HIGHLIGHTS
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The study focuses on the efficacy and safety of scleral-suture fixation of intraocular lens (SFIOL) in children with nontraumatic ectopia lentis (EL) in a real-world setting.
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SFIOL can effectively improve the visual acuity in children with nontraumatic EL.
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The cumulative incidence of postoperative complications at the final follow-up was 21.8%, with an additional surgery rate of 7.7%.
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SFIOL is an effective method for managing children with nontraumatic EL; however, the technique must be enhanced in the future to prevent suture exposure, IOL dislocation, and other postoperative complications.
PURPOSE
To report the efficacy and safety of scleral-suture fixation of intraocular lens (SFIOL) in children with nontraumatic ectopia lentis (EL) in a real-world setting.
DESIGN
Retrospective case series.
METHODS
The retrospective study included 220 eyes of 123 children with nontraumatic EL completing a minimum of 3 years of postoperative follow-up, and was conducted at the Zhongshan Ophthalmic Center, Sun Yat-sen University (Guangzhou, China). Lens extraction with primary SFIOL was performed in all eyes. The efficacy outcome was postoperative corrected distance visual acuity (CDVA). The safety outcomes were postoperative complications and the rate of additional surgery. The secondary outcomes were change in refraction and IOL centration.
RESULTS
The mean age at surgery of the cohort was 7.62 ± 3.41 years, and the median follow-up duration was 4.04 (interquartile range [IQR] = 3.41-5.17) years. In all, 87.2% eyes had CDVA greater than or equal to 0.5 at final follow-up. The postoperative complications included suture exposure in 19 eyes (8.6%), IOL dislocation in 17 eyes (7.7%), IOL pupillary capture in 7 eyes (3.2%), persistent high intraocular pressure in 4 eyes (1.8%), retinal detachment in 3 eyes (1.3%), and endophthalmitis in 2 eyes (0.9%). The additional surgery rate was 7.7%, including retinal detachment in 3 eyes and IOL dislocation in 14 eyes. The postoperative refraction showed a tendency toward myopia. The mean IOL tilt and decentration were 8.6 ± 5.7° and 0.75 ± 0.38 mm, respectively.
CONCLUSIONS
SFIOL is an effective method for managing children with nontraumatic EL, but with a certain incidence of complications. Suture exposure and IOL dislocation are the most common complications and may occur over time. Strengthening the postoperative long-term follow-up is crucial for children with nontraumatic EL.
P ediatric nontraumatic ectopia lentis (EL) is a rare but severe hereditary disease characterized by the dislocation of lens from its normal position, which occurs due to the dysplasia and weakness of the lens zonular. , According to previous study, the prevalence of EL is estimated to be 6.4 in 100,000. Children with nontraumatic EL often experience severe refractive problems, including high refractive error and irregular astigmatism, which can potentially result in severe visual impairment and amblyopia. , Additionally, EL can lead to other severe complications such as secondary glaucoma and retinal detachment (RD). Surgical intervention is recommended to improve visual quality and prevent complications when conservative management is ineffective.
Once the crystalline lens of children with EL is removed, optical correction in aphakia eyes with inadequate capsular support became a challenge. Refractive errors can be corrected with spectacles or contact lenses. However, the spectacles for correcting high hyperopia in aphakic eyes often require thick lenses, which is inconvenient for children. Additionally, the noticeable change in appearance due to such thick glasses may have a negative impact on the mental health of these children. Contact lens, as a noninvasive treatment method, have the advantages of small magnification and image distortion, but their use requires high compliance by children and parents, and more attention needs to be paid.
