Anterior segment imaging and treatment of a case with syndrome of ectopia lentis, spontaneous filtering blebs, and craniofacial dysmorphism

Management of an inadvertent late filtering bleb and hypotony in a scleral fixated intraocular lens implantation

PURPOSE

To report a case of inadvertent cystic filtering bleb in a patient with scleral fixated intraocular lens (SFIOL) implantation 7 years after initial procedure.

CASE PRESENTATION

A 14-year-old boy underwent lensectomy, vitrectomy and a sutured rigid SFIOL for microspherophakia in the right eye. Seven years later, the patient presented with hypotony related ocular changes. Examination revealed an inadvertent cystic filtering bleb at the scleral section. Anterior segment optical coherence tomography (ASOCT) revealed gap in inner lips of the scleral wound, bridged by a thin strip of scleral tissue. A conservative management with bandage contact lens (BCL) failed after an initial improvement. Injection of trypan blue dye in the anterior chamber confirmed the presence and site of wound filtration. Surgical closure of the fistula was done and patient showed both structural and visual improvement.

CONCLUSION

Meticulous wound construction and water tight closure at the end of the surgery can avoid such complications. ASOCT can be helpful in diagnosing the area of fistula. A conservative management with BCL can help by tamponading the filtering bleb. However, in unresponsive cases, surgical closure of the fistula is recommended to improve the hypotony-related changes.

Traboulsi syndrome without features of Marfan syndrome caused by a novel homozygous ASPH variant associated with a heterozygous FBN1 variant

BACKGROUND

Traboulsi syndrome is a rare disease clinically characterized by facial dysmorphism, abnormal spontaneous filtering blebs, ectopia lentis (EL) and multiple anterior segment abnormalities.

MATERIAL AND METHODS

An 18-year-old female was referred to the Emergency Service of Hospital São Geraldo (HSG) claiming decreased right eye (RE) visual acuity associated with ocular pain that was noticed approximately 2 months earlier. She underwent a complete ophthalmic and physical examination including hands, ankle, wrist and chest X-ray, abdominal ultrasound, echocardiogram and genetic analysis (whole-exome sequencing).

RESULTS

The ophthalmic examination revealed a high myopia with spherical equivalent of - 9.50 D and best corrected visual acuity (BCVA) of 20/60 in RE and - 9.25 D with BCVA of 20/30 in the left eye (LE). Slit-lamp examination showed normal conjunctiva in both eyes (BE) and a superior-temporal cystic lesion in RE and nasal in LE; the flat anterior chamber in BE with the transparent crystalline lens touches the central corneal endothelium in the RE. Fundoscopy suggested glaucoma as the cup/disc ratio was 0.7, although the intraocular pressure (IOP) was 10 mmHg in BE without medication. Validation of data from whole exome demonstrated a novel splicing homozygous pathogenic variant (PV) (c.1765-1G>A) of the ASPH gene as well as a heterozygous variant of unknown significance (VUS) of the FBN1 gene (c.6832C>T).

CONCLUSION

We here report a novel splice-affecting homozygous pathogenic variant in the ASPH gene that was detected in a Brazilian patient with clinical features of Traboulsi syndrome.

Filtering Pseudo-Bleb Secondary to Sutured Posterior Chamber Intraocular Lens with Implications for Ocular Surgery in Marfan Syndrome

A 51-year-old female Caucasian patient with a history of Marfan syndrome and multiple previous bilateral ocular surgeries presented with increasing discomfort, epiphora, and blurred vision in her right eye for a few months. On examination, we found an overhanging cystic Seidel-positive filtering pseudo-bleb with hypotony in her right eye and a smaller Seidel-negative filtering pseudo-bleb in the left eye secondary to sutured intraocular lens (IOL) in both eyes. Intraoperatively, two full-thickness scleral defects were found close to the limbus, suggesting a melting flap in the location of the previous sutured IOL implant in the right eye. The defects were plugged with two pieces of donor sclera and covered with a larger donor scleral patch, the ischemic conjunctiva was excised, and the remaining healthy conjunctiva was advanced and sutured along the limbus. At last follow-up, intraocular pressure and vision in the right eye increased to preoperative levels, and no pseudo-bleb or leak was detected.

Expanding the clinical spectrum and management of Traboulsi syndrome: report on two siblings homozygous for a novel pathogenic variant in ASPH

BACKGROUND

Traboulsi syndrome is a very rare, syndromic form of ectopia lentis that is potentially sight-threatening at a young age. It is characterized by typical facial, skeletal and ocular signs.

MATERIALS AND METHODS

Two siblings, born to consanguineous parents, with a clinical phenotype consistent with Traboulsi syndrome, underwent extensive ophthalmic imaging and exome-based genetic testing. Both were treated with unilateral clear lens extraction via a limbal approach.

