Posterior Chamber Implantable Collamer Lens Research Articles

The comparison of corneal higher-order aberration and surgically induced astigmatism between the clear corneal incision and the limbus tunnel incision of posterior chamber implantable collamer lens implantation

BackgroundThis study aimed to compare the corneal high-order aberrations and surgically induced astigmatism between the clear corneal incision and limbus tunnel incision for posterior chamber implantable collamer lens (ICL/TICL) implantation.MethodsA total of 127 eyes from 73 myopic patients underwent ICL V4c implantation, with 70 eyes receiving clear corneal incisions and 57 eyes receiving limbus tunnel incisions. The anterior and back corneal surfaces were measured and the Root Mean Square of all activated aberrations (TRMS) was calculated, including higher-order aberration (HOA RMS), spherical aberration Z40, coma coefficients (Coma RMS) Z3−1 Z31, and surgically induced astigmatism (SIA). The measurements were taken preoperatively and postoperatively at 1 day, 1 week, and 1, 3, and 6 months. In this study, the corneal higher-order aberration was estimated as the Zernike coefficient calculated up to 5th order. The measurements were taken at a maximum diameter of 6.5 mm using Pentacam.ResultsOne week after the operation, the corneal back Z31 of the clear corneal incision group was 0.06 ± 0.06, while the limbus tunnel incision group showed a measurement of 0.05 ± 0.06 (p = 0.031). The corneal back Z40 of the clear corneal incision group was -0.02 ± 0.25, compared to -0.04 ± 0.21 in the limbus tunnel incision group (p = 0.01). One month after the operation, the corneal back SIA of the clear corneal incision group was 0.11 ± 0.11, compared to 0.08 ± 0.11of the limbus tunnel incision group (p = 0.013), the corneal total SIA of the clear corneal incision group was 0.33 ± 0.30, compared to 0.15 ± 0.16 in the limbus tunnel incision group (p = 0.004); the clear corneal incision group exhibited higher levels of back astigmatism and total SIA than the limbus tunnel incision in the post-operation one month period. During the 6- month post-operative follow-up period, no significant difference in Z31, Z40, and other HOA RMS data was observed between the two groups. The total SIA of the corneal incision group and the limbus tunnel incision group were 0.24 ± 0.14 and 0.33 ± 0.32, respectively (p = 0.393), showing no significant difference between the two groups 6 months after the operation.ConclusionOur data showed no significant difference in the high-order aberration and SIA between clear corneal incision and limbus tunnel incision up to 6 months after ICL-V4c implantation.

Efficacy and safety after posterior chamber Implantable Collamer Lens implantation according to preoperative anterior chamber depth: Short-term comparative study.

To compare visual, refractive, and safety outcomes of posterior chamber Implantable Collamer Lens (ICL) implantation for the correction of myopia according to the preoperative anterior chamber depth (ACD). Retrospective, comparative study, patients submitted to implantation of myopic posterior-chamber phakic Implantable Collamer Lens (ICL), model V4C/V5, minimum follow-up of 12 months; two groups were created: Group 1 (ACD 2.80 to 2.99 mm) and Group 2 (ACD equal to or greater than 3.00 mm). The parameters evaluated were uncorrected and corrected visual acuity, subjective refraction, efficacy and safety index, predictability, endothelial cell density, central vault, anterior chamber angle and postoperative complications. A total of 558 eyes from 298 patients were evaluated: 111 eyes (19.9%) in group 1 and 447 eyes (80.1%) in group 2. At 12 months, the efficacy index was similar in both groups (p = 0.264); the safety index was higher in group 1 (p = 0.031); the mean central Vault was significantly lower in group 1 (212.8 vs 410.6 μm; p < 0.001). Respectively, 93 (83.8%) and 366 (84.1%) eyes were within ±0.50 D of targeted refraction. Anterior chamber angle significantly decreased during follow-up in both groups (p < 0.001; p < 0.001). Intraocular pressure did not change significantly (p = 0.310 and p = 0.446, respectively). There were no significant differences in endothelial cell density loss (p = 0.278) or in the rate of complications observed (p = 0.733). ICL implantation is an effective and safe procedure in eyes with shallow anterior chambers, with visual and refractive results and complication rates identical to those obtained in deeper anterior chambers.

