Collagen copolymer posterior chamber phakic intraocular lens for hyperopia correction: Three-year follow-up

Successful Phakic Intraocular Lens Implantation with the Usage of Topical Ascorbic Acid in Patient with Reduced Corneal Endothelial Cell Density

We aimed to describe the use of topical ascorbic acid (AA) in a patient with reduced endothelial cells density (ECD) who was scheduled for phakic intraocular lens (pIOL) implantation. A 28-year-old woman presenting with dry eye and reduced ECD would like to have her high myopia (spherical equivalence >−15.0 D) corrected. The procedure of laser refractive surgery or even pIOL was not indicated for the reduced ECD of 1865/mm2 in the right eye and 2188/mm2 in the left eye, as well as level 3 dry eye. Fortunately, the ECD increased to 3144/mm2 in the right eye and 2538/mm2 in the left eye after topical AA was prescribed for one year preoperatively and one month postoperatively, with concomitant improvement of dry eye to level 1. Finally, bilateral pIOL implantation was performed smoothly and no sign of corneal decompensation was found postoperatively. Three months postoperatively, the ECD showed a satisfactory level of 2983/mm2 in the right eye and 3003/mm2 in the left eye. In conclusion, topical AA instillation might increase and maintain the density of central human corneal endothelial cells (HCECs) even after pIOL implantation.

Long-term efficacy and safety results after iris-fixated foldable phakic intraocular lens for myopia and astigmatism: 6-year follow-up

PURPOSE

To evaluate the long-term efficacy and safety of iris-fixated foldable phakic intraocular lenses (pIOLs) for the management of myopia and astigmatism after 6-year follow-up.

SETTING

Ophthalmology Department, Hospital Braga, Portugal.

DESIGN

Retrospective cohort study.

METHODS

Patients included underwent iris-fixated foldable Artiflex pIOL implantation between January 2010 and December 2013. Follow-up evaluations were performed 6 months postoperatively and every 12 months until 72 months. Preoperative and follow-up data on uncorrected and corrected distance visual acuity (CDVA), manifest refraction, endothelial cell density (ECD), and anterior chamber depth (ACD) were analyzed.

RESULTS

A total of 177 eyes of 98 patients with a mean age of 32.33 ± 7.13 years were analyzed. There was a statistically significant improvement in CDVA from 0.09 ± 0.02 logMAR preoperatively to 0.04 ± 0.02 logMAR (P < .0001) at 6 years postoperatively. The spherical equivalent demonstrated a statistically significant improvement from -9.50 ± 2.93 diopters (D) to -0.41 ± 0.45 D at 6 years. At 72 months, the efficacy and safety indexes were 0.94 and 1.15, respectively. A mean loss of 31.77 cells/mm2 (1.19%) was observed each year until the sixth year. The overall mean ECD loss after correction for the physiological loss was 3.02% after 6 years. No correlations were observed between the mean ECD loss and the preoperative ACD.

CONCLUSIONS

The Artiflex pIOL was a safe, effective, and a stable option to correct myopia. A mean ECD loss of 3.02% was observed over 6 years. No pIOL was explanted due to corneal decompensation.

Phakic intraocular lens implantation for the correction of hyperopia

The prevalence of myopia is much higher than hyperopia. Hence, there are relatively few studies investigating phakic intraocular lens (pIOL) implantation for the correction of hyperopia. This review aimed to summarize the available relevant literature on the efficacy and safety of pIOL implantation for the correction of hyperopia and hyperopic astigmatism. At present, two types of pIOLs are used to correct hyperopia and hyperopic astigmatism: anterior chamber iris-fixated pIOLs and posterior chamber implantable collamer lenses. Both have been found to be safe and effective. No serious events (eg, retinal or choroidal detachment, endophthalmitis) were reported in the reviewed articles. Implantation of pIOLs might be the optimal refractive surgery for the correction of high hyperopia.

Safety and visual outcomes following posterior chamber phakic intraocular lens bilensectomy

Background

To evaluate the safety, efficacy, refractive outcomes and causes for bilensectomy (phakic intraocular lens – pIOL – explantation with cataract surgery and pseudophakic intraocular lens implantation) in patients previously implanted with posterior chamber pIOLs.

