Bilateral Cataract after Phakic Posterior Chamber Top Hat-style Silicone Intraocular Lens

Prototype posterior chamber phakic IOL - 35 year follow up

Purpose

To present a case involving a rarely seen prototype posterior chamber phakic IOL (PC-pIOL) in a highly myopic patient with bilateral cataract.

Observations

A 64-year-old male presented to our clinic with poor vision in both eyes. Clinical examination revealed bilateral mature cataract, phacodonesis as well as a PC-pIOL implanted 35 years ago to address his high myopia. The visual acuity (VA) was 20/200 in the right eye and no light perception in the left eye. PC-pIOL extraction as well as 23G pars plana vitrectomy (PPV) and fragmentation surgery was scheduled for the right eye. The left eye was treated conservatively. Successful extraction of the PC-pIOL was performed while it was easy to remove. It was a bow-tie shaped lens with a collar-stud-like button in the middle which extended anteriorly into the anterior chamber through the pupil. PPV with lens fragmentation was successful and the patient was left aphakic in order to avoid the placement of a zero diopter IOL. Final best corrected VA was 20/25 one month post-surgery.

Conclusions and importance

Removal of this rarely seen pIOL was performed without difficulty while excellent VA was achieved. Aphakia following complete vitrectomy represented a viable option in this case. Furthermore, we highlight the clinical manifestations associated with this IOL more than three decades after implantation.

Scheimpflug Analysis of Centration and Bending of Posterior Chamber Phakic Intraocular Lenses

PURPOSE

The aim of the study was to present a novel technique for the assessment of postoperative centration and bending in phakic intraocular lens (PIOL), illustrated through 4 patient examples.

DESIGN

This was a prospective observational study.

METHODS

Four patients (7 eyes) who presented with complaints of reduced quality of vision after implantation with a Staar Collamer plate haptic PIOL were recruited for assessment. Scheimpflug images were obtained and analyzed with respect to the apical axis and the crystalline lens by means of an in-house-developed algorithm. The program provides an estimate for the PIOL centration and bending through an analysis of the distance between the PIOL and the crystalline lens.

RESULTS

The algorithm detected PIOL bending in 5 of the 7 eyes and PIOL decentration in 3 eyes. The PIOL bending or decentration detected corresponded, in all cases, with the axis of the astigmatism-like complaints in the patient. In 2 eyes of the same patient, the analysis could not be performed because the distance between PIOL and crystalline lens was too short for reliable analysis.

CONCLUSIONS

This algorithm is a useful tool to objectively assess the postoperative complaints of patients implanted with a posterior chamber PIOL. Bending and decentration due to anatomical variations of the sulcus lens position can be measured and in many cases correlated with patients' complaints.

Long-term follow-up of first-generation posterior chamber phakic intraocular lens

We present a patient who received a first-generation posterior chamber phakic intraocular lens (PC pIOL) (Fyodorov IOL) to correct myopia 18 years previously. After a long lapse in the follow-up, the patient presented with a reduced endothelial cell count. Although the cataractogenic effect of first-generation PC pIOLs is well known, no sign of cataract was present. The patient was totally satisfied even after 18 years. To our knowledge, this is the first report of a long follow-up of a patient implanted with a first-generation PC pIOL.

Cataractous Changes due to Posterior Chamber Flattening with a Posterior Chamber Phakic Intraocular Lens Secondary to the Administration of Pilocarpine

OBJECTIVE

To present the first reported case of cataract formation as a consequence of instillation of pilocarpine in an eye with a posterior chamber phakic intraocular lens (IOL).

DESIGN

Interventional case report.

INTERVENTION

A 46-year-old man received a hyperopic implantable collamer lens (ICL) bilaterally.

MAIN OUTCOME MEASURES

Determination of best-corrected visual acuity (BCVA); contrast sensitivity testing with and without glare; and intraocular pressure (IOP), specular endothelial cell, and slit-lamp examinations were performed serially. In addition, the distance between the ICL and crystalline lens was measured with optical coherence tomography.

