Level of Eye Care Among Eye Care Providers Themselves.

OBJECTIVES: To assess the prevalence of eye disease and frequency of eye examinations among eye care providers themselves. METHODS: In this cross-sectional study, an anonymous questionnaire was used to evaluate occurrence of eye disease and frequency of eye examinations among eye care providers including the clinicians (ophthalmologists, ophthalmology residents, and optometrists) as well as the support staff (ophthalmic technicians and eye clinic administrative staff). RESULTS: The survey response rate was 98 of 173 (56.6%) including 50 ophthalmic technicians, 27 ophthalmologists, 7 ophthalmology residents, 6 optometrists, and 8 eye clinic administrative staff members. The most common reported ocular condition was dry eye disease (36.7%). Myopia and hyperopia were present in 60 (61.2%) and 13 (13.3%), respectively. Myopia was significantly more prevalent among the clinicians (75.0%) than in the support staff (51.7%, P =0.02). The most recent eye examination was within the past year in 42 (42.9%), 1 to 2 years in 28 (28.6%), 3 to 5 years in 14 (14.3%), and over 5 years in 10 (10.2%). Four (4.1%) had never had an eye examination before. The number of eye examinations received was significantly higher in the support staff compared with the clinicians for the past one year (0.86±0.74 vs 0.43±0.59, respectively, P =0.003) and the past five years (2.81±2.08 vs 1.75±1.78, respectively, P =0.01). CONCLUSIONS: Dry eye disease and myopia are common among eye care providers. A significant portion of eye care providers do not have regular eye examinations for themselves.

Suboptimal Intermediates Underlie Evolution of the Bicoid Homeodomain.

Changes in regulatory networks generate materials for evolution to create phenotypic diversity. For transcription networks, multiple studies have shown that alterations in binding sites of cis-regulatory elements correlate well with the gain or loss of specific features of the body plan. Less is known about alterations in the amino acid sequences of the transcription factors (TFs) that bind these elements. Here we study the evolution of Bicoid (Bcd), a homeodomain (HD) protein that is critical for anterior embryo patterning in Drosophila. The ancestor of Bcd (AncBcd) emerged after a duplication of a Zerknullt (Zen)-like ancestral protein (AncZB) in a suborder of flies. AncBcd diverged from AncZB, gaining novel transcriptional and translational activities. We focus on the evolution of the HD of AncBcd, which binds to DNA and RNA, and is comprised of four subdomains: an N-terminal arm (NT) and three helices; H1, H2, and Recognition Helix (RH). Using chimeras of subdomains and gene rescue assays in Drosophila, we show that robust patterning activity of the Bcd HD (high frequency rescue to adulthood) is achieved only when amino acid substitutions in three separate subdomains (NT, H1, and RH) are combined. Other combinations of subdomains also yield full rescue, but with lower penetrance, suggesting alternative suboptimal activities. Our results suggest a multistep pathway for the evolution of the Bcd HD that involved intermediate HD sequences with suboptimal activities, which constrained and enabled further evolutionary changes. They also demonstrate critical epistatic forces that contribute to the robust function of a DNA-binding domain.