One important role of epigenetic regulation is controlling gene expression in development and homeostasis. However, little is known about epigenetics’ role in regulating opsin expression. Cell cultures (HEK 293, Y79, and WERI) producing different levels of opsins were treated with 5-aza-2’-deoxycytidine (5-Aza-dc) and/or sodium butyrate (SB) or suberoylanilide hydroxamic acid (SAHA) for 72 h. Global DNA methylation, site-specific methylation, and expressions of opsins were measured by LUMA assay, bisulfite pyrosequencing, and qPCR, respectively. Mouse retinal explants from wild-type P0/P1 pups were ex vivo cultured with/without 5-Aza-dc or SAHA for 6 days. The morphology of explants, DNA methylation, and expressions of opsins was examined. The drugs induced global DNA hypomethylation or increased histone acetylation in cells, including DNA hypomethylation of rhodopsin (RHO) and L-opsin (OPN1LW) and a concomitant increase in their expression. Further upregulation of RHO and/or OPN1LW in HEK 293 or WERI cells was observed with 5-Aza-dc and either SB or SAHA combination treatment. Mouse retinal explants developed normally but had drug-dependent differential DNA methylation and expression patterns of opsins. DNA methylation and histone acetylation directly regulate opsin expression both in vitro and ex vivo. The ability to manipulate opsin expression using epigenetic modifiers enables further study into the role of epigenetics in eye development and disease.
Background: Repair of margin-involving eyelid lacerations is a challenge for beginning ophthalmology residents, yet no commercially-available simulation models exist for learning this skill. The objective of the study was to modify a mannequin-based surgical simulator originally developed for trachomatous trichiasis surgery training to teach margin-involving eyelid laceration repair and to evaluate its success within a residency wet-lab environment. Methods: We modified a previously developed mannequin-based training system for trachomatous trichiasis surgery into a simulator for margin-involving eyelid laceration repair. Six ophthalmology residents from a tertiary care academic institution performed at least one simulated margin-involving eyelid laceration repair using the surgical simulator between September 2019 and March 2020. Each session was video recorded. Two oculoplastic surgeons reviewed the videos in a blinded fashion to assess surgical proficiency using a standardized grading system. Participants were surveyed on their comfort level with eyelid laceration repair pre- and post-completion of simulation. They were also queried on their perceived usefulness of the surgical simulator compared to past methods and experiences. Results: Six residents completed 11 simulation surgeries. For three residents who completed more than one session, a slight increase in their skills assessment score and a decrease in operative time over two to three simulation sessions were found. Self-reported comfort level with margin-involving eyelid laceration repairs was significantly higher post-simulation compared to pre-simulation (p = 0.02). Residents ranked the usefulness of our surgical simulator higher than past methods such as fruit peels, surgical skill boards, gloves, and pig feet (p = 0.03) but lower than operating room experience (p = 0.02). Residents perceived the surgical simulator to be as useful as cadaver head and emergency department/consult experience. Conclusions: We developed a surgical simulator for teaching eyelid laceration repair and showed its utility in developing trainees’ surgical skills. Our surgical simulator was rated to be as useful as a cadaver head but is more readily available and cost effective.
24 September 2021 in Ophthalmic Plastic & Reconstructive Surgery
Introduction: The World Health Organization has identified management of postoperative trichiasis (PTT) as one of the key remaining areas of focus needed to eliminate blinding trachoma as a public health problem. We developed the Bevel-Rotation Advancement Procedure (B-RAP) to treat individuals who need repeat trichiasis surgery. Methods: Scarring caused by trichiasis surgery can cause the eyelid to become thick and distorted, making repeat surgery more difficult. To minimize eyelid thickness following B-RAP, a beveled incision of the tarsus is made allowing a marginal rotation of the eyelash fragment. Dissection between the anterior and posterior lamellae above the beveled incision and removal of scar tissue allows the marginal rotation to be combined with a posterior lamellar advancement to treat severely scarred eyelids with PTT and eyelid contour abnormalities (ECAs). Results: Two surgeons performed B-RAP on 44 eyelids of 30 patients with PTT. The number of prior trachomatous trichiasis (TT) surgeries ranged from 2 to more than 4. At the 3–6 months postoperative visit, 37 eyelids (84%) had no recurrence of PTT. Three eyelids had central lashes touching; the remaining eyelids with recurrent PTT had nasal and temporal lashes touching. Fifteen eyelids (34%) had ECAs, but only 1 was severe. Conclusions: B-RAP was developed considering the altered eyelid anatomy found in the postsurgical eyelid with TT. Thinning of the eyelash fragment and removal of postoperative scar tissue improves the ability to advance and stabilize the eyelash fragment after external rotation. B-RAP shows promise as a procedure for improving outcomes of repeat trichiasis surgery.
11 September 2025 in American Journal of Ophthalmology
Lomentaspora prolificans is a rare fungal infection that has emerged as an opportunistic pathogen, particularly in immunosuppressed patients. Infection can caused disseminated infection, as well as localized infections in multiple organs in the body, including the eye. Endophthalmitis is a sight-threatening condition most commonly caused by bacterial pathogens and rarely associated with fungal infection. Endophthalmitis caused by L. prolificans is typically the result of ocular penetration, active keratitis, or endogenous seeding with positive blood cultures. Infection with L. prolificans is very difficult to treat because of the limited efficacy of currently available antifungal medications. Thus, the prognosis of endophthalmitis secondary to L. prolificans is guarded. We present a case of a 70-year-old woman who developed isolated endophthalmitis from L. prolificans infection with no identifiable source.