Efficacy and Safety After Toric Posterior Chamber Implantable Collamer Lens and Toric Iris-Fixated Foldable Phakic Intraocular Lens for Myopic Astigmatism.

To compare visual, refractive, and safety outcomes of toric posterior chamber Implantable Collamer Lens (T-ICL) (STAAR Surgical) and toric iris-fixated foldable phakic intraocular lens (IOL) (T-Artiflex; Ophtec BV) implantation for the correction of myopic astigmatism. This retrospective cohort study included 312 eyes of 312 patients who had phakic IOL implantation for myopic astigmatism. Two groups were defined: 205 eyes that underwent T-ICL implantation and 107 eyes that underwent T-Artiflex implantation. Safety, efficacy, and predictability outcomes were evaluated preoperatively and at 12 months postoperatively. Refractive and corneal astigmatic vector analysis were performed using the Alpins method. One year postoperatively, uncorrected distance visual acuity was 0.05 ± 0.18 (T-ICL) and 0.10 ± 0.16 (T-Artiflex) logMAR, with efficacy indexes of 1.16 ± 0.27 and 1.05 ± 0.31, respectively (P < .001). Safety indexes were 1.28 ± 0.30 and 1.21 ± 0.31, respectively (P = .04). Spherical equivalent was within ±0.50 diopters (D) of emmetropia in 165 (80.5%) and 88 (82.2%) eyes, respectively. Refractive astigmatic analysis showed an index of success of 0.28 ± 0.33 (T-ICL) and 0.31 ± 0.26 (T-Artiflex) (P = .07). Surgically induced corneal astigmatism was 0.48 ± 0.74 and 0.81 ± 0.61 D, respectively (P < .001). Mean endothelial loss was 1.11% and 2.05%, respectively (P = .42). Six (2.9%) eyes in the T-ICL group and 1 (0.9%) eye in the T-Artiflex group had phakic IOL repositioning due to significant misalignment. No vision-threatening complications occurred. Both the T-ICL and T-Artiflex groups showed high visual and refractive efficacy with a good safety profile for the correction of myopic astigmatism. T-ICL implantation demonstrated significantly better efficacy and safety indexes after 12 months. Vector analysis showed similar refractive astigmatic correction in both groups, but T-Artiflex implantation revealed higher surgically induced corneal astigmatism. [J Refract Surg. 2022;38(6):339-347.].

Implantable collamer lens for the correction of post-keratoplasty myopia and astigmatism

AIM: To evaluate the safety, refractive outcomes and vision after phakic posterior chamber implantable collamer lens (ICL) after keratoplasty (KP). METHODS: This retrospective single center study evaluated 32 (35 eyes) patients who received an ICL for myopia and/or astigmatism after keratoplasty. Patients underwent ICL surgery if they were unable to wear glasses or contact lenses and excimer laser surgery was contraindicated. Data were collected on uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refraction and complications. Data were analyzed for the preoperative and last postoperative visits (16.7±13mo) (P&lt;0.05). RESULTS: Preoperatively, spherical equivalent (SE) ranged from -4.00 to -20.00 D and cylinder from -2.00 to -9.00 D. The mean SE decreased statistically significantly from -11.41±3.62 D preoperatively to -1.95±1.78 D postoperatively (P&lt;0.0001). Mean UDVA increased statistically significantly from 20/400 preoperatively to 20/25 postoperatively (P&lt;0.0001). There was a mean improvement in postoperative CDVA of 1.5 lines compared to preoperatively, 37% of eyes had an increase of 2 or more lines. One eye (2.8%) lost ≥1 line of CDVA. There were no intraoperative or postoperative complications. CONCLUSION: Posterior chamber phakic intraocular lens implantation is a safe and effective treatment for post-keratoplasty myopia and astigmatism in patients unable to wear spectacles or contact lenses and where corneal refractive surgery is contraindicated.

