Phakic Research Articles

Cornea endothelial cell loss before and after explantation of Artisan and Artiflex iris-fixated phakic intraocular lenses

PurposeTo investigate the risk factors for corneal endothelial cell density (ECD) loss of two types of iris-fixated phakic intraocular lenses (pIOL) and indicate the cutoff values for preventing irreversible ECD loss after explantation. DesignThe retrospective, comparative, clinical cohort study MethodsTotal 114 eyes of 61 patients were included in this study. Fifty-five eyes with Artisan pIOL and 59 eyes with Artiflex pIOL had undergone explantation of pIOLs due to continuous ECD loss. Correlation analysis was performed to assess the ocular parameters associated with ECD loss. Receiver operating characteristic (ROC) curve was performed to set cutoff values of ocular parameters to prevent ECD loss after explantation. ResultThe mean ECD before explantation was 1637 cells/mm2 in Artisan group and 1769 cells/mm2 in Artiflex group. The distance of cornea endothelium to IOL center and edges were all significantly higher in Artisan group (p <0.05). The risk factor of decreased ECD in Artisan group were small anterior chamber angle (ACA), and distance of nasal edge of IOL to endothelium and iris fixation to nasal limbus distance, and differences of fixation length. In Artiflex group, ACA, distance of nasal edge of IOL to endothelium, both limbus to IOL fixation length, fixation length, iris pigmentation grading were the risk factors. At 1 year after the pIOL removal, the population demonstrating ΔECD >10% were significantly higher in Artisan group than Artiflex group (p <0.05). In ROC curve analysis, the cutoff value of preoperative ECD to prevent significant post-explantation ECD loss was 1683.5 cells/mm2 in Artisan group and 1648 cells/mm2 in Artiflex group. ConclusionThis study examined the existing explantation guidelines for these lenses. In analyzing the longterm prognosis of cornea ECD with Iris-fixated phakic intraocular lens, it is important to identify the relevant anatomical factors. Small ACA, and short distances from IOL to endothelium and from limbus to iris fixation especially in the nasaSSSl region were significant risk factors to continuous ECD loss in both lenses. To minimize irreversible ECD loss after explantation, it is important to determine the optimal period of explantation by observing both ECD and structural changes.

Phakic intraocular lens exchange due to severe uveitis/inflammation: case report

Introduction: Phakic intraocular lenses (IOLs) provide excellent visual and refractive outcomes with a high safety profile. This report illustrates a case of a rare episode of severe anterior segment inflammation after iris-claw foldable lens implantation, which required surgical reintervention. Patient and Clinical Findings: A 22-year-old woman was submitted to Artiflex implantation for the correction of myopia. Three months postoperatively, a severe anterior segment inflammation developed with pigment deposition, pupillary membrane formation, and decreased visual acuity in the left eye. Diagnosis, Intervention, and Outcomes: Given the nonresponse to medical treatment (topical and systemic corticosteroid for 3 months), surgical explantation of the IOL with peeling of a pigmentary membrane over the crystalline lens was performed. During a 24-month follow-up period, the patient was monitored to exclude the development of cataract or glaucoma. Afterward, an implantable collamer lens was implanted with an uneventful intraoperative and postoperative period. During the long-term follow-up, no further pigment dispersion, uveitis, or cataract was described. Conclusions: Persistent anterior uveitis with pigmentary membrane formation after iris-claw lens implantation is a rare complication. IOL explantation needs to be considered to prevent further sequelae after severe uveitis when the situation is unresponsive to medical treatment.

One-Year Results of a Posterior Chamber Toric Phakic Intraocular Lens Implantation in Patients with Keratoconus.