In addition, various surgical techniques of intraocular lens (IOL) implantation have been introduced for EL patients, including anterior chamber IOL implantation, Cionni-modified capsular tension ring (MCTR) with IOL implantation, sutured scleral fixation of IOL, and sutureless scleral fixation of IOL. Sutured scleral fixation of intraocular lens (SFIOL) is considered to be one of the most commonly used procedures and has shown promising short-term efficacy and safety in these patients. Nevertheless, surgical complications such as IOL dislocation and RD may still occur with time. , Therefore, long-term follow-up is critical in this vulnerable population, to enable early detection, timely management, and optimization of long-term visual outcomes for EL. Unfortunately, there are limited long-term and large-sample data regarding surgical outcomes in pediatric patients with EL.
The objective of this study was to evaluate the efficacy and safety of SFIOL among pediatric nontraumatic EL patients in a real-world setting. In this study, indexes of efficacy and safety for SFIOL such as corrected distance visual acuity (CDVA), postoperative complications and rate of additional surgeries, and changes in refraction and IOL position are analyzed based on real-word data.
METHODS
PATIENTS AND PROCEDURES
In this retrospective case series, the medical record of children with nontraumatic EL who underwent lens extraction and primary SFIOL from January 2016 to December 2020 at the Zhongshan Ophthalmic Center were reviewed. The study was approved by the Ethics Committee of Zhongshan Ophthalmic Center (ID: 2022KYPJ207), and was performed in full accordance with the tenets of the Declaration of Helsinki.
The inclusion criteria for this study comprised patients under 18 years old diagnosed with nontraumatic EL who had received surgical treatment. The exclusion criteria were as follows: (1) preexisting severe ocular disease such as corneal disease, uveitis, or retinal disease; (2) patients with a history of ocular trauma or surgery; and (3) patients with a follow-up period of less than 36 months.
Clinical data, including age, sex, and medical history were extracted from electronic records. Comprehensive ophthalmic examinations, including CDVA, refractive error, intraocular pressure (IOP), slitlamp biomicroscopy, indirect ophthalmoscopy, and ocular biological parameters were performed before and during each postoperative visit. The extent of lens subluxation was assessed by slitlamp biomicroscopy. IOP elevation was defined as IOP ≥21 mm Hg. Ocular biological parameters, including axial length (AL), keratometry (Km), and corneal astigmatism (AST), were obtained by using Zeiss IOLMaster (Carl Zeiss Meditec AG). CDVA and refractive error were determined by subjective refraction following an objective measurement. Spherical equivalent (SE) was calculated by spherical diopter plus half of cylinder diopter. IOL tilt and decentration were evaluated using anterior segment optical coherence tomography (CASIA2, Tomey Corp). Postoperative follow-up visits were scheduled for 1 day, 1 week, 1 month, 3 months, 6 months, and then annually thereafter.
The primary outcome of interest included efficacy and safety of SFIOL in children with nontraumatic EL. The main efficacy index was postoperative CDVA, and the safety analysis focused mainly on postoperative complications and the rate of additional surgery. The secondary efficacy and safety index included change in refraction, tilt, and decentration of IOL.
SURGICAL PROCEDURE
All surgical procedures were performed under general anesthesia by the same experienced surgeon (DZ). In cases in which surgery was required for both eyes, the interval between surgeries was within 6 months. The detailed surgical technique used in this study has been described previously. Briefly, 2 partial-thickness scleral flaps were created at the 4 and 10 o’clock positions. A 3.0-mm clear corneal tunnel incision was made at the 12 o’clock position, and a continuous curvilinear capsulorhexis was performed. The lens material was aspirated using an irrigation/aspiration handpiece with the assistance of capsular retractors to stabilize the capsular bag. An appropriate amount of the ophthalmic viscosurgical device (OVD) was injected between the lens capsular bag and the anterior vitreous membrane to create a protective cushion. The residual lens zonules were cut off using intraocular scissors, and the capsular bag was removed through the main incision. Polypropylene suture, 10-0 or 8-0, was inserted into the globe, 2 mm posterior to the corneal limbus, under the scleral flaps using an ab interno technique. The sutures were then pulled out through the main incision and tied at symmetric points on each IOL haptic. Two models of IOL were used in this study: AR40e (a 3-piece hydrophobic acrylic IOL, Advanced Medical Optics) and Rayner 920H/970C (a single-piece hydrophilic acrylic IOL). For children under 7 years of age, the refractive target was set between +0.00 D and +1.25 D according to their age. For children older than 7 years, the refractive target was emmetropia. The suture knots were buried under the scleral flaps. A 10-0 nylon suture was used to suture the scleral flaps and the main corneal incision. Anterior vitrectomy was performed only in cases with severe vitreous prolapse.
