ANATOMIC OUTCOMES OF LENS-SPARING VITRECTOMY FOR STAGE 3 OR 4 FAMILIAL EXUDATIVE VITREORETINOPATHY.

PURPOSE: To report the anatomic outcomes and retinal structure changes from lens-sparing vitrectomy (LSV) for eyes with Stage 3 or 4 familial exudative vitreoretinopathy (FEVR). METHODS: Overall, 133 consecutive eyes of 119 patients with Stage 3 (51 eyes) or 4 (82 eyes) FEVR who underwent LSV between January 2012 and May 2023 were retrospectively reviewed. RESULTS: One hundred twenty-nine eyes (97.0%) achieved traction relief through one LSV operation. The extent of retinal detachment improved in 98 eyes (73.7%), remained stable in 32 eyes (24.1%), and progressed in three eyes (2.3%). At long-term follow-up, 39 (29.3%) and 60 (45.1%) eyes had completely or partially reattached retina, respectively. The median change of venular angle was 3.6° (95% CI, 3.5-10.5; P < 0.001) and -9.9° (95% CI, -15.8 to -4.6; P < 0.001) for temporal and nasal vessels, respectively. The mean disk-fovea distance was 0.3 papillary diameter shorter (95% CI, -0.4 to -0.2; P < 0.001), and the mean temporal venular arcade distance was 0.02 papillary diameter larger (95% CI, -0.16 to 0.21; P = 0.361). CONCLUSION: These results suggest that LSV can relieve vitreoretinal traction and reattach the retina in late-stage FEVR eyes. Improvements in temporal and nasal venular angle and disk-fovea distance reflect positive retinal structure changes for patients.

Vitreoretinopathy in Asymptomatic Children With CTNNB1 Syndrome.

Importance: Previous studies have identified familial exudative vitreoretinonpathy (FEVR) in patients with CTNNB1 syndrome based on severe congenital ocular phenotypes. However, ophthalmoscopy may not be sufficient to detect vision-threatening vitreoretinopathy in all patients. Objective: To report a consecutive retrospective case series of 11 patients with CTNNB1 variants who had previously unremarkable ophthalmoscopic examination results and to describe their detailed ophthalmic phenotypes. Design, Setting, and Participants: This retrospective case series was conducted at the Children's Hospital of Philadelphia from October 2022 to November 2023 among patients with identified variants in CTNNB1 and previously documented normal results in office retinal examinations. These consecutive patients subsequently underwent an examination under anesthesia with fluorescein angiography. Detailed genotype information was analyzed for all patients, and each variant was mapped on the CTNNB1 gene to observe any associations with severity of vitreoretinopathy. Main Outcomes and Measures: Number of patients with vitreoretinopathy and number requiring treatment for vitreoretinopathy. Results: The mean (SD) age at the time of CTNNB1 syndrome diagnosis was 2 (1) years, and the mean (SD) age at examination was 6 (3) years for the 11 total patients. A total of 9 patients had a diagnosis of strabismus, and 5 patients had undergone strabismus surgery. FEVR was present in 5 of 11 patients and in 9 eyes. The presence of disease requiring treatment was identified in 6 eyes, including 1 retinal detachment. Detailed genotype analysis of the patients found no clearly delineated high-risk loci in CTNNB1 in association with high severity of FEVR. Conclusions and Relevance: In this case series study, nearly all patients with CTNNB1 syndrome required ophthalmic care for refractive error and strabismus, and a subset also required treatment for FEVR. These findings support consideration of ultra-widefield fluorescein angiography among individuals with CTNNB1 syndrome when feasible, including the use of sedation if such an assessment is not possible in the office setting.

Familial exudative vitreoretinopathy (FEVR) in a child with a Jagged 1 variant identified on genetic testing.

