Congenital cataract is the most common cause of treatable blindness in children. With the continuous improvement of surgical techniques, clinical success rates have been greatly improved. However, successful surgery is just the first step in visual functional recovery. The establishment of a specialized pediatric ophthalmic treatment system that selects the appropriate indications and timing of surgery is of great importance. The system could help surgeons master congenital cataract-specific surgical skills and improve standard refractive correction, amblyopia treatment, and binocular vision training.
Persistent fetal vasculature (PFV) is a group of abnormal clinical manifestations associated with the failure of the regression of fetal vasculature. Clinical manifestations can include such conditions as persistent pupillary membranes, persistent posterior fetal fibrovascular sheath of the lens, Mittendorf dot, Bergmeister papilla, macular abnormalities, optic nerve abnormalities, retinal folds and so on, most of which are accompanied by lens opacity. PFV can present in three forms: purely anterior, purely posterior or a combination of both. Due to the scarcity of clinical cases and the heterogeneity of clinical manifestations, an accurate diagnosis and appropriate treatment have a marked effect on a patient's prognosis. With the fertility boom after the second child policy, there may be an increase in the number of children with PFV. The purpose of this review is to discuss the clinical manifestations, diagnosis, types and treatment, to standardize the diagnosis and treatment, and to improve the curative prognosis of PFV.
Objective: We investigated the relationship between msh homeobox 2 (Msx2) conditional deletion and congenital cataract formation. Methods: In this experimental study, development of the ocular lens in Msx2CKO (Msx2fl/fl/Le-Cre+) and control Msx2WT (Msx2fl/fl) embryos and postnatal mice were documented. Embryo heads at E17.5 (late embryo stage) were fixed, and frozen sections were processed for RNA in situ hybridization for detecting normal Msx2 expression. Morphological and histological differences were detected by hematoxylin and eosin staining of lenses from Msx2CKO and Msx2WT at E17.5 and P8 (8 days parturition). Lens axis diameter and weight were examined between Msx2CKO and Msx2WT mice at 2 months old. Statistical analyses were performed by independent t-tests. Results: More than 50% of the Msx2CKO mice exhibited minor corneal opacity, small lens formation (weight and axial diameter), nuclear sclerotic cataract, and microphthalmia compared with the wild-type littermates at two months. Msx2CKO embryos and postnatal specimens had differentiated lens fibers that were disorganized, and equatorial lens epithelial cells and lens fibers were vacuolated. Lens axis diameter in Msx2CKO micewas smaller than in Msx2WT mice, and weight was lighter in Msx2CKO mice than in Msx2WT mice.Conclusions: The Msx2 gene plays an important regulatory role during mouse lens development, and conditional deletion of Msx2 may cause congenital cataract formation.
Objective: To optimize the spherical aberrations of toric intraocular lens (IOL): to design toric IOLs with different spherical aberrations, and to study the rotation, the tolerance to decentration, and imaging rules. Methods: In this experimental study, the spherical aberrations of toric IOLs were optimized in the Hwey-Lan Liou model eye. The spherical structure, the curvature radius, and the thickness of the anterior and posterior surfaces of the toric IOLs, and the aspheric coefficients of the anterior surface of toric IOLs were optimized respectively. The targets was optimized to produce IOLs with -0.26 μm, -0.1 μm and 0 μm spherical aberrations. In the computer optical simulation system, the effect on the modulation transfer function (MTF) was evaluated when spherical and aspherical IOLs were decentrated in the horizontaldirection with 0.25 mm, 0.50 mm and 0.75 mm at 3- and 5-mm pupil diameters. The effect on MTF was also evaluated when the two types of IOLs were rotated by 3°, 5° and 10° at 4-mm pupil diameter. Results:At the center, the aspherical toric IOL displayed a better image performance with the increased pupil diameter. When the decentration was 0.5 mm at 3-mm pupil diameters, the imaging quality of the -0.26 μm toric IOL decreased and was worse than that of 0 or -0.1 μm IOL. At 5-mm pupil diameter, when the decentration was 0.75 mm, the MTF of -0.26 μm toric IOL was close to that of the spherical toric IOL, while the MTF of toric IOL with 0 μm and -0.1 μm spherical aberration was slightly better than that of the spherical toric IOL. The MTF of aspherical toric IOLs was better than that of the spherical toric IOL with 3° to 5° rotation, but the curve was equal or even worse than that of the spherical toric IOL with 10° rotation in high spatial frequency. Conclusions: Toric IOLs with a spherical aberration of -0.26 μm have good imaging quality at the center but lower tolerance to decentration. The proper optimization of the spherical aberration of toric IOLs can improve the imaging quality of the model eye, while maintaining the tolerance for decentration and rotation errors. Optimized toric IOLs can attain better optical quality under comprehensive conditions.
