Iris-fixated toric phakic intraocular lens: Three-year follow-up

Endothelial Cell Loss in Patients with Phakic Intraocular Lenses

Although the safety of phakic intraocular lenses (pIOLs) has been continuously improved over 70-years of development, high endothelial cell losses can occur even with current pIOL models. Numerous studies have demonstrated that the distance of a pIOL to the corneal endothelium plays a crucial role in the extent of endothelial cell loss. For this reason alone, higher endothelial cell loss tends to be observed with anterior chamber lenses than with posterior chamber lenses. Adequate preoperative anterior chamber depth is essential, at least for iris-fixed pIOLs, in order to ensure a safe distance from the endothelium. However, the anterior chamber becomes shallower with age and therefore it may be useful to consider patient age in the safety criteria. Although endothelial cell loss is generally low with current pIOL models, regular monitoring of the endothelial cell density remains essential due to large interindividual differences in patients with pIOLs. If the endothelial cell loss is greater than expected and the follow-up visits confirm the trend, the pIOL should be explanted without delay. The endothelial reserve should be considered on an individual basis by taking into account patient age, physiological endothelial cell loss, and loss due to further surgery. With careful indication and long-term patient care, pIOLs remain a safe treatment option.

Controversy and Consideration of Refractive Surgery in Patients with Heritable Disorders of Connective Tissue

Heritable Disorders of Connective Tissue (HDCTs) are syndromes that disrupt connective tissue integrity. They include Osteogenesis Imperfecta (OI), Ehlers Danlos Syndrome (EDS), Marfan Syndrome (MFS), Loeys-Dietz Syndrome (LDS), Epidermolysis Bullosa (EB), Stickler Syndrome (STL), Wagner Syndrome, and Pseudoxanthoma Elasticum (PXE). Because many patients with HDCTs have ocular symptoms, commonly myopia, they will often present to the clinic seeking refractive surgery. Currently, corrective measures are limited, as the FDA contraindicates laser-assisted in-situ keratomileusis (LASIK) in EDS and discourages the procedure in OI and MFS due to a theoretically increased risk of post-LASIK ectasia, poor wound healing, poor refractive predictability, underlying keratoconus, and globe rupture. While these disorders present with a wide range of ocular manifestations that are associated with an increased risk of post-LASIK complications (e.g., thinned corneas, ocular fragility, keratoconus, glaucoma, ectopia lentis, retinal detachment, angioid streaks, and ocular surface disease), their occurrence and severity are highly variable among patients. Therefore, an HDCT diagnosis should not warrant an immediate disqualification for refractive surgery. Patients with minimal ocular manifestations can consider LASIK. In contrast, those with preoperative signs of corneal thinning and ocular fragility may find the combination of collagen cross-linking (CXL) with either photorefractive keratotomy (PRK), small incision lenticule extraction (SMILE) or a phakic intraocular lens (pIOL) implant to be more suitable options. However, evidence of refractive surgery performed on patients with HDCTs is limited, and surgeons must fully inform patients of the unknown risks and complications before proceeding. This paper serves as a guideline for future studies to evaluate refractive surgery outcomes in patients with HDCTs.

Eight-year follow-up of Artiflex and Artiflex Toric phakic intraocular lens

PURPOSE

To analyse long-term efficacy, safety, visual and refractive stability and physiological changes of Artiflex Myopia and Toric phakic intraocular lenses (pIOL) separately throughout an 8-year follow-up.

DESIGN

Retrospective cohort study.

METHODS

A total of 67 eyes of 37 patients underwent Artiflex Myopia (47 eyes) or Artiflex Toric (20 eyes) implantation for correcting myopia and/or astigmatism. Follow-up evaluations were performed 1, 3, 5 and 8 years after surgery. Preoperative and postoperative data included corrected (CDVA) and uncorrected distance visual acuity (UDVA), manifest refraction, endothelial cell density (ECD) and intraocular pressure (IOP) assessments. Efficacy and safety indexes were analysed. The vectorial analysis was performed using the Thibos method.