INTRODUCTION: Familial Exudative Vitreoretinopathy (FEVR) is a heritable retinal vascular disease characterized by incomplete vascularization of the peripheral retina resulting in ischemia. Fifty percent of FEVR cases 10 are due to known pathogenic genetic variants, and disease phenotype can vary greatly. FEVR is a clinical diagnosis, however, genetic testing can play a key role in screening for FEVR in genetically susceptible populations, thus leading to early treatment and improved patient outcomes. CASE: A 2-year-old male with no known past ocular or medical history was diagnosed with FEVR upon examination under anesthesia and multimodal retinal imaging. Genetic testing identified a Jagged 1 (JAG1) variant of uncertain significance, 15 which has been linked to FEVR in recent studies. Despite close follow-up and treatment, the patient experienced a funnel retinal detachment in the right eye approximately one year after diagnosis. DISCUSSION: This case in conjunction with recent literature suggests that JAG1 variants are likely associated with FEVR. Further investigations are necessary to identify the frequency of JAG1 variants among patients with FEVR. Robust understanding of FEVR's heterogenous genetic profile will lead to improved treatment modalities 20 and patient outcomes.

Unveiling novel LRP5 pathogenic variant in familial exudative vitreoretinopathy: Diverse phenotypic expressions in a mother-daughter duo.

PURPOSE: This report aims to delineate distinct phenotypes of Familial Exudative Vitreoretinopathy (FEVR) observed in a mother and her daughter, both harboring a novel LRP5 pathogenic variation. METHODS: The investigation involves a retrospective review of medical records accompanied by multimodal imaging. Molecular characterization was performed using whole exon sequencing, and the pathogenic variant was subsequently confirmed through Sanger sequencing. RESULT: A 6-year-old girl diagnosed with anisometropic amblyopia exhibited macular dragging and peripheral avascular retina in her right eye. Whole exon sequencing identified a previously unreported heterozygous missense LRP5 pathogenic variation, Glu528Lys. Simultaneously, her 43-year-old mother also carried the same mutation, manifesting peripheral exudations, avascular areas, and multiple microaneurysms. Notably, both cases presented distinctive phenotypes of FEVR. CONCLUSION: Our findings underscore the diversity in clinical presentations associated with FEVR, emphasizing the pivotal role of genetic evaluation. Despite variations in severity between the eyes of the same patient, it is crucial to remain vigilant for potential progression to a pathological status in the seemingly normal eye. Additionally, this study contributes to expanding the genetic spectrum of FEVR.

Coats-Like Presentation of Familial Exudative Vitreoretinopathy Associated With a Novel LRP5 Variant.

This report describes a unique case of a Coats-like presentation of familial exudative vitreoretinopathy in an 11-year-old girl. The patient was originally referred for evaluation of presumed Coats disease and presented with telangiectatic vessels, perivascular exudates, diffuse peripheral exudation, and intraretinal hemorrhages. Clinical and angiographical findings were consistent with familial exudative vitreoretinopathy, while genetic testing identified variants of uncertain significance in two associated genes, LRP5 and ZNF408. In silico analysis predicts the LRP5 variant to be pathogenic. Retinal vasculopathies often have phenotypic overlap, warranting angiographic examination of both eyes and genetic testing to uncover the correct diagnosis and guide proper treatment. [Ophthalmic Surg Lasers Imaging Retina 2024;55:462-466.].

Retinopathy With Variant of Unknown Significance and Atypical Chorioretinal Coloboma in the Setting of Prematurity.

A 37-week-old girl underwent ophthalmic examination. Born at 32 weeks, the infant weighed 680 grams and received high-flow nasal cannula for respiratory distress of the newborn. Dilated fundus examination of the right eye revealed an atypical chorioretinal coloboma; the left eye revealed hyperpigmentary changes in the macula. Fluorescein angiography of both eyes showed retinal vascularization to zone II. Genetic testing revealed a heterozygous variant of uncertain significance in the catenin Alpha 1 (CTNNA1) gene. CTNNA1 gene abnormalities have been implicated as causes of familial exudative vitreoretinopathy (FEVR). It is important to recognize possible simultaneous retinopathy of prematurity and FEVR. [Ophthalmic Surg Lasers Imaging Retina 2024;55:285-288.].

Mutations in TSPAN12 gene causing familial exudative vitreoretinopathy.

