Talk:Sensory - Vision Abnormalities
|About Discussion Pages|
Cite this page: Hill, M.A. (2021, March 5) Embryology Sensory - Vision Abnormalities. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Talk:Sensory_-_Vision_Abnormalities
Berry V, Georgiou M, Fujinami K, Quinlan R, Moore A & Michaelides M. (2020). Inherited cataracts: molecular genetics, clinical features, disease mechanisms and novel therapeutic approaches. Br J Ophthalmol , , . PMID: 32217542 DOI.
Inherited cataracts: molecular genetics, clinical features, disease mechanisms and novel therapeutic approaches Abstract Cataract is the most common cause of blindness in the world; during infancy and early childhood, it frequently results in visual impairment. Congenital cataracts are phenotypically and genotypically heterogeneous and can occur in isolation or in association with other systemic disorders. Significant progress has been made in identifying the molecular genetic basis of cataract; 115 genes to date have been found to be associated with syndromic and non-syndromic cataract and 38 disease-causing genes have been identified to date to be associated with isolated cataract. In this review, we briefly discuss lens development and cataractogenesis, detail the variable cataract phenotypes and molecular mechanisms, including genotype-phenotype correlations, and explore future novel therapeutic avenues including cellular therapies and pharmacological treatments. © Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. KEYWORDS: embryology and development; genetics; lens and zonules PMID: 32217542 DOI: 10.1136/bjophthalmol-2019-315282
|ICD-11 Structural developmental anomalies of the eye, eyelid or lacrimal apparatus|
LA10.0 Microphthalmos - This is a developmental disorder of the eye that literally means small eye (micros = small; ophthalmos = eye). One (Unilateral Microphthalmia) or both (Bilateral Microphthalmia) eyes may be involved.
LA10.1 Clinical anophthalmos - This refers to the clinical absence of one or both eyes. Both the globe (human eye) and the ocular tissue are missing from the orbit. The absence of the eye will cause a small bony orbit, a constricted mucosal socket, short eyelids, reduced palpebral fissure and malar prominence. Genetic mutations, chromosomal abnormalities, and prenatal environment can all cause anophthalmia. Anophthalmia is an extremely rare disease and is mostly rooted in genetic abnormalities.
LA10.3 Congenital macrophthalmos - A condition caused by failure of the eye to develop correctly during the antenatal period. This condition is characterized by enlargement of the globe of the eye.
Functional and Molecular Characterization of Rod-like Cells from Retinal Stem Cells Derived from the Adult Ciliary Epithelium
PLoS One. 2012;7(3):e33338. Epub 2012 Mar 14.
Demontis GC, Aruta C, Comitato A, De Marzo A, Marigo V. Source Department of Psychiatry, Neurobiology, Pharmacology and Biotechnology, University of Pisa, Pisa, Italy. Abstract In vitro generation of photoreceptors from stem cells is of great interest for the development of regenerative medicine approaches for patients affected by retinal degeneration and for high throughput drug screens for these diseases. In this study, we show unprecedented high percentages of rod-fated cells from retinal stem cells of the adult ciliary epithelium. Molecular characterization of rod-like cells demonstrates that they lose ciliary epithelial characteristics but acquire photoreceptor features. Rod maturation was evaluated at two levels: gene expression and electrophysiological functionality. Here we present a strong correlation between phototransduction protein expression and functionality of the cells in vitro. We demonstrate that in vitro generated rod-like cells express cGMP-gated channels that are gated by endogenous cGMP. We also identified voltage-gated channels necessary for rod maturation and viability. This level of analysis for the first time provides evidence that adult retinal stem cells can generate highly homogeneous rod-fated cells.
Stem cell therapy for retinal disease
Curr Opin Ophthalmol. 2012 May;23(3):226-34.
Tibbetts MD, Samuel MA, Chang TS, Ho AC. Source aWills Eye Institute Retina Service, Mid Atlantic Retina, Philadelphia, Pennsylvania bRetina Institute of California, Pasadena, California, USA.
PURPOSE OF REVIEW: Stem cell therapy holds great promise for the treatment of retinal diseases. This review summarizes recent advances in stem cell biology, outlines ongoing clinical trials and details the obstacles that must be overcome for stem cell therapy to be a viable treatment for retinal disease. RECENT FINDINGS: Stem cells can now be directed to specific retinal cell fates with high yields and acceptable purity for clinical trials. New stem cell sources have been discovered including induced pluripotent stem cells that can be derived from adult tissues then differentiated into multiple retinal cell types. The initial results of clinical trials of subretinal transplantation of human embryonic stem cell-derived retinal pigment epithelium cells in patients with Stargardt's macular dystrophy and dry age-related macular degeneration showed preliminary safety and possible visual acuity benefits. A phase I trial of intravitreally injected autologous bone marrow-derived mononuclear cells for hereditary retinal dystrophy demonstrated no evidence of toxicity with possible visual acuity benefits but no structural or functional changes. Ongoing trials are examining the trophic effects of undifferentiated umbilical cells for the treatment of geographic atrophy in age-related macular degeneration. SUMMARY: Stem cell therapy is a promising treatment under active investigation in multiple retinal diseases. Ongoing clinical trials should yield further insights into the potential for stem cell-based retinal therapies.