To determine clinical and refractive results after the implantation of EyeCryl Phakic Toric intraocular lens in patients with stable keratoconus. The study included all patients diagnosed with keratoconus who underwent implantation of an EyeCryl Phakic Toric intraocular lens (Biotech Healthcare Holding; Ahmedabad, India) in at least one eye and had a follow-up of at least 12 months. Visual and refractive data were collected for all patients, along with corneal tomography measurements using Pentacam, and vault measurement using optical coherence tomography. This retrospective study was conducted at a high-volume private refractive surgery center in Medellín, Colombia. A total of 83 eyes from 47 patients were included in the study. The majority (71.1%) were female, with a mean age of 31.2 ± 5.1 years. After 12 months of follow-up post-surgery, the spherical equivalent improved significantly from -8.19 ± 4.04 D to -0.06 ± 0.48 D (p < 0.001). Furthermore, 77% of eyes had a post-surgical spherical equivalent within ±0.50 D, while 92% had residual astigmatism ≤0.50 D. Twelve months after surgery, mean manifest astigmatism was -0.28 ± 0.27 D. Uncorrected visual acuity also showed improvement, from 1.11 ± 0.35 LogMAR to 0.14 ± 0.11 LogMAR. Moreover, 52.4% of eyes demonstrated an improvement of at least one line in best-corrected visual acuity. Notably, no intraoperative or postoperative complications were observed in the study population. The implantation of EyeCryl Phakic Toric intraocular lenses represents a highly effective and safe option for correcting refractive errors in patients with a history of keratoconus. Refractive accuracy is excellent, and a significant proportion of patients experienced an improvement in their best-corrected vision by at least one line.

Using First Eye Early Vault to Determine ICL Size for the Second Eye: A Retrospective Analysis of Bilateral Phakic Intraocular Lens Implantation.

To evaluate the role of the first eye vault after the implantation of implantable collamer lens (ICL) V4c in selecting ICL size for the second eye and analyze the changing characteristics of the vault. Qingdao Eye Hospital of Shandong First Medical University. Retrospective case series. In this retrospective study, 509 patients (1018 eyes) receiving bilateral ICL V4c implants were evaluated. Surgical management method was as follows: the vault was measured at 2 hours after the first eye surgery, and we selected ICL size for the second eye based on the vault of the first eye. The bilateral vault was measured and evaluated between different periods of follow-up. The rate of ICL re-alignment or exchange due to abnormal vault was 1.47% (15/1018), with the second eye showing a significantly lower incidence (0.39%) compared to the first eye (2.55%)(P<0.01). Patients were categorized into four groups based on the vault value obtained at 2 hours postoperatively (baseline). There was significant difference in the value of vault decrease among the four groups at 1day, 1week, 1month, and 3months follow-up(all P<0.01). There was a significant positive correlation between the decrease in the vault and the baseline vault(all P < 0.01). Selecting the ICL size for the second eye based on the first eye's vault measurement 2 hours postoperatively can effectively minimize the need for further surgeries. Notably, eyes with a higher initial vault experienced a more pronounced decrease.

Clinical Outcomes of Iris-Supported Phakic Toric Intraocular Lenses in Corneal Ectasia.

Our aim was to evaluate the visual and refractive outcomes of iris-fixated phakic toric intraocular lenses (IOLs)for visual rehabilitation in eyes with stable corneal ectasia. We conducted a study looking at the clinical outcomes of iris-fixated toric IOLs (Artisan) in 33 eyes of 27 patients diagnosed with mild-to-moderate corneal ectasia at a single center (Queen Victoria Hospital, East Grinstead, UK). The main outcome measures were functional improvement [accuracy of post-operative spherical equivalent (SE), astigmatic correction, topographic parameters, uncorrected and corrected distance visual acuity (UCVA, CDVA)] and safety of the procedure: endothelial cell count and intra- and post-operative complications. Eighteen males and nine females of mean age 38.85 were included in the study with a mean follow-up of 18months. All patients had ectasia due to keratoconus except one with post-refractive laser ectasia. Twelve patients had crosslinking, eight had intracorneal rings, and eight had previous keratoplasties. Mean pre-operative logMAR UCVA was 0.75 ± 0.35 improving to 0.02 ± 0.17 (p = 0.000). Mean pre-operative logMAR CDVA was 0.16 ± 0.17 improving to 0.02 ± 0.17 (p = 0.000). Mean pre-operative (SE) was -3.5 ± 3.9 improving to -2.75 ± 1.39 (p = 0.000) with up to 36-42months of follow-up. The mean value of endothelial cell density in the overall sample was 2252.54 ± 473.24cells/mm2 pre-operatively and 2126.75 ± 365.21cells/mm2 at 24-36months of follow-up visit. Two patients have intra-operative hyphemia secondary to iris prolapse. Implantation of iris-fixated phakic toric IOLs has shown high efficacy and safety in patients with mild-to-moderate astigmatism in corneal ectasia.