BACKGROUND: To report newly found TSPAN12 mutations with a unique form of familial exudative vitreoretinopathy (FEVR) and find out the possible mechanism of a repeated novel intronic variant in TSPAN12 led to FEVR. RESULTS: Nine TSPAN12 mutations with a unique form of FEVR were detected by panel-based NGS. MINI-Gene assay showed two splicing modes of mRNA that process two different bands A and B, and mutant-type shows replacement with the splicing mode of Exon11 hopping. Construction of wild-type and mutant TSPAN12 vector showed the appearance of premature termination codons (PTC). In vitro expression detection showed significant down-regulated expression level of TSPAN12 mRNAs and proteins in cells transfected with mutant vectors compared with in wild-type group. On the contrary, translation inhibitor CHX and small interfering RNA of UPF1 (si-UPF1) significantly increased mRNA or protein expression of TSPAN12 in cells transfected with the mutant vectors. CONCLUSIONS: Nine mutations in TSPAN12 gene are reported in 9 FEVR patients with a unique series of ocular abnormalities. The three novel TSPAN12 mutations trigger NMD would cause the decrease of TSPAN12 proteins that participate in biosynthesis and assembly of microfibers, which might lead to FEVR, and suggest that intronic sequence analysis might be a vital tool for genetic counseling and prenatal diagnoses.

Genetic Characteristics and Clinical Manifestations of Foveal Hypoplasia in Familial Exudative Vitreoretinopathy.

PURPOSE: This study aimed to ascertain the occurrence of foveal hypoplasia (FH) in individuals diagnosed with familial exudative vitreoretinopathy (FEVR). DESIGN: Retrospective cohort study. METHODS: In this study, FEVR families and sporadic cases were diagnosed at the Eye and ENT Hospital, Fudan University, between 2017 and 2023. All patients attended routine ophthalmologic examinations and genetic screenings. The classification of FH was determined using optical coherence tomography (OCT) scans. The FH condition was classified into 2 subgroups: group A (FH being limited to the inner layers) and group B (FH affecting the outer layers). A total of 102 eyes from 58 patients were suitable for analysis. RESULTS: Forty-nine mutations in LRP5, FZD4, NDP, TSPAN12, KIF11, CTNNB1, and ZNF408 were examined and detected, with 26 of them being novel. Forty-seven eyes (46.1%) revealed FH. The majority (53.2%) were due to the typical grade 1 FH. Patients with mutations in LRP5 and KIF11 were found to exhibit a higher prevalence of FH (P = .0088). Group B displayed the lowest visual acuity compared with group A (P = .048) and the group without FH (P < .001). The retinal arteriolar angle in group B was significantly smaller than in group A (P = .001) and those without FH (P < .001). CONCLUSIONS: This study offers a new diagnostic approach and expands the spectrum of FEVR mutations. LRP5 and KIF11 were found to be more susceptible to causing FH in patients with FEVR. FEVR eyes with FH exhibited both greater visual impairment and reduced retinal arteriolar angles. The assessment of foveal status in patients with FEVR should be valued.

LONG-TERM CLINICAL OUTCOMES AND GENOTYPE-PHENOTYPE CORRELATION IN FAMILIAL EXUDATIVE VITREORETINOPATHY IN A TERTIARY REFERRAL CENTER.

BACKGROUND/PURPOSE: To evaluate clinical outcomes and assess genotype-phenotype correlations in patients with familial exudative vitreoretinopathy (FEVR). METHODS: Clinical charts of 40 patients with FEVR were reviewed. FEVR was staged per Pendergast and Trese, and retinal dragging and folds further classified per Yaguchi et al. We performed whole-exome sequencing and compared clinical characteristics between genetic-positive and genetic-negative groups. RESULTS: The mean duration of follow-up was 5.4 years (range: 0.33, 15) for genetic-positive and 6.9 (range: 1, 20) for genetic-negative patients. The mean age at diagnosis was 5.6 years (0.25, 27) for genetic-positive and 6.0 (0, 32) for genetic-negative patients. Genetic-positive patients reported 100% full-term births and genetic-negative patients reported 45% full-term births ( P = 0.0012). There were more patients with retinal folds with all major vessels affected (Yaguchi's Group 4) in genetic-positive compared with genetic-negative patients (21.4% vs. 2.6%, P = 0.045). TSPAN12 was the most common (57.1%) genetic mutation in our population of which 50% exhibited asymmetric presentation. CONCLUSION: Patients who test positive for a typical FEVR gene mutation reported more term births and had more severe disease by Yaguchi's classification. TSPAN12 was the most common genetic mutation in our population and had highly asymmetrical disease.