Objective: To evaluate and compare long-term visual outcome and complications between premature and mature infants after bilateral cataract surgery during infancy. Methods: This prospective cohert study included children with bilateral congenital cataracts who were recruited between January 2002 and July 2012 at Peking University People's Hospital. All patients received simultaneous bilateral cataract extraction combined with primary capsulotomy and anterior vitrectomy. After the operation, all patientswore aphakic glasses during the follow-up periods. The children were divided into premature (gestational age equal or less than 36 weeks) and mature (more than 36 weeks) groups based on their gestational age. The unilateral and bilateral best corrected visual acuity (BCVA), unilateral and bilateral BCVA distribution, and postoperative complications at the last visit were evaluated and compared. The data were analyzed with student's t test and chi-square test. Results: Thirty-six premature and 15 mature infants with bilateral congenital cataracts were recruited. The age at surgery, gender composition, longest follow-up period, and the rate of secondary intraocular lens implantation at the last visit were similar between the mature and premature groups. At last visit, the unilateral BCVA (LogMAR) of mature and premature groups was 0.66±0.28 and 0.52±0.27 respectively (t=-2.316, P=0.023), while the bilateral BCVA was 0.54±0.25 and 0.42±0.24 (P>0.05), respectively. The unilateral BCVA (Snellen) was ≥30/50 in 14 eyes (14/72) of the premature group, while the BCVAs of all children in the mature group were <30/50. The distribution of unilateral BCVA was significantly different between the two groups (χ2=11.229, P=0.022).However, the bilateral BCVA distribution was similar for the two groups (χ2=7.174, P=0.140). The long-term postoperative complications of the mature and premature children included strabismus (3/15 vs. 8/36),nystagmus (4/15 vs. 14/36), optical opacity (3/15 vs. 3/36), and ocular hypertension (1/15 vs. 1/36). The incidence of each condition was similar between the groups. Conclusions: For most children with bilateral congenital cataracts, intervention and treatment in the earlier stages of life can still influence long-term visual outcomes. If the condition permits, surgery should be performed as early as possible.
Objective: To observe the clinical characteristics and prognosis of surgical intervention in congenital cataract associated with persistent fetal vasculature (PFV). Methods: In this retrospective case series study, 28 eyes of 24 congenital cataract children with PFV were enrolled from May 2011 to June 2017 at Eye Hospital, Wenzhou Medical University (Hangzhou). Age at surgery, surgical approaches, clinical signs, and visual acuity (VA) were collected both before and after surgery. Results: We found congenital pupil anomalies in 14 eyes, umbilication of lens or zonular anomalies in 6 eyes, posterior capsule defect in 9 eyes, congenital microcornea or corneal limbal stem cell anomalies in 2 eyes, fundus lesion in 2 eyes, nystagmus in 5 eyes, strabismus in 7 eyes, and cleft palate in 1 children. Seven children over 3-years old (10 eyes)underwent lensectomy combined with anterior vitrectomy and intraocular lens (IOL) implantation. The median follow-up duration was 8 months (quartile range, 2.5-41.0 months), and all patients had achieved VAs over 0.1 at the last follow up, and 2 patients had VAs over 0.3. Seventeen children (18 eyes) under 1 year of age underwent lensectomy combined with anterior vitrectomy. The Snellen VA measured by preferential looking cards was over 0.1 in all patients, with significant improvement of pursuit and nystagmus. Six children (6 eyes) underwent both primary lensectomy combined with anterior vitrectomy (mean ± standard deviation 5.5 ± 2.6 months) and secondary IOL implantation (mean age 23.5 ± 8.1 months). One eye achieved a VA of 0.6, close to normal for children of the same age, and 5 eyes reached the standard logarithmic chart VA of more than 0.1. The follow-up duration ranged from 4 months to 6 years, and the median follow-up time was 12 months. No serious postoperative complications occurred.Conclusions: Most congenital cataracts with PFV are unilateral. The incidence of complications after microincision lensectomy combined with anterior vitrectomy is low, with significantly improved visual outcomes. Normal visual acuity can be expected in a few cases.