Digital versus manual axis marking for toric phakic intraocular lens alignment: a prospective randomized intraindividual trial.

This study compares visual and refractive outcomes and postoperative axis alignment for toric Implantable Collamer Lens (ICL) implantation in astigmatic myopia using manual versus digital marking techniques. Department of Ophthalmology, Medical University of Graz, Austria. Prospective randomized single-centered intraindividual comparison. Patients undergoing bilateral toric ICL implantation for myopia with astigmatism ≥ 0.5 diopters (D) were enrolled. Patients received both marking techniques and randomization was performed. Postoperative retroillumination photography assessed axis alignment, and visual and refractive parameters were evaluated. Duration of the surgeries was recorded. The study includes 20 patients and 40 eyes. Preoperative visual and refractive parameters showed no significant differences. Postoperatively, residual astigmatism (p=0.824) and spherical equivalent (p=0.309) were comparable. No notable differences between right and left eyes in terms of preoperative (p=0.371) and postoperative (p=0.824) astigmatism were observed. Although slight, corrected distance visual acuity (CDVA) increased in both groups postoperatively (p=0.381). Gain in CDVA was comparable between marking techniques (p=0.637). Safety and efficacy indices were comparable (p=0.991 and p=0.189, respectively). Postoperative axial misalignment was 2.8±3.1 degrees in the digital- and 4.4±5.1 degrees in the manual group (p=0.260). Vector analysis showed no significant differences between manual and digital marking. Duration remained uninfluenced by the marking technique (p=0.970) and side of surgery (p=0.682). In conclusion digital and manual marking techniques provided comparable results in axis alignment, surgical duration and visual and refractive outcomes. Both methods are viable for precise axis alignment, with digital marking offering a potential advantage in efficacy.

A comparison of white-to-white measurements obtained by Anterion AS-OCT versus three optical devices in refractive surgery candidates.

To assess the agreement between Anterion AS-OCT and three optical devices in measuring the white-to-white (WTW) diameter in candidates for refractive surgery. In this cross-sectional prospective study, 129 right eyes of 129 normal individuals underwent consecutive scans with the Anterion, the Pentacam AXL, the IOLMaster 700, and the Orbscan IIz. Mean difference (MD), 95% limits of agreement (LoA), and concordance correlation coefficient (CCC) were calculated to assess agreement and interchangeability. The mean age of participants was 30.4 ± 5.9 (range: 21-47) years. The mean WTW distance measured by the different instruments was as follows: 12.00 ± 0.42 mm (range, 10.57 to 13.05) using the Anterion, 11.87 ± 0.34 (11.10 to 12.80) using the Pentacam, 12.12 ± 0.44 (11.00 to 13.30) using the IOLMaster, and 11.73 ± 0.37 (11.00 to 13.10) using the Orbscan. The MD and 95% LoA for Anterion vs. Pentacam, IOLMaster, or Orbscan were [0.11; -0.31 to 0.54 mm], [-0.13; -0.93 to 0.66], and [0.25; -0.28 to 0.78], respectively. The corresponding CCCs were 0.803, 0.514, and 0.631. This study found weak agreement between Anterion and Pentacam AXL, IOLMaster 700, and Orbscan IIz devices regarding WTW distance measurements in refractive surgery candidates. Therefore, it is not recommended to use Anterion's WTW measurements interchangeably with the other three devices, particularly for phakic intraocular lens sizing.