Methods

This multi-center retrospective study included 87 eyes of 55 patients who underwent bilensectomy for posterior chamber pIOL with a follow up time of 12 months. The uncorrected and best corrected distance visual acuities (UDVA, CDVA), endothelial cell density before and after bilensectomy were assessed, as well as the cause of bilensectomy and intra or postoperative complications.

Results

There was a statistically significant improvement in uncorrected and best corrected visual acuities after bilensectomy (p = 0.00). The main reason for bilensectomy was cataract development (93.1% of the cases), followed by miscalculation of lens size, and corneal edema. The endothelial cell count remained stable without a statistically significant change after surgery (p = 0.67). The refractive efficacy index was 0.8, none of the patients lost lines of CDVA after surgery, 73% of the patients were within ±1 D (spherical equivalent) of the target refraction. Intraoperative complications were one posterior capsule rupture with the intraocular lens (IOL) implanted in the sulcus, and 3 eyes required the use of pupil expanders for adequate pupil dilation. Postoperatively, one eye developed retinal detachment. The three pIOLs models explanted were the Implantable Collamer Lens (ICL), Implantable Phakic Contact Lens (IPCL) and the Phakic Refractive Lens (PRL).

Conclusions

Good safety and visual outcomes were observed 1 year after bilensectomy for posterior chamber phakic intraocular lenses (PC pIOLs). There were few intra and postoperative complications and there was no significant endothelial cell loss after the bilensectomy procedure.

[Intraocular pressure after implantation of an ICL with aquaport : Development of intraocular pressure after implantation of an ICL (model V4c) with aquaport without iridotomy]

BACKGROUND AND OBJECTIVE

The latest version of the intraocular lens (ICL V4c) has a central hole (aquaport) that avoids a pupillary block. Due to this laser iridotomy or intraoperative surgical peripheral iridectomy are no longer required. In this study, we examined the intraocular pressure (IOP) after implantation of the ICL with aquaport, with special reference to the development of a possible pupillary block glaucoma.

MATERIAL AND METHODS

This retrospective non-randomized study included 87 eyes from 46 patients (consecutive case series). These patients had the ICL model V4c (without a laser iridotomy or peripheral iridectomy) implanted between January 2013 and October 2014. The preoperative IOP values were compared with the postoperative values 1-2 h, 1 day, 1 week and 1 month after implantation.

RESULTS

The median intraocular pressure was 14 ± 2 mm Hg before implantation of the ICL, palpatory normotensive 1-2 h after implantation, 13 ± 3 mm Hg 1 day after implantation, 15 ± 3 mm Hg 1 week after implantation and 16 ± 4 mm Hg 1 month after implantation (a slight statistically significant increase of the intraocular pressure, p < 0.05). In 2 patients there was a steroid response in both eyes with IOP reaching up to a maximum of 28 mm Hg. There were no peaks of intraocular pressure due to a pupillary block.

CONCLUSION

It is possible to implant the latest ICL V4c with a central hole (Aquaport) without a laser iridotomy or peripheral iridectomy or development of a pupillary block.

Femtosecond laser-assisted cataract surgery in patients with phakic intraocular lenses and low endothelial cell counts: a case report

Background

Phakic intraocular lens (PIOL) implantation has been used to correct myopia and myopic astigmatism, although corneal decompensation can occur after implantation. Femtosecond laser-assisted cataract surgery (FLACS) has gained in popularity due to its lower postoperative astigmatism and endothelial loss. Herein, we report the use of FLACS in patients who previously received PIOL implantation and have a low corneal endothelial cell count.

Case presentation

Two patients with a previous iris-claw PIOL implantation were enrolled. The preoperative corrected distance visual acuity (CDVA) and diopter sphere (DS) were 20/32 and −0.25 D in patient 1 and 20/32 and −3.00 D in patient 2. Specular microscope examination revealed an endothelial cell density (ECD) of 1532/mm² in patient 1 and 1620/mm² in patient 2. Capsulotomy was performed smoothly using a femtosecond laser. Postoperative CDVA improved in both eyes, with a difference of DS less than 1 D from the preoperative estimation. Specular microscope examination revealed a decreased endothelial cell density (ECD) in patient 2, but no signs of corneal decompensation were detected.