Objective: To assess the long-term outcome and complications profile of primary scleral-fixated posterior chamber intraocular lenses in patients with congenital lens subluxation. Methods: In this retrospective case series study, all patients who had undergone lens surgery between January 2005 and June 2014 were reviewed for visual outcomes and complications. Demographic data and information on baseline preoperative best corrected visual acuity (BCVA), intraocular pressure (IOP) before surgery, indication for surgery, intraoperative complications, postoperative complications, last postoperative visual acuity, intraocular lens position, and indication for any subsequent surgical procedures were collected and analyzed using paired t-tests and independent t-tests. Results: Patients mean age at surgery was 23±20 years (5 to 67 years), with a mean follow-up of 38±26 months (12 to 130 months). For the 77 eyes included, the mean preoperative BCVA (LogMAR) was 0.84±0.55, which improved significantly to 0.26±0.43 postoperatively (t=8.55,P<0.001). IOP decreased only in patients with spherophakia. Complications included transient intraocular hemorrhage (2 eyes, 2.6%), early vitreous incarceration (2 eyes, 2.6%), retinal detachment (6 eyes, 7.8%),and intraocular lens dislocation (1 eye, 1.3%). Conclusions: Based on long-term follow-up data, primary scleral-fixated posterior chamber intraocular lenses can significantly improve visual acuity in patients with congenital lens subluxation. However, ophthalmologists should be alert for potential long-term postoperative complications.
Objective: To evaluate the postoperative complications and additional surgeries of limbal and pars plana approaches using microincision vitrectomy (25G/23G) for removal of congenital cataracts. Methods: In this retrospective cohort study, patients with a congenital cataract were referred to the Eye & ENT Hospital of Fudan University from March 2009 to December 2013. There, they underwent cataract surgeries through either the limbal approach or the pars plana approach. All of the surgeries were performed by one surgeon. For patients older than 1 year, primary intraocular lens implantation was performed. For patients younger than 1 year, secondary intraocular lens implantation was performed during follow-up after theinitial cataract surgery. Complications and additional surgeries were recorded. Logistic regression was used to test the influence of potential risk factors on the incidence of postoperative complications. Fisher exact test was used to compare the incidence of postoperative complication between the different surgical approaches. Results: Of the 67 patients, 99 eyes with congenital cataract were included. The mean follow-up time was 4.4 years (range 0.9-8.3 years). Postoperative complications that required additional surgeries occurred 15 times in 11 eyes. These included 5 times of visual axis opacification in 5 eyes, 4 times of intraocular lens (IOL) pupillary capture in 3 eyes, 1 time of dislocation of IOL in vitreous in 1 eye, 2 times of retained cortex in 2 eyes, 2 times of pupillary membrane in 2 eyes, and 1 time of retinal detachment in 1 eye. Surgery at less than 1 year of age and surgery through the limbal approach were risk factors of complication requiring additional surgery (OR=17.9, P=0.009; OR=7.9, P=0.041; respectively). There was no statistical significance in the type of postoperative complications between the limbal approach and the pars plana approach (P>0.05). Conclusions: Age at surgery of less than 1 year and surgery through the limbal approach are the risk factors for postoperative complications requiring additional surgeries in patients with congenital cataract. The distribution of postoperative complications is not correlated with either of the two surgical approaches.