Visual Prognosis Following Cataract Surgery in Highly Myopic Patients with Prior History of Verisyse Phakic Intraocular Lens Implantation.

Background/Objectives: This study aimed to evaluate the visual outcomes and prognosis after cataract surgery in patients with prior history of Verisyse phakic intraocular lens (pIOL) implantation. Methods: A retrospective cohort study involving 215 Verisyse pIOL implantations and 17 explantations was conducted. The Verisyse pIOL was disenclaved and removed through a superior scleral tunnel incision. Cataract extraction with phacoemulsification was then performed through a temporal clear corneal incision. Results: An occurrence rate of 7.9% of eyes with cataract formation was found. Both uncorrected (UDVA) and corrected visual acuity (CDVA) three months after cataract surgery were significantly improved (0.24 ± 0.30 vs. 0.73 ± 0.48; p < 0.001 and 0.10 ± 0.14 vs. 0.30 ± 0.31; p = 0.004, respectively). The UDVA was 20/20 or better in 41% of eyes and 20/40 or better in 65% of eyes. The CDVA was 20/20 or better in 53% of eyes and 20/40 or better in 88% of eyes. The safety and efficacy indices were 1.96 ± 1.68 and 1.60 ± 1.36, respectively. Conclusions: Various complications including cataracts may develop in these patients. Verisyse pIOLs have a lower incidence of cataract formation and are more likely to lead to age-related cataracts rather than the anterior subcapsular cataracts commonly seen in implantable collamer lens (ICL) patients. Patients with a prior history of Verisyse pIOL can expect to have a good visual prognosis after cataract extraction.

CHARACTERIZATION OF VAULT WITH TWO MODELS OF POSTERIOR CHAMBER PHAKIC INTRAOCULAR LENSES.

To evaluate and compare the dynamic vault range (DVR) as well as the asymmetry of the vault during a 3-month follow-up after the implantation of two posterior chamber phakic intraocular lenses (pIOLs). Aver Clinic, Madrid, Spain. Prospective comparative study. One hundred and nineteen eyes (65 patients) that underwent refractive surgical correction with implantation of one of two distinct pIOLs were enrolled: Eyecryl Phakic from Biotech Vision Care (Eyecryl group, 72 eyes) and Evo Visian Implantable Contact Lens from Staar Surgical (ICL group, 47 eyes). Besides evaluation of visual acuity, refraction, and ocular integrity, the pIOL vault was measured centrally and at 2 mm nasally and temporally as well as the DVR from photopic (50 lux) to mesopic (10 lux) illuminations conditions. No significant differences were found between pIOL groups in visual and refractive outcomes (p≥0.454). No significant differences between groups were found in central (523.72±168.4 vs. 494.16±156.7 µm, p=0.248) and temporal vault (499.43±155.8 vs. 431.28±150.5 µm, p=0.067). However, nasal vault was significantly lower in ICL group (465.6±149.1 vs. 375.4±144.0 µm, p=0.045). A trend to a larger DVR was observed in the ICL group, although differences between groups did not reach statistical significance (54.00±36.39 vs. 86.5±57.9 µm p=0.070). The pIOL diameter only correlated significantly with vault measurements in ICL group (r≥0.650, p<0.001). The Eyecryl pIOL shows more symmetric vaults and a trend to fewer light-induced changes in the central vault compared to the ICL pIOL. The clinical relevance of this finding should be investigated further.