Three-Year Effect of Phakic Intraocular Lenses on the Corneal Endothelial Cell Density.

PurposeTo compare the effect of three different phakic intraocular lenses (pIOLs) on the corneal endothelial cell density (ECD).Patients and MethodsThis was a prospective observational cohort study that included 60 eyes (30 patients) with axial myopia of −6.50 to −22.00 diopters (D). The Verisyse anterior chamber (AC) rigid iris fixated pIOL, the Veriflex (AC) flexible iris fixated pIOL, and the Visian posterior chamber (PC) implantable collamer lens (ICL) were implanted in three equal groups of patients. The effect of the three pIOLs on the ECD was compared over a follow-up period of one week, and one, three, and six months, and one, two, and three years. Specular microscopy was done to evaluate the cornea before the surgery and throughout the study. Changes were statistically analyzed and compared.ResultsIn the first three postoperative months, Verisyse and Veriflex pIOLs induced almost the same amount of endothelial cells loss of 10.3% and 10.6%, respectively, while ICLs showed endothelial cells loss of 3.5%. At the end of the three-year study, Veriflex pIOLs induced the highest rate of endothelial cell loss of 25%, while Verisyse and ICL lenses showed endothelial cells loss of 15.7% and 13.4%, respectively. The main effect of time and type of lens was statistically significant (p<0.001).ConclusionAll pIOLs cause a decrease in ECD. The AC pIOLs tend to be associated with more cell loss than PC pIOLs. Surgical insult is the important factor responsible for the early endothelial cell loss, while the material from which the pIOL is made may be an important factor for the continuous corneal endothelial cell loss over a long time.

Clinical efficacy of modified posterior chamber intraocular lens implantation in phakic eyes

Objective To evaluate the clinical efficacy of modified posterior chamber implantable collamer lens (ICL) implantation in phakic eyes. Methods A prospective case-control study. The data of 128 eyes of 64 cases with high myopia who received ICL were analyzed. All cases were randomly divided into two groups.The control group, 64 eyes of 32 cases, were treated with traditional posterior chamber intraocular lens implantation assisted with viscoelastics. The modified group, 64 eyes of 32 cases, were treated with intraocular lens implantation without viscoelastics. The postoperative visual acuity, arch height and intraocular pressure of the two groups were compared. The visual acuity, the changes of central vaulting and intraocular pressure of the two groups were compared after surgery. Results There was no significant difference in visual acuity postoperatively between two groups(P>0.05). The high intraocular pressure occurred at 2 h after operation in 4 eyes (6.2%) in the modified group and 8 eyes (12.5%) in the control group. The high intraocular pressure after anterior chamber penetration remained in 4 eyes (6.2%) of the control group and no eye of modified group.The difference was statistically significant (χ2=10.267, P=0.025). The difference in the change of central vaulting was not significant between the two groups after operation (P>0.05). Conclusion Modified posterior chamber implantable collamer lens implantation in phakic eyes is safe and effective. Key words: Implantation, lens, intraocular, phakic, modified; Efficacy, clinical

Posterior chamber phakic intraocular lens for the correction of high myopic anisometropic amblyopia in adults.

This study aims to evaluate the clinical results of posterior chamber implantable collamer lens (ICL) implantation in adults with high myopic anisometropic amblyopia. Thirteen patients aged 27.04±7.24y (range 19.2 to 42.5) were studied. ICL implantation was performed in 13 amblyopic eyes. The mean myopic anisometropia was significantly dropped from -10.70±3.02 D preoperatively to +0.09±1.67 D at 1mo postoperatively. The logMAR CDVA at 3d, 1, 3 and mean 9mo postoperatively improved by a mean of 1.69, 2.50, 3.01 and 3.00 lines and gained more than 2 lines accounted for 23.08% (3 eyes), 41.67% (5 eyes), 63.63% (7 eyes) and 55.56% (5 eyes), respectively. The contrast sensitivity of amblyopic eyes was significantly increased after surgery. Four patients partially recovered near stereopsis (400″ to 100″). There was no severe complications were observed. ICL implantation alone can improve vision, contrast sensitivity, and partial restoration of binocular vision in adult patients with high myopic anisometropia.