RESULTS

Both eyes underwent uneventful ICL implantation for the correction of a manifest spherical equivalent of +7 diopters (D) in the right eye and +7.1 D in the left eye. The left eye was followed for 2 years without developing complications. The right eye, however, showed on the first postoperative day a fleckenlike opacification on the anterior pole of the crystalline lens after instillation on the operative day of 2% pilocarpine in an attempt to accelerate recovery from unwanted pupil dilation causing patient complaints of glare disability after surgery. Optical coherence tomography demonstrated complete contact of the ICL with the natural lens 24 hours postoperatively. Serial IOP measurements were always within the normal limits. The instillation of 1% cyclopentolate resulted in an increase in the ICL vault that measured 132 mum 24 hours later. Three days after the completion of a 3-day course of topical 1% cyclopentolate, the opacification was less dense and demarcated, and a 124-mum vault was measured. Three months postoperatively, the cataract was associated with a 3-line loss of BCVA and considerable degradation of the contrast sensitivity, especially at higher spatial frequencies and with a glare source, and corneal endothelial cell changes were within normal limits. One year after ICL implantation, the right eye had to undergo phacoemulsification and IOL implantation, which were uneventful.

CONCLUSIONS

Posterior chamber flattening with resulting crystalline lens opacification can occur immediately after the instillation of pilocarpine in an eye with a hyperopic ICL. Therefore, caution should be taken with the administration of cholinergic agonists such as pilocarpine in patients with phakic IOLs, at least if they are hyperopic ICLs.

Decentration and Cataract Formation 10 Years Following Posterior Chamber Silicone Phakic Intraocular Lens Implantation

PURPOSE

To report a 10-year follow-up for bilateral implantation of a Chiron Adatomed silicone posterior chamber phakic intraocular lens (PIOL).

METHODS

A 32-year-old man presented with bilateral blurred vision and monocular diplopia in the left eye of 2 years' duration.

RESULTS

Slit-lamp microscopy showed bilateral anterior subcapsular cataract and temporal PIOL decentration, and no visible space between the PIOL and crystalline lens in the right eye. After explantation of the posterior chamber PIOL, lens aspiration, and IOL implantation, uncorrected visual acuity improved to 20/15 in the right eye. Scanning electron microscopy examination showed denser deposits on the central portion of the back surface when compared with the edges.

CONCLUSIONS

Long-term follow up of certain designs of posterior chamber PIOLs may reveal late occurrence of complications. Cataract formation may be related to direct contact between the implanted and crystalline lenses.

Phakic Intraocular Lenses

An analytical review of the data available in the field of phakic intraocular lens implantation was conducted. Particular attention was paid to the more critical issues of intraocular lens sizing and safety guidelines. A comprehensive, competitive analysis of different implantation sites, intraocular lens model designs, and safety guidelines has been included. Specialized biometry techniques, such as very high frequency ultrasound and Scheimpflug imaging, have been reviewed, and a critical review of commercial claims regarding intraocular lens technologies has been included. Clinical studies of phakic intraocular lenses demonstrate increasing promise for the correction of refractive errors not amenable to mainstream excimer laser refractive surgery. The main issues currently revolve around adequate lens design (VHF ultrasound study suggests that custom-design and sizing may be the most effective and safest approach for every phakic IOL model), because these devices will be required to remain physiologically inert and anatomically compatible with internal ocular structures and relations for several decades. The possibility of safe removing or exchanging the IOL should remain a feasible option over time. It is of utmost importance that we continue to critically evaluate current encouraging short-term outcomes, which are being extrapolated to the longer term by ongoing high resolution imaging and monitoring of the anatomical and functional relations of implanted phakic IOLs.