Conclusions

The influence of using PIOL on capsulotomies performed via FLACS, in combination with preoperative refraction calculation, is minimal. A mild decrease in ECD may occur, but there is a low probability of severe corneal decompensation, even in patients with a low endothelial cell count.

Implantation of posterior chamber phakic intraocular lens for myopia and hyperopia - long-term clinical outcomes

PURPOSE

To evaluate long-term refractive outcomes of implantable collamer lens (ICL) implantation and late postoperative complications.

METHODS

We assessed outcomes of patients who underwent ICL implantation (type ICM V4 for myopia, ICH V3 for hyperopia, TICM V4 for astigmatism) in our department between 1998 and 2013. It comprised 62 eyes (40 myopic and 22 hyperopic). The average follow-up period was 10.5 years. We evaluated: uncorrected and best-corrected visual acuity (UCVA and BCVA), spherical equivalent (SE), ICL vault, endothelial cell density and late postoperative complications.

RESULTS

In myopes, the average UCVA was 1.0±0.37 and BCVA 1.18±0.38, in hyperopes 0.78±0.19 and 1.14±0.18, respectively. The average SE in myopes, whose target refraction was emmetropia, was -0.6±0.83 Dsf, in hyperopes +0.73±0.93. Central ICL vault was 206.16μm±105.94, (range 10-427) in myopes, 195.5μm±109.09, (range 20-404) in hyperopes. The most common late postoperative complication was cataract formation. Three myopic eyes (7.5%) developed symptomatic anterior subcapsular opacities with loss of at least two lines of BCVA. Cataract significantly affecting visual acuity occurred in 5 myopic eyes (12.5%) and 2 hyperopic eyes (9.09%). In these eyes, ICL removal and cataract surgery was performed.

CONCLUSIONS

In our experience, ICL implantation in moderate and high ametropia was effective and relatively safe. The most common late complication was cataract formation. This complication can be managed effectively surgically with good refractive outcomes without loss of BCVA.

Ghost-image analysis in phakic intraocular lenses with central hole as a potential cause of dysphotopsia

PURPOSE

To analyse the optical effect of an artificial hole in the optic centre of posterior chamber phakic intraocular lenses.

SETTING

Institute of Experimental Ophthalmology, Saarland University, Homburg/Saar, Germany.

DESIGN

Experimental simulation study.

METHODS

Four eye models with an ametropia of -4 D, -8 D, +4 D, and +8 D were created in the ray tracing software ASAP. Refractive correction of these models was implemented with a model of an Implantable Collamer Lens (ICL). Each eye was set up twice with 1 eye receiving a conventional ICL without a central hole and the second an ICL with a central hole. Ray bundles were traced for lateral visual field angles from 0 to 60 degrees in steps of 1 degree. Ray propagation and retinal illumination were then compared between the 2 ICL models.

RESULTS

All eye models showed ghost images originating from the anterior surface of the ICL. Eye models with the ICL with central hole showed additional light spots in the peripheral areas of the retina originating from reflections at the cylindrical wall of the central hole in the ICL. The average intensity of ghost images in the temporal retinal hemisphere was between 30 and 40 dB less than the maximum intensity of the primary image.

CONCLUSION

A central hole within a posterior chamber phakic intraocular lens may cause stray light and ghost images (positive dysphotopsia) although the on-axis visual quality of the eye with the ICL is mostly unaffected.

FINANCIAL DISCLOSURE

The authors have no financial interest in any of the material presented in this paper.

Optical quality comparison between 2 collagen copolymer posterior chamber phakic intraocular lens designs

PURPOSE

To compare the optical quality in vitro of 2 designs of the Visian Implantable Collamer Lens phakic intraocular lens (pIOL) for different powers and optical apertures.

SETTING

University of Valencia, Valencia, Spain.

DESIGN

Experimental study.

METHODS

The Nimo TR1504 deflectometry device was used to measure the V4c pIOL, which has a smaller optic diameter, and the V5 pIOL, which has a larger optic diameter. The pIOLs were measured for -3.00 diopters (D), -6.00 D, -9.50 D, and -10.50 D at different optical apertures from 3.00 to 6.00 mm depending on the IOL power and model. The root mean square of higher-order aberrations (RMS HOAs) was analyzed. The Strehl ratio, point-spread functions (PSFs), and simulated images were calculated from wavefront aberrations.