An SNX31 variant underlies dominant familial exudative vitreoretinopathy-like pathogenesis.

Familial exudative vitreoretinopathy (FEVR) is a complex hereditary eye disorder characterized by incomplete development of the retinal vasculature, which thereby affects retinal angiogenesis. But the genetic factors contributing to FEVR's development or pathogenesis remain elusive. In a Chinese family with FEVR with 19 members, by using whole-exome sequencing, we identified a candidate disease-causing DNA variant in sorting nexin 31 (SNX31) (c.963delG; p. Trp321Cys), which results in a frameshift mutation. We studied the biochemical mechanism of this mutation and determined that it is deficient in ß1-integrin binding and stability. The SNX31 c.963delG point mutation mouse model (SNX31m/m) was constructed with CRISPR/Cas9 technology. At 2-4 months of age, SNX31m/m mice showed fundus phenotypes similar to FEVR-like changes, including vascular leakage and retinal atrophy. Moreover, we found that VEGF and apoptotic pathways were involved in these ocular phenotypes. Hence, our study extended the FEVR mutation spectrum to include SNX31. These findings expanded our understanding of the molecular pathogenesis of FEVR and may facilitate the development of methods for the diagnosis and prevention of FEVR.

FZD4 in a Large Chinese Population With Familial Exudative Vitreoretinopathy: Molecular Characteristics and Clinical Manifestations.

Purpose: The purpose of this study was to establish a genotype-phenotype correlation of familial exudative vitreoretinopathy (FEVR) caused by FZD4 gene mutations. Methods: Six hundred fifty-one probands and their family members were recruited based on a clinical diagnosis of FEVR between 2015 and 2021 at Zhongshan Ophthalmic Center. Ocular examinations were performed in all participants. Targeted gene panel sequencing and whole-exome sequencing were performed in the probands, and Sanger sequencing was used to verify the mutations and segregation analysis was performed in the family members. Results: Fifty-one FZD4 mutations (24 novels and 27 known) were detected in 84 families. Of these 168 eyes with FEVR, the eyes at stages 1, 2, 3, 4, and 5 were 29 (17.3%), 15 (8.9%), 19 (11.3%), 55 (32.7%), and 12 (7.1%), respectively. Exact stage of 38 (22.6%) eyes could not be determined. The FEVR phenotypes were more severe in the probands than the phenotypes in the family members (P < 0.001). The families were divided into two groups, probands that inherited the variant from the mother, and probands that inherited the variant from the father. In addition, the FEVR stage differences between these two groups were different (P < 0.05). Despite the mutations being located in different domains of FZD4, no significant differences were identified among the domains in terms of FEVR staging, retinal folds, retinal detachment, temporal midperipheral vitreoretinal interface abnormality, and foveal hypoplasia. Conclusions: The FZD4 probands had severer phenotype than the family members, and the FEVR stage difference was greater between the probands and mothers than that between the probands and fathers.

Whole exome sequencing revealed novel pathogenic variants in Vietnamese patients with FEVR.

Background: Familial exudative vitreoretinopathy (FEVR) is a rare inherited disorder marked by incomplete retinal vascularization associated with exudation, neovascularization, and tractional retinal detachment. FEVR is genetically heterogeneous and is caused by variants in six genes: FZD4, LRP5, NDP, TSPAN12, ZNF408, and CTNNB1. In addition, the phenotypic overlap between FEVR and other disorders has been reported in patients harboring variants in other genes, such as KIF11, ATOH7, and RCBTB1. Purpose: To identify pathogenic variants in Vietnamese pediatric patients diagnosed with FEVR and to investigate the clinical findings in correlation with each causative gene. Methods: A total of 20 probands underwent ocular examinations with fundoscopy (ophthalmoscopy) or fluorescein angiography. Genomic DNA was extracted from the peripheral blood of the probands and their family members. Multiplex ligation-dependent probe amplification (MLPA) was employed to detect copy number variants of FEVR-causing genes. Short variants were screened by whole-exome sequencing (WES) and then validated by Sanger sequencing. Results: Fluorescein angiography showed retinal vascular anomalies in all patients. Other ocular abnormalities commonly found were strabismus, nystagmus, exudation, and retinal detachment. Genetic analysis identified 12 different variants in the FZD4, NDP, KIF11, and ATOH7 genes among 20 probands. Four variants were novel, including FZD4 c.169G>C, p.(G57R); NDP c.175-3A>G, splicing; KIF11 c.2146C>T, p.(Q716*) and c.2511_2515del, p.(N838Kfs*17). All patients with the KIF11 variant showed signs of microcephaly and intellectual disability. The patient with Norrie syndrome and their family members were found to have a deletion of exon 2 in the NDP gene. Conclusions: This study sheds light on the genetic causes of ocular disorders with the clinical expression of FEVR in Vietnamese patients. WES was applied as a comprehensive tool to identify pathogenic variants in complex diseases, such as FEVR, and the detection rate of pathogenic mutations was up to 60%.

