Comparative analysis of changes in retinal layer thickness following femtosecond laser-assisted cataract surgery and conventional cataract surgery.

BACKGROUND: To investigate the influence of femtosecond laser-assisted cataract surgery (FLACS) on macula by examining changes in retinal layers after FLACS and to compare these changes with those after conventional cataract surgery (CCS). METHODS: This study included 113 unrelated Korean patients with age-related cataract who underwent CCS or FLACS in Severance Hospital between September 2019 and July 2021. Optical coherence tomography was performed before and 1 month after surgery. The total retinal layer (TRL) was separated into the inner retinal layer (IRL) and outer retinal layer (ORL); moreover, the IRL was subdivided into the retinal nerve fiber layer, ganglion cell layer, inner plexiform layer, inner nuclear layer (INL), outer plexiform layer, and outer nuclear layer. We performed between-group comparisons of the postoperative thickness in each retinal layer and the postoperative differences in retinal thickness. The average retinal thickness of the four inner macular ring quadrants was used for comparative analysis. RESULTS: Compared with the CCS group, the FLACS group exhibited a thicker ORL (P = 0.004) and a thinner INL (P = 0.007) after surgery. All retinal layer thickness values showed significant postoperative changes regardless of the type of surgery (P < 0.05). The postoperative increase in TRL and IRL thickness was significantly smaller in the FