Hauser BM, Hoyek S, Greenstein SH, Patel NA.
Hyperacute Cutibacterium acnes Endophthalmitis Following Cataract Surgery. Retin Cases Brief Rep 2023;
AbstractPURPOSE: Postoperative endophthalmitis is a relatively uncommon, but potentially visually devastating, complication associated with cataract surgery. Specific microbial causes of endophthalmitis are characteristically associated with particular disease time courses. Though Cutibacterium acnes is typically associated with an indolent course of inflammation, we report a case of C. acnes endophthalmitis with onset on postoperative day (POD) 1 and a positive culture from POD 2. METHODS: Case report. RESULTS: A 56-year-old man underwent cataract extraction and posterior chamber intraocular lens placement in his left eye. On POD 1, he presented with severe discomfort, reduced visual acuity, and significant inflammation. On POD 2, his anterior chamber was tapped and injected with broad-spectrum antibiotics and steroids. The inflammation ultimately resolved, and his visual acuity improved to 20/20. CONCLUSIONS: C. acnes is a rare cause of hyperacute onset postoperative endophthalmitis. Maintaining a high clinical suspicion and initiating prompt treatment can help to optimize long-term visual outcomes.
Hemmati HD, Gologorsky D, Pineda R.
Intraoperative wavefront aberrometry in cataract surgery. Semin Ophthalmol 2012;27(5-6):100-6.
AbstractIntraoperative wavefront aberrometry is a relatively new technology that aims to improve refractive outcomes following cataract surgery by optimizing the spherical power of the intraocular lens implant or calculating the appropriate axis and power of toric lenses during cataract surgery in an aphakic state. This article reviews the literature on intraoperative wavefront aberrometry and provides a critical assessment of the benefits and shortcomings of that technology.
Hu WF, Chen SH.
Advances in capsulorhexis. Curr Opin Ophthalmol 2019;30(1):19-24.
AbstractPURPOSE OF REVIEW: Continuous curvilinear manual capsulorhexis is currently the standard of cataract surgery. In the past several years, new technologies have been developed to improve the consistency and safety of capsulorhexis creation. This article reviews the most recent technologies in capsulotomy formation and their advantages and disadvantages. RECENT FINDINGS: Guidance devices, femtosecond laser capsulotomy and precision pulse capsulotomy improve the centration, circularity and precision of anterior capsulorhexis and capsulotomy. These developments show particular promise for complex cataract surgeries, though clinical data on the refractive outcomes and complication rates of these technologies are currently limited and warrant additional investigation. SUMMARY: New technological advances in capsulorhexis help surgeons achieve a more ideal capsulotomy geometry. Whether this translates into more predictable refractive outcomes and safer surgeries remains an area of future study.
Hu Z, Riquelme MA, Gu S, Jiang JX.
Regulation of Connexin Gap Junctions and Hemichannels by Calcium and Calcium Binding Protein Calmodulin. Int J Mol Sci 2020;21(21)
AbstractConnexins are the structural components of gap junctions and hemichannels that mediate the communication and exchange of small molecules between cells, and between the intracellular and extracellular environment, respectively. Connexin (Cx) 46 is predominately expressed in lens fiber cells, where they function in maintaining the homeostasis and transparency of the lens. Cx46 mutations are associated with impairment of channel function, which results in the development of congenital cataracts. Cx46 gap junctions and hemichannels are closely regulated by multiple mechanisms. Key regulators of Cx46 channel function include Ca and calmodulin (CaM). Ca plays an essential role in lens homeostasis, and its dysregulation causes cataracts. Ca associated CaM is a well-established inhibitor of gap junction coupling. Recent studies suggest that elevated intracellular Ca activates Cx hemichannels in lens fiber cells and Cx46 directly interacts with CaM. A Cx46 site mutation (Cx46-G143R), which is associated with congenital Coppock cataracts, shows an increased Cx46-CaM interaction and this interaction is insensitive to Ca, given that depletion of Ca reduces the interaction between CaM and wild-type Cx46. Moreover, inhibition of CaM function greatly reduces the hemichannel activity in the Cx46 G143R mutant. These research findings suggest a new regulatory mechanism by which enhanced association of Cx46 with CaM leads to the increase in hemichannel activity and dysregulation may lead to cataract development. In this review, we will first discuss the involvement of Ca/CaM in lens homeostasis and pathology, and follow by providing a general overview of Ca/CaM in the regulation of Cx46 gap junctions. We discuss the most recent studies concerning the molecular mechanism of Ca/CaM in regulating Cx46 hemichannels. Finally, we will offer perspectives of the impacts of Ca/CaM and dysregulation on Cx46 channels and vice versa.