Targeted 'next-generation' sequencing in anophthalmia and microphthalmia patients confirms SOX2, OTX2 and FOXE3 mutations
BMC Med Genet. 2011 Dec 28;12:172.
Jimenez NL, Flannick J, Yahyavi M, Li J, Bardakjian T, Tonkin L, Schneider A, Sherr EH, Slavotinek AM. Source Department of Pediatrics, Division of Genetics, University of California, San Francisco, 533 Parnassus St, Room U585P, San Francisco, CA 94143-0748 USA. Abstract BACKGROUND: Anophthalmia/microphthalmia (A/M) is caused by mutations in several different transcription factors, but mutations in each causative gene are relatively rare, emphasizing the need for a testing approach that screens multiple genes simultaneously. We used next-generation sequencing to screen 15 A/M patients for mutations in 9 pathogenic genes to evaluate this technology for screening in A/M. METHODS: We used a pooled sequencing design, together with custom single nucleotide polymorphism (SNP) calling software. We verified predicted sequence alterations using Sanger sequencing. RESULTS: We verified three mutations - c.542delC in SOX2, resulting in p.Pro181Argfs*22, p.Glu105X in OTX2 and p.Cys240X in FOXE3. We found several novel sequence alterations and SNPs that were likely to be non-pathogenic - p.Glu42Lys in CRYBA4, p.Val201Met in FOXE3 and p.Asp291Asn in VSX2. Our analysis methodology gave one false positive result comprising a mutation in PAX6 (c.1268A > T, predicting p.X423LeuextX*15) that was not verified by Sanger sequencing. We also failed to detect one 20 base pair (bp) deletion and one 3 bp duplication in SOX2. CONCLUSIONS: Our results demonstrated the power of next-generation sequencing with pooled sample groups for the rapid screening of candidate genes for A/M as we were correctly able to identify disease-causing mutations. However, next-generation sequencing was less useful for small, intragenic deletions and duplications. We did not find mutations in 10/15 patients and conclude that there is a need for further gene discovery in A/M.
The effect of prematurity on tear production
Curr Eye Res. 2004 Feb;28(2):145-51.
Akar Y, Cira A, Apaydin C, Erman MA, Yilmaz A. Source Department of Ophthalmology, Akdeniz University School of Medicine, Antalya, Turkey. firstname.lastname@example.org Abstract PURPOSE: To evaluate the effect of the birth weight and the postconceptional age on the tear production of preterm and term newborn infants and to evaluate the changes in tear production during the first two months of life. SUBJECTS--METHODS: Both eyes of medically stable term and preterm infants were included in the study. Based on postconceptional age and birth weight, we divided preterm infants into three groups. Then, we measured the basal and reflex tear secretions of both eyes by Schirmer tests before and after instillation of topical anesthetic agent. We performed initial tear measurements on the second day of life (between first 24 hours to first 48 hours after birth): and at 2 weeks, 4 weeks and 8 weeks after birth.
RESULTS: We tested a total of 138 infants (63 preterm and 75 term), 72 males and 66 females. Schirmer-1-test of preterm and terms on the 2nd day of life revealed a mean basal tear secretion (BTS) of 4.8 +/- 4.1 and 8.8 +/- 3.2 mm, respectively (p < 0.0001). The mean reflex tear secretion (RTS) within 48 hours of life was 6.1 +/- 3.9 mm and 10.3 +/- 4.4 mm in preterm and term infants, respectively (p < 0.0001). The mean values of both basal and reflex tear secretion were significantly lower in the preterm than the term infants during the first two months of the life. In preterm infants, both basal and reflex tear secretions were found to be highly correlated with postconceptional age (r: 0.79 and 0.74, respectively, both p values: 0.001); however, there was a weak correlation with birth weight (r: 0.16 and 0.19, respectively, both p values: 0.01). Statistically significant differences for both BTS and RTS existed among the three postconceptional age groups: there were no such difference among the three different birth weight groups. We found no gender or laterality dependent (side of the eyes) differences in the tear production (both p values >0.05).
CONCLUSIONS: Preterm infants have significantly reduced tear secretion compared with term infants. Postconceptional age, rather than birth weight, seems to be more correlated with the tear secretion. Sex and laterality does not appear to have an effect on tear production in infants. Tear production of preterm infants is significantly reduced than that of term infants during the first two months of life. Term infants increased their tear production significantly in each examination during the neonatal period while the preterms increase tear production significantly only at mean postconceptional age of eight and a half (8.5) months.
PMID: 14972720 http://www.ncbi.nlm.nih.gov/pubmed/14972720