Intraocular lens exchange for high myopia in pseudophakic children

Outcome of intraocular lens exchange for the management of myopic shift in pseudophakic children

PURPOSE

To evaluate the visual outcome of intraocular lens (IOL) exchange for the management of myopic shift in pseudophakic children.

METHODS

The medical records of children who underwent IOL exchange for myopic shift were examined. The preoperative data, operative details and the postoperative outcome were analyzed.

RESULTS

Twenty-one eyes (16 patients) were identified. Mean age at cataract extraction was 20 ± 26 months (range, 2-84 months). Twelve patients (6 unilateral, 6 bilateral) had primary IOL implantation. Mean age at IOL exchange was 7.3 ± 3.2 years. Mean spherical equivalent (SE) at IOL exchange was -14 ± 5 D (range, -7 to -21 D): Mean SE at IOL exchange was -13.64 ± 4.99 D, -12 ± 1.53 D, and -15.5 ± 4.7 D in unilaterally pseudophakic cases (8 patients), in the eye that underwent unilateral IOL exchange (3 patients) in bilaterally pseudophakic cases, and in bilateral IOL exchange cases (5 patients), respectively. Mean axial length at IOL exchange was 24 ± 1.3 mm (range, 23 to 27 mm). Following IOL exchange, mean SE was reduced to -2 ± 1.8 D (range, -4 to +2.5 D). An average of three logMAR line improvement in the best-corrected visual acuity was observed in 12/16 eyes of patients for whom pre- and post-exchange visual acuity were available, while visual acuity remained unchanged in 4 eyes. Mean logMAR visual acuity improvement was 0.35 and 0.49 in unilateral and bilateral pseudophakic cases, respectively.

CONCLUSIONS

IOL exchange is a safe procedure that should be considered to improve visual rehabilitation in pseudophakic patients with myopic shift.

Anisometropia and its association with refraction development in highly myopic children

CLINICAL RELEVANCE

Anisometropia can affect visual development in children. Investigations of anisometropia in high myopes would explore potential causes related to anisometropia, highlighting the management of anisometropia in high myopia.

BACKGROUND

The prevalence of anisometropia ranged from 0.6% to 4.3% in general paediatric population and from 7% to 14% in myopes. Anisometropia is regarded as an associated factor for myopia development, while myopia progression is a stimulus driving anisometropic development. The purpose of this study was to investigate the prevalence of anisometropia and its association with refraction development in Chinese children with high myopia.

METHODS

In the cohort study, a total of 1,577 highly myopic (spherical equivalent ≤-5.0D) children aged 4-18 years were included. Refractive parameters (dioptre of sphere, dioptre of cylinder, corneal curvature radius, and axial length) of both eyes were measured after cycloplegia. The prevalence and degree of anisometropia were compared among refractive groups (non-parametric tests or chi-square tests), and regression analyses were used to determine associated factors of anisometropia. The statistical significance was set to P < 0.05 (two-tailed).

RESULTS

In highly myopic children with a mean (standard deviation) age of 13.06 (2.80) years, the proportions of spherical equivalent anisometropia, cylindrical anisometropia and spherical anisometropia ≥1.00 D were 34.5%, 21.9% and 39.9%, respectively. There was more spherical equivalent anisometropia associated with more severe astigmatism (P for trend <0.001). In the multivariate regression analysis, more spherical equivalent anisometropia, cylindrical anisometropia and spherical anisometropia were associated with higher degrees of astigmatism (standard beta = -0.175, -0.148 and -0.191, respectively). More spherical anisometropia was associated with better spherical power (standard beta = 0.116).

CONCLUSION

The proportion of anisometropia in highly myopic children was high, compared with previously reported general population, and more severe anisometropia was associated with higher degree of cylindrical power, but not spherical power.

The impact of pre-operative axial length on myopic shift 3 years after congenital and developmental cataract surgery and intraocular lens implantation

Purpose

To investigate the impact of the pre-operative axial length (AL) on myopic shift (MS) 3 years after primary intraocular lens (IOL) implantation in congenital/developmental cataract patients.

Methods

A retrospective study of patients who underwent congenital/developmental cataract surgery and primary IOL implantation at age 2-3 years at EENT Hospital was conducted. All patients were followed up regularly for at least 3 years after surgery. Refractive outcomes, including spherical equivalent (SE) and MS, were collected at each follow-up.