Implanting a posterior chamber phakic intraocular lens in highly myopic eyes with peripheral primary iris and ciliary body cysts.

To investigate the safety and efficacy of implanting a posterior chamber implantable collamer lens with a central hole in cases of high myopia with peripheral primary iris or ciliary body cysts. A total of 37 eyes of 19 patients with primary iris or ciliary body cysts detected by ultrasonic biological microscope were included, with spherical powers of -10.26 ± 3.28 D and cylinder powers of -1.71 ± 1.18 D. Each patient received ultrasonic biological microscope and a routine examination before implantation of the implantable collamer lens. A routine postoperative follow-up was performed to observe changes in the iris or ciliary body cyst, ranging from 3 to 18 months. There were no complications. At the last follow-up, 56.8% (21/37) of eyes achieved the same corrected distance visual acuity as their preoperative measurements, 43.2% of eyes were enhanced by ≥1 line, and no patients' corrected distance visual acuity declined. The efficacy index and safety index were 0.95 and 1.11, respectively. After 18 months, 66.7% of the spherical equivalents were between ±0.5 D with 100% between ±1.0 D. The postoperative mean spherical equivalents at 1, 3, 6, 12, and 18 months were -0.45 ± 0.31 D, -0.39 ± 0.29 D, -0.36 ± 0.30 D, -0.39 ± 0.38 D, and -0.48 ± 0.23 D (p = 0.789). The vaults were 516 ± 140, 548 ± 124, 498 ± 133, 582 ± 161, and 557 ± 110 μm (p = 0.355). There were no changes in size (p > 0.05), number, or position of the iris or ciliary body cysts. Implantable collamer lens implantation is safe and effective for highly myopic patients with peripheral primary iris and ciliary body cysts. The cysts did not change after operation in this study.

Phakic posterior chamber intraocular lens for unilateral high myopic amblyopia in Chinese pediatric patients.

To assess the outcomes of posterior chamber implantable collamer lens (ICL) implantation in Chinese pediatric patients with unilateral high myopic amblyopia. Eleven eyes of 11 amblyopic patients aged 11.02±3.34y underwent ICL (model V4, Staar Surgical Inc.) implantation to treat unilateral anisometropia were studied. Visual acuity, cycloplegic refraction, contrast sensitivity, stereopsis, intraocular pressure (IOP), vaulting, corneal endothelial cell count and complications were evaluated. Patients completed follow-up at 3d, 1, 3mo and the last follow-up time (mean 8.18±2.82mo) after surgery. The mean myopic anisometropia was -13.70±3.25 D preoperatively and +0.69±2.63 D at 8mo postoperatively. The logMAR corrected distance visual acuity (CDVA) of the amblyopic eye was 1.51±0.72 preoperatively and 0.75±0.40 at 8mo postoperatively. The logMAR CDVA at 3d, 1, 3 and 8mo postoperatively improved by a mean of 0.64, 1.55, 1.82 and 2.64 lines and gained more than 2 lines accounted for 18%, 45%, 45%, 64%, respectively. The contrast sensitivity of 0.5, 1 and 2 cpd in amblyopic eyes was significantly increased after surgery. No patient had near stereopsis recovery. The vaulting at 3 and 8mo was significantly lower than that at 1mo postoperatively. No other intraoperative or postoperative complications were observed, except an acute pupillary block glaucoma happened in a patient at two weeks postoperatively. This short-term results indicate that ICL implantation can be a promising alternative therapy for high myopic anisometropic amblyopia in pediatric patients who have failed with conventional treatments and not suitable to corneal refraction surgery.