RESULTS

Mean CDVA and UDVA of both pIOLs significantly improved from preoperative to 1 year after implantation, and then it remained stable over the 8-year follow-up. The efficacy and safety indexes after 8 years were 0.94 ± 0.16 and 1.07 ± 0.18 for Artiflex Myopia and 1.00 ± 0.11 and 1.10 ± 0.15 for Artiflex Toric, respectively. The spherical equivalent (SE) significantly improved after surgery. J0, J45 and SE refractive components showed no changes between postoperative visits. A total ECD loss of 4.8% (p < 0.001) and 10.4% (p = 0.005) was found after 8 years for Artiflex Myopia and Toric, respectively.

CONCLUSIONS

Artiflex Myopia and Toric pIOLs are a safe, efficient and predictable option for the correction of myopia and/or astigmatism. The vectorial analysis showed excellent rotation stability for the toric version.

Phakic intraocular lenses: An overview

Phakic intraocular lenses (pIOLs) are a common solution for the surgical correction of high myopia and myopia in thin corneas. Global trends result in increasing rates of patients with high myopia which will result in increased rates of pIOL implantation. Three types of lenses can be distinguished: anterior chamber angle-supported, anterior chamber iris-fixated, and posterior chamber phakic IOLs. The efficacy of phakic intraocular lenses is generally very good, but pIOLs have undergone many changes over the years to improve the safety profile and decrease pIOL-related complications such as endothelial cell loss, corneal decompensation and cataract formation. This article describes the efficacy and safety profiles of the most recent pIOLs, as well as suggests gaps of knowledge that are deserve additional research to optimize the results of pIOLs.

Long-term changes in visual outcomes and ocular morphometrics after myopic and toric phakic intraocular lens implantation: Five- and 10-year results

PURPOSE

To evaluate the long-term refractive and visual, anterior chamber depth, and axial length (AL) changes and complications after rigid iris-fixated phakic intraocular lens (pIOL) implantation to treat myopia or astigmatism.

SETTING

University Eye Clinic Maastricht, Maastricht UMC+, the Netherlands.

DESIGN

Prospective case series.

METHODS

The study evaluated patients who had implantation of an Artisan myopic or toric iris-fixated pIOL as of January 1998. Changes were measured annually and reported after 1, 5, and 10 years postoperatively.

RESULTS

The study comprised 460 eyes (250 patients; mean age 41.1 years ± 10.7 [SD]). Over 10 years, the mean myopization was -0.79 diopters (D) (P < .001), with 52% of eyes within ±1.0 D of target. The mean increase in the logarithm of the minimum angle of resolution (logMAR) corrected distance visual acuity (CDVA) over 10 years was 0.05 (P < .001); 95% of eyes had a CDVA of 20/40 or more and 7% lost 2 or more lines of CDVA. The mean logMAR uncorrected visual acuity (UDVA) increased by 0.14 over 10 years (P < .001); 96% had a UDVA 20/40 or better. The AL increased by 1.14 mm over 10 years (P = .009). Ten percent of pIOLs were explanted because of cataract formation after a mean of 97.9 ± 34.9 months. A higher preoperative age (hazard ratio [HR], 1.08; P < .001) and longer AL (HR, 1.34; P < .001) were risk factors for shorter survival because of cataract formation.

CONCLUSION

Ten years after rigid iris-fixated pIOL implantation, the CDVA and UDVA decreased significantly as a result of significant myopization caused by an increased AL unrelated to the pIOL.

The visual and functional impacts of astigmatism and its clinical management

PURPOSE

To provide a comprehensive overview of research examining the impact of astigmatism on clinical and functional measures of vision, the short and longer term adaptations to astigmatism that occur in the visual system, and the currently available clinical options for the management of patients with astigmatism.

RECENT FINDINGS

The presence of astigmatism can lead to substantial reductions in visual performance in a variety of clinical vision measures and functional visual tasks. Recent evidence demonstrates that astigmatic blur results in short-term adaptations in the visual system that appear to reduce the perceived impact of astigmatism on vision. In the longer term, uncorrected astigmatism in childhood can also significantly impact on visual development, resulting in amblyopia. Astigmatism is also associated with the development of spherical refractive errors. Although the clinical correction of small magnitudes of astigmatism is relatively straightforward, the precise, reliable correction of astigmatism (particularly high astigmatism) can be challenging. A wide variety of refractive corrections are now available for the patient with astigmatism, including spectacle, contact lens and surgical options.

