Angstrom-Resolved Interfacial Structure in Buried Organic-Inorganic Junctions.

Charge transport processes at interfaces play a crucial role in many processes. Here, the first soft x-ray second harmonic generation (SXR SHG) interfacial spectrum of a buried interface (boron-Parylene N) is reported. SXR SHG shows distinct spectral features that are not observed in x-ray absorption spectra, demonstrating its extraordinary interfacial sensitivity. Comparison to electronic structure calculations indicates a boron-organic separation distance of 1.9 Å, with changes of less than 1 Å resulting in easily detectable SXR SHG spectral shifts (ca. hundreds of milli-electron volts).

The Effects of Axis-flip of the Refractive Cylinder on vision and patient reported outcome measures following Toric Intraocular Lens implantation.

PURPOSE: To investigate the effects of cylinder axis-flip following toric intraocular lens (TIOL) implantation on vision and patient reported outcome measures (PROMs). SETTING: Teaching hospital in the United Kingdom. DESIGN: Post-hoc analysis of data from patients who participated in a prospective randomised study of TIOLs. METHODS: Axis-flip was defined as a change in post-operative refractive cylinder axis of 900 +/- 22.50 from the pre-operative biometric axis. Uncorrected distance visual acuity (UDVA), best-corrected distance visual acuity (BDVA), residual refractive cylinder (RC), and CATPROM-5 and EQ5D3L quality of life (QOL) scores were analysed. RESULTS: At 6 months, axis flip occurred in 29 (34.5%) of 84 eyes, of which 28 had with-the-rule astigmatism (WTR) pre-operatively. Mean (+/-standard deviation) UDVA (logMAR) was 0.13 (0.16) in flipped cases (FC) and 0.10 (0.14) in un-flipped cases (UF) (p=0.88). BDVA was 0.01 (0.11) in FC and was 0.00 (0.09) in UF (p=0.68). Mean RC was 0.74 dioptres (D) (0.41) in FC and 0.93D (0.47) in UF (p=0.08). Mean CATPROM-5 score was -6.22.98 (2.56) in FC and -5.52 (3.03) in UF (p=0.29). Mean EQ5D3L calibrated score was 0.89 (0.19) in FC and 0.85 (0.19) in UF (p=0.35). Retrospectively applying coefficients of adjustment to account for posterior corneal astigmatism (PCA), suggested that 6 eyes (21%) of FC with WTR might have avoided axis-flip. CONCLUSIONS: Axis flipping following TIOL implantation did not adversely influence visual acuity or PROMs scores. Most FC had WTR pre-operatively. Adjusting for PCA might have reduced axis flip in some of these eyes.

Comment on Fernández-Vigo et al. Objective Classification of Glistening in Implanted Intraocular Lenses Using Optical Coherence Tomography: Proposal for a New Classification and Grading System. J. Clin. Med. 2023, 12, 2351.

We read with interest your article describing a new objective method for evaluating glistenings in intraocular lenses (IOLs) in vivo [...].

Corneal astigmatic outcomes after femtosecond laser-assisted cataract surgery combined with surface penetrating arcuate keratotomies.

AIM: To evaluate corneal astigmatic outcomes of femtosecond laser-assisted arcuate keratotomies (FAKs) combined with femtosecond-laser assisted cataract surgery (FLACS) over 12mo follow-up. METHODS: Totally 145 patients with bilateral cataracts and no ocular co-morbidities were recruited to a single-centre, single-masked, prospective randomized controlled trial (RCT) comparing two monofocal hydrophobic acrylic intraocular lenses. Eyes with corneal astigmatism (CA) of >0.8 dioptres (D) received unpaired, unopened, surface penetrating FAKs at the time of FLACS. Visual acuity, subjective refraction and Scheimpflug tomography were recorded at 1, 6, and 12mo. Alpins vectoral analyses were performed. RESULTS: Fifty-one patients (61 eyes), mean age 68.2±9.6y [standard deviation (SD)], received FAKs. Sixty eyes were available for analysis, except at 12mo when 59 attended. There were no complications due to FAKs. Mean pre-operative CA was 1.13±0.20 D. There was a reduction of astigmatism at all post-operative visits (residual CA 1mo: 0.85±0.42 D, P=0.0001; 6mo: 0.86±0.35 D, P=0001; and 12mo: 0.90±0.39, P=0.0001). Alpins indices remained stable over 12mo. Overall, the cohort was under-corrected at all time points. At 12mo, 61% of eyes were within ±15 degrees of pre-operative astigmatic meridian. CONCLUSION: Unpaired unopened penetrating FAKs combined with on-axis phacoemulsification are safe but minimally effective. CA is largely under-corrected in this cohort using an existing unmodified nomogram. The effect of arcuate keratotomies on CA remained stable over 12mo.

The osteo-odonto-keratoprosthesis (OOKP).

The osteo-odonto-keratoprosthesis (OOKP), although described over 40 years ago, remains the keratoprosthesis of choice for end-stage corneal blindness not amenable to penetrating keratoplasty. It is particularly resilient to a hostile environment such as the dry keratinized eye resulting from severe Stevens-Johnson syndrome, ocular cicatricial pemphigoid, trachoma, and chemical injury. Its rigid optical cylinder gives excellent image resolution and quality. The desirable properties of the theoretical ideal keratoprosthesis is described. The indications, contraindications, and patient assessment (eye, tooth, buccal mucosa, psychology) for OOKP surgery are described. The surgical and anaesthetic techniques are described. Follow-up is life-long in order to detect and treat complications, which include oral, oculoplastic, glaucoma, vitreo-retinal complications and extrusion of the device. Resorption of the osteo-odonto-lamina is responsible for extrusion, and this is more pronounced in tooth allografts. Regular imaging with spiral-CT or electron beam tomography can help detect bone and dentine loss. The optical cylinder design is discussed. Preliminary work towards the development of a synthetic OOKP analogue is described. Finally, we describe how to set up an OOKP national referral center.

Optical functional performance of the osteo-odonto-keratoprosthesis.

PURPOSE: The aim of this study was to evaluate optical and visual functional performance of the osteo-odonto-keratoprosthesis (OOKP). METHODS: Optical design and analysis was performed with customized optical design software. Nine patients with implanted OOKP devices and 9 age-matched control patients were assessed. Contrast sensitivity was assessed and glare effect was measured with a brightness acuity test. All OOKP patients underwent kinetic Goldmann perimetry and wavefront aberrometry and completed the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25). RESULTS: Optical analysis showed that the optical cylinder is near diffraction-limited. A reduction in median visual acuity (VA) with increasing glare settings was observed from 0.04 logMAR (without glare) to 0.20 logMAR (with glare at "high" setting) and significantly reduced statistically when compared with the control group at all levels of glare (P < 0.05). Contrast sensitivity was significantly reduced when compared with age-matched controls at medium and high spatial frequencies (P < 0.05). Median Goldmann perimetry was 65 degrees (interquartile range, 64-74 degrees; V-4e isopters) and 69 degrees excluding 2 glaucomatous subjects. Several vision-related NEI VFQ-25 subscales correlated significantly with VA at various brightness acuity test levels and contrast sensitivity at medium spatial frequencies, including dependency, general vision, near activities and distance activities. CONCLUSIONS: The OOKP optical cylinder provides patients with a good level of VA that is significantly reduced by glare. We have shown in vivo that updates to the optical cylinder design have improved the patient's field of view. Reduction of glare and refinement of cylinder alignment methods may further improve visual function and patient satisfaction.