Posterior chamber toric implantable collamer lenses vs LASIK for myopia and astigmatism: systematic review

This systematic review compares the visual and refractive outcome of laser in situ keratomileusis with (toric) implantable collamer lens (ICL) in the treatment of myopic astigmatism. An electronic literature search led to 19 comparative articles. Refractive outcome, efficacy, safety, predictability, and stability as well as differences in contrast sensitivity and higher-order aberrations (HOAs) were analyzed for moderate (-3 to -6 diopters [D]) and high (≥-6 D) myopia. Results were either significantly in favor of (toric)-ICL or equal. Fewer HOAs and better contrast sensitivity after (toric)-ICL seem to be the largest asset in its refractive and clinical superiority. However, longer follow-up studies are indicated, specifically for systematically comparing long-term adverse effects.

Effect of the Difference Between the White-to-White and Sulcus-to-Sulcus on Vault and the Related Factors After ICL Implantation

INTRODUCTION

To assess the differences between the horizontal white-to-white (WTW) and horizontal sulcus-to-sulcus (STS) diameter measurements, their related factors, and their effects on vault after implantable Collamer lens (ICL) implantation.

METHODS

This retrospective study included 429 eyes of 429 patients (145 men and 284 women with a mean age of 29.22 ± 8.06 years) who underwent ICL implantation. The choice of the ICL size depended on the WTW diameter and anterior chamber depth (ACD). The information of WTW diameter, STS diameters, ACD, and their relationships on vault were analyzed.

RESULTS

Horizontal STS and WTW diameters were correlated (r = 0.71, P < 0.001). The mean difference between the STS and WTW diameters was -0.02 ± 0.33 (-1.36 to 1.11) mm. The average vaults of the ^△STS-WTW < -0.1 group, - 0.1 ≤ ^△STS-WTW ≤ 0.1 group, and ^△STS-WTW > 0.1 group were 558.36 ± 163.58 (250-1100) μm, 513.10 ± 121.42 (190-850) μm, and 469.01 ± 133.23 (120-750) μm, respectively. There were significant differences between these groups (P < 0.05). ^△STS-WTW was correlated with the horizontal STS diameter (r = 0.30, P < 0.001), the WTW diameter (r = -0.17, P = 0.001), and the ACD (r = 0.17, P < 0.001). When the WTW diameter was further away from 11.08 to 12.51 mm or the ACD was further away from 2.81 to 3.74 mm, the difference between the STS and WTW diameters was larger and the correlation between the STS and WTW diameters was weaker.

CONCLUSIONS

The difference between the WTW and STS diameters was larger for cases with a WTW diameter or anterior chamber depth outside a certain range; this may be associated with an undesirable vault after ICL implantation. Special attention should be paid to these patients.

Polar value analysis of astigmatic change and rotational stability after implantation of V4c toric implantable collamer lens

Background

To evaluate the clinical results and rotational stability of V4c toric implantable collamer lens (TICL, STAAR Surgical Company, Monrovia, CA, USA) in patients with moderate to high myopic astigmatism. Retrospective, interventional case series was performed at Shenzhen Eye Hospital, Shenzhen, Guangdong, China.

Methods

This study enrolled 43 patients (72 eyes) who received TICL implantation to correct myopia and myopic astigmatism. The patients underwent visual and refractive examinations before and 1 month after surgery. Astigmatic changes were estimated using polar value analysis. The difference between the achieved axis and the intended axis at the last follow-up was taken as the rotation of the V4c TICL.

Results

At 1 month postoperatively, the mean safety and efficacy indices were 1.17 and 1.13, respectively. A significant reduction of 8.92±2.58 D was observed in the spherical equivalent refraction (SER), which decreased from −9.29±2.41 D preoperatively to −0.37±0.55 D postoperatively. The astigmatic error of treatment in cylinder format was calculated to 0.50±0.41 @ 15.08° relative to the preoperative stronger meridian at 1 month, postoperatively. At 1 month postoperatively, the mean absolute rotation was 8.30±10.00 degrees (median =5.46 degrees; range, 0.00–58.88 degrees).