Visual outcomes in adult amblyopic eyes with moderate myopia after corneal laser surgery versus copolymer phakic intraocular lens implant

To assess visual acuity and refractive correction in moderately myopic adult eyes with suboptimal preoperative corrected distance visual acuity (CDVA) after laser in situ keratomileusis (LASIK) or insertion of a posterior chamber Implantable Collamer Lens phakic intraocular lens (pIOL). Clínica Baviera, Instituto Oftalmológico Europeo, Torrevieja Hospital, Madrid, Spain. Retrospective study. The study sample included 1310 eyes that had LASIK and 94 that had insertion of a pIOL from July 2002 to September 2013. Suboptimal preoperative CDVA was defined as equal to logMAR 0.15 or below and moderate myopia as a spherical equivalent of -5.0 to -10.0 diopters (D). The preoperative mean CDVA was 0.22 logMAR ± 0.09 (SD) in the LASIK group and 0.23 ± 0.09 logMAR in the pIOL group. Postoperative uncorrected distance visual acuity (UDVA) was 0.13 ± 0.12 logMAR in the laser group and 0.12 ± 0.09 logMAR in the pIOL group, with a postoperative CDVA of 0.11 ± 0.10 logMAR and 0.08 ± 0.07 logMAR, respectively. Compared with preoperative values, amblyopic eyes with moderate myopia having LASIK or implantation of a pIOL demonstrated a statistically significant improvement in UDVA and CDVA (P < .001). The pIOL group performed significantly better than the LASIK group in terms of safety and efficiency. 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.

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

IMPLANTABLE COLLAMER LENS IMPLANTATION AND IRIS CERCLAGE FOR THE TREATMENT OF URRETS-ZAVALIA SYNDROME

A 27-year-old woman with bilateral high myopia had anterior chamber iris-claw phakic IOL implantation in her left eye (LE) under local anesthesia, without intraoperative complications. The preoperative slitlamp examination was normal and she had no past medical history. On the second day post-operatory, she developed fixed dilated mydriasis and one month later we documented IOL subluxation. There had been no history of intra-ocular hypertension and no mydriatic drops were used. Diagnosis of Urrets-Zavalia syndrome was established. We removed the IOL and observed for six months after adapting coloured contact lens. During this time she complained about glare, photophobia and developed contact lens intolerance. We decided to implant a posterior chamber Implantable Collamer Lens (ICL) and to perform iris cerclage in the LE, with good aesthetic and refractive outcome. Posterior chamber ICL implantation with iris cerclage seems to be a simple and effective approach to this situation.

Clinical outcomes after implantation of a posterior chamber collagen copolymer phakic intraocular lens with a central hole for myopic correction

To evaluate the efficacy, predictability, safety, and stability of a new-model posterior chamber Implantable Collamer Lens phakic intraocular lens (pIOL) (V4c Visian) to correct myopia. Private practice, Oviedo, Spain. Case series. This study enrolled patients who had implantation of a new pIOL design with a central hole for more natural aqueous flow, eliminating the need for neodymium:YAG iridotomy or peripheral iridectomy. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refractive error, intraocular pressure (IOP), endothelial cell count, central vault, and adverse events were evaluated 6 months postoperatively. The study enrolled 138 eyes (70 patients). The mean spherical equivalent decreased from -8.73 diopters (D) ± 2.54 (SD) preoperatively to -0.03 ± 0.19 D 6 months postoperatively; 98.5% of eyes were within ±0.50 D and 100% of eyes were within ±1.00 D. The mean UDVA and CDVA were 20/20 or better in 92.1% and 95.0% of eyes, respectively, at 6 months. The safety and efficacy indices were 1.01 and 1.00, respectively. Postoperatively, the IOP remained stable over time. No significant rises in IOP (including pupillary block) and no secondary cataract were found. After 6 months, the mean vault was 482.7 ± 210.5 μm (range 90 to 970 μm) and the mean endothelial cell loss was 8.5%. Implantation of the pIOL was effective, predictable, safe, and stable for the correction of moderate to high myopic errors. This design, which avoids iridotomy or iridectomy, provided good IOP outcomes. No author has a financial or proprietary interest in any material or method mentioned.

