New Observations regarding the Assessment of Cilioretinal Arteries Coexistence with Optic Disc Pit.

Purpose: To investigate the coexistence of cilioretinal arteries (CRAs) with optic disc pit (ODP), and to delineate the characteristics of CRAs related to their number, location of their emergence and their association with the size of ODP. Methods: 47 patients (49 eyes) with ODP were diagnosed and followed-up between 1997 and 2017, using slit-lamp biomicroscopy, color fundus photographs, fluorescein angiography and indocyanine green angiography. The presence of CRAs was recorded in association with the size of the ODP, along with their number and location of emergence. The fellow normal eyes of patients were also analyzed. Results: 42 out of 49 eyes with ODP (85.7%) presented CRAs. In 35 out of 42 eyes (83.3%) CRAs emerged from the pit, either from bottom or from its margin. In 7.1% of cases, CRAs were emerged outside the ODP, while in 9.6% of cases, the type of CRA emergence could be characterized as mixed. The number of CRAs, that ranged from 1 to 4, was positively associated with ODP size. In the fellow normal eyes, CRAs was found in 22.2% of cases, difference which was significant compared to patients with ODP. Conclusion: Based on the high percentage of CRAs coexistence with ODP and the excessive frequency of their emergence from ODP (83.3%), it is supported that ODP as a developmental disorder could go along with further anatomic peculiarities, that also include the presence of multiple CRAs.

Phenotypic and molecular assessment of seven patients with 6p25 deletion syndrome: relevance to ocular dysgenesis and hearing impairment.

BACKGROUND: Thirty-nine patients have been described with deletions involving chromosome 6p25. However, relatively few of these deletions have had molecular characterization. Common phenotypes of 6p25 deletion syndrome patients include hydrocephalus, hearing loss, and ocular, craniofacial, skeletal, cardiac, and renal malformations. Molecular characterization of deletions can identify genes that are responsible for these phenotypes. METHODS: We report the clinical phenotype of seven patients with terminal deletions of chromosome 6p25 and compare them to previously reported patients. Molecular characterization of the deletions was performed using polymorphic marker analysis to determine the extents of the deletions in these seven 6p25 deletion syndrome patients. RESULTS: Our results, and previous data, show that ocular dysgenesis and hearing impairment are the two most highly penetrant phenotypes of the 6p25 deletion syndrome. While deletion of the forkhead box C1 gene (FOXC1) probably underlies the ocular dysgenesis, no gene in this region is known to be involved in hearing impairment. CONCLUSIONS: Ocular dysgenesis and hearing impairment are the two most common phenotypes of 6p25 deletion syndrome. We conclude that a locus for dominant hearing loss is present at 6p25 and that this locus is restricted to a region distal to D6S1617. Molecular characterization of more 6p25 deletion patients will aid in refinement of this locus and the identification of a gene involved in dominant hearing loss.