Results

Forty eyes from 40 patients were included. The mean age at surgery was 2.56 ± 0.57 years old, and the mean follow-up time was 3.05 ± 0.22 years. Patients were divided into two groups: Group 1 included 20 patients with longer pre-operative ALs (≥22 mm), and Group 2 included 20 patients with average pre-operative ALs (<22 mm). By the last follow-up, the MS was 2.13 (0.38, 2.63) D in Group 1 and 3.88 (2.85, 5.72) D in Group 2. The post-operative MS in Group 2 was statistically greater than that in Group 1 at 3 years after surgery (P < 0.001).

Conclusion

In congenital/developmental cataract patients who underwent cataract extraction and primary IOL implantation at age 2-3 years, eyes with longer pre-operative ALs had a slower MS than those with average pre-operative ALs 3 years after surgery. This finding could have implications for the target refraction decision in congenital/developmental cataract surgery.

Ocular biometric changes following unilateral cataract surgery in children

Purpose

To analyze ocular biometric changes following unilateral cataract surgery in children.

Methods

A total of 57 children aged under 13 years who underwent unilateral cataract surgery were analyzed. Groups were classified according to their age at surgery: group I (age <3), II (3≤ age <6), III (6≤ age <9), and IV (age ≥9). The myopic shift, axial growth, and corneal curvature changes were compared between the pseudophakic eyes and the fellow phakic eyes.

Results

During 7.81 ± 4.39 years, the overall myopic shift (D) and the rate of myopic shift (D/year) were significantly higher at -3.25 ± 3.21 D and -0.45 ± 0.44 D/year in the pseudophakic eyes than -1.78 ± 2.10 D and -0.22 ± 0.29 D/year in the fellow phakic eyes (P = 0.01, 0.004). Group I (-1.14 ± 0.66 vs -0.02 ± 0.45 D/year) and group II (-0.63 ± 0.37 vs -0.31 ± 0.29 D/year) showed significantly higher rate of myopic shift in the pseudophakic eyes than in the phakic eyes. The rate of myopic shift in the pseudophakic eyes decreased in the older age groups (P = 0.001). There was no significant between-eye difference in the changes in axial length and keratometric values postoperatively.

Conclusion

Following unilateral cataract surgery, a significant postoperative myopic shift was noticed in the pseudophakic eyes compared to the fellow phakic eyes in groups under 6 years old. Postoperative myopic shift and the resultant anisometropia should be considered when selecting the optimal power of IOL in young children requiring unilateral cataract surgery.

Refractive Lens Exchange Surgery in Early-Onset High Myopia Patients With Partial Cataract

Purpose

By reporting clinical characteristics and retinal image quality before and after refractive lens replacement surgery in early-onset high myopia (eoHM) patients presenting with partial cataract, we emphasized the need for an objective way to grade the severity of partial cataracts.

Methods

This retrospective, consecutive case series included six Chinese patients (nine eyes). Analysis of previous medical records, visual acuity, optometry, retinal image quality, and axial length (AXL) before surgery and after surgery was performed.

Results

Five females and one male (nine eyes) with a mean (± SD) age of 11.6 ± 7.9 years (range: 4–25 years) were included in this study. The preoperative spherical power ranged from −7.5 to −42 D. The mean follow-up time was 36 months (range: 24–48 months). Phacoemulsification was followed by in-the-bag implantation of intraocular lens. For patients who were under 6 years old, posterior capsulotomy + anterior vitrectomy were performed simultaneously. All surgeries were uneventful and no postoperative complications occurred during the entire follow-up period. All patients’ uncorrected visual acuity improved by ≥2 lines postoperatively(Snellen acuity). LogMAR best-corrected visual acuity was improved at 24-month (P = 0.042) and endpoint (P = 0.046) follow-ups. Modulation transfer function cutoff frequency (MTF_cutoff) and objective scatter index (OSI) was significantly improved at 12-month (P = 0.025, P = 0.038), 24-month (P = 0.005, P = 0.007) and endpoint (P = 0.005, P = 0.008) follow-ups. Postoperative AXL remained stable during 2–4 year follow-ups (P > 0.05).

