Diagnosis and treatment of microspherophakia

The secondary childhood glaucomas

The secondary childhood glaucomas are a heterogenous group, often associated with other ocular or systemic abnormalities. These childhood glaucomas are distinct from primary childhood glaucomas, both in terms of their clinical features and their response to conventional treatment. Surgical management can be challenging in children with secondary glaucoma. On average, this group undergo more surgical procedures and revisions than those with primary congenital glaucoma. We provide a synopsis of secondary childhood glaucomas in terms of classification, clinical features, and management strategies, with emphasis on recent developments.

Genetic landscape and ocular biometric correlations in microspherophakia: insights from a comprehensive patient cohort

AIMS

The aim of this study is to elucidate the genetic landscape of microspherophakia (MSP) and describe the genotype-phenotype correlation of MSP. Additionally, the study seeks to enhance the understanding of the pathogenic mechanisms of MSP through the discovery of novel loci.

METHODS

Patients diagnosed with MSP at the Eye and ENT Hospital of Fudan University, Shanghai, were included in the study and all underwent panel-based next-generation sequencing and bioinformatics analysis. Comprehensive ophthalmologic evaluations were conducted for each participant.

RESULTS

Our analysis encompassed 118 eyes from 59 patients with MSP, revealing 13 gene variations linked to the condition. Notably, FBN1 mutations were identified in 31 patients (52.5%), highlighting its higher prevalence. Among the genetic variations discovered, 28 represented novel mutations. Statistical analysis unveiled significant associations between specific gene mutations and ocular biometric parameters: axial length (AL, p = 0.011), Z-score axial length (Z-AL, p < 0.001), white-to-white (WTW, p = 0.009), Z-score white-to-white (p = 0.012), mean keratometry (p < 0.001), astigmatism (AST, p = 0.021), anterior chamber depth (ACD, p = 0.003), lens thickness (LT, p = 0.012) and central endothelial cell count/mm2 (p = 0.005). Patients with FBN1 mutations had the longest AL, while those with CBS mutations showed significantly wilder WTW measurements. Patients with ADAMTS17 mutations presented with increased LT and decreased WTW, ADAMTSL4 mutations were linked to the greater Km and AST. Patients with LTBP mutations exhibited the largest WTW, and ASPH mutations was associated with the shortest AL but thick LT. Additionally, there was a relationship among gene mutations, diagnostic age and ocular biometric parameters.

CONCLUSION

The study demonstrates that MSP is associated with a diverse range of genetic mutations, with FBN1 being the most common. Novel mutations were identified, and significant correlations were found between specific genetic variations and ocular biometric parameters. These results provide new insights into the genetic underpinnings of MSP and its clinical characteristics, advancing our understanding of the condition's pathogenic mechanisms.

Microspherophakia associated with congenital miosis: Coincidence or causality?

Congenital miosis and microspherophakia are rare congenital disorders of the anterior chamber that are associated with multiple other ophthalmological and systemic pathologies or disorders. Nevertheless, the association of both entities have not been described yet. We present the case of a 2-years-old patient without other relevant medical history that presented with high myopia secondary to microspherophakia and associated with congenital miosis.

Clinical characteristics and diagnostic test for spherophakia: A retrospective analysis

Background

This study aimed to analyze ocular characteristics in patients diagnosed with spherophakia, establish effective diagnostic criteria, and aid clinicians in prompt identification and management.

Methods

A retrospective case series identified spherophakia cases through medical records and literature searches. The case group included spherophakia patients, and the control group comprised individuals with similar eye conditions. Intraocular lens calculations used the SRK-T formula, and statistical analyses were performed using SPSS. Diagnostic efficacy was assessed through receiver operating characteristic (ROC) curve analysis.

Results

The study included 12 cases (23 eyes) from medical records and 86 patients (142 eyes) from literature sources. Characteristics of spherophakia included bilateral involvement, younger age, shallow anterior chamber depth, lens dislocation, and secondary glaucoma. A diagnostic criterion based on lens power demonstrated high sensitivity (94.3 %) and specificity (91.9 %). ROC analysis yielded area under the ROC curve (AUROC) values of 0.974 for lens power, outperforming refractive error (0.119), corneal curvature (0.465) and axial length (0.496). The lens power cutoff for diagnosing spherophakia was 31.25D.

Conclusion

The study offers crucial insights into spherophakia's clinical characteristics and presents a practical diagnostic criterion using lens power, enhancing early detection and management. Further research is needed to validate and refine these findings, establishing standardized diagnostic criteria for spherophakia.

Pediatric Microspherophakia Treatment With Scleral Fixated IOL Using a Z-suture Technique

Microspherophakia constitutes a rare, mostly bilateral anomaly of the crystalline lens, which is characterized by the presence of an increased lens thickness and reduced equatorial diameter. It is frequently associated with lens subluxation, translating into a high degree of variable lenticular myopia and defective accommodation. The purpose of this report is to describe the treatment of a three-year-old female patient with microspherophakia, with the scleral fixation of an intraocular lens using the z-suture technique. A three-year-old female patient with Marfan Syndrome presented with high bilateral myopia and esotropia. Lens subluxation was perceived, and she was proposed for bilateral surgery. Scleral fixation of the intraocular lens was performed using the z-suture technique. During the five-year follow-up period, she maintained a best-corrected visual acuity of 20/20 in both eyes wearing bifocal glasses.  Microspherophakia is a rare but impactful condition, frequently related to severe and variable refractive error due to the lens shape and zonule instability. Intraocular lens implantation in the capsular bag is usually impossible, and scleral fixation is a valid alternative. The z-suture technique avoids suture knots and the need for intrascleral flaps, reducing the risk of suture-related complications.

Congenital anomalies of lens shape

The crystalline lens is an important structure in the eye that starts to develop as early as the 22nd day of gestation, with further differentiation that continues after the induction. Congenital anomalies of the lens may involve the size, shape, and position of the lens. They may sometimes be associated with anterior segment dysgenesis or persistence of the tunica vasculosa lentis and hyperplastic vitreous and hyaloid system. Manifestations of anomalies of the lens shape are usually seen in early or late childhood however may sometimes be delayed into adulthood based on the level of visual impairment or the presence or absence of any syndromic associations. While lens coloboma has more often been reported in isolation, the more commonly implicated genes include the PAX6 gene, lenticonus in particular anterior is often part of Alport syndrome with extra-ocular manifestations in the kidneys and hearing abnormalities due to mutations in the alpha 5 chain of the Type IV collagen gene. Recognition of these manifestations and obtaining a genetic diagnosis is an important step in the management. The level of visual impairment and amblyopia dictates the outcomes in patients managed either conservatively with optical correction as well as surgically where deemed necessary. This review discusses the various anomalies of the lens shape with its related genetics and the management involved in these conditions.

Characteristics and genotype-phenotype correlations in ADAMTS17 mutation-related Weill-Marchesani syndrome

Weill-Marchesani syndrome (WMS) manifests as ectopia lentis (EL), microspherophakia and short stature, which is caused by ADAMTS10, LTBP2, or ADAMTS17 gene defects. This study aims to investigate the characteristics and genotype-phenotype correlations of WMS with ADAMTS17 mutations. WMS patients with ADAMTS17 variants were identified by whole-exome sequencing from 185 patients with EL. All the included patients underwent comprehensive ocular and systemic examinations. ADAMTS17 variants were reviewed from included patients, published literature, and public databases. Bioinformatics analysis, co-segregation analysis, species sequence analysis, and protein silico modeling were used to verify the pathogenic mutations. A total of six novel ADAMTS17 mutations (c.1297C > T, c.2948C > T, c.1322+2T > C, c.1716C > G, c.1630G > A, and c.1669C > T) were identified in four WMS probands in our EL cohort (4/185, 2.16%). All probands and their biological parents presented with apparent short stature compared with the standard value. In particular, one child was detected with valvular heart disease, which has not previously been reported in patients with ADAMTS17 mutations. Conserved residues were greatly affected by the substitution of amino acids caused by these six mutations. Short stature could be considered a clue for EL patients with ADAMTS17 mutations, and much more attention needs to be paid to heart disorders among these patients. This study not only reported the characteristics of ADAMTS17 mutation-related WMS but also helped to recognize the genotype-phenotype correlations in these patients.

Microspherophakic Angle Closure Glaucoma in a Patient with Coffin-Siris Syndrome: Case Report

Background

Bilateral secondary angle closure glaucoma is a presenting symptom of microspherophakia and ectopia lentis. Characterizing the associated syndrome and confirmation by genetic testing can identify associated systemic abnormalities and provide appropriate genetic counseling.

