Posterior chamber phakic intraocular lens implantation for high myopia

Clinical outcomes of implantation of posterior chamber phakic intraocular lens for pathologic and non-pathologic myopia

BACKGROUND

To compare the clinical outcomes of posterior chamber phakic intraocular lens (pIOL) implantation for non-pathological myopia and pathological myopia.

METHODS

This retrospective case series study which were conducted in Beijing Tongren Eye Center between July 2017 and Oct 2021 comprised 192 eyes of 100 consecutive patients undergoing pIOL implantation. Eyes were divided into two groups based on having pathological myopia or not. Predictability, efficacy, safety, and adverse events were compared at 6 months after pIOL implantation.

RESULTS

Our study included 86 non-pathological myopes (171 eyes, group1) and 14 pathological myopes (21eyes, group2) to analysis. The average ages were 25.5 and 33.0, respectively, and the spherical equivalent (SE) were -9.31D and -17.50D pre-operation. Six months after pIOL implantation, the SE were 0.00 and -0.50, respectively, and the refraction changes were statistically significant (P ≤ 0.05). Six months after surgery, 76.92% and 80.41% were within ± 0.50 D of the target and 92.31% and 95.88% were within ± 1.00 D. All eyes had unchanged BCVA or gained 1 or more lines in both groups and mean BCVA both improved a line 6m after operation. The efficacy index in the two groups were 0.95 and 0.88 and the safety index were 1.20, 1.33, respectively which was significantly different (P ≤ 0.05). Over the 6-month follow-up, no cataract, pigment dispersion glaucoma, pupillary block, or other vision-threatening complications happened, either.

CONCLUSIONS

The pIOL performed well for the correction of both non-pathological and pathological myopia throughout the 6-month observation period. The clinical outcomes of pIOL implantation for non-pathological myopia are essentially equivalent to those for pathological myopia.

Analysis of perioperative problems related to intraocular Implantable Collamer Lens (ICL) implantation

PURPOSE

To introduce a modified procedure of ICL implantation, to summarize the perioperative problems and their corresponding treatment after myopia correction with Implantable Collamer Lens (ICL), and to compare the difference of complications between the no-hole ICL and hole ICL.

METHODS

We searched all articles on ICL-related perioperative problems and their corresponding treatment in Scopus, Embase, PubMed and Web of Science databases for the last 22 years.

RESULTS

ICL implantation is safe, effective, stable and predictable in the correction of myopia, hyperopia and astigmatism, but can also cause a series of perioperative problems, including intraoperative and postoperative complications.

CONCLUSION

There are many kinds of complications related to ICL, but the common intraoperative and postoperative complications mainly include abnormality of arch height, abnormal position of ICL, loss of corneal endothelial cells and corneal decompensation, high intraocular pressure and secondary glaucoma, cataract and night vision symptoms. Compared with ICL without central pore, the incidence of complications such as loss of corneal endothelial cells and corneal decompensation, high intraocular pressure and secondary glaucoma and cataract was relatively lower in central hole ICL, while postoperative complications such as night vision symptoms were obvious.

A Prospective Comparative Study between Implantable Phakic Intraocular Contact Lens and Implantable Collamer Lens in Treatment of Myopia in Adults

Purpose

To compare implantable collamer lenses (ICLs) and acrylic implantable phakic contact lenses (IPCLs) in the treatment of myopia in adults, as regards refractive outcome and adverse effects.

Methods

Prospective, randomized comparative study with phakic intraocular lenses (IOLs) was carried out for treatment of myopia. Patients were randomized into two groups: one for ICL and the other for IPCL. Preoperative assessments included a full examination, pentacam, endothelial cell count, and biometry. We compared the adverse effects and refractive outcomes between both groups. The study was registered in clinical trials and the registration number is NCT04624035.

Results

Sixty eyes of sixty patients (28 in the ICL group and 32 in the IPCL group) with a follow-up period of 12 months. The mean preoperative spherical equivalent was −12.7 ± 3.4 D and −13.6 ± 4.4 D in the ICL and IPCL groups, respectively (P=0.37). The mean postoperative spherical equivalent value was ±0.4 ± 0.2 D and ±0.6 ± 0.1 D in the ICL and IPCL groups, respectively. Uncorrected visual acuity (UCVA) has improved from 1.3 ± 0.06 to 0.15 ± 0.02 Log MAR in the ICL group (P < 0.001) and from 1.3 ± 0.02 to 0.15 ± 0.01 Log MAR in the IPCL group (P < 0.001). The mean endothelial cell count was reduced by 3.3% in the IPCL group and by 3.2% in the IPCL group.