CONCLUSION

Astigmatism is one of the most common refractive errors managed in clinical ophthalmic practice. The significant visual and functional impacts of astigmatism emphasise the importance of its reliable clinical management. With continued improvements in ocular measurement techniques and developments in a range of different refractive correction technologies, the future promises the potential for more precise and comprehensive correction options for astigmatic patients.

Comparison of patient outcomes after implantation of Visian toric implantable collamer lens and iris-fixated toric phakic intraocular lens

PURPOSE

We compared visual and refractive outcomes after implantation of Visian toric implantable collamer lenses (toric ICLs) and iris-fixated toric pIOLs (toric Artisans).

PATIENTS AND METHODS

A comparative retrospective analysis was performed. Toric ICLs were implanted into 30 eyes of 18 patients, and toric Artisans into 31 eyes of 22 recipients. We measured the logarithms of the minimum angle of resolution of uncorrected visual acuity (logMAR UCVA), logMAR of best spectacle-corrected corrected VA (logMAR BSCVA), MR, SE, and astigmatism (by the power vector method) before surgery and 1, 3, and 6 months thereafter. Differences between patients receiving each type of lens were compared by using a mixed model of repeated measures.

RESULTS

Visual improvements were evident after operation in both groups. By comparing the attempted to the achieved SE values, we were able to confirm that correction of refractive error was similar in both groups. However, the logMAR UCVA was significantly higher in the toric ICL group at all postoperative time points. Although manifest cylinder power and astigmatism (calculated by using the power vector method) gradually decreased in the toric ICL group, cylinder power 1 month postoperatively increased from -2.62 to -2.75 D; astigmatism was also increased at this time in the toric Artisan group.

CONCLUSION

The two tested toric pIOLs were similar in terms of the ability to correct refractive error, as assessed 3 months postoperatively. However toric ICLs corrected astigmatism more rapidly and safely. Notably, the large difference in astigmatism level between the two groups 1 month postoperatively indicates that toric ICLs are more effective when used to correct astigmatism.

Toric phakic implantable collamer lens for correction of astigmatism: 1-year outcomes

Purpose:

The purpose of this study was to assess predictability, efficacy, safety and stability in patients who received a toric implantable collamer lens to correct moderate to high myopic astigmatism.

Methods:

Forty-three eyes of 23 patients underwent implantation of a toric implantable collamer lens (STAAR Surgical Inc) for astigmatism correction. Mean spherical refraction was −4. 98 ± 3.49 diopters (D) (range: 0 to −13 D), and mean cylinder was −2.62 ± 0.97 D (range: −1.00 to −5.00 D). Main outcomes measures evaluated during a 12-month follow-up included uncorrected visual acuity (UCVA), refraction, best-corrected visual acuity (BCVA), vault, and adverse events.

Results:

At 12 months the mean Snellen decimal UCVA was 0.87 ± 0.27 and mean BCVA was 0.94 ± 0.21, with an efficacy index of 1.05. More than 60% of the eyes gained ≥1 line of BCVA (17 eyes, safety index of 1.14). The treatment was highly predictable for spherical equivalent (r² = 0.99) and astigmatic components: J₀ (r² = 0.99) and J₄₅ (r² = 0.90). The mean spherical equivalent dropped from −7.29 ± 3.4 D to −0.17 ± 0.40 D at 12 months. Of the attempted spherical equivalent, 76.7% of the eyes were within ±0.50 D and 97.7% eyes were within ±1.00 D, respectively. For J₀ and J₄₅, 97.7% and 83.7% were within ±0.50 D, respectively.

Conclusion:

The results of the present study support the safety, efficacy, and predictability of toric implantable collamer lens implantation to treat moderate to high myopic astigmatism.

Axis alignment and rotational stability after implantation of the toric implantable collamer lens for myopic astigmatism

PURPOSE

To assess axis alignment and stability of the Toric Implantable Collamer Lens (TICL; STAAR Surgical Co) over time.

METHODS

Thirty-five consecutive eyes of 19 patients received the TICL for treatment of myopic astigmatism. Manifest refraction spherical equivalent (MRSE) and manifest refractive cylinder were measured preoperatively and at 3 months postoperatively. The axis alignment of the TICL was measured using the internal OPD map obtained with the OPD-Scan II (NIDEK Co Ltd).