CLINICAL FEATURES AND SURGICAL OUTCOMES OF ENCIRCLING SCLERAL BUCKLING WITH CRYOTHERAPY IN FAMILIAL EXUDATIVE VITREORETINOPATHY-ASSOCIATED RHEGMATOGENOUS RETINAL DETACHMENT.

PURPOSE: To report the clinical features and surgical outcomes of encircling scleral buckling surgery with cryotherapy in familial exudative vitreoretinopathy (FEVR) patients with rhegmatogenous RD. METHODS: This study was a consecutive, retrospective interventional case series. Clinical features, including the FEVR stage, proliferative vitreoretinopathy grade, range of RD and degeneration, and presence of retinal breaks, and surgical outcomes, including the success rate, best-corrected visual acuity, and myopic shift, were analyzed. RESULTS: There were 16 eyes with Stage 3A FEVR and eight eyes with Stage 4A FEVR. 13 eyes had Grade A proliferative vitreoretinopathy, and 11 eyes had Grade B proliferative vitreoretinopathy. Retinal reattachment was achieved in 22 of 24 eyes (91.67%) with FEVR-rhegmatogenous RD after initial encircling scleral buckling surgery. The best-corrected visual acuity improved from a mean of 1.08 ± 0.86 logarithm of the minimum angle of resolution preoperatively to 0.45 ± 0.41 logarithm of the minimum angle of resolution postoperatively (P < 0.01). A myopic shift of -2.39 ± 1.38 (range, -1 to -6) diopter (P < 0.01) was observed. The mean follow-up period was 34.5 ± 27.7 (range, 7-104) months. CONCLUSION: Our study clarified the efficacy of encircling scleral buckling surgery with cryotherapy in FEVR-rhegmatogenous RD with Stage 3A or 4A FEVR and Grade A or B proliferative vitreoretinopathy, especially in patients with multiple retinal holes.

Ocular Features and Mutation Spectrum of Patients With Familial Exudative Vitreoretinopathy.

Purpose: To investigate the clinical findings in Chinese patients diagnosed with familial exudative vitreoretinopathy (FEVR) and carrying pathogenic mutations. Methods: One hundred twenty unrelated patients with FEVR were enrolled in this study. Genomic DNA and ophthalmic examinations were collected from all the patients and their available relatives. Targeted next-generation sequencing was performed to detect mutations. In silico programs were used to evaluate the pathogenicity of all the mutations. Results: Eighty identified mutations were found in 81 unrelated patients (31/81 in LRP5, 25/81 in FZD4, 12/81 in TSPAN12, 8/81 in NDP, 4/81 in KIF11, and 1/81 in ZNF408). Among those mutations, 53 were novel (23/35 in LRP5, 15/21 in FZD4, 8/11 in TSPAN12, 3/8 in NDP, 3/4 in KIF11, 1/1 in ZNF408). Patients with LRP5, FZD4, TSPAN12, or NDP mutations were mainly classified into stage 4 and stage 5 and one-half of patients with KIF11 mutations were in stage 4. In addition, all the patients in NDP group were found to have bilateral symmetry in FEVR stage. Conclusions: Our results present profound phenotypic variability and a wide mutation spectrum of FEVR in the Chinese population, which could be useful for a precise and comprehensive genetic diagnosis for patients with FEVR in the future.