Objective: To conduct research on Alzheimer's disease (AD) that is specifically focused on retinal functional and structural changes in TgAPPswePS1 transgenic mice; to demonstrate the role amyloid beta(Aβ) plays in retinal dysfunction; to provide new in sight into retinal AD pathology. Methods: APPswe/PS1 bigenic mice about 24 months of age (experimental group) and non-transgenic littermates about 24 months of age (control group) were grouped for experiments. The eyes of the TgAPPswePS1 mice were examined with electroretinography (ERG). The change in retinal morphology was investigated, while the expressions of the amyloid precursor protein (APP) and Aβ were examined with immunohistochemistry using retinal sections. All of the results were quantified and statistically analyzed by a student's t test. Results: In the experimental group, the rod response, which showed a reduction of the amplitudes of both a and b waves, was compared to the control group. The difference in the b wave amplitude was statistically significant (t=5.23, P=0.002). For maximum response amplitudes, both flash-triggered a waves and b waves showed a striking decrease compared to the control group. The difference in the a and b waves was statistically significant (t=15.69, 15.76, P<0.001). There were no significant structural abnormalities in the retinal sections in either the experimental or control groups. We found a decrease in the thickness of the retina in the experimental group compared to the controls, but the the difference was not statistically significant(t=1.85, P=0.087). In the experimental group, APP immunoreactivity was predominantly detected in the cytoplasm of cells in the ganglion cell layer as well as the inner nuclear layer. By comparison, a much lower staining intensity was observed in the control group in the corresponding regions of the retina. The Aβ accumulation in the retina could be detected by a diffuse pattern and plaque deposits. A majority of the Aβ-immunoreactive plaques were detected from the ganglion cell layer to the inner plexiform layer, the outer nuclear layer, and even in the photoreceptor outer segment layer. However, no Aβ positive immunoreactivity was detected in the retinas of mice in the control group. Conclusions: Aβ deposits accumulate in the retina of aged TgAPPswePS1 mice, which is associated with retinal degenerative changes in both function and structure. This suggests that AD-related pathology changes in the retina may contribute to the visual deficits seen in AD.
Objective: To evaluate the change in intraocular pressure (IOP) measured by non-contact tonometer after small incision lenticule extraction (SMILE), and to calculate a regression equation for estimating IOP. Methods: In this prospective case-series study, 87 patients (171 eyes) who underwent SMILE from April to December 2016 were enrolled. IOP, refractive error, central corneal thickness (CCT) and corneal curvature were measured preoperatively and postoperatively. We analyzed the relationship to different variables and calculated a correction formula for IOP after SMILE. Results: The mean IOP values were 13.6±3.1 mmHg and 8.7±2.1 mmHg before and after SMILE 6 months. Postoperative IOP decreased by 4.9±2.5 mmHg, and a t test showed that the difference was significant (t =25.93, P<0.001). Postoperative IOP was positively correlated with preoperative IOP and postoperative CCT (r =0.608, 0.237, P<0.01). Postoperative IOP was negatively correlated with preoperative spherical equivalent(SE), maximum lenticule thickness, and the rate of change rate of CCT and corneal curvature, △Km and △CCT (r =-0.190, -0.170, -0.200, -0.240, -0.250,-0.201, P<0.05). The multiple linear regression equation is IOPpos=5.021+0.414×IOPpre-0.018×maximumlenticule thickness (F=57.78, P<0.05, R2=0.400). Conclusions: Postoperative IOP is underestimated after SMILE. The proposed correction formula may be used to predict postoperative IOP measurement.
The incidence of myopia has increased in recent years. Studies of myopic animal models and clinical trials have demonstrated that matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) play important roles in the development of myopia. We summarizes the association between MMPs/TIMPs and myopia development. It also clarifies the effect of MMPs/TIMPs on scleral and other ocular tissues from the perspective of gene expression, mRNA levels, and protein concentrations.