Intraokularlinsen zur Korrektur von Refraktionsfehlern

In this overview, the current status of intraocular lens surgery to correct refractive error is reviewed. The interventions are divided into additive surgery with intraocular lens implantation without extraction of the crystalline lens (phakic intraocular lens, PIOL) or removal of the crystalline lens with implantation of an IOL (refractive lens exchange, RLE). Phakic IOLs are constructed as angle-supported or iris-fixated anterior chamber lenses and posterior chamber lenses which are fixated in the ciliary sulcus. The implantation of phakic IOLs has been demonstrated to be an effective, safe, predictable and stable procedure to correct higher refractive errors. Complications are rare and differ for the three types of PIOL; for posterior chamber lenses these are mainly cataract formation and pigment dispersion. RLE is preferable in cases of high ametropia in which the natural lens has lost its accommodative effect. The main complications for myopic RLA include retinal detachment, while hyperopic refractive lens exchange may be associated with surgical problems in the narrower anterior eye segment.

Intraokularlinsen zur Korrektur von Refraktionsfehlern

In this overview, the current status of intraocular lens surgery to correct refractive error is reviewed. The interventions are divided into additive surgery with intraocular lens implantation without extraction of the crystalline lens (phakic intraocular lens, PIOL) or the removal of the crystalline lens with implantation of an IOL (refractive lens exchange, RLE). Phakic IOLs are constructed as angle-supported or iris-fixated anterior chamber lenses and posterior chamber lenses that are fixated in the ciliary sulcus. The implantation of phakic IOLs has been demonstrated to be an effective, safe, predictable and stable procedure to correct higher refractive errors. Complications are rare and differ for the three types of PIOL; for anterior chamber lenses these are mainly pupil ovalization and endothelial cell loss.

Ten-year follow-up of a ciliary sulcus-fixated silicone phakic posterior chamber intraocular lens

In 1992, a ciliary sulcus-fixated, silicone, phakic posterior chamber intraocular lens (PPC IOL) (Adatomed, Fyodorov type) was implanted in both eyes of a 42-year-old white woman to correct high myopia (right eye, -17.0 diopters [D]; left eye, -11.5 D). In the right eye, localized cortical opacification was present in the anterior part of the natural lens preoperatively but did not progress during a 10-year follow-up period. With Scheimpflug photography, it was possible to detect a space between the natural lens and the IOL that was not evident on slitlamp examination. Maintenance of space between an IOL and the natural lens appears to be an important factor in preventing cataract formation after PPC IOL implantation.

Rate of Cataract Formation in 343 Highly Myopic Eyes After Implantation of Three Types of Phakic Intraocular Lenses

PURPOSE

To assess the feasibility of using phakic intraocular lenses (PIOL) to treat high myopia, and evaluate the incidence of cataract, comparing three different lens types.

METHODS

From 1989 to 2002, we implanted three different phakic intraocular lenses (PIOL) in 343 eyes of 232 patients; 231 eyes recieved an Ophtec (Worst-Fechner model, iris-claw), 89 an Adatomed (silicone posterior chamber), and 23 a Staar (posterior chamber, models V2, V3, V4). Average follow-up was 96.2 months for the Ophtec group, 31.5 months for the Adatomed group, and 19.3 months for Staar group. Eyes that subsequently developed cataract were studied for clinical evolution and had PIOL explantation and cataract extraction.

RESULTS

Nuclear cataract developed in 7 of 231 eyes (3.04 %) with an Ophtec lens. Anterior subcapsular cataract developed with the two types of posterior PIOLs (Adatomed group: 38/89 eyes, 42.69%; Staar group: 3/23 eyes, 13.04%). Anterior subcapsular cataract in the Adatomed group developed more rapidly compared to the Staar group. We explanted 7 lenses in the Ophtec group, 16 lenses in the Adatomed group, and 2 lenses in the Staar group (models V2 and V3 only). Patient age older than 40 years at implantation of PIOLs and axial length greater than 30 mm were factors significantly related to nuclear cataract formation and the Ophtec lens. However, these two factors had a weaker correlation with the posterior phakic lenses (Adatomed, Staar) for high myopia than with the Ophtec lens. Postoperative best spectacle-corrected visual acuity remained stable after explantation, phacoemulsification, and posterior chamber lens implantation.

CONCLUSIONS

Delayed cataract development and cataract type (nuclear) in patients with an Ophtec lens and the variables of patient age (>40 yr) and axial length (>30 mm) may considered prognostic factors. Other factors such as lens design, material, and placement probably influenced cataract formation in patients with the Adatomed and Staar PIOLs. The lens styles used in this study are no longer manufactured.