RESULTS

Mean refractive cylinder was reduced from 2.80+/-1.45 diopters (D) preoperatively to 0.63+/-0.75 D at 3 months postoperatively; MRSE was -7.61+/-4.02 D preoperatively and -0.14+/-0.38 D at 3 months. Mean absolute value of the measured axis misalignment from baseline (day 1) to 1 month was 2.90+/-2.11 degrees and from 1 month to 3 months was 4.6+/-11.2 degrees. Mean absolute value of the measured changes in axis misalignment from baseline to 3 months was 2.68+/-2.11 degrees (after excluding one eye that required repositioning due to TICL rotation). At 3 months postoperatively, 96.8% (30/31) eyes had <or=8 degrees and 90.3% (28/31) had <or=5 degrees of axis misalignment.

CONCLUSIONS

The TICL showed minimal axis misalignment after implantation and remained stable 3 months postoperatively.

Influence of anterior chamber morphometrics on endothelial cell changes after phakic intraocular lens implantation

PURPOSE

To analyze the position of iris-fixated phakic intraocular lenses (pIOLs) using anterior segment optical coherence tomography (AS-OCT) and evaluate the effect of anterior chamber morphometrics on endothelial cell changes.

SETTING

Department of Ophthalmology, Academic Hospital Maastricht, The Netherlands.

METHODS

In this cross-sectional study, AS-OCT was used to measure the distances from the center and the edges of the pIOL to the corneal endothelium in 242 eyes with various models of myopic pIOLs. Endothelial cell measurements were performed preoperatively and at each follow-up examination.

RESULTS

The mean follow-up was 34.1 months+/-24.7 (SD) (range 3 months to 7 years). The mean distance between the edge of the pIOL and the endothelium was 1.37+/-0.22 mm. Although this distance was smaller than the safety value of 1.50 mm in 68.6% of the eyes, no eye developed corneal decompensation. There was a significant endothelial cell density (ECD) loss of 1.28%+/-8.46%, 3.25%+/-8.24%, and 5.02%+/-10.40% at 2 years, 5 years, and 7 years, respectively. Linear mixed-model analysis predicted a yearly ECD loss of 0.98% for a mean edge distance of 1.37 mm, 0.15% for an edge distance of 1.59 mm (mean plus 1 SD), and 1.80% for an edge distance of 1.15 mm (mean minus 1 SD).

CONCLUSIONS

A shorter distance between the edge of the pIOL and the endothelium was significantly associated with higher ECD loss. For safety reasons, the postoperative examination should include long-term evaluation of the anterior chamber morphometrics in addition to ECD counts.

Phakic iris-claw IOL implantation, with Bursa technique, through a self-sealing scleral tunnel and without iridotomy or iridectomy

PURPOSE

To present a novel technique for the implantation of phakic iris-claw intraocular lenses (IOL) in highly myopic cases.

METHODS

Twelve cases, under the age of 40, with high myopia were included in this retrospective study. The mean follow-up span was 14.4+/-5.8 months. Phakic iris-claw IOL implantation was performed, through a 5.5 or 6.5 mm self sealing scleral tunnel with Bursa technique. No suturing and opening a peripheral iridectomy or iridotomy was required in our study. Pre- and postoperative patient evaluation included manifest and cycloplegic refractions, uncorrected visual acuity, best-corrected visual acuity (BCVA), induced astigmatism, and intraocular pressure (IOP) assessments.

RESULTS

All eyes gained one to nine lines of BCVA of the Snellen chart. The vector analysis revealed an induced astigmatism of 0.63 D. No significant IOP change was detected throughout the follow-up.

CONCLUSIONS

The data suggest that nonfoldable iris fixated phakic IOL implantation, through a self-sealing incision with Bursa technique, is safe and requires no iridectomy or iridotomy in cases with deep anterior chambers.