Case Presentation

A 42-year-old woman with severe intellectual disability presented with light perception visual acuity and glaucoma, with intraocular pressure (IOP) in her right and left eyes of 69 and 70 mmHg, respectively. She underwent two sessions of 270-degree laser diode transscleral cytophotocoagulation treatment at a 6-month interval and was prescribed topical anti-glaucoma medication. Her family noticed a progressive decrease in her vision while on treatment for 2 years. She was diagnosed with apparent Weill-Marchesani syndrome, accompanied by angle closure glaucoma and microspherophakia. Cataract surgery and intraocular lens implantation were successful in both eyes and post-operative IOP was controlled with anti-glaucoma medication but her vision did not improve from severe glaucomatous optic neuropathy. Her underlying syndrome was investigated genetically by whole exome sequencing.

Results

Sequencing showed a pathogenic variant in ARID1B, c.3955dupC (p.Gln1319Profs*14), diagnostic of Coffin-Siris syndrome. This is the first report of Coffin-Siris syndrome associated with microspherophakia and angle closure glaucoma.

Conclusion

Bilateral angle closure glaucoma from ectopia lentis in patients with genetic syndromes could be an indicator of microspherophakia in adulthood. Ophthalmological surveillance is important in patients with Coffin-Siris syndrome.

Outcomes of lensectomy with glued intraocular lens and factors associated with failure in eyes with spherophakia and glaucoma

Purpose

To evaluate the outcomes of lensectomy with a glued intraocular lens (IOL) in spherophakic eyes with secondary glaucoma and assess factors associated with failure.

Methods

We prospectively evaluated outcomes of lensectomy with glued IOL in 19 eyes with spherophakia and secondary glaucoma (intraocular pressure (IOP) ≥22 mm Hg and/or glaucomatous optic disc damage) between 2016 and 2018. The vision, refractive error, IOP, antiglaucoma medications (AGMs), optic disc changes, need for glaucoma surgery, and complications were assessed. Success was defined as complete when IOP was ≥5 and ≤21 mmHg without AGMs; qualified success as similar IOP with up to 3 AGM; the need for >3AGM/additional surgery for IOP control was considered a failure.

Results

Preoperatively, the median (interquartile range: IQR) age was 18 (13.5-30) years. IOP was 16 (14-22.5) mmHg on a median of 3 (2,3) AGMs. Median postoperative follow up was 27.7 months (11.9, 39.7). Postsurgery, most patients achieved emmetropia, with significantly decreased refractive error from a median spherical equivalent of -12.5D to + 0.5D, P < 0.0002. The complete success probability was 47% (95% confidence intervals (CIs): 29-76%) at 3 months and was 21% (8 - 50%) at 1 year and 3 years. The qualified success probability was 93% (82-100%) at 1 year, which reduced to 79% (60-100%) in 3 years. None of the eyes had any retinal complications. The higher number of preoperative AGM was found to be a significant risk factor (p < 0.02) for the failure of complete success.

Conclusion

One-third of the eyes had IOP control without the need for AGM postlensectomy with glued IOL. Surgery resulted in significant improvement in visual acuity. The higher number of preoperative AGM was associated with poor glaucoma control after glued IOL surgery.

Bilateral Anteriorly Displaced Microspherophakia in a Female Child With Marfanoid Habitus

Microspherophakia is a rare congenital anomaly characterized by an abnormally small and spherical crystalline lens, which can be associated with several systemic syndromes. We present an extremely rare case of bilateral anteriorly displaced microspherophakia in a female child with Marfanoid habitus. The patient displayed phenotypic features resembling Marfan syndrome, including tall stature, muscle hypotonia, dolichostenomelia, and increased arm span than body length. However, unlike Marfan syndrome, Marfanoid habitus is not associated with mutations in the fibrillin-1 gene. The association between microspherophakia and Marfanoid habitus is a unique presentation that has not been reported in the literature. This case report aims to increase awareness of microspherophakia as a possible ocular association of Marfanoid habitus.

Visual outcomes and safety profile of intraocular lens implantation versus aphakia in children with microspherophakia with no subluxation

Objective

To study the visual, refractive and surgical outcomes of intraocular lens (IOL) implantation versus aphakia in children with microspherophakia.