The phakic intraocular lens implant: in-depth focus on posterior chamber phakic IOLs

Phakic Intraocular surgery has come a long way in the past 20 years, especially in the evolution of posterior chamber phakic intraocular lenses (PC PIOLs). Clinical trials worldwide are showing acceptable results concerning efficacy, predictability, stability, and safety. PC PIOLS are proving to be a promising option for patients with high and extreme ametropia who cannot benefit from conventional corneal refractive procedures. This article provides an in-depth examination of PC PIOLs, their origin and evolution, and the results of past and current clinical studies. Reports of historical importance and studies published since the 1990s in peer-reviewed journals, textbooks, and monthly eye magazines, as well as Food and Drug Administration preliminary clinical findings, are reviewed. Anterior chamber phakic intraocular lenses are mentioned briefly.

High incidence of cataract formation after implantation of a silicone posterior chamber lens in phakic, highly myopic eyes

OBJECTIVE

To assess the effectiveness and safety of implantation of a negative, silicone, posterior chamber intraocular lens (IOL) in the ciliary sulcus of phakic, highly myopic eyes.

DESIGN

Noncomparative consecutive interventional series.

PARTICIPANTS

Eighteen eyes of 10 patients suffering from high-degree myopia (spherical equivalent < -10 diopters) undergoing implantation of a Fyodorov 094M-1 IOL by the same surgeon (P.H.B.) were evaluated.

INTERVENTION

A standard surgical technique was used in all patients under peribulbar anesthesia. The IOL was implanted in the ciliary sulcus immediately in front of the natural lens under protection of a viscoelastic substance (Healon) through a 3.5-mm temporal or nasal clear-corneal tunnel. No sutures were necessary in any case. A peripheral iridectomy was performed intraoperatively in 14 eyes, whereas 4 additional eyes received a yttrium-aluminum-garnet peripheral iridectomy after surgery. At the end of surgery, gentamicin and dexamethasone were given both topically and subconjunctivally.

MAIN OUTCOME MEASURES

Visual acuity and refraction were measured before surgery, as well as 1 day, 3 months, 6 months, and 2 years after surgery. Postoperative complications were recorded.

RESULTS

Best-corrected visual acuity remained unchanged (1 eye) or improved (6 eyes by 1, 5 eyes by 2, and 2 eyes by 3 Snellen lines, respectively) in 14 of 17 eyes, whereas 3 eyes experienced a decrease in best-corrected visual acuity by 1 Snellen line. Postoperative refraction approached the desired slight undercorrection at all times of examination. Cataract formation of the anterior subcapsular (8 eyes) or nuclear (only 1 eye) type was observed in overall 9 (52.9%) of 17 eyes. When considering only the patients with a follow-up of 2 years, the incidence of cataract formation was 81.9% (9 of 11 eyes).

CONCLUSIONS

The high incidence of cataract formation should discourage the implantation of the type of IOL used in this study in phakic eyes to correct high-degree myopia.

Cataract development after implantation of the Staar Collamer posterior chamber phakic lens

Implantation of a posterior chamber phakic intraocular lens is an effective refractive procedure with a good safety record in the short-term follow-ups reported in the literature. Cataract formation is a potential complication of the procedure. Two patients developed lens opacities in 3 eyes after the procedure was performed for myopic astigmatism. The possible causes are discussed. This is not a dangerous complication as cataract extraction is easily achieved if necessary. However, it is undesirable and further research is required to assess the long-term incidence, causes, and ways to prevent its occurrence.

Cataract formation after posterior chamber phakic intraocular lens implantation

Posterior chamber phakic intraocular lens (PCP IOL) implantation is an emerging refractive procedure. We report a case of cataract formation 6 months after uneventful implantation of a Staar PCP IOL to correct high myopia. Visual recovery was achieved after explantation of the phakic IOL and phacoemulsification with implantation of a foldable IOL through the same unenlarged self-sealing corneal incision.