RESULTS

There were no statistically significant differences in any Zernike RMS or RMS HOAs between the 2 pIOL models with the same power and optical aperture (P > .05). Both pIOLs had negative spherical aberration that increased with the pIOL power. Strehl ratio values showed no statistically significant differences between the pIOLs with the same power and pupil aperture. Minimal differences were seen in the PSFs and simulated images between the pIOLs.

CONCLUSIONS

Both pIOLs showed good and comparable in vitro optical quality similar that of a perfect lens in that they should not affect visual performance after implantation. Patients with larger pupil diameters could benefit from the pIOL with the larger optic diameter because it showed better in vitro optical quality than the previous design with a smaller optic diameter.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Correction of moderate to high hyperopia with an implantable collamer lens: medium-term results

PURPOSE

To evaluate the medium-term results of phakic posterior chamber implantable collamer lens implantation to correct moderate and high hyperopia.

METHODS

In this retrospective study, patients were treated for hyperopia with the Visian Implantable Collamer Lens (ICH model V3; STAAR Surgical AG, Nidau, Switzerland). Examined parameters were manifest refraction spherical equivalent, uncorrected distance visual acuity, corrected distance visual acuity, vault, anterior chamber depth, anterior chamber angle width, endothelial cell density, intraocular pressure, patient satisfaction, and complications.

RESULTS

The mean age of 15 patients (28 eyes) was 28 years (range: 18 to 36 years), with a mean follow-up period of 3.6 years (range: 3 to 6 years). The mean manifest refraction spherical equivalent decreased from +6.30 ± 1.42 diopters (D) (range: +4.25 to +8.50 D) preoperatively to -0.37 ± 0.56 D (range: -1.25 to +1.00 D) at 3 years postoperatively. The mean uncorrected distance visual acuity improved from 0.77 ± 0.38 logMAR (range: 0.16 to 1.30 logMAR) to 0.20 ± 0.17 logMAR (range: 0.00 to 0.48 logMAR) at the 3-year follow-up. Postoperatively, 62% of eyes gained one line of corrected distance visual acuity or remained unchanged. The mean vault reduced from 367.1 ± 253.6 μm (range: 70.0 to 1,190.0 μm) at 1 month postoperatively to 283.6 ± 210.0 μm (range: 75.0 to 915.0 μm) at the last follow-up visit (P = .005). The mean preoperative anterior chamber depth and anterior chamber angle width also decreased at the last follow-up visit (P = .037 and < .0001, respectively). The mean endothelial cell loss was 4.91% (P = .089). No serious complications occurred. Thirteen (87%) patients were satisfied with the outcomes and no patient was dissatisfied.

CONCLUSIONS

Implantation of a posterior chamber implantable collamer lens is a safe, effective, predictable, and stable method for the correction of moderate and high hyperopia in highly selected patients. No case of cataract or anterior subcapsular opacities formation was recorded in relation to the decrease of vault over the studied period and low vault in some eyes.

Accuracy and stability of hyperopic treatments

PURPOSE OF REVIEW

Treatment of hyperopia presents greater challenges than treatment of myopia for multiple reasons, including the fact that hyperopia tends to progress with age and becomes more symptomatic with the loss of accommodation.

RECENT FINDINGS

Despite these issues, surgeons have multiple options to treat hyperopia successfully. Modern laser vision correction has high success rates for most patients and performs acceptably in the presence of high hyperopia or high cylinder. Early studies combining excimer laser treatment with collagen cross-linking (CXL) suggest that this may improve refractive stability. Recent studies have also described femtosecond lenticule extraction and use of a solid-state laser in place of the excimer. In addition to cornea-based treatment, long-term studies of a hyperopic phakic intraocular lens have shown excellent visual outcomes and good safety. Cross-linking is increasingly being applied to the hyperopia that follows radial keratotomy.

SUMMARY

The established treatments for hyperopia continue to accumulate evidence supporting their safety and efficacy. The next step forward in treatment may arise from combining these treatments with CXL to stabilize the cornea long-term.