Design

Retrospective, comparative, non-randomised interventional study.

Methods

All consecutive children with microspherophakia who satisfied the inclusion criteria were included. The eyes that underwent in-the-bag IOL implantation and those that were left aphakic were included in groups A and B, respectively. The postoperative visual outcomes, IOL stability and complications during the follow-up period were studied.

Results

22 eyes (13 patients, male 76%), of which 12 eyes were in group A and 10 eyes in group B. The mean±SE of age at surgery was 9.4±1.4 and 7.3±0.9 years in group A and group B, respectively (p value 0.18). The mean follow-up of group A was 0.9±0.4 years (median 0.5 years; Q1 0.04, Q3 2.16) and group B was 1.3±0.9 years (median 0.147 years; Q1 0.08, Q3 0.39) (p value 0.76). All the baseline biometric variables including best-corrected visual acuity (BCVA) were comparable in each group. The final BCVA in logMAR adjusted for follow-up was comparable in both group A (0.29±0.06) and group B (0.52±0.09) (p value 0.06). Mean predictive error of IOL power in microspherophakia was 0.17±0.43.

The most common complication in group A was visual axis opacification of two eyes (16.7%, 95% CI 2.9% to 49.1%), of which one eye (8.3%, 95% CI 0.4% to 40.2%) needed membranectomy. Vitreous in anterior chamber was the most common complication in group B, seen in two eyes (20%, 95% CI 3.5% to 55.8%), of which one eye (10%, 95% CI 0.5% to 45.9%) underwent YAG laser vitreolysis. The survival analysis (p value 0.18) was comparable in each group.

Conclusion

In-the-bag IOL is an option, which can be considered in selected cases of microspherophakia in developing nations where regular follow-up and economic constraints are a major concern.

Scleral rupture during retinal detachment repair with primary scleral buckle and cryoretinopexy in a patient with microspherophakia

Purpose

The purpose of this report is to describe a case of a patient with microspherophakia (MSP) who had a scleral rupture during a retinal detachment (RD) repair with primary scleral buckle and cryoretinopexy.

Observations

A 48-year-old woman with MSP presented with six days of expanding loss of vision and photopsias. Examination revealed a superior retinal detachment involving the macula associated with two superior retinal tears. The patient underwent successful placement of a segmental buckle. During cryoretinopexy treatment of the tears, a 4 mm full-thickness scleral rupture occurred. The sclera was immediately closed with interrupted 8-0 nylon sutures and reinforced with a processed pericardium allograft. Subsequent combined phacoemulsification with capsulectomy, zonulectomy, and pars plana vitrectomy with retinal reattachment was performed nine days post buckle placement.

Conclusions and importance

This case illustrates that a patient with MSP, even observed in the absence of a genetic syndrome or familial condition, may be at increased risk of scleral rupture during RD repair. Though future investigations are necessary to confirm this association, surgeons should take a conservative approach by having a high clinical suspicion for compromised scleral integrity in patients with MSP and proceeding with caution in procedures that may pose a risk of scleral rupture. A pericardium allograft can be an effective adjunct for scleral rupture repair.

Factors Related to Visual Outcomes after Lens Surgery in Isolated Microspherophakia

Purpose. To evaluate the main factors influencing visual performance after lens subluxation surgery in subjects with isolated MSP. Design. Retrospective study. Methods. In this study, 38 eyes of subjects with isolated MSP (microspherophakia) were included and divided into two groups based on preoperative IOP (intraocular pressure), IOP <21 mmHg, or IOP ≧21 mmHg. Phacoemulsification and scleral-fixated modified capsular tension ring implantation were performed with or without goniosynechialysis according to the IOP. Some ocular biometric parameters, such as corneal curvature, corneal pachymetry, endothelial cell count (ECC), anterior chamber depth (ACD), and axial length, were evaluated. The best-corrected visual acuity (BCVA) and IOP of these subjects were measured before the surgery and during <1 month and 3- to 6-month postoperative follow-ups. Results. Compared with the high IOP group, the normal IOP group was significantly younger and had better preoperative BCVA, a higher ECC, deeper ACD, a lower postoperative IOP, and flatter total corneal refractive power K1. The multivariable analysis revealed that preoperative ACD (b = −0.113, t = −2.070, $P=0.047$ ) and preoperative BCVA (b = 0.153, t = 2.562, $P=0.015$ ) were significantly associated with postoperative BCVA at 3–6 months. A preoperative ACD of 1.86 mm was found to be the optimal cut-off point for 3- to 6-month postoperative BCVA of ≧20/63 (≤0.52 logMAR). Conclusions. In addition to the effect of normal IOP, better preoperative BCVA and deeper ACD also correlated with better visual outcomes after lens surgery. Preoperative ACD served as a warning for isolated MSP subjects, especially for the risk of irreversible loss of postoperative vision. This trial is registered with “ChiCTR2000039132.”