STATISTICAL ANALYSIS
The decimal CDVA was converted to the logarithm of the minimum angle of resolution (logMAR) units for the statistical analysis. Visual acuity scores were assigned 1.8 logMAR for counting fingers and 1.9 logMAR for hand movement, respectively. Age-normal visual acuity was defined as a CDVA of 0.5 or better at 3 to 5 years of age, and 0.7 or better at 6 years of age or older. The paired t test and Wilcoxon signed-rank test were used to determine the significance of any association between the preoperative and postoperative CDVA and refractive error. A Kaplan–Meier curve was used to analyze time to the incidence of postoperative complications. The log-rank test and generalized estimating equations (GEEs) were used for evaluating the association between suture type and IOL dislocation. Statistical analysis was performed using SPSS v.24.0 software (SPSS, Inc.). P values less than .05 were considered to be statistically significant.
RESULTS
BASELINE CHARACTERISTIC
In this study, 145 children with EL underwent SFIOL, and 22 children (15.2%) were excluded because of loss to follow-up. Table 1 shows the demographic data and clinical characteristic of the study population. The baseline characteristics of the excluded patients were comparable to those of included patients (all P > .05). The median follow-up time and CDVA at last follow-up of patients excluded were 1.33 (interquartile range [IQR] = 1.00-1.98) years and 0.15 logMAR (IQR = 0.10-0.30). The CDVA of patients excluded was comparable to that of the included patients at the 3-year follow-up (0.15 logMAR [IQR = 0.10-0.30] vs 0.10 logMAR [IQR = 0.07-0.22], P = .075). Finally, a total of 220 eyes from 123 children (76 male and 47 female) with EL were enrolled in the present study. The mean age at surgery was 6.80 ± 3.17 (range = 318) years, and median follow-up time was 4.04 (IQR = 3.41-5.17) (range = 3-7) years. Among the included eyes, 60 of 220 eyes (27.3%) had a follow-up period exceeding 5 years. Regarding the relevant ophthalmological history, simple ectopia lentis was present in 35.0%, Marfan syndrome was present in 63.2%, Weill–Marchesani syndrome was present in 0.9%, and homocystinuria was present in 0.9%.
| Characteristic | Patients with follow-up | Patients lost to follow-up | p |
|---|---|---|---|
| No. of eyes (no. of patients) | 220 (123) | 40 (22) | — |
| Age at surgery, y | 6.80 ± 3.17 | 7.30 ± 4.24 | .391 |
| Sex, male/female | 142/78 | 24/16 | .582 |
| Etiology, no. of eyes (%) Simple ectopia lentis Marfan syndrome Weill–Marchesani syndrome homocystinuria | 77 (35.0%) 139 (63.2%) 2 (0.9%) 2 (0.9%) | 12 (30.0%) 38 (70.0%) 0 0 | .344 |
| Degree of ectopia lentis, no. of eyes (%) Mild Moderate Severe | 26 (11.8%) 132 (60.0%) 62 (28.2%) | 7 (17.5%) 22 (55.0%) 11 (27.5%) | .641 |
| Preoperative AL, mm | 24.75 ± 2.10 | 25.05 ± 2.17 | .413 |
| Preoperative CDVA, logMAR | 0.70 (0.40, 0.82) | 0.52 (0.40, 0.82) | .212 |
| With strabismus, no. of eyes (%) | 90 (41.0%) | 14 (35%) | .599 |
| Follow-up time, y | 4.39 ± 1.01 | — | — |
INTRAOPERATIVE CONDITIONS
A total of 53 eyes (24.1%) were implanted with a 3-piece IOL (AR40e) and 167 eyes (75.9%) with a single-piece IOL (Rayner 920H/970C). In a total of 134 eyes (60.9%), IOL was fixed with 10-0 polypropylene suture and in 86 eyes (39.1%) IOL was fixed with 8-0 polypropylene suture. Anterior vitrectomy was performed in 21 eyes (9.5%) because of severe vitreous prolapse during surgery. No other intraoperative complications such as intraocular hemorrhage and RD were observed.