RESULTS

Two siblings, one male and one female, presented with systemic and ocular features consistent with Traboulsi syndrome. Lens subluxation was present in all 4fouraffected eyes, and spontaneous subconjunctival bleb formation was detected in one eye. This eye also showed evidence of keratoconus-related corneal thinning. The clinical diagnosis of Traboulsi syndrome was confirmed molecularly. A homozygous, novel, pathogenic nonsense variant was identified in exon 25 of the ASPH gene: c.2181_2183dup, p.(Val727_Trp728insTer). Excellent visual outcomes following clear lens extraction and postoperative rigid gas-permeable contact lens fitting were obtained.

CONCLUSIONS

We expanded the genetic spectrum of Traboulsi syndrome with a novel frameshift variant in the ASPH gene. We showed that lensectomy followed by gas-permeable contact lenses is an efficient therapeutic approach to treat lens subluxation in Traboulsi syndrome. However, lifelong follow-up is crucial to avoid (late) postoperative complications.

Recurrent unintentional filtering blebs after vitrectomy: A case report

A lady who underwent lensectomy for microspherophakia and pars plana vitrectomy for retinal detachment in her left eye developed recurrent filtering blebs at the site of sclerotomies. Filtering blebs were managed by suturing the sclerotomies. Targeted gene sequencing identified a variant of ASPH gene (p.Arg688Gln) which is not known to be associated with Traboulsi syndrome. But considering the paucity of cases with genetic analysis, it would be possible that p.Arg688Gln is a pathogenic variant. This is the first case report of Traboulsi syndrome due to an ASPH variant not reported earlier that can lead to recurrent filtering blebs.

A novel mutation in the aspartate beta-hydroxylase (ASPH) gene is associated with a rare form of Traboulsi syndrome

BACKGROUND

Traboulsi syndrome is a rare autosomal recessive genetic disorder. The present study aimed to identify the pathogenic variants in the ASPH gene responsible for a rare and unique presentation of Traboulsi syndrome associated with cardiac disorder.

METHODOLOGY

DNA was isolated from the blood samples from 3 clinically diagnosed Traboulsi syndrome patients (n = 3) after obtaining a prior-informed consent. All three had classical ocular and facial dysmorphic features, and two of them also had associated cardiac problems. Mutation screening was performed for the exons of ASPH gene by Sanger sequencing in these patients and 350 controls. Sequence data analysis was performed using Seqscape and insilico protein analysis by SIFT, PyMOL, and Dynamut softwares.

RESULTS

A novel homozygous variant(c.1853 T > A) in exon 21 was identified by Sanger sequencing in two of the three cases while a known pathogenic variant in exon 25 was identified in the third proband. The novel nonsense variant in exon 21 results in a premature truncation of gene resulting in a protein of 543 amino acids. This variant is not reported in ExAC, dbSNP and 1000 genome databases. Both the patients harboring this novel variant, had a unique presentation of Traboulsi syndrome with cardiac dysfunction. In silico analysis predicted the mutation to affect the calcium-binding activity of the gene which might explain the associated cardiac dysfunction in these two patients.

CONCLUSION

The novel pathogenic mutation displayed a perfect genotype-phenotype correlation in two probands of Traboulsi syndrome with cardiac dysfunction.

Whole-exome sequencing identified a novel homozygous ASPH frameshift variant causing Traboulsi syndrome in a Chinese family

Background

Traboulsi syndrome is a rare disorder characterized by ectopia lentis and facial dysmorphism (large beaked nose), which was only reported in 18 individuals to date. It is caused by homozygous/compound heterozygous variants in the aspartate/asparagine‐β‐hydroxylase (ASPH) gene, which hydroxylates the aspartic acid and asparagine in epidermal growth factor‐like domains of various proteins.

Methods

Whole‐exome and Sanger sequencing were used to identify the disease‐causing gene of the patient in a consanguineous Chinese family. Domain analysis was applied to predict the impact of the variant on ASPH protein.

Results

Through exome and Sanger sequencing, we identified a novel homozygous ASPH variant (NM_004318.4:c.1910del/NP_004309.2: p.(Asn637MetfsTer15)) in the patient, which may lead to blockage of the ASPH function through truncating the AspH oxygenase domain of the ASPH protein and/or nonsense‐mediated decay of the ASPH transcript. This is the first report of Traboulsi syndrome in a Chinese patient who was combined with ventricular septal defect, lung bullae, and recurrent spontaneous pneumothorax.

Conclusion

Our results revealed the clinical characteristics of the first Chinese patient with Traboulsi syndrome. Additionally, our study expands the mutational spectrum of Traboulsi syndrome and provides information for clinical genetic counseling to this family.