Accuracy of intraocular lens calculation formulas based on swept-source OCT biometer in cataract patients with phakic intraocular lens

PurposeTo research the accuracy of intraocular lens (IOL) calculation formulas and investigate the effect of anterior chamber depth (ACD) and lens thickness (LT) measured by swept-source optical coherence tomography biometer (IOLMaster 700) in patients with posterior chamber phakic IOL (PC-pIOL).MethodsRetrospective case series. The IOLMaster 700 biometer was used to measure axial length (AL) and anterior segment parameters. The traditional formulas (SRK/T, Holladay 1 and Haigis) with or without Wang-Koch (WK) AL adjustment, and new-generation formulas (Barret Universal II [BUII], Emmetropia Verifying Optical [EVO] v2.0, Kane, Pearl-DGS) were utilized in IOL power calculation.ResultsThis study enrolled 24 eyes of 24 patients undergoing combined PC-pIOL removal and cataract surgery at Xiamen Eye Center of Xiamen University, Xiamen, Fujian, China. The median absolute prediction error in ascending order was EVO 2.0 (0.33), Kane (0.35), SRK/T-WKmodified (0.42), Holladay 1-WKmodified (0.44), Haigis-WKC1 (0.46), Pearl-DGS (0.47), BUII (0.58), Haigis (0.75), SRK/T (0.79), and Holladay 1 (1.32). The root-mean-square absolute error in ascending order was Haigis-WKC1 (0.591), Holladay 1-WKmodified (0.622), SRK/T-WKmodified (0.623), EVO (0.673), Kane (0.678), Pearl-DGS (0.753), BUII (0.863), Haigis (1.061), SRK/T (1.188), and Holladay 1 (1.513). A detailed analysis of ACD and LT measurement error revealed negligible impact on refractive outcomes in BUII and EVO 2.0 when these parameters were incorporated or omitted in the formula calculation.ConclusionThe Kane, EVO 2.0, and traditional formulas with WK AL adjustment displayed high prediction accuracy. Furthermore, the ACD and LT measurement error does not exert a significant influence on the accuracy of IOL power calculation formulas in highly myopic eyes implanted with PC-pIOL.

Impact and Correction of an Anterior Phakic Intraocular Lens on Swept-Source Optical Coherence Tomography Biometry.

To evaluate the impact of anterior chamber phakic intraocular lens (pIOL) on swept-source optical coherence tomography (SS-OCT) biometric measurements and IOL power calculation. This retrospective analysis of 67 eyes of 49 patients with previous anterior chamber pIOL implantation analyzed the accuracy of automatic segmentation of the anterior surface of the crystalline lens and its impact on anterior chamber depth (ACD, measured from epithelium to lens), lens thickness measurements, and IOL power calculation. The sample was divided into two groups: correct detection of the anterior surface of the crystalline lens and inaccurate detection. Segmentation of eyes from the inaccurate detection group was manually corrected and ACD and lens thickness were calculated using ImageJ software. IOL power was calculated using 7 formulas for both measurements. The anterior surface of the crystalline lens was mis-identified in 13 (19.4%) eyes. ACD was underestimated (Δ -0.85 ± 0.33 mm, P < .001) and lens thickness was overestimated (Δ +0.81 ± 0.25 mm, P < .001). Manual correction changed the target spherical equivalent only in the Haigis formula (P = .009). After correction for segmentation bias, the Pearl DGS, Cooke K6, and EVO 2.0 formulas showed the lowest prediction error, with the Pearl DGS showing greatest accuracy within ±1.00 diopters of prediction error range (81.0%). SS-OCT biometry misidentifies the anterior surface of the crystalline lens in a significant proportion, resulting in significant IOL power calculation error in the Haigis formula. Manual proofing of segmentation is mandatory in every patient with anterior chamber pIOL implantation. After correct segmentation, the Pearl DGS, Cooke K6, and EVO seem to be the best formulas. [J Refract Surg. 2024;40(8):e562-e568.].