Conclusions

TICL could achieve good astigmatic outcomes for correcting moderate to high myopic astigmatism. After TICL implantation, corneal astigmatism remained unchanged. To optimize postoperative astigmatic outcomes in TICL, polar value analysis can be used to build a nomogram.

Rotational Stability and Visual Outcomes of V4c Toric Phakic Intraocular Lenses

PURPOSE

To investigate the clinical outcomes and rotational stability following implantation of V4c toric implantable collamer lenses (ICLs) (STAAR Surgical Company, Monrovia, CA) and to analyze the factors that influence rotational stability.

METHODS

In this prospective observational case series, the authors analyzed the visual outcomes and rotational stability in 52 eyes of 52 patients immediately and 3 and 6 months after implantation. Postoperative rotation was defined as the angle between the adjusted axis and alignment axis. Central vaulting of the ICL was measured in a non-accommodative state using Visante optical coherence tomography (Carl Zeiss Meditec, Jena, Germany). Vector analysis of refractive astigmatism was performed. Regression analysis was used to investigate the association between the degree of rotation 6 months postoperatively and the associated variables.

RESULTS

The mean efficacy index and safety index 6 months postoperatively were 1.35 ± 0.19 and 1.38 ± 0.22, respectively. In vector analysis, the magnitude of error was -0.20 diopters (D), indicating slight undercorrection. Absolute degree of rotation was 2.81° ± 1.87° immediately after the operation and 3.75° ± 2.92° and 3.87° ± 3.07° at 3 and 6 months postoperatively, respectively (P = .009). Bonferroni-adjusted post-hoc comparison showed that the absolute degree of rotation immediately after the operation was significantly smaller than that after 3 (P = .043) and 6 (P = .023) months, with barely any change after 3 months. No explanatory variable relevant to the absolute degree of rotation was discovered.

CONCLUSIONS

The V4c toric ICL is predictable, safe, and effective in correcting low and high levels of astigmatism, showing relatively good postoperative rotational stability. [J Refract Surg. 2018;34(7):489-496.].

Analysis of intraocular positions of posterior implantable collamer lens by full-scale ultrasound biomicroscopy

Background

To analyze the positions of intraocular posterior Implantable Collamer Lens (ICL) and its possible relationship with vault.

Methods

This cross-sectional study included 72 patients with high myopia (134 eyes) who were followed up after phakic intraocular lens implantation. The postoperative time ranged from 1 week to 7 years. We obtained the images of ICL by using Compact Touch STS UBM and observed the position of ICL in posterior chamber and ciliary sulcus. The horizontal lines vault was measured and recorded.

Results

There were various positions in the posterior chamber as observed by full-scale ultrasound biomicroscopy and the haptics were inserted at different positions. -Eight seven eyes (64.9%) that obtained ideal vault, 29 eyes (21.6%) had insufficient vaults and 18 eyes (13.4%) had excessive vault. The vault with various positions of haptics was in ideal range (250 μm–750 μm) almost in each group. Three eyes in this study with haptics on the top of ciliary sulcus obtained excessive vault (mean vault, 850.00 ± 70.71 μm) and one eye appeared one side haptics pushing forward the iris. Among five eyes (3.7%) with iridociliary body cysts, three eyes (60%) obtained ideal vault. One eye (0.7%) with ICL decentralization after implantation surgery had an ideal vault, but the patient had serious glare.

Conclusions

Though ICL in the posterior chamber had different positions and the haptics in most cases were not in the ciliary sulcus, the postoperative vault was almost in the ideal range.

Iridociliary cysts do not impact on posterior phakic intraocular lens implantation for high myopia correction: A prospective cohort study in 1569 eyes

Purpose

To investigate the clinical characters and effect of iridociliary cysts among patients who had undergone posterior phakic intraocular lens implantation.