Phacoemulsification Combined With Supra-Capsular and Scleral-Fixated Intraocular Lens Implantation in Microspherophakia: A Retrospective Comparative Study

Background

Microspherophakia (MSP) is a rare ocular condition, the lens surgery of which is complicated by both insufficient zonules and undersized capsule.

Methods

This study included MSP eyes managed with phacoemulsification combined with supra-capsular and scleral-fixated intraocular lens implantation (SCSF-IOL) and made the comparison with those treated by transscleral-fixated modified capsular tension ring and in-the-bag intraocular lens implantation (MCTR-IOL).

Results

A total of 20 MSP patients underwent SCSF-IOL, and 17 patients received MCTR-IOL. The postoperative best corrected visual acuity was significantly improved in both groups (P &lt; 0.001), but no difference was found between the groups (P = 0.326). The IOL tilt was also comparable (P = 0.216). Prophylactic Nd:YAG laser posterior capsulotomy was performed 1 week to 1 month after the SCSF-IOL procedure. In the SCSF-IOL group, two eyes (10.00%) needed repeated laser treatment and one eye (5.00%) had a decentered capsule opening. Posterior capsule opacification was the most common complication (6, 35.29%) in the MCTR group. No IOL dislocation, secondary glaucoma, or retinal detachment was observed during follow-up.

Conclusions

SCSF-IOL is a viable option for managing MSP and is comparable with the MCTR-IOL. Nd:YAG laser posterior capsulotomy was necessary to prevent residual capsule complications after the SCSF-IOL procedure.

Cysteine Substitution and Calcium-Binding Mutations in FBN1 cbEGF-Like Domains Are Associated With Severe Ocular Involvement in Patients With Congenital Ectopia Lentis

Purpose: To investigate the clinical manifestations of congenital ectopia lentis (CEL) in patients with fibrillin (FBN1) calcium-binding epidermal growth factor (cbEGF)-like mutations.

Design: Retrospective cohort study.

Methods: Consecutive 68 CEL probands with FBN1 cbEGF-like mutations were recruited, mostly comprising Marfan syndrome (MFS) patients. Patients were classified into the cysteine group (n = 43), calcium (Ca²⁺)-binding group (n = 13) or the others (n = 12) according to their genotypes. Ocular biometrics, morbidities and visual performance were compared among different mutation groups. Linear regression was used to evaluate the risk factors for axial length (AL) elongation.

Results: With age-adjustment, cysteine substitution and Ca²⁺-binding mutations positively contributed to AL elongation (standardized coefficient: 0.410 and 0.367, p = 0.008 and 0.017, respectively). In addition, cataract formation was more frequently detected in patients with Ca²⁺-binding mutations (observed n = 3, expected n = 1.0; p = 0.036). Patients with cysteine substitutions had the poorest preoperative visual acuity among the three groups (p = 0.012) and did not recover as well as other patients. More MFS diagnoses were made in patients with cysteine substitutions (observed n = 16, expected n = 12.6), while ectopia lentis syndrome was detected more often in patients with cbEGF-like mutations out of the functional regions (observed n = 6, expected n = 2.5; p = 0.023).

Conclusion: Compared with patients with cbEGF-like mutations out of functional regions, patients with cysteine substitutions or Ca²⁺-binding mutations had longer ALs with age adjustment, poorer ocular involvement, visual performance, and systematic manifestations.

Lens Biometry in Congenital Lens Deformities: A Swept-Source Anterior Segment OCT Analysis

Aims: To investigate the lens biometric parameters in congenital lens deformities, using a novel technique of swept-source anterior segment optical coherence tomography (SS-ASOCT).

