanted with foldable iris-fixated myopic and toric phakic IOLs include: cataract, endothelial cell loss, cataract after retinal surgery, endothelial cell loss after retinal surgery, high IOP, and excessive pigment on pIOL,” Dr. Findl said.
Iris-claw pIOL implantation does not always produce significant corneal endothelial cell loss, according to evidence that included patient data from more than a 10-year time span, comparing endothelial cell counts in iris-claw patients with unoperated eyes and individuals who had undergone corneal refractive surgery.4 Dr. Findl explained that strict inclusion criteria might explain the study’s good outcomes and suggested further monitoring was necessary.
Implantable collamer lenses (ICL) are phakic IOLs that are implanted behind the iris in the posterior chamber and are used in the eyes of myopic patients.
“Although anterior subcapsular cataracts were a problem at first with these lenses, the aquaport has largely alleviated this complication by allowing aqueous flow around the lens,” Dr. Findl said. “Sizing is still critical, however. The sulcus to sulcus diameter determines vault. Little vault can cause cataract while large vault allows less iris to endothelium distance and possible endothelial cell loss or angle closure in hyperopic eyes. ICL symptoms of glare and halos do not seem to be worse postoperatively, and endothelial cell count seems to level out after 5 years from surgery as well,” he said.

RLE

RLE can be a life-changing surgery, which puts the full weight of responsibility on the surgeon to be aware of potential problems. Surgeons performing RLE in long eyes should be aware of lens-iris diaphragm retropulsion syndrome, a relatively common complication of phacoemulsification in vitrectomized eyes (42%), eyes with long axial length (12%), and larger incision size.5
RLE is a standardized surgery that can nonetheless bring about serious complications in myopic eyes, such as retinal detachment, cystoid macular edema, and posterior capsule opacification. According to Dr. Findl, one problem with what we know about pseudophakic retinal detachment (PRD) is the difficulty in comparing the data from the literature owing to highly varying study criteria. One study that assessed outcomes from 21 different studies on the subject found the incidence of PRD in myopes is around 2.2%.6 Evidence suggests patient age as a further influence on the risk of PRD, with younger patients at a higher risk of developing the complication.

In the works

According to Dr. Findl, retinal detachment is a major issue in RLE, which in a number of studies has been associated with posterior vitreous detachment and capsule rupture in eyes with long axial lengths. It is associated with post-surgical pseudophakia and with the mechanical changes within the eye after lens surgery, including the new vitreous composition, which all can contribute to altered forces and differences in dynamic traction.
Dr. Findl is the lead investigator in the MYOpic Pseudophakic REtinal Detachment Study (MYOPRED Study), which aims to determine the influence of preoperative and postoperatively developed PVD on the occurrence of retinal detachment, in a myopic patient collective only. While the association between the occurrence of PVD and RD is well documented in clinical trials, it has not yet been described for myopic patients, who have a higher risk of developing the complication.
The study will involve performing SD-OCT and funduscopy prior to surgery in myopes with an axial length in excess of 25 mm, dividing patients into groups according to PVD levels (complete PVD, partial PVD, and no PVD). Patients will be followed after surgery for the incidence of retinal detachment.
“We are currently in the recruitment process, having already recruited more than 400 eyes and aiming for 618 with an axial length of 25 mm or longer. The main outcome of retinal detachment is assessed at 3 years, with a follow-up time of all together 5 years. The study will encompass 11 participating centers in six countries. The results of this study will contribute to a higher patient safety level, as cataract surgeons will be able to better inform myopic patients about their individual risk profile for RD after RLE,” he said.

About the doctor
Oliver Findl, MD
Vienna Institute for Research in Ocular Surgery
Hanusch Hospital
Vienna, Austria

Contact information
Findl
: oliver@findl.at

References

1. Budo C, et al. Multicenter study of the Artisan phakic intraocular lens. J Cataract Refract Surg. 2000;26:1163–71.
2. Jonker SMR, et al. Five-year endothelial cell loss after implantation with Artiflex myopia and Artiflex toric phakic intraocular lenses. Am J Ophthalmol. 2018;194:110–119.
3. Jonker SMR, et al. Long-term endothelial cell loss in patients with Artisan myopia and Artisan toric phakic intraocular lenses. Ophthalmology. 2018;125:486–494.
4. Morral M, et al. Paired-eye comparison of corneal endothelial cell counts after unilateral iris-claw phakic intraocular lens implantation. J Cataract Refract Surg. 2016;42:117–26.
5. Lim DH, et al. The incidence and risk factors of lens-iris diaphragm retropulsion syndrome during phacoemulsification. Korean J Ophthalmol. 2017;31:313–319.
6. Rosen E. Risk management for rhegmatogenous retinal detachment following refractive lens exchange and phakic IOL implantation in myopic eyes. J Cataract Refract Surg. 2006;32:697–701.

Financial interests
Findl
: None

IOL preferences in long eyes and their complications IOL preferences in long eyes and their complications
Ophthalmology News - EyeWorld Magazine
283 110
220 159
,
2019-04-05T09:21:18Z
True, 4