Methods

A total 1569 eyes of 866 high myopia patients, who underwent phakic intraocular lens implantation from 1 September 2011 to 31 August 2016, was included in this prospective cohort study. These patients were followed up for more than 12 months postoperatively.

Results

During the study period, 218 eyes (14%) of 154 patients were diagnosed with iridociliary cysts by ultrasound biomicroscopy. There were 74.3% patients with unilateral cysts and the cysts tended to have occurred in patients ages 20 to 30 years old (22%). The location of the cysts varied with temporal position as the most (50%) and superior position as the least (9.6%). After 1 week postoperative follow-up, there were no significant differences in clinical outcomes between the cysts group and no cysts group, but the proportion of 20/20 or better uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), and the 2 types of vector astigmatism. Intraocular pressure (IOP), refraction, and vault remained stable at different time points of the follow-up period, while vault of cysts patients tend to be lower than patients without cysts at more than 12 months.

Conclusions

Iridociliary cysts were more common than estimated and it had no impact on Phakic Intraocular Lens implantation because there was no clue to show significantly difference on postoperative clinical outcomes between the patients with and without iridociliary cysts in this study.

Comparison between toric and spherical phakic intraocular lenses combined with astigmatic keratotomy for high myopic astigmatism

BACKGROUND

To compare the outcomes of a toric phakic intraocular lens (PIOL) and a spherical PIOL combined with astigmatic keratotomy (AK) for the correction of high myopic astigmatism.

METHODS

This study enrolled patients with high myopic astigmatism, including 30 eyes (22 patients) that received a toric PIOL implantation (TICL group), and 32 eyes (24 patients) that received combined AK and a spherical PIOL implantation (AK+ ICL group). The outcomes were compared between the two groups before surgery, and at the following time points after surgery: 1 week, 1, 3, 6 months, and 1, 2 years.

RESULTS

Preoperatively, the mean manifest spherical equivalent (SE) was -14.14 ± 2.12 D in the TICL group and -14.83 ± 2.79 D in the AK + ICL group (P = 0.28), and the mean manifest refractive cylinder, -2.87 ± 1.09 D and -2.58 ± 0.85 D, respectively (P = 0.28). Two years postoperatively, the mean safety index was 1.53 ± 0.55 in the TICL group and 1.60 ± 0.70 in the AK + ICL group (P = 1.00), and the mean efficacy index, 1.18 ± 0.45 and 1.38 ± 0.52, respectively (P = 0.86). The mean manifest refractive cylinder correction was 1.94 ± 1.07 D in the TICL group and 1.39 ± 0.71 D in the AK + ICL group (P = 0.02). The mean changes in SE and refractive cylinder from 1 week to 2 years were less than 0.50 D in both groups.

CONCLUSIONS

Both TICL implantation and AK + ICL implantation are a good alternative for correction of astigmatism in addition to high myopia. TICL implantation has better predictability in correction of high myopic astigmatism.

TRIAL REGISTRATION

NCT03202485.

Refractive outcomes and safety of the implantable collamer lens in young low-to-moderate myopes

Purpose

To evaluate visual and refractive outcomes and safety of implantable collamer lens (ICL) implantation in low-to-moderate myopia.

Setting

Private Practice – Dougherty Laser Vision, Westlake Village, CA, USA.

Methods

A chart review was performed in 56 (104 eyes) consecutive patients who underwent implantation of the Visian ICL V4 model. Inclusion criteria were age between 21 and 40 years, spherical equivalent between −3.00 D and −10.00 D, and cylinder up to −5 D. Data on visual acuity, refraction, and complications were collected.