Conclusion

Both ICL and IPCL are effective methods to correct high myopia in adults with no statistically significant differences between the two lenses as regarding adverse effects.

Evaluation of changes in choroidal thickness after surgical implantation of collamer lens in patients with different degrees of high myopia

The aim of the present study was to investigate the potential changes in the choroidal thickness (CT) after surgical implantation of collamer lens (ICL) and to determine whether the variations in CT were associated with the degree of myopia. In the study, 98 eyes from 98 myopia patients were divided into two groups according to the degree of myopia: High myopia and super-high myopia. All eyes were measured using the swept-source optical coherence tomography (SS-OCT) technique. CT and CT variations were also recorded. The foveal CT increased significantly in high-myopia patients at 2 h after surgery and 3 months after surgery; the same tendency was observed in the inner nasal CT and outer nasal CT at the same time-points. In patients with super-high myopia, the subfoveal CT increased significantly at 2 h and 3 months after surgery compared with the pre-operative values. No statistically significant differences were obtained in any of the nine different choroidal regions evaluated at post-operative week 1 and post-operative month one. Furthermore, the increase in the subfoveal CT in the super-myopia group was significantly higher than that in the high-myopia group at 2 h and at 3 months after ICL. The results of the present study indicated that the CT significantly increased 2 h after the surgery and then reached a peak at 3 months, particularly in the subfoveal and nasal areas. A higher degree of myopia was associated with greater subfoveal choroidal changes.

Anterior segment optical coherence tomography for evaluation of cornea and ocular surface

Current corneal assessment technologies make the process of corneal evaluation extremely fast and simple. Several devices and technologies allow to explore and manage patients better. Optical coherence tomography (OCT) technology has evolved over the years, and hence a detailed evaluation of anterior segment (AS) structures such as cornea, conjunctiva, tear meniscus, anterior chamber, iris, and crystalline lens has been possible in a noncontact and safe procedure. The purpose of this special issue is to present and update in the evaluation of cornea and ocular surface, and this paper reviews a description of the AS-OCT, presenting the technology and common clinical uses of OCT in the management of diseases involving cornea and ocular surface to provide an updated information of the clinical recommendations of this technique in eye care practice.

Anterior Chamber Changes After Implantable Collamer Lens Implantation in High Myopia Using Pentacam: A Prospective Study

INTRODUCTION

The objective of this study was to evaluate the changes of the anterior chamber (AC) of the eye after implantable Collamer lens (ICL) implantation in high myopia by using the Pentacam.

METHODS

The prospective study included 34 high myopic patients (34 eyes). All patients were treated with Visian implantable Collamer lens (ICL) (Staar Surgical Co.) implantation. The Pentacam (Oculus) was used for all cases preoperatively and 1, 3 and 6 months postoperatively. AC angle (ACA), AC volume (ACV), central AC depth (CACD), ICL vault, central corneal thickness (CCT), pupil diameter (PD), K readings and intraocular pressure (IOP) were recorded.

RESULTS

Our study included 34 eyes of 34 patients, 20 females (59%) and 14 males (41%). Mean ACA was 36.93° ± 4.75° preoperatively, 25.17° ± 5.64° and 25.23° ± 6.05° 1 and 3 months postoperatively (p < 0.001). Mean ACV was 191.24 ± 11.18 mm³ preoperatively, 141.53 ± 16.77 and 142.11 ± 15.89 mm³ 1 and 3 months postoperatively (p < 0.001). Mean CACD was 3.59 ± 0.17 mm preoperatively, 2.83 ± 0.24 mm and 2.96 ± 0.25 mm 1 and 3 months postoperatively (p < 0.001). The ICL vault decreased from 0.556 ± 0.033 mm 1 month postoperatively to 0.431 ± 0.056 mm 3 months postoperatively (p < 0.001). There were no statistically significant differences for any of the AC parameters among measurements taken 3, 6 and 12 months postoperatively. There were no statistically significant differences between preoperative and any postoperative measurements of CCT, PD and K readings.