INTRAVITREAL RANIBIZUMAB TREATMENT FOR ADVANCED FAMILIAL EXUDATIVE VITREORETINOPATHY WITH HIGH VASCULAR ACTIVITY.

PURPOSE: To determine the efficacy of intravitreal ranibizumab (IVR) treatment for advanced familial exudative vitreoretinopathy with high vascular activity. METHODS: The retrospective interventional case series included 28 eyes (20 patients) that had IVR in combination or not with other treatment, for Stage 3 to 5 familial exudative vitreoretinopathy with active fibrovascular proliferation and prominent subretinal exudation. Outcome measures were fundus features after treatment, associated clinical variables, and genetic mutations. RESULTS: The age of patients at the first IVR ranged from 0.2 to 36 months. An average of 1.3 IVR injections per eye were given. Familial exudative vitreoretinopathy regressed in 16 (57%) eyes and progressed in 12 eyes (43%) after IVR. Laser and/or vitrectomy was performed on 13 eyes. The retina was reattached in 22 eyes (78%) after 24 to 58 months follow-up. Clinical variables associated with progression after IVR were preexisting fibrovascular proliferation over one quadrant and persistent vascular activity after the initial injection (P < 0.05). Familial exudative vitreoretinopathy-causative genetic mutations in 11 patients were related to variable response to IVR treatment. CONCLUSION: Intravitreal ranibizumab treatment may effectively regress advanced familial exudative vitreoretinopathy with high vascular activity in selected cases. Different treatment outcomes may be relevant to variable presentation and genetic heterogeneity of familial exudative vitreoretinopathy.

Familial exudative vitreoretinopathy with TGFBR2 mutation without signs of Loeys-Dietz syndrome.

Background: Familial exudative vitreoretinopathy (FEVR) is an inherited retinal disorder with high genetic heterogeneity, and it is characterized by a defect in the development of the retinal vascular system. Loeys-Dietz syndrome (LDS) is an autosomal dominant systemic connective tissue disorder that is caused by mutations in the genes related to transforming growth factor signaling systems including the TGFBR2 gene. Two earlier studies reported that patients with LDS from mutations in the TGFBR2 gene were associated with FEVR-like retinal phenotype. The purpose of this study was to determine the characteristics of a case of FEVR without systemic abnormalities who had a mutation in the TGFBR2 gene.Materials and Methods: The clinical appearances and surgical outcomes were determined from the medical records. Genetic analysis was performed by whole exome sequencing.Results: A 15-year-old boy was diagnosed with FEVR by the appearance of the peripheral retina of both eyes and a retinal detachment in the left eye. Whole exome sequencing revealed a heterozygous deletion mutation in the TGFBR2 gene. A de novo mutation was confirmed by examining the family members. No systemic abnormalities were detected in the patient including those associated with LDS.Conclusions: FEVR can be associated with a TGFBR2 mutation without showing signs of LDS.

Whole-Exome Sequencing Reveals Novel TSPAN12 Variants in Autosomal Dominant Familial Exudative Vitreoretinopathy.

Background: Familial exudative vitreoretinopathy (FEVR), a group of rare inherited retinal vascular disorders, is the major cause of vision loss in juveniles. At present, the diagnosis of FEVR remains difficult due to its clinical and genetic heterogeneities. Aims: To identify the causative genetic variants in two unrelated FEVR-affected families: one Indian family and one Chinese Han family. Materials and Methods: Five affected patients from two families were recruited for this study. Whole-exome sequencing was applied to the probands, and Sanger sequencing was performed for validation. Stringent whole-exome sequence data analyses were performed to evaluate all of the identified pathogenic variants. Results: Two novel variants in the TSPAN12 gene, were identified: a missense variant c.437 T > G (p.Leu146Arg); and a nonsense variant c.477 C > A (p.Cys159*). Both variants cosegregated with the disease in the investigated FEVR-affected families. Additionally, both variants inactivated the ability of TSPAN12 protein to enhance Norrin/ß-catenin signaling. Conclusion: This study expands the mutational spectrum of TSPAN12 for FEVR.