EFFICACY
The median preoperative CDVA was 0.70 logMAR (IQR = 0.40-0.82), which significantly improved to 0.30 logMAR (IQR = 0.15-0.40), 0.10 logMAR (IQR = 0.07-0.22), 0.10 logMAR (IQR = 0.05-0.22), and 0.10 logMAR (IQR = 0.05-0.22) at 1 month, 3 years, and 5 years postoperatively and last visit, respectively (all P < .001) ( Figure 1 , A). Improvement or stabilization in CDVA was observed in 95.9% of eyes at the last visit. The distribution of postoperative CDVA is shown in Figure 1 , B. Additionally, at the final follow-up, the incidence of CDVA lower than normal visual acuity in the same age was 36.8% (95% CI = 30.4%-43.2%).
SAFETY
In the early postoperative period (within 1 month after surgery), the most common complication was transient elevation of IOP (15 of 220 eyes, 4.1%). Among these cases, 9 eyes occurred at the first day after surgery. All eyes were successfully controlled within the normal range of IOP (<21 mm Hg) through the use of topical IOP-lowering medication.
The cumulative incidence rate of postoperative complications in the late period (>1 month after surgery) is described in Table 2 , and the time to the incidence of postoperative complications is shown by the Kaplan–Meier curve in Figure 2 . Suture exposure was observed in 19 eyes, and among them, 2 eyes developed endophthalmitis. The 2 eyes with endophthalmitis underwent anterior chamber washout and intracameral antibiotic injection, combined with topical and systemic antibiotic treatment after surgery, and the inflammation was effectively controlled. Suture exposure was resolved by cauterizing the suture, and no recurrence of suture exposure was observed during the subsequent follow-up period. IOL dislocation occurred in 17 eyes with suture breakage in 9 eyes, knot slippage in 3 eyes, IOL haptics fracture in 2 eyes, ocular trauma in 1 eye, and uncertain reason in 2 eyes. No significant difference was found between 8-0 and 10-0 polypropylene sutures in preventing IOL dislocation due to suture-related issues in children with EL (log-rank test, P = .577 and GEE model, odds ratio = 0.850, 95% CI = 0.242-2.953, P = .800). A total of 14 eyes required additional IOL surgery, and 1 eye underwent vitreoretinal surgery due to the combination of traumatic RD. Two eyes had mild IOL subluxation but maintained CDVA greater than 0.8 and did not require surgical intervention. Seven eyes that were implanted with 3-piece IOLs developed pupillary capture; however, no additional intervention was necessary, as all of these eyes had a CDVA greater than 0.5, and no other complications such as elevated IOP were observed. Retinal detachment occurred in 3 eyes, 1 case of which was due to postoperative ocular trauma. Additionally, 4 eyes of 2 children experienced persistent IOP elevation after surgery, requiring long-term use of topical IOP-lowering drugs. These 2 children had preexisting high IOP and microspherophakia in both eyes. Specific genetic mutations were identified in each child. One case (no. 98) was that of a 5-year-old girl with biallelic mutations in LTBP2. The other case (no. 104) was that of an 11-year-old boy with ADAMTS17 gene mutations. In addition to ocular abnormalities, this child also presented with presented with significant short stature and brachydactyly, consistent with the diagnosis of Weill–Marchesani syndrome.