Results

The mean time to the last postoperative visit was 13.1±14.0 months (range, 2 to 50 months). The mean preoperative spherical equivalent was −6.96±1.60 D and the mean preoperative cylinder was −1.03±0.88 D. The mean preoperative corrected distance visual acuity (CDVA) was 20/20 (range, 20/15 to 20/80) that remained unchanged at last postoperative visit. At the last postoperative visit, the spherical equivalent was −0.08±0.01 D and the cylinder was 0.29±0.71 D. Comparison of postoperative uncorrected distance visual acuity (UCDVA) to preoperative CDVA indicated that 27 eyes (26%) had better postoperative UCDVA and 61 eyes (59%) had UDVA equivalent to the preoperative CDVA. Postoperatively, 4 eyes lost 1 line of CDVA and no eyes lost >1 line of CDVA. There were 32 eyes that gained at least ≥1 of CDVA. There were no intraoperative complications. Postoperatively, 3 patients (6 eyes) had dry eye, and 1 patient complained of nighttime halos in 1 eye. At the last postoperative visit, there were no eyes with lens opacity or glaucoma.

Conclusion

ICL implantation for low and moderate myopia up to −10 D in patients up to 40 years of age was safe, accurate, and efficacious. ICL implantation may be a good alternative to laser in situ keratomileusis for young myopes less than −10.00 D.

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.

Changes in vaulting of myopic and toric implantable collamer lenses in different lighting conditions

PURPOSE

To evaluate the changes in vaulting of myopic and toric Implantable Collamer Lenses (ICLs) in different lighting conditions.

METHODS

Thirty-seven eyes of 37 patients implanted with a myopic ICL and 26 eyes of 26 patients implanted with a toric ICL were examined using Visante optical coherence tomography (OCT) in photopic (257 lux) and mesopic (2 lux) conditions. Pupil diameter and distance changes between the ICL and adjacent intraocular structures were measured.

RESULTS

The mean horizontal pupillary diameters in mesopic conditions were 5.3 ± 0.9 (SD) mm. In photopic conditions, a mean decrease of -1.8 ± 0.6 mm [95% confidence interval (95% CI) -2.0 to -1.7; p < 0.0001] was observed. The mean distances between the ICL and the crystalline lens in mesopic conditions were 0.33 ± 0.17 mm. In photopic conditions, a mean decrease of -0.04 ± 0.06 mm (95% CI -0.05 to -0.02; p < 0.0001) in the ICL-crystalline lens distance was found. There was a -0.02 ± 0.04 mm (95% CI -0.03 to -0.01; p = 0.0022) decrease in the anterior chamber depth and a 0.02 ± 0.06 mm (95% CI 0.002 to 0.032; p = 0.0275) increase in the distance between the cornea and the ICL. We found no difference in the change in vaulting between the two ICLs in different lighting conditions.

CONCLUSION

There is a decrease in the central vaulting of myopic and toric ICLs in photopic conditions. This is due to both posterior movement of the ICL and anterior protrusion of the crystalline lens.

Comparison of visual and refractive results of Toric Implantable Collamer Lens with bioptics for myopic astigmatism

PURPOSE

To compare visual and refractive results of Toric Implantable Collamer Lens (TICL) and bioptics (ICL plus excimer corneal surgery) to treat myopic astigmatism.

METHODS

Eighty-one eyes underwent TICL implantation and 83 eyes were treated with bioptics (corneal ablation was performed between 1.5 and 6 months after ICL implantation). Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refraction, adverse events, safety, and efficacy were evaluated 12 months postoperatively.

RESULTS

At 12 months postoperatively, the mean spherical equivalent was -0.15 ± 0.36 diopters (D) in the TICL group and -0.08 ± 0.26 D in the bioptics group (p = 0.099). Sixty-six (81.5 %) and 78 (94.0 %) eyes were within ±0.50 D for TICL and bioptics groups, respectively. The mean Snellen UDVA was not statistically different between both procedures (p = 0.909); 53 (65.4 %) and 54 (65.1 %) eyes achieved at least 20/25 or better in TICL and bioptics groups, respectively. No eye had lost more than two lines of CDVA, and 32.1 % of eyes (26/81) in the TICL group and 57.8 % of eyes (48/83) in the bioptics group had better postoperative UDVA than preoperative CDVA (p < 0.001). Safety was not statistically different between groups (p = 0.464) while efficacy was significantly higher in the bioptics group (p = 0.000). Two eyes with a TICL were treated to correct TICL decentration.