Comparison of automated corneal endothelial cell analysis in healthy and postoperative eyes with phakic intraocular lens: a cross-sectional study and literature review

PurposeMeasurement of corneal endothelial cells is critical for postoperative evaluation of phakic intraocular lens (pIOL) surgery. However, inter-instrument differences in corneal endothelial cell density (ECD) after pIOL implantation have not yet been reported. This study aimed to compare automated corneal endothelial cell analysis between CellChek-20 (Konan Medical, Hyogo, Japan) and EM-4000 (Tomey, Nagoya, Japan) in healthy and postoperative eyes with pIOL.MethodsWe retrospectively analyzed 154 healthy and 236 postoperative eyes after pIOL surgery. Endothelial cell measurements were performed using CellChek-20 and EM-4000 with autofocusing and automated image analysis. ECD, percentage of hexagonal cells (HEX), coefficient of variation in cell size (CoV), and central corneal thickness (CCT) were compared between the two devices.ResultsThe ECDs of the two devices were highly correlated in both healthy (Spearman’s correlation coefficient [r] = 0.805; p < 0.001) and postoperative (r = 0.901; p < 0.001) groups. ECD from CellChek-20 was higher than EM-4000 in both healthy (mean difference = 228.9 cells/mm2; p < 0.001) and postoperative (mean difference = 115.6 cells/mm2; p < 0.001) groups. The CCT values also showed a strong correlation in healthy eyes (r = 0.974; p < 0.001) and in postoperative eyes (r = 0.936; p < 0.001); however, significant inter-instrument differences were observed. HEX and CV showed significant differences and relatively weak correlations (r < 0.7) between the two devices in both healthy and postoperative groups.ConclusionThe ECD values between the two instruments were correlated, but that of the CellChek-20 was significantly higher than that of the EM-4000 in both healthy and postoperative eyes after pIOL surgery. Most previous studies have also shown that the Konan software overestimated the ECD compared to other products in automatic measurement mode. The possibility of measurement bias should be considered when replacing equipment used for corneal endothelial cell measurements.

Refractive Surgery in Myopic Children.

In this paper, we summarize the current knowledge on refractive surgery performed in the myopic pediatric population. We describe the main concerns about refractive surgery in myopic children and the indications for refractive surgery in this age group. We present a range of surgical procedures that are being used for the management of unilateral/bilateral myopia in children: corneal refractive surgery (PRK, LASEK, LASIK, FS-LASIK and SMILE) and intraocular refractive surgery (phakic intraocular lens implantation, refractive lens exchange or clear lens extraction), with both their advantages and drawbacks. We also describe the various complications and measures to prevent them.

Implantation of phakic intraocular lenses in patients with stabilized keratoconus

To date, extensive experience has been accumulated in the correction of high myopia and myopic astigmatism through the implantation of additional negative lenses (phakic intraocular lenses). However, the use of this method in patients with anatomically altered corneas due to keratoconus remains unresolved.Purpose: to assess the effectiveness and safety of correcting high myopia combined with myopic astigmatism by implanting phakic intraocular lenses in patients with stabilized keratoconus at stages 1–2.Materials and methods. The study encompassed results from 27 surgeries involving the implantation of phakic intraocular lenses in patients with high myopia and myopic astigmatism (12.63 ± 4.25 D). These patients had thin corneas and were diagnosed with stage 1–2 keratoconus after undergoing corneal collagen crosslinking treatment – this constituted the main group. The control group comprised 35 surgeries performed on patients with subclinical non-progressive keratoconus (Forme Fruste). All participants underwent evaluations for visual acuity dynamics and refractive stability of spherical and cylindrical components before surgery, immediately post-surgery, and then at 1, 6, and 12 months after implantation. Additional assessments included intraocular pressure measurements, gonioscopy, ultrasonic echobiometry, ultrasonic ophthalmoscopy, biomicroscopy, ophthalmoscopy, endothelial microscopy, vision character and stereopsis determination, ultrasound biomicroscopy, anterior segment optical coherence tomography, electrophysiological studies, and statistical analysis. An IPCL (a type of phakic intraocular lenses made from hydrophilic acrylic) was implanted, capable of correcting myopia up to 30 D and astigmatism up to 10 D.Results. All patients achieved high uncorrected visual acuity 0.86 ± 0.11. Astigmatism correction was successful in 96% of cases. The average postoperative vault – the distance from the back surface of the phakic intraocular lenses to the anterior lens capsule – was 527.5 ± 40.27 μm (range 460–600 μm), and the intraocular pressure was 11.7 ± 2.08 mm Hg. There was a minor decrease in corneal endothelial cell count from 2599 ± 157.3 to 2375 ± 125.3 cells/mm² in the first group and from 2614 ± 104.8 to 2375 ± 43.3 cells/mm² in the second group respectively (p &gt; 0.05), which falls within the acceptable loss range of 4–7% from preoperative values for both groups. Throughout the observation period, there were no cases of cataract development, pigmentary glaucoma, pupillary block, or other vision-threatening complications.Conclusions. Implantation of phakic intraocular lenses in patients with early-stage stabilized keratoconus and subclinical non-progressive keratoconus provides an effective and practically safe means of correcting high myopia and astigmatism.