Bilateral spontaneous filtering blebs

Purpose

To report a case of bilateral spontaneous filtering bleb, scleral thinning, microspherophakia, and mild craniofacial dysmorphism.

Observations

An 18-year-old girl was referred to our clinic for evaluation of bilateral spontaneous filtering blebs. Her corrected distance visual acuity (CDVA) was 20/400 in the right eye (RE) and 20/100 in the left eye (LE). She had superior scleral thinning, multicystic filtering bleb, and microspherophakia bilaterally. The IOP was 9 mmHg in the RE and 8 mmHg in the LE. A mild craniofacial dysmorphism including downward slanting of palpebral fissures and malar hypoplasia was present. There was no sign of corneal ectasia in tomography. Anterior segment optical coherence tomography revealed the filtering blebs as subconjunctival low reflective fluid-filled spaces. Due to severe scleral thinning un the RE we performed a tectonic scleral patch graft. 6 months after surgery the depth of the anterior chamber increased and CDVA improved.

Conclusion and importance

This case indicated that the formation of spontaneous filtering blebs may occur in a syndromic condition. In any case with this symptom, special attention should be paid to craniofacial features, sclera, crystalline lens, and IOP. Tectonic scleral patch graft could be a valuable option in selected patients.

Traboulsi syndrome due to ASPH mutation: an under-recognised cause of ectopia lentis

Traboulsi syndrome is an extremely rare ophthalmological disorder characterised by facial dysmorphism, lens dislocation, anterior segment abnormalities and spontaneous filtering blebs. It is caused by pathogenic variants in the ASPH gene. To date, only 13 individuals with Traboulsi syndrome from three families have been reported in the literature. We report the first UK family with Traboulsi syndrome associated with two novel ASPH variants. This condition, which has some phenotypic overlap with both Marfan syndrome and homocystinuria, is most likely under ascertained, and we further delineate the clinical features to aid its recognition.

Unilateral spontaneous filtering bleb dissecting into the cornea in a patient with high myopia

PURPOSE

To report a case of a unilateral spontaneous filtering bleb dissecting into the cornea in a patient with high myopia.

CLINICAL CASE

A 33-year-old woman with high myopia (-18 D) presented with discomfort in the left eye. Ocular history included pars plana vitrectomy and cataract extraction and posterior chamber intraocular lens implantation in the left eye. Best-corrected visual acuity was 0.65 and intraocular pressure was 20 mmHg. Slit-lamp examination showed a filtering bleb in the upper-temporal quadrant, which extended and dissected the proximal cornea without affecting the visual axis. The morphology and content of the bleb was studied with anterior segment optical coherence tomography, which ruled out a corneal-scleral fistulization into the subconjunctival space. The spontaneous filtering bleb was resected surgically. Due to her high myopia, two strips of fascia lata were used to strengthen the area. In the postoperative period, a complete resection of the bleb was confirmed, without apparent leaking points and with a well-vascularized conjunctiva. No complications were noted. The patient maintained the same best-corrected visual acuity and intraocular pressure than before surgery.

CONCLUSION

The formation of a spontaneous filtering bleb is a rare entity in patients with high myopia, whose risk increases due to their thinned sclerae. The risk is even greater if they have undergone ocular surgeries. Resection of the filtering bleb in our case halted the progression of the corneal dissection, therefore respecting the transparency of the visual axis and preserving visual acuity.

Loss of ciliary zonule protein hydroxylation and lens stability as a predicted consequence of biallelic ASPH variation

PURPOSE

Stability of the crystalline lens requires formation of microfibril bundles and their higher-order structures of ciliary zonules. Trauma, malformation, or degeneration of the ciliary zonules can lead to dislocation or displacement of the lens, which in turn can cause transient or permanent loss of visual acuity. The purpose of this study was to identify the predicted substrates of aspartyl/asparaginyl hydroxylase (ASPH), a 2-oxoglutarate- and Fe²⁺-dependent hydroxylase, which may account for the lens instability phenotype of ASPH-associated syndromes.

METHODS

A single proband of European ancestry with spherophakia and high myopia was subjected to exome sequencing. Proteins containing the ASPH hydroxylation motif were identified within the SwissProt protein database.

RESULTS

We identified 105 putative substrates of ASPH-mediated hydroxylation in the human proteome, of which two (fibrillin-1 and latent transforming growth factor beta binding protein-2) are associated with inherited ectopia lentis syndromes, and are essential for microfibril and ciliary zonule development.

CONCLUSION

Our results implicate ASPH-mediated hydroxylation in the formation of FBN1/LTBP2 microfibril bundles and competent ciliary zonules.