CONCLUSIONS

Bioptics showed slightly better outcomes in some clinical measures such as uncorrected visual acuity, efficacy, and refractive predictability. TICL implantation shows reliable results similar to bioptics. A single procedure with TICL implantation might be preferred, eliminating the inherent risks of laser treatments and the risks of a second surgical procedure.

Toric implantable collamer lens for high myopic astigmatism in keratoconic patients after six months

BACKGROUND

The aim was to evaluate the safety, efficacy, stability and predictability of posterior chamber collagen copolymer phakic intraocular lens (pIOL) implantation to correct myopia and myopic astigmatism associated with keratoconus.

METHODS

The unaided vision and visual acuity, refraction and adverse events were measured in 22 keratoconic eyes of 14 patients after using an implantable collamer lens (ICL) (STAAR Surgical Inc.) to correct refractive error. The outcome was evaluated over six months.

RESULTS

The mean pre-operative spherical equivalent (SE) and cylinder changed from -4.98 ± 2.63 DS and -2.77 ± 0.99 DC to -0.33 ± 0.51 DS and -1.23 ± 0.65 DC, respectively at the end of six months. Before the surgery the mean Snellen decimal visual acuity was 0.63 ± 0.20. The mean unaided vision and visual acuity changed to 0.76 ± 0.23 and 0.85 ± 0.21, respectively at the end of six months. The mean safety and efficacy indices were 1.40 ± 0.32 and 1.24 ± 0.34, respectively. No eye lost a line of visual acuity and 17 eyes (77.3 per cent) gained one or more lines. Fifteen eyes (68.2 per cent) were within 0.50 D and 20 (90.9 per cent) were within 1.00 D of the desired spherical equivalent refraction. There was a change in manifest refraction of 0.09 ± 0.21 (ranging from -0.25 to +0.75) from one week to six months after the surgery.

CONCLUSION

The clinical outcomes of the current study demonstrate the safety, efficacy and predictability of toric implantable collamer lens in the correction of myopia and myopic astigmatism associated with keratoconus. The patients' refractions achieved early stability and remained stable during the course of the study.

Efficacy, predictability, and safety of wavefront-guided refractive laser treatment: metaanalysis

PURPOSE

To compare the efficacy, predictability, safety, and induced higher-order aberrations (HOAs) between wavefront-guided and non-wavefront-guided ablations.

SETTING

Division of Ophthalmology and Visual Sciences, University of Nottingham, Nottingham, United Kingdom.

DESIGN

Metaanalysis.

METHODS

The Cochrane Central Register of Controlled Trials, PubMED, and EMBASE were searched for randomized controlled trails. Trials meeting the selection criteria were quality appraised and data extracted by 2 independent authors. Measures of association were pooled quantitatively using metaanalytical methods. Comparison between wavefront-guided and non-wavefront-guided ablations was measured as pooled odds ratios (ORs) or weighted mean differences. The pooled ORs and 95% confidence intervals (CIs) were computed for efficacy, safety, and predictability. The weighted mean difference and 95% CIs were used to compare induced HOAs.

RESULTS

Eight trials involving 955 eyes were included. After wavefront-guided LASIK, the pooled OR of achieving uncorrected distance visual acuity (UDVA) of 20/20 (efficacy) was 1.10 (95% CI, 0.66-1.83; P=.72), the pooled OR of achieving a result within ± 0.50 diopter of intended target (predictability) was 1.03 (95% CI, 0.60-1.75; P=.92), and the weighted mean difference in induced HOAs was -0.09 (95% CI, -0.17 to -0.01; P=.04). No study reported loss of 2 or more lines of Snellen acuity (safety) with either modality.