Moxifloxacin-associated acute pigment dispersion and iris transillumination after phakic lens surgery

Introduction: Acute pigment dispersion and elevated intraocular pressure (IOP) were found after phakic intraocular lens surgery where 0.5% moxifloxacin was used. While scattered reports can be found in the literature, to the authors' knowledge, this is the first time it has been linked to intracameral 0.5% moxifloxacin. Patient and Clinical Findings: A 23-year-old man experienced symptoms of unilateral eye pain, increased IOP, diffuse pigment dispersion, transillumination defects, and mydriasis after successful bilateral Starr Visian EVO implantable collamer lens implantation. Diagnosis, Intervention and Outcomes: Intracameral moxifloxacin (0.5%) was given at the time of the procedure and was suspected to be the cause of this patient's postoperative findings. These findings are consistent with iris toxicity associated with systemic moxifloxacin. Supportive care was given, however, the resulting pigment dispersion and mydriasis are permanent. Conclusions: Although generally safe for intracameral use, moxifloxacin has the potential to be toxic to the iris. Patients with phakia may be at higher risk of this toxicity, and lower concentrations of intracameral moxifloxacin should be considered in these patients.

Paying attention to safety of posterior chamber phakic intraocular lens implantation

Posterior chamber phakic intraocular lens implantation is a type of intraocular surgery. With advancements in implant materials and design, this procedure has seen rapid adoption and widespread use in ophthalmology clinics in recent years. However, the changes in surgical techniques and the occurrence of postoperative complications have raised safety concerns that require significant attention in clinical practice. This paper aims to address the key factors influencing the safety of posterior chamber phakic intraocular lens implantation, exploring relevant characteristics, mechanisms, and current challenges. By emphasizing the importance of this surgery and proposing effective measures, it aims to provide guidance for clinical practice, enhance the safety of posterior chamber phakic intraocular lens implantation, and foster the healthy advancement of this surgical technique.

A comparative study of two phakic posterior chamber implantable lenses.

This study aimed to compare the postimplantation clinical outcomes of 2 types of posterior chamber phakic intraocular lenses (IOLs): Visian™ implantable collamer lenses (ICL; EVO+ V5; Staar Surgical, Monrovia, CA) and an implantable phakic contact lens (IPCL) (IPCL V2.0, Care Group Sight Solution, India) to correct high myopia and myopic astigmatism. This retrospective study included patients who had undergone phakic IOL implantation performed by a single surgeon between March 2021 and March 2022. Preoperative assessments included slit-lamp examination, fundus examination, spherical equivalent, uncorrected distant visual acuity (UDVA), corrected distant visual acuity (CDVA), specular microscope parameters, and optical quality analysis system parameters. Postoperative assessments after 1 year included slit-lamp examination to detect adverse effects and spherical equivalent, UDVA, CDVA, specular microscope, optical quality analysis system, and anterior-segment optical coherence tomography. Eighty eyes from 42 patients (47 eyes from 24 patients in the ICL group and 33 eyes from 18 patients in the IPCL group) were included. No statistically significant differences were observed between the 2 groups regarding preoperative parameters. At 1-year postoperatively, the mean UDVA in the ICL and IPCL groups was 0.019 ± 0.040 logMAR and 0.019 ± 0.041 logMAR, respectively. The mean CDVA was 0.001 ± 0.008 logMAR and 0.001 ± 0.007 logMAR in the ICL and IPCL groups, respectively, showing no statistically significant differences. The postoperative parameters did not differ significantly between the 2 groups. The visual acuity and refractive results of both groups were excellent, and both groups exhibited similar efficacy and safety profiles.