Methods: This prospective study included patients with microspherophakia (MSP), coloboma lentis (CL), and posterior lenticonus (PL). For this cohort, 360-degree high-resolution lens images were obtained using the latest SS-ASOCT (CASIA2, Tomey Corp, Nagoya, Japan). The lens biometric parameters were calculated by the CASIA2 built-in software for anterior lens radius (ALR), posterior lens radius (PLR), anteroposterior distance (APD), anterior chamber depth (ACD), equatorial diameter (Eq Dia), rear projection length (RPL), and maximum diameter of the lesion (MDL).

Results: This study included two eyes each with MSP and CL and one eye with PL. The lens of MSP was spherical and posteriorly dislocated, with decreased ALR and PLR, Eq Dia, but increased APD. In patients with CL, the coloboma was isolated, bilateral, inferior, and located toward the maldeveloped ciliary body. High astigmatism was mainly lenticular, and this was calculated by the ALR and PLR. Regarding the site of coloboma, a significant decrease in ALR was observed, while the PLR and APD were not affected. The PL eyes had a cone-shaped protrusion of the posterior lens surface with a subtle cataractous region around the apex. An extremely high posterior surface curvature was observed with a mean PLR of 1.67 mm. The RPL and MDL were about 1.80 and 0.4 mm, respectively, which were homogenous at different sections.

Conclusions: The CASIA2 is a valuable option for in vivo crystalline lens measurement for congenital lens deformities, enabling the accurate diagnosis and providing illuminating insights into the pathogenesis of MSP, CL, and PL

Correlation between FBN1 mutations and ocular features with ectopia lentis in the setting of Marfan syndrome and related fibrillinopathies

Mutations of fibrillin-1 (FBN1) have been associated with Marfan syndrome and pleiotropic connective tissue disorders, collectively termed as "type I fibrillinopathy". However, few genotype-phenotype correlations are known in the ocular system. Patients with congenital ectopia lentis (EL) received panel-based next-generation sequencing, complemented with multiplex ligation-dependent probe amplification. In a total of 125 probands, the ocular phenotypes were compared for different types of FBN1 mutations. Premature termination codons were associated with less severe EL and a thinner central corneal thickness (CCT) than the inframe mutations. The eyes of patients with mutations in the C-terminal region had a higher incidence of posterior staphyloma than those in the middle and N-terminal regions. Mutations in the TGF-β-regulating sequence had larger horizontal corneal diameters (white-to-white [WTW]), higher incidence of posterior staphyloma, but less severe EL than those with mutations in other regions. Mutations in the neonatal region were associated with thinner CCT. Longer axial length (AL) was associated with mutations in the C-terminal region or TGF-β regulating sequence after adjusting for age, EL severity, and corneal curvature radius. FBN1 genotype-phenotype correlations were established for some ocular features, including EL severity, AL, WTW, CCT, and so forth, providing novel perspectives and directions for further mechanistic studies.

Compound heterozygous mutations in the LTBP2 gene associated with microspherophakia in a Chinese patient: a case report and literature review

BACKGROUND

Microspherophakia (MSP, OMIM 251,750) is a rare inherited autosomal recessive eye disorder characterized by small spherically shaped lens. Several studies have indicated that the transforming growth factor-beta (TGF-beta) binding proteins(LTBP2) gene mutation is the predominant cause of MSP. In our study, novel compound heterozygous mutations in the LTBP2 gene associated with MSP were reported, which was different from previous reported homozygous mutations.

CASE PRESENTATION

The proband was an 18-year-old male in Western China with bilateral MSP, accompanied by ectopia lentis, secondary glaucoma and blindness in both eyes. In our hospital, he received bilateral lens resection and trabeculectomy combined with peripheral iridotomy. Using next-generation sequencing (NGS)-based gene panel tests, we identified pathogenic mutations in the peripheral blood DNA sample from the proband: c.3614_3618dupCTGGC (exon24, NM_000428) and c.2819G > A (exon18, NM_000428). The presence of the novel compound heterozygous mutations in the LTBP2 gene was linked with the development of MSP. Sanger sequencing confirmed the existence of one of the two variants in each parent respectively.

CONCLUSION

Our results demonstrated a rare case of MSP phenotype associated with novel compound heterozygous mutations in the LTBP2 gene using NGS technology.