CONCLUSIONS

Metaanalysis showed no clear evidence of a benefit of wavefront-guided over non-wavefront-guided ablations. However, there was a lack of standardized reporting of UDVA better than 20/20, which might mask an advantage in wavefront-guided treatment. With high preexisting HOAs, wavefront-guided has advantages over non-wavefront-guided treatment.

Collagen copolymer toric posterior chamber phakic intraocular lens in eyes with keratoconus

PURPOSE

To assess the safety, efficacy, stability, and predictability of collagen copolymer toric phakic intraocular lens (pIOL) implantation to correct myopia and astigmatism in eyes with keratoconus.

SETTING

Fernández-Vega Ophthalmological Institute, Oviedo, Spain.

METHODS

This prospective study comprised keratoconic eyes that had implantation of a toric Intraocular Collamer Lens. Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, and postoperative complications were evaluated 1, 3, 6, and 12 months postoperatively.

RESULTS

Preoperatively, the mean spherical equivalent in the 30 eyes (21 patients) was -5.38 diopters (D) +/- 3.26 (SD) (range -13.50 to -0.63 D) and the mean cylinder, -3.48 +/- 1.24 D (range -1.75 to -6.00 D). At 12 months, 86.7% of the eyes were within +/-0.50 D of the attempted refraction and all eyes were within +/-1.00 D. For the astigmatic components J0 and J45, 83.3% of eyes and 86.7% of eyes, respectively, were within +/-0.50 D. The mean Snellen UDVA was 0.81 +/- 0.20 and the mean CDVA, 0.83 +/- 0.18; CDVA was 20/40 or better in 29 eyes 96.7% of eyes and 20/25 or better in 22 eyes (73.3%). No eyes lost more than 2 lines of CDVA; 29 eyes (96.7%) maintained or gained 1 or more lines. The efficacy index was 1.07 and the safety index, 1.16. There were no complications or adverse events.

CONCLUSIONS

The results confirm that toric ICL implantation is a predictable, effective procedure to correct ametropia in eyes with keratoconus. Predictability and stability were achieved early and remained fairly stable up to 12 months.

Comparison of the toric implantable collamer lens and bioptics for myopic astigmatism

PURPOSE

To compare results between toric implantable collamer lens (TICL) implantation and bioptics (ICL and excimer laser ablation) for the correction of myopic astigmatism.

METHODS

A retrospective evaluation was performed in 29 eyes (20 patients) with TICL implantation and 26 eyes (17 patients) treated with bioptics. For eyes treated with bioptics, corneal ablation was performed at 1.5 to 5 months (mean 2.56 months) after ICL implantation by laser epithelial keratomileusis in 17 eyes, LASIK in 8 eyes, and photorefractive keratectomy in 1 eye. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity, refraction, adverse events, safety, and efficacy were assessed preoperatively and 1, 6, and 12 months postoperatively.

RESULTS

At 1 month postoperatively, UDVA in the TICL group was significantly higher than in the bioptics group (P=.02). However, the difference in UDVA at 12 months was not significant. At 12 months, mean spherical equivalent refraction was 0.33±0.21 diopters (D) in the TICL group and 0.29±0.41 D in the bioptics group (P=.07). Mean astigmatic error was higher in the TICL group (-0.42±0.32 D) than in the bioptics group (-0.32±0.38 D) (P=.10). In the bioptics group, the mean refractive cylinder at 12 months decreased from that reported at 6 months because of retreatment performed in two eyes. Safety and efficacy were not statistically different between groups. One eye with a TICL was treated to correct TICL decentration. Two crystalline lens opacities were observed after bioptics.

CONCLUSIONS

This study demonstrates that TICL implantation provides reliable visual outcomes similar to bioptics. The advantages of TICL implantation are a more stable visual outcome and the elimination of laser treatments and their inherent risks.