Analysis after posterior chamber phakic intraocular lens implantation: 17- to 19-year follow-up study.

To evaluate the clinical outcomes of the Visian implantable collamer lens (ICL) in eyes with ≥17 years of follow-up. Single-center. Retrospective observational study. 70 eyes from 38 patients who underwent surgery between 2002 and 2006 with V4 ICL implantation were analyzed. Preintervention data included corrected distance visual acuity (CDVA), refraction, and intraocular pressure (IOP). At the 19-year mark, CDVA, refraction, IOP, endothelial count, and vault were measured using Tomey Casia 2 anterior pole tomography, along with recording long-term events. The operated patients had a spherical correction between -4 diopters (D) and -21 D and a cylinder up to 7.5 D. The mean CDVA (decimal) at the 17-year check-up was 0.89 ± 0.18, with a spherical equivalent of -1.05 ± 1.36 D. IOP has remained stable because mean measurements before surgery and currently were 15.16 ± 2.54 mm Hg and 16.19 ± 3.29 mm Hg, respectively. The endothelial cell count showed values of 2191 ± 386 cells/mm2, with a maximum of 2804 cells and a minimum of 1125 cells. Finally, the vault obtained was 348.53 ± 234.58 mm. Over the years, 2 eyes developed angle-closure glaucoma and 9 eyes were operated on for the development of anterior subcapsular cataracts. Visian ICL implantation demonstrated long-term visual and refractive stability, indicating it as a low-risk procedure. The ICL V4 model yielded satisfactory results for myopia and astigmatism correction after 17 years.

РЕЗУЛЬТАТЫ ДВУСТОРОННЕЙ ИМПЛАНТАЦИИ ФАКИЧНОЙ ТОРИЧЕСКОЙ ИНТРАОКУЛЯРНОЙ ЛИНЗЫ У ПАЦИЕНТА С РЕФРАКЦИОННОЙ АМБЛИОПИЕЙ СРЕДНЕЙ СТЕПЕНИ И МИОПИЕЙ ВЫСОКОЙ СТЕПЕНИ. КЛИНИЧЕСКИЙ СЛУЧАЙ

A case of bilateral implantation of a phakic toric intraocular lens “IPCL V2.0 TORIC” in a patient with moderate refractive amblyopia and high myopia is considered. The results of dynamic observation are presented: refraction data and indicators of maximum correctable visual acuity in the preoperative and postoperative periods, which allow monitoring the results of the surgical period with determining the timing of the postoperative period.

Surgical options and clinical outcomes for high myopia.

Higher degrees of myopia are currently being treated with refractive surgery. However, there is limited characterization and outcomes data for this cohort. This article aims to review the literature on highly myopic patients who had refractive surgery and present a retrospective analysis of 149 patients (270 eyes) with high to extreme myopia (≤-5.0D SE) who underwent refractive surgery [laser-assisted subepithelial keratomileusis (LASIK), photorefractive keratectomy (PRK), or implantable collamer lense (ICL)] at a single practice. There is substantial literature on the efficacy of LASIK, PRK, and phakic intraocular lenses for refractive error correction, but a dearth of studies on patients with high to extreme myopia undergoing different types of refractive surgery. Our study reveals that this cohort of patients has excellent outcomes with minimal complications. Our study reveals that the average preoperative myopia was highest in ICL patients (-10.03D), followed by PRK (-7.21D), and LASIK (-7.04D) patients. Not surprisingly, eyes with high myopia and thin corneas were offered and elected ICLs for their procedure. Highly myopic patients achieved outcomes consistent with data reported in the literature- average postoperative uncorrected visual acuity was 20/20 for LASIK and ICL eyes and 20/25 for PRK eyes.