Hwang AD, Tuccar-Burak M, Goldstein R, Peli E.
Impact of Oncoming Headlight Glare With Cataracts: A Pilot Study. Front Psychol 2018;9:164.
AbstractOncoming headlight glare (HLG) reduces the visibility of objects on the road and may affect the safety of nighttime driving. With cataracts, the impact of oncoming HLG is expected to be more severe. We used our custom HLG simulator in a driving simulator to measure the impact of HLG on pedestrian detection by normal vision subjects with simulated mild cataracts and by patients with real cataracts.Five normal vision subjects drove nighttime scenarios under two HLG conditions (with and without HLG: HLGY and HLGN, respectively), and three vision conditions (with plano lens, simulated mild cataract, and optically blurred clip-on). Mild cataract was simulated by applying a 0.8 Bangerter diffusion foil to clip-on plano lenses. The visual acuity with the optically blurred lenses was individually chosen to match the visual acuity with the simulated cataract clip-ons under HLGN. Each nighttime driving scenario contains 24 pedestrian encounters, encompassing four pedestrian types; walking along the left side of the road, walking along the right side of the road, crossing the road from left to right, and crossing the road from right to left. Pedestrian detection performances of five patients with mild real cataracts were measured using the same setup. The cataract patients were tested only in HLGY and HLGN conditions. Participants' visual acuity and contrast sensitivity were also measured in the simulator with and without stationary HLG.For normal vision subjects, both the presence of oncoming HLG and wearing the simulated cataract clip-on reduced pedestrian detection performance. The subjects performed worst in events where the pedestrian crossed from the left, followed by events where the pedestrian crossed from the right. Significant interactions between HLG condition and other factors were also found: (1) the impact of oncoming HLG with the simulated cataract clip-on was larger than with the plano lens clip-on, (2) the impact of oncoming HLG was larger with the optically blurred clip-on than with the plano lens clip-on, but smaller than with the simulated cataract clip-on, and (3) the impact was larger for the pedestrians that crossed from the left than those that crossed from the right, and for the pedestrians walking along the left side of the road than walking along the right side of the road, suggesting that the pedestrian proximity to the glare source contributed to the performance reduction. Under HLGN, almost no pedestrians were missed with the plano lens or the simulated cataract clip-on (0 and 0.5%, respectively), but under HLGY, the rate of pedestrian misses increased to 0.5 and 6%, respectively. With the optically blurred clip-on, the percent of missed pedestrians under HLGN and HLGY did not change much (5% and 6%, respectively). Untimely response rate increased under HLGY with the plano lens and simulated cataract clip-ons, but the increase with the simulated cataract clip-on was significantly larger than with the plano lens clip-on. The contrast sensitivity with the simulated cataract clip-on was significantly degraded under HLGY. The visual acuity with the plano lens clip-on was significantly improved under HLGY, possibly due to pupil myosis. The impact of HLG measured for real cataract patients was similar to the impact on performance of normal vision subjects with simulated cataract clip-ons.Even with mild (simulated or real) cataracts, a substantial negative effect of oncoming HLG was measurable in the detection of crossing and walking-along pedestrians. The lowered pedestrian detection rates and longer response times with HLGY demonstrate a possible risk that oncoming HLG poses to patients driving with cataracts.