Pseudophakic hyperopia in nanophthalmic eyes managed by a posterior chamber implantable collamer lens

We report a case of a bilateral posterior chamber implantable collamer lens (ICL) implantation post-clear lens extraction, to reduce the residual hyperopia, in a patient with nanophthalmic eyes. A 30-year-old female patient, keen to reduce her dependency on glasses and contact lenses, came to our refractive surgery department. Her refractive error was +12.0 and +12.5 diopters in the right and left eye, respectively, with steep corneas on keratometry and a shallow anterior chamber depth. She underwent clear lens extraction with implantation of +35.0 D and +40.0 D IOL in the right eye and left eye, respectively. Her post-operative best-corrected visual acuity was 20/30 with +8.5 D in the right eye and +6 D in the left. She underwent bilateral ICL implantation. Postoperatively after 6 months, her unaided visual acuity was 20/30 in both eyes. In conclusion, ICL implantation can be considered to correct residual hypermetropic ametropia in pseudophakic eyes when other options have limitations.

Techniques and Pearls in the Insertion of the Posterior Chamber Implantable Collamer Lens for Moderate to High Myopia

Techniques and Pearls in the Insertion of the Posterior Chamber Implantable Collamer Lens for Moderate to High Myopia

Three-year follow-up of subjective vault following myopic implantable collamer lens implantation

To evaluate changes of subjective vault during a period of 36 months after implantation of phakic posterior chamber implantable collamer lens (ICL) for myopia correction. Nine hundred and sixty four myopic eyes of 531 patients, 353 females (66.5%) and 178 (33.5%) males, who received a Visian ICL (model V4, Staar Surgical Inc.) implantation were included in the study. Subjective vault classified in five levels (0, 1, 2, 3 and 4) was assessed at each of the follow-up visits by a trained ophthalmologist during a period of 36 months. Mean vault decreased from 2.30 ± 0.87 immediately after surgery to 2.10 ± 0.92 at 12 months and to 2.06 ± 1.05 at 36 months. For patients presenting vault 2, 3, and 4 post-operatively, there was a decrease with time, with changes becoming statistically significant (p < 0.05) after the 3-month follow-up visit. The few eyes developing anterior subcapsular cataract (ASC) were older, had a tendency to vault 2 or lower post-operative, shallower anterior chamber depth and smaller ICL size. Eyes with acute increase in intraocular pressure (IOP) were significantly more myopic, had smaller white-to-white diameter and had larger photopic pupil diameters. Decrease in subjective vault after ICL implantation became statistically significant after the third month postoperatively. Several patients and lens-related factors have been identified as potential predictors of ASC or acute increase in IOP. A tight follow-up during the critical post-operative period should be considered in those particular cases.

Myopic Phakic STAAR Collamer Posterior Chamber Intraocular Lenses for Keratoconus

To evaluate the efficacy, predictability, and safety of myopic phakic posterior chamber Implantable Collamer Lens (ICL) to correct myopia associated with keratoconus. In a prospective, noncomparative, interventional case series, outcomes in 25 consecutive keratoconus eyes of 16 patients, myopia from -3.00 to -18.00 diopters (D) and astigmatism from -0.50 to -3.00 D, were analyzed 12 months after implantation of myopic ICLs (STAAR Surgical). All eyes showed best spectacle-corrected visual acuity (BSCVA) > or =20/50, central keratometric values < or =52.00 D, and refractive cylinder < or =3.00 D. Myopic ICL implantation was performed through a corneal incision in the steepest meridian. The mean uncorrected visual acuity and BSCVA after ICL implantation were 0.17+/-0.19 and 0.12+/-0.12 logMAR, respectively. The efficacy index was 0.98. No eyes lost 2 or more lines of visual acuity, 2 eyes lost 1 line, 18 eyes did not change after surgery, and 5 eyes gained 1 or more lines. The safety index was 1.05. Best spectacle-corrected visual acuity after ICL implantation was statistically significantly better than preoperative BSCVA (P=.0021). Spherical equivalent refraction was within +/-1.00 D of the desired refraction in all cases and 84% of cases were within +/-0.50 D. Mean postoperative spherical equivalent refraction was 0.32+/-0.55 D at 12 months. Myopic ICL implantation was a safe, effective, and predictable procedure for the correction of myopia associated with keratoconus.