[Toric phakic intraocular lenses]

After more than 3 years of follow-up, the satisfactory results achieved with the toric iris-fixated phakic intraocular lens (IOL) mean we can regard implantation of this lens as a procedure with the potential to provide safe, predictable, effective and stable correction of astigmatic errors, providing patients are carefully selected and receive adequate preparation for surgery. The iris-fixated toric phakic IOL (Verisyse, Advanced Medical Optics; Artisan, Ophtec) is a PMMA lens with a total diameter of 8.5 mm and an optic diameter of 5 mm. It has a spherical anterior and a toric posterior surface. Its refractive power ranges from -2 dpt to -21 dpt for myopia and from +2 dpt to +12.5 dpt for the correction of hyperopia. Cylindrical correction is available from 2 dpt to 7.5 dpt. The Visian toric implantable Collamer lens (Staar) differs in that it is foldable and can be inserted through a very small incision of about 2.8 mm. It is placed in front of the natural lens in the ciliary sulcus. The aim of implanting these phakic IOLs is to correct the entire refractive error, meaning both the spherical and the astigmatic error, in a single step. Different lens models are available, and the selection depends on the direction of the cylinder axis and the anatomical situation, among other things.

Implantation of Artisan toric phakic intraocular lens following Intacs in a patient with keratoconus

We report a 24-year-old man with bilateral keratoconus in whom Intacs (Addition Technology, Inc.) were implanted in both eyes. The procedure was followed by Artisan toric phakic intraocular lens (Ophtec) implantation to correct the residual myopic and astigmatic refractive error.

Artisan iris-fixated toric phakic and aphakic intraocular lens implantation for the correction of astigmatic refractive error after radial keratotomy

We report 2 patients who had radial keratotomy (RK) to correct myopia. The first patient developed a postoperative hyperopic shift and cataract. Nine years post RK, she had intracapsular cataract extraction and implantation of an Artisan aphakic intraocular lens (IOL). Twenty years post RK, hyperopia and astigmatism progressed to +7.0 -5.75 x 100 with a best corrected visual acuity (BCVA) of 20/20. Due to contact lens intolerance, the Artisan aphakic IOL was exchanged for an Artisan toric aphakic IOL. Three months later, the BCVA was 20/20 with +1.0 -0.50 x 130. The second patient demonstrated residual myopic astigmatism 6 years after bilateral RK and had become contact-lens intolerant. An Artisan toric phakic IOL was implanted in both eyes. Four months later, the BCVA was 20/25 with a refraction of +0.25 -1.0 x 135 and 20/20 with a refraction of -1.0 x 40. Both patients were satisfied with the visual outcomes.

Ultrasound biomicroscopy study of the Verisyse aphakic intraocular lens combined with penetrating keratoplasty in pseudophakic bullous keratopathy

PURPOSE

To evaluate anterior segment modifications after penetrating keratoplasty (PKP), previous anterior chamber intraocular lens (IOL) removal, and Verisyse IOL (AMO) implantation over the iris or under the iris for the treatment of pseudophakic bullous keratopathy (PBK) using ultrasound biomicroscopy.

SETTING

Department of Ophthalmology, Poitiers University Hospital, Poitiers, France.

METHODS

A prospective randomized comparative case series included 27 patients (27 eyes) with PBK who had PKP and implantation of a Verisyse VRSA54 aphakic IOL. The IOL was implanted over the iris in 13 patients (Group A) and under the iris in a reversed position in 14 patients (Group B). Ultrasound biomicroscopy scans 6 months after surgery measured central anterior chamber depth (ACD), iris thickness (IT), distance of the haptics from the corneal endothelium (CED), distance of the haptics from the ciliary body (CBD), angle opening distance (AOD) 500 mum from the scleral spur (AOD500) and the iridocorneal angle theta on the 4 o'clock meridian lines (AOD3; AOD9; AOD12; AOD6/theta12, theta6, theta3, theta9).

RESULTS

No significant difference was found in IT, CBD, or AOD12 between Group A and Group B (P >.05). In Group B, the mean ACD was deeper by approximately 55% (P = .008); CED3 was larger by 69% (P = .0162), CED9 by 80% (P = .0128), AOD3 by 57% (P = .0309), AOD9 by 140% (P = .0057), and AOD6 by 44% (P = .0399); and theta3 was wider by 52% (P = .046), theta9 by 123% (P = .0068), theta12 by 50% (P = .0492), and theta6 by 81% (P = .0237).