Conclusion

Refractive lens replacement surgery is safe and effective for improving functional vision in eoHM patients presenting with partial cataract. Retinal image quality could provide a useful and objective way to facilitate partial cataract severity evaluation and surgery decision making.

Retropupillary Iris Fixation of an Artisan Myopia Lens for Intraocular Lens Dislocation and Aphakia in Eyes with Extremely High Myopia: A Case Series and a Literature Review

Introduction

To describe the outcomes of retropupillary iris fixation of an iris claw Artisan Myopia intraocular lens (IOL), and to review literature on retropupillary iris fixation of iris claw models for myopia for the correction of aphakia and IOL dislocation in eyes with extremely high myopia.

Methods

Single-center, retrospective case series. Three patients (three eyes) with pathological myopia underwent retropupillary iris fixation of the iris claw Artisan Myopia model 204 for the correction of aphakia and IOL dislocation. After IOL power calculation, we found that the Artisan Aphakia IOL was not available for these patients. One patient had a history of previous extracapsular cataract extraction and two patients exhibited IOL–bag complex dislocation. The target lens power was calculated using ultrasound biometry and the Sanders–Retzlaff–Kraff theoretical and T2 formulae, with an A-constant of 103.8. All surgeries were performed by a single surgeon. Visual outcomes were assessed at 12–48 months after surgery.

Results

The mean axial length was 34.33 ± 0.21 mm. The power of the implanted Artisan IOLs ranged between − 4.00 and − 3.00 diopter. The corrected distance visual acuity, measured in logarithm of the minimum angle of resolution units, improved after surgery in all eyes, from 0.60 ± 0.36 logMAR before surgery to 0.40 ± 0.43 logMAR after surgery at 12 months postoperatively and remained stationary thereafter. There were no postoperative complications.

Conclusions

Retropupillary iris fixation of Artisan Myopia IOLs may be a safe and effective surgical treatment option for the correction of aphakia and IOL dislocation in patients with extremely high myopia.

The effect of retaining intact posterior capsule in congenital cataract surgery in children aged 4-8 years

Background

The present study sought to observe the effect of retaining intact posterior capsule in congenital cataract surgery in children aged 4–8 years.

Methods

This is a retrospective case control study. Seventy-seven children (130 eyes) aged from 4 to 8 years who underwent cataract surgery were divided into two groups. In Group A, 50 eyes underwent phacoemulsification, intraocular lens implantation and posterior capsule capsulotomy combined with anterior vitrectomy. In Group B, 80 eyes underwent cataract phacoemulsification and intraocular lens implantation. The postoperative visual acuity and the rate of complications were compared.

Results

In all patients, cataract surgeries were performed evenly without intraoperative complications. The follow-up time ranged from 6 months to 42 months. No apparent visual axis opacity was detected in group A during the follow-up. By the last visit, apparent visual axis opacity was detected in 31 eyes (38.75%) in group B. Among them, 9 eyes (29.03%) with mild posterior capsule opacification (PCO) were treated with Nd:YAG laser, 3 eyes (9.68%) with thick proliferative membranes were treated with posterior capsule capsulotomy combined with anterior vitrectomy and proliferative membranes in 19 eyes (61.29%) were completely aspired and the posterior capsule was retained. During follow-up, only 2 (6.45%) eyes had PCO recurrence and were treated with Nd:YAG laser. The visual acuity was significantly higher than that before surgery in all patients.

Conclusions

For older children, the incidence of PCO will be low even if intact posterior capsule is retained. Either Nd:YAG laser or surgical treatment for PCO will be able to maintain good vision.

Factors influencing myopic shift in children after intraocular lens implantation

Introduction:

Intraocular lenses have always been a controversial topic in pediatric cataract surgery. In the early 1990s in the post-Soviet states of Eastern Europe, intraocular lenses promised an easier full-time correction and amblyopia treatment. Since 1991, ophthalmologists in Latvia have been implanting intraocular lenses in infants. Amount of the postoperative myopic shift and its influencing factors, analyzed in this article, are important indicators of congenital cataract treatment.