A novel ASPH variant extends the phenotype of Shawaf-Traboulsi syndrome

Shawaf-Traboulsi syndrome (or Traboulsi syndrome; MIM 601552) is an infrequently reported entity characterized by a typical face (long face, large nose, convex nasal ridge, underdeveloped malae, crowded teeth, retrognathia), skeletal signs (long and slender fingers, sometimes pectus deformation and hypermobile joints), and ectopia lentis with conjunctival blebs, shallow anterior chamber and iridocorneal adhesions. The entity is caused by homozygous variants in ASPH. Here, we report on a boy with the clinical diagnosis of Shawaf-Traboulsi syndrome, in whom exome sequencing allowed identification of a novel variant in ASPH. We compare the findings in the present patient to those of earlier reported patients; furthermore add new signs for this entity.

A rare ocular complication of neisseria gonorrhoeae

BACKGROUND

Spontaneous formation of subconjunctival filtering blebs is rare and has been observed after penetrating ocular surgery, in association with connective tissue diseases and inflammatory conditions.

METHOD

We describe here a case of a spontaneous formation of subconjunctival filtering bleb as sequelae of gonococcal conjunctivitis in an adult patient.

RESULTS

Spontaneous filtering bleb is a rare complication of gonococcal conjunctivitis. In this case, the patient presented with a recent history of gonococcal conjunctivitis treated with moxifloxacin eye drops and intravenous cephalothin for a week. On the first exam, there was superior corneal thinning with surrounding conjunctival hyperemia and edema in the right eye, but after the patient lost the follow-up for 2 weeks, the corneal thinning had become a pseudopterygium. After another week, we observed a focal elevation on the superior conjunctiva that had the appearance of a bleb, although the anterior chamber remained deep. The filtering bleb was confirmed by ultrasound biomicroscopy examination (UBM).

CONCLUSION

This case is relevant to the clinical practice because filtering blebs should be considered as a complication of gonococcal conjunctivitis because they pose a threat to the eye when substantial leakage occurs.

Mutations in ASPH cause facial dysmorphism, lens dislocation, anterior-segment abnormalities, and spontaneous filtering blebs, or Traboulsi syndrome

We have previously described a syndrome characterized by facial dysmorphism, lens dislocation, anterior-segment abnormalities, and spontaneous filtering blebs (FDLAB, or Traboulsi syndrome). In view of the consanguineous nature of the affected families and the likely autosomal-recessive inheritance pattern of this syndrome, we undertook autozygosity mapping and whole-exome sequencing to identify ASPH as the disease locus, in which we identified two homozygous mutations. ASPH encodes aspartyl/asparaginyl β-hydroxylase (ASPH), which has been found to hydroxylate aspartic acid and asparagine residues on epidermal growth factor (EGF)-domain-containing proteins. The truncating and missense mutations we identified are predicted to severely impair the enzymatic function of ASPH, which suggests a possible link to other forms of ectopia lentis given that many of the genes implicated in this phenotype encode proteins that harbor EGF domains. Developmental analysis of Asph revealed an expression pattern consistent with the proposed link to the human syndrome. Indeed, Asph-knockout mice had a foreshortened snout, which corresponds to the facial abnormalities in individuals with Traboulsi syndrome. These data support a genetic basis for a syndromic form of ectopia lentis and the role of aspartyl hydroxylation in human development.

Results of fibrillin-1 gene analysis in children from inbred families with lens subluxation

BACKGROUND

Autosomal dominant mutation of the FBN1 gene (fibrillin-1) results in a spectrum of disease (type 1 fibrillopathies) ranging from Marfan syndrome with lens subluxation and cardiovascular complications to milder connective tissues phenotypes. The likelihood of FBN1 mutation in children referred to ophthalmologists because of lens subluxation is unclear. We report the results of routine FBN1 sequencing for children from inbred families referred with nontraumatic lens subluxation without cataract or vitreoretinal degeneration.

METHODS

Medical records of such patients from 2009 to 2012 were retrospectively reviewed.

RESULTS

Eight identified probands (3-11 years old; 4 boys) from consanguineous and/or endogamous Saudi Arabian families all harbored FBN1 mutation--7 autosomal dominant and 1 autosomal recessive (homozygous). Four mutations were novel. One child had a family history for lens subluxation. Seven had facial and/or skeletal features suggestive of type 1 fibrillinopathy. The parents of the autosomal recessive case were confirmed to be heterozygous carriers without lens subluxation or other clinical signs of type 1 fibrillinopathy.

CONCLUSIONS

Autosomal dominant type 1 fibrillinopathy was the major cause for lens subluxation in this cohort despite the fact that families were inbred and thus at higher risk for recessive disease. This highlights the frequency of new mutations in the gene and has important implications for genetic counseling and systemic assessment. The autosomal recessive case represents the fourth such case reported to date. Her heterozygous parents were unaffected carriers, suggesting that some FBN1 mutations can act as hypomorphic alleles rather than exhibiting the dominant negative effect typically attributed to FBN1 mutations.