CONCLUSION

Ultrasound biomicroscopy showed that in eyes that had PKP with Verisyse IOL enclavation to the posterior plane of the iris, which involved posterior translation of the iridal plane, the ACD was significantly deeper and the CED and AOD were significantly larger than in eyes with anterior enclavation of the IOL.

Status of toric intraocular lenses

PURPOSE OF REVIEW

To provide an update on the status of toric intraocular lenses. These lenses can be used as an alternative or adjunct to corneal astigmatic incisions for correcting preexisting astigmatism in patients with cataracts. They are a particularly attractive option in those cases where limbal-relaxing incisions are not powerful or predictable enough. Other toric lenses may correct astigmatism in addition to spherical refractive errors in phakic patients.

RECENT FINDINGS

Toric lenses have continued to gain popularity with the US Food and Drugs Administration (FDA) approval of the Acrysof Toric intraocular lenses. This lens is designed to be implanted in patients undergoing cataract removal and who have significant preexisting corneal astigmatism. In the FDA clinical trial, study patients received one of the three cylindrical powers, and control patients received a standard monofocal intraocular lenses. The study found that the Acrysof Toric intraocular lenses provided excellent visual outcomes and exhibited excellent rotational stability. With the Acrysof Toric intraocular lenses, the average lens rotation was less than 4 degrees from the lens' initial placement at 6 months after surgery.

SUMMARY

Toric intraocular lenses provide excellent vision for astigmatic cataract patients, and new designs are significantly improving visual acuity by minimizing the risk of rotation.

Toric Implantable Collamer Lens for moderate to high myopic astigmatism

PURPOSE

To assess the efficacy of the Toric Implantable Collamer Lens (ICL) to treat moderate to high myopic astigmatism.

DESIGN

Prospective nonrandomized clinical trial.

PARTICIPANTS

Two hundred ten eyes of 124 patients with between 2.38 and 19.5 diopters (D) of myopia (spherical equivalent [SE]) and 1 to 4 D of astigmatism participating in the United States Food and Drug Administration clinical trial of the Toric ICL.

INTERVENTION

Implantation of the Toric ICL.

MAIN OUTCOME MEASURES

Uncorrected visual acuity (UCVA), refraction, best spectacle-corrected visual acuity (BSCVA), adverse events, and postoperative complications.

RESULTS

At 12 months postoperatively, the proportion of eyes with 20/20 or better UCVA (83.1%) was identical to the proportion of eyes with preoperative 20/20 or better BSCVA (83.1%); 76.5% had postoperative UCVA better than or equal to preoperative BSCVA. The mean manifest refractive cylinder dropped from 1.93 D (+/-0.84) at baseline to 0.51 D (+/-0.48) postoperatively, a 73.6% decrease in astigmatism. Although only 21.0% of eyes had 1-D refractive cylinder preoperatively (none less), 91.4% of cases had < or =1 D of cylinder postoperatively. Furthermore, 65.6% had < or =0.5 D and 40.9% had < or =0.25 D of refractive cylinder postoperatively. Mean manifest refraction SE (MRSE) improved from -9.36 D (+/-2.66) preoperatively to 0.05 D (+/-0.46) postoperatively. A total of 76.9% of eyes were predicted accurately to within +/-0.5 D, 97.3% to within +/-1.0 D, and 100% to within +/-2.0 D of predicted MRSE. Postoperatively, 37.6% of eyes had a BSCVA of 20/12.5 or better, compared with a preoperative level of 4.8%. Furthermore, BSCVA of 20/20 or better occurred in 96.8% postoperatively, compared with 83.1% preoperatively. Mean improvement in BSCVA was 0.88 lines; there were 3 cases (1.6%) that lost > or =2 lines of BSCVA after 12 months postoperatively, whereas 18.9% of cases improved by > or =2 lines. A total of 76.4% of cases gained > or =1 lines of BSCVA, whereas only 7.5% of cases lost the equivalent amount. Three ICL removals were performed without significant loss of BSCVA, and 1 clinically significant lens opacity was observed.

CONCLUSION

The results support the efficacy and predictability of Toric ICL implantation to treat moderate to high myopic astigmatism. Important safety concerns were not identified.