Materials and methods:

A retrospective chart review off 85 children (137 eyes) who underwent foldable posterior chamber intraocular lens implantation at the Clinical University Hospital in Riga, Latvia, from 1 January 2006 until 31 December 2016, was performed. Depending on the age at surgery, patients were divided into six groups: 1–6, 7–12, 13–24, 25–48, 49–84, and 85–216 months.

Results:

The largest and more variable myopic shift was found in a group of diffuse/total and nuclear cataract with surgery before the age of 6 months. There was a statistically significant correlation between the acquired best-corrected visual acuity and the amount of myopic shift (rs = 0.33; p < 0.001). Comparing the amount of myopic shift in two groups of different intraocular lens implantation target refraction tactics, we did not find statistically significant differences. Comparing the amount of myopic shift and implanted intraocular lens power, a negative, statistically significant correlation was found.

Conclusion:

The earlier the cataract extraction surgery and intraocular lens implantation is performed, the larger the myopic shift. The morphological type of cataract, best-corrected visual acuity, secondary glaucoma, and intraocular lens power influence the amount of myopic shift.

Long-term uveal and capsular biocompatibility of a novel modular intraocular lens system

BACKGROUND

We evaluated the long-term biocompatibility and safety of a new modular posterior chamber intraocular lens (IOL) system in rabbit eyes.

METHODS

Seven New Zealand rabbits underwent bilateral phacoemulsification with placement of the modular IOL in OD and a control IOL (SA60AT) in OS. Slit-lamp examinations were performed at postoperative weeks 1, 2, 3, 4, 6 and 8 and months 3 and 6. All rabbits were then sacrificed and eyes enucleated. The eyes were examined grossly from the Miyake-Apple view. Selected IOLs were explanted and underwent surface staining for implant cytology. All globes were then sectioned and processed for histopathological examination.

RESULTS

The modular IOL remained stable in all seven rabbits through the entire follow-up period. Biocompatibility was better than the control lens at six months postoperatively, on account of less extensive synechiae formation as assessed by slit-lamp examination. At the six-week examination, posterior capsule opacification (PCO) was significantly better in the test group (scored as 1.71 ± 0.8 versus 3.28 ± 0.48 in the control group, p = 0.0008). On gross examination with the Miyake-Apple view, Soemmering's ring formation was significantly better in the test group, (5.14 ± 1.57 versus 10.85 ± 1.95 in the control group, p = 0.002).

CONCLUSION

Previous studies showed that explantation/exchange of the modular system optic was safer and easier than with a standard IOL. The new modular IOL system has demonstrated better long-term biocompatibility compared to the control lens at six months postoperatively in the rabbit model.

Anisometropia at Age 5 Years After Unilateral Intraocular Lens Implantation During Infancy in the Infant Aphakia Treatment Study

PURPOSE

To report the prevalence of anisometropia at age 5 years after unilateral intraocular lens (IOL) implantation in infants.

DESIGN

Prospective randomized clinical trial.

METHODS

Fifty-seven infants in the Infant Aphakia Treatment Study (IATS) with a unilateral cataract were randomized to IOL implantation with an initial targeted postoperative refractive error of either +8 diopters (D) (infants 28 to <48 days of age) or +6 D (infants 48-210 days of age). Anisometropia was calculated at age 5 years. Six patients were excluded from the analyses.

RESULTS

Median age at cataract surgery was 2.2 months (interquartile range [IQR], 1.2, 3.5 months). The mean age at the age 5 years follow-up visit was 5.0 ± 0.1 years (range, 4.9-5.4 years). The median refractive error at the age 5 years visit of the treated eyes was -2.25 D (IQR -5.13, +0.88 D) and of the fellow eyes +1.50 D (IQR +0.88, +2.25). Median anisometropia was -3.50 D (IQR -8.25, -0.88 D); range -19.63 to +2.75 D. Patients with glaucoma in the treated eye (n = 9) had greater anisometropia (glaucoma, median -8.25 D; IQR -11.38, -5.25 D vs no glaucoma median -2.75; IQR -6.38, -0.75 D; P = .005).

CONCLUSIONS

The majority of pseudophakic eyes had significant anisometropia at age 5 years. Anisometropia was greater in patients that developed glaucoma. Variability in eye growth and myopic shift continue to make refractive outcomes challenging for IOL implantation during infancy.