More to it than meets the eye: a case report of incomitant esotropia in a child caused by a giant basilar aneurysm

Background:Esotropia is a common concern in pediatric ophthalmology consultations.While most cases stem from strabismus,it is crucial for physicians to differentiate atypical features that might indicate underlying organic causes,such as VI nerve palsy,hinting at the presence of intracranial spaceoccupying lesions.Although the occurrence of cerebral aneurysms in children is rare,they can have severe consequences.Case Description:Here,we described an extremely rare case of giant basilar fusiform aneurysm measuring 4.0 cm×3.9 cm×3.9 cm in an otherwise healthy 8-year-old child,and analyzed its atypical features that suggested an intracranial etiology.We further described an endovascular approach,performed by interventional radiologists,and discussed its advantages over the conventional neurosurgery.The patient continued to be followed by our multidisciplinary team.He had a stable post-operative course and made an excellent recovery neurologically.At the 1-year follow-up,he was orthophoria with excellent vision and stereopsis.Conclusions:To our knowledge,this is the first pediatric case in Canada where a giant intracranial aneurysm was treated endovascularly.The salient red flags—progressive incomitant esotropia and diplopia,the presence of myopia(rather than hyperopia),nystagmus and abnormal saccadic movements—should be astutely recognized by clinicians as intracranial giant aneurysms carry a poor prognosis.A multidisciplinary approach is essential for the management of such cases.

AB043.Long-standing choroidal thinning in oxygen-induced retinopathy

Background:Retinopathy of prematurity(ROP),the most common cause of blindness in premature infants,has long been associated with pathologic retinal vasculature.However,recent studies reveal choroidal involution in adolescent patients formerly afflicted with ROP.We have recently demonstrated that choroidal thinning occurs early in retinopathy and persists into adulthood.Unlike retinal vessels,the damaged choroidal vasculature in ROP is incapably to regenerate.Herein,we investigated the molecular mechanism implicated in the lack of choroidal repair in ischemic retinopathy.Methods:The oxygen-induced retinopathy(OIR)model was used.Newborn Sprague-Dawley(albino)or Long-Evans rats(pigmented)rats were placed under oxygen concentration which cycles at 50%±1%or 10%±1%every 24 hours(hr)from postnatal day(P)0 to P14.On P14,all rats were returned to room air.Western blotting and qPCR were used to quantify protein and RNA abundances,respectively.The Dual-Luciferase®Reporter Assay System was used to confirm microRNA(miRNA)-mRNA interaction.Results:We detected a substantial oxidative stress in retinal pigment epithelium(RPE)and choroidal tissue,accompanied by a drastic reduction in insulin-like growth factor 1 receptor(IGF1R),a critical player in post-injury revascularization.The mechanism of decreasing IGF1R involves the over-activation of the p53 tumor suppressor that regulates miRNA let-7b,which subsequently silences Igf1r mRNA in the RPE/choroid complex of OIR subjects.Luciferase reporter assay confirmed that let-7b directly targets Igf1r mRNA at its 3’untranslated region(UTR).Indeed,silencing p53 resulted in a decreased let-7b expression,and re-established IGF1R abundance that promoted choroidal regeneration.Conclusions:Together,this study sets forth new mechanistic notion by uncovering the novel p53/let-7b/IGF1R axis;timely intervention of this pathway facilitates healthy choroidal revascularization.Future investigations on anti-angiogenic miRNAs can better our understanding on degenerative choroidopathy,such as geographic atrophy.

The Vision Health Research Network Annual Research Day,and International Symposium on Retinal and Choroidal Angiogenesis(Montreal)

The Vision Health Research Network of Québec(the Network)was established in 1995 and funded by the Fonds de la recherche du Québec en santé(FRQS).In the past 23 years,it has been the major venue to foster collaborations within Quebec’s research community and beyond.The Network aims to increase research capacity,improve infrastructure and enhance competitiveness of Quebec’s vision research on the international stage.Focusing on key matters proposed by Canadian health policy,the Network strikes to improve visual outcomes among patients.