Isolated aniridia caused by a novel PAX6 heterozygous deletion mediated by multi-exon complex rearrangement.

PURPOSE: Mutations in PAX6 gene (chromosome 11p13) encoding a transcriptional regulator involved in oculogenesis mostly present with aniridia. Aniridia is not uncommon in the Philippines but only limited information is available as yet. The purpose of this study was to present a novel, deletion mediated by complex rearrangement in PAX6 gene causing an isolated aniridia in a Filipino girl. PATIENTS AND METHODS: The patient is an 8-year-old girl who came in due to leukocoria with associated nystagmus and esotropia. She presented with subnormal vision, nystagmus, aniridia, and cataractous lenses in both eyes. The family history reveals presence of the aniridia and cataract with the mother and a sibling. The patient underwent lens extraction without intraocular lens implantation bilaterally, where patient subsequently underwent intraocular lens implantation on her left eye. Systemic workup was performed including whole abdomen, renal ultrasound, blood chemistry, and urinalysis. Targeted cataract panel with WT1 and PAX6 genes revealed a novel, heterozygous PAX6-inherited mutation from the mother. This variant is a complex rearrangement in PAX6 involving partial deletions of exons 3-5, including the initiator codon. Deletions of PAX6 are part of a contiguous gene deletion syndrome - Wilms tumor, aniridia, genitourinary anomalies, and intellectual disability syndrome - and therefore evaluation of the WT1 gene was necessary to rule out this life-threatening syndrome. CONCLUSION: This rare, complex rearrangement of multiple exons and deletions in PAX6 causing an isolated aniridia phenotype is probably the first reported case. The patient was managed by a multidisciplinary team and the guardians were counseled regarding the prognosis and complications.

Novel compound heterozygous pathogenic BBS5 variants in Filipino siblings with Bardet-Biedl syndrome (BBS).

PURPOSE: Bardet-Biedl syndrome (BBS) is rare in the Philippines and only limited information on the prevalent subtypes is available as yet. The purpose of this study is to present the clinical characteristics of two Filipino siblings presenting with mutations in BBS5. PATIENTS AND METHODS: The Filipino female siblings, aged 11 and 14 years underwent comprehensive ophthalmologic evaluation. Fundus photography, macular optical coherence tomography (OCT) and electroretinography (ERG) were also obtained. Systemic workup was performed including radiographic imaging of limb defects, renal ultrasound, blood chemistry, and transvaginal ultrasound. Targeted Bardet-Biedl sequence analysis and deletion/duplication analysis were performed to determine potential pathogenic mutations. RESULTS: Both children had poor visual acuity with a myopic refraction. There was a pigmentary retinopathy with retinal pigment epithelium changes and attenuation of vessels without waxy disc pallor. Generalized macular thinning and undetectable ERG responses were recorded. Physical examination revealed obesity, facial anomalies, brachydactyly, postaxial polydactyly, and clinodactyly of fifth digits. Both patients displayed cognitive developmental delay and hypogonadism. Molecular analysis revealed novel compound heterozygous mutations in BBS5 with c.143-1 G > A (splice acceptor) and c.925_931del (p.Gln309ilefs*14), each inherited from one asymptomatic parent. CONCLUSION: These are probably the first reported BBS5 mutations causing Bardet-Biedl syndrome in the Philippines. Patients were managed by a multi-disciplinary team and the parents were counseled regarding the prognosis and additional complications associated with the syndrome.

Organophosphate retinopathy.

Organophosphates have rarely been reported to cause various ocular sequelae including retinal degeneration. Retinal manifestations have been rarely reported and poorly characterized. We describe a case of a 76-year-old man with vision loss beginning in his 20s due to acute on chronic exposure to dimethoate, an organophosphate. He presented with bilateral geographic macular atrophy and midperipheral pigmentary clumping which we characterized by dilated fundoscopic examination, optical coherence tomography, and fundus autofluorescence.

Macular cystoid spaces in patients with retinal dystrophy.

BACKGROUND: Non leaking macular cystoid spaces (MCS) are seen in some retinal dystrophies. Carbonic anhydrase inhibitor (CAI) treatment may reduce the size of MSC and improve vision. METHODS: A retrospective study of patients with retinal dystrophy with MCS seen between 2009 and 2013 at two sites. Patients had ophthalmic examination, optical coherence tomography (OCT) and genetic testing. Patients with vision worse than 20/30 were treated with CAI. Post treatment visual acuity (VA), central foveal zone (CFZ) thickness, and qualitative estimation of MCS size were assessed. RESULTS: Eighteen patients, 6-47 years old, were included. IVFA was performed in 15 (83%) patients. Of the 26 eyes in 13 patients who were treated and followed, VA improved in 15 eyes (58%) of 10 patients. Ten of these 15 eyes had decreased CFZ thickness and 9/10 showed qualitative MCS improvement. Regression analysis showed that change in CFZ thickness was not significantly predictive of change in final visual acuity (p = 0.405). Five of 15 eyes with improved VA had paradoxically increased CFZ thickness and 2/5 had enlarged MCS. Three of the treated eyes (11%) in two patients had decreased VA with decreased CFZ thickness and improved MCS in 2/3 eyes. Eight eyes (31%) in six patients showed no change in VA with decreased CFZ thickness in 6/8 eyes with improved MCS. Genetic testing showed mutations of NR2E3, XLRS, CRB1, GPR98 and CNGB1. CONCLUSION: Non-leaking MCS occur in a variety of retinal dystrophies. Therapy with topical or systemic CAI has variable efficacy and may result in VA improvement with or without qualitative improvement in MCS and CFZ thickness.

Anterior lentiplane associated with posterior lenticonus and microcornea.

We report a 12-year-old boy with a rare condition consisting of familial bilateral anterior lentiplane (a flat anterior lens capsule) posterior lenticonus, and microcornea.

Ocular manifestations of 22q11.2 microduplication.

PURPOSE: To report a new ocular manifestation of the dup22q11 syndrome and explore involved genes that may offer insight to mechanisms of pathogenesis. DESIGN: Case series. PARTICIPANTS: Two male patients with this syndrome diagnosed with dup22q11.2. METHODS: Medical records were reviewed. Duplication was detected in the oligo-single nucleotide polymorphism chromosomal microarray and duplicated genes within the segment where determined by literature and database review. Potential associations between the ophthalmologic manifestations and their physiopathology were investigated. MAIN OUTCOME MEASURES: Microarray results and identification of candidate genes within the duplicated segment. RESULTS: Our patients demonstrate previously unreported findings of dup22q11.2, including Marcus Gunn jaw winking, Duane's retraction syndrome, and other abnormal eye movements consistent with a congenital cranial dysinnervation disorder (CCDD), retinal vascular tortuosity, and primary infantile glaucoma. The duplicated segment in case 1 includes SNAP29, which could be linked with the development of retinal vascular tortuosity, and MAPK1, which seems to play a role in axonal development through the semaphorin pathway, which may serve as a candidate gene for CCDD. In case 2, the CLDN5 gene is within the duplicated segment. CLDN5 could be involved in the pathophysiology of glaucoma. CONCLUSIONS: Our cases expand the ocular phenotype for duplication of 22q11 and serve to identify potential candidate genes for the development of CCDD, retinal vascular tortuosity, and glaucoma.

Lyonization in ophthalmology.

PURPOSE OF REVIEW: To describe the entity of Lyonization in ocular eye diseases, along with its clinical and counseling implications. RECENT FINDINGS: Several X-linked ocular diseases such as choroideremia, X-linked retinitis pigmentosa, and X-linked ocular albinism may have signs of Lyonization on ocular examination and diagnostic testing. These findings may aid in the proper diagnosis of ocular disease in both female carriers and their affected male relatives. SUMMARY: Manifestations of Lyonization in the eye may help in the diagnosis of X-linked ocular diseases which may lead to accurate diagnosis, appropriate molecular genetic testing and genetic counseling.

A mysterious case of bilateral stromal keratitis

OBJECTIVES: To describe a rare case of bilateral stromal keratitis and demonstrate the effectiveness of penetrating keratoplasty in the management of toxocara keratitis. METHOD: This is a case report. RESULTS: A 53-year-old male farmer had a 10-month history of bilateral corneal opacity, photophobia, redness, foreign body sensation, and eye pain. The diagnosis was central microbial keratitis with the following etiologies considered: Epstein-Barr virus, herpes simplex, fungal, syphilis, tuberculosis (TB), myobacteria other than TB, and acanthamoeba. Despite treatment with topical steroids and antibiotics, both eyes worsened. Penetrating keratoplasty markedly improved the patient's visual acuity. Histopathology of the left corneal button revealed toxocara keratitis. CONCLUSION: Good history taking, complete systemic and ocular examinations, and a histopathology of the corneal tissues are vital to the diagnosis of toxocara keratitis. Penetrating keratoplasty was shown to be effective in its management. Emphasis is given on prevention to decrease the incidence of the disease.