CONCLUSIONS

ICL implantation for correction of high myopia leads to significant changes in the anterior chamber angle, volume and depth and insignificant changes in the pupil diameter, CCT and K readings.

Comparison of anterior section parameters using anterior segment optical coherence tomography and ultrasound biomicroscopy in myopic patients after ICL implantation

AIM

To compare the agreement of anterior chamber depth (ACD) and central vault measurements obtained by anterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM) of post surgical high myopic eyes with posterior chamber phakic intraocular lens (Visian ICL; STAAR Surgical) implantation.

METHODS

Fifty-two phakic eyes of 28 high myopic patients who underwent implantable Collamer lens (ICL) surgery for the correction of high myopia were studied. The postoperative ACD, the distance between the corneal endothelium and the anterior surface of ICL (cornea-ICL) and the central vault were measured with the AS-OCT system and the UBM system. Intraclass correlation coefficient (ICC) and the Bland-Altman plot were used to evaluate the repeatability and agreement of two devices.

RESULTS

The mean ACD, cornea-ICL and central vault in the 52 phakic eyes after ICL surgery was 3.19±0.28 mm, 2.47±0.28 mm, 0.50±0.19 mm by AS-OCT and 3.13±0.25 mm, 2.49±0.25 mm, 0.44±0.19 mm by UBM, respectively. Pairwise comparison of ACD and central vault measurements showed significant differences between AS-OCT and UBM (P<0.05). However, no statistically significant difference was found between these imaging techniques in cornea-ICL (P>0.05). The Pearson correlation coefficient (r) between AS-OCT and UBM measurements for ACD, cornea-ICL and vault was 0.88, 0.80 and 0.89, respectively (P<0.001). The ICC was 0.89-0.94 for the measurements of AS-OCT and UBM. Bland-Altman analysis showed the 95% limits of agreement of ACD, cornea-ICL, central vault measurements between these two devices were -0.20 to 0.32 mm, -0.36 to 0.32 mm and -0.12 to 0.24 mm, respectively.

CONCLUSION

Central ACD and vault measurements using AS-OCT demonstrated a slight significantly higher value than using UBM in phakic eyes after ICL surgery. These two devices should not be used interchangeably for measurements of central ACD and vault in patients after phakic intraocular lens implantation.

Pupil Diameter Changes in High Myopes after Collamer Lens Implantation

PURPOSE

To observe the changes in pupil size under photopic and scotopic conditions after Implantable Collamer Lens (ICL) implantations in eyes with high myopia.

METHODS

The ICL was implanted in 90 eyes belonging to 45 patients with high myopia. Photopic pupil diameters, scotopic pupil diameters, anterior chamber depths, and ICL vaults were examined at the preoperative, postoperative 1-month, and postoperative 3-month stages. The preoperative and postoperative photopic pupil diameters and scotopic pupil diameters were also compared with each other to note the differences between them. The correlations between preoperative and postoperative pupil diameter changes under different light conditions and presurgical refractive error were analyzed alongside patient's age and ICL vault.

RESULTS

Pupil diameters at both postoperative 1-month and postoperative 3-month stages were smaller than those before operation in distinct light environments, as well as pupil constriction amplitude. Correlation analysis showed that there was a statistically significant correlation between pupil diameter changes under different light conditions and presurgical refractive error at 1 month and 3 months after ICL implantation; pupil diameter decreased more when presurgical refractive error powers were less myopic. Statistically significant correlations were not found, however, with patient's age and ICL vault. Postoperative 1-month and mean postoperative 3-month anterior chamber depths were decreased when compared with preoperative anterior chamber depths. Statistically significant correlations were found in change in preoperative and postoperative anterior chamber depth and ICL vault. No statistically significant difference was found between ICL vault at the postoperative 1-month and postoperative 3-month stages.

CONCLUSIONS

Pupil diameter may decrease at the 1- and 3-month stages after ICL implantation under both photopic and scotopic conditions. This indicates that reduction of pupil diameter may be caused by mechanical contact between the ICL and the posterior iris surface.