Endothelial distance after phakic iris-fixated intraocular lens implantation: a new safety reference

Abstract

PurposeTo evaluate the distance between the endothelial surface of the cornea to the anterior edge of an Artiflex® phakic intraocular lens (IOL) implant to improve the safety profile of this implant.MethodsThis is a retrospective clinical case series of 45 patients who had Artiflex phakic IOL implantation (Artiflex p-IOL) with a follow-up period of 3 years. A Pentacam HR imaging system was used to measure the distance from various points of the anterior edge of the Artiflex IOL to the endothelial surface of the cornea, which we called endothelial–IOL (E–IOL) distance, in 45 eyes. The E–IOL distances were assessed at 1, 3, 6, 12, 24, and 36 months. Corresponding correlations of central endothelial distance to temporal and nasal edges and center of the IOL anterior surface were tabulated.ResultsMean follow-up was 21.39±11.28 months. A statistically significant reduction of the E–IOL distance was observed over the follow-up period (P<0.05), with the mean annual reduction being 24.70 μm. A strong positive correlation between the E–IOL distance of the edges of the IOL and the central distance was observed (correlation coefficients nasal/central: month 1, 0.905; month 36, 0.806; temporal/central: month 1, 0.906; month 36, 0.806; P<0.001). Moderate negative correlations were found between the spherical equivalent power of the implanted IOL and the E–IOL distance (correlation coefficients −0.271 to −0.412, P>0.05). For an E–IOL distance of the IOL edge >1500 μm, the distance from the endothelium to the central point of the p-IOL optic should be a minimum of 1,700 μm to improve the safety profile for Artiflex p-IOL implantation and reduce the potential complication of accelerated endothelial cell loss.ConclusionAfter Artiflex IOL implantation, the mean annual reduction of the E–IOL distance was 25 μm. A negative correlation existed between the spherical equivalent power of the implanted IOL and the postoperative E–IOL distance. The minimum E–IOL distance from the center of the IOL to minimize the risk of endothelial cell loss was 1.7 mm. This distance, as is the 1.5 mm initially proposed by Baikoff, is a postoperative value. We cannot make that assumption for the preoperative evaluation, as the morphometry of the anterior chamber changes with the implant.

Pars Plana Lensectomy and Iris-Claw Artisan Intraocular Lens Implantation in Patients with Marfan Syndrome

“…Artisan implantation is an effective method to manage the aphakia in the absence of capsular support. Although anterior chamber Artisan IOL implants were associated with some complications such as iritis, IOL disenclavation, and endothelial cell compromise; numerous studies indicated that despite some endothelial cell loss in the long term, IOL and corneal endothelium keep a safe distance from each other (ranging from 2.99 to 3.01 ± 0.56 mm) [20][21][22][23][24]. Several studies have shown that artisan IOL had several advantages and fewer complications when compared with the transscleral sutured PCIOLs and anglesupported ACIOLs [11].…”

Differences between Scheimpflug and optical coherence tomography in determining safety distances in eyes with an iris-fixating phakic intraocular lens

“…Correct positioning of an IF-pIOL in the anterior chamber is of high importance to determine long-term safety, as a smaller ACD and smaller distance from the edge of the pIOL to the endothelium can cause accelerated EC loss, which could lead to the need for early pIOL removal [ 19 , 22 ]. Jonker et al have recently reported a prevalence of IF-pIOL explantation due to excessive EC loss of up to 6.0% during 5- and 10-year follow-up [ 19 ].…”

“…Baikoff [ 11 ] at first suggested a minimum safety distance between the pIOL and corneal endothelium of 1.5 mm, a distance based on Scheimpflug results from earlier studies [ 11 , 17 ]. Doors et al [ 12 , 13 ] evaluated pIOL clearances with the Visante OCT. Ferreira et al [ 22 ] provided the clinicians with a new safety reference in 2014: a minimum central clearance distance of 1.7 mm, based on their Pentacam results. Recently, Jonker et al [ 19 ] have demonstrated a 10.3% EC loss over 5 years and 20.5% over 10 years with a mean distance between the central pIOL edge and endothelium of 2.17 mm using the Visante AS-OCT.…”

“…For example, based on Eq. 1 , the minimum safety distance should be 1.84 mm, instead of 1.7 mm as proposed by Ferreira [ 22 ], when using AS-OCT. This difference of 0.14 mm is relevant for the follow-up of the patients, as it could explain increased EC loss.…”

Refractive surgery following corneal graft

“…The revolution of anterior segment imaging (HR AS-OCT and Pentacam HR) has increased the accuracy and safety profile [100,101]. Many authors published good results using Artisan after keratoplasty with astigmatic correction up to 90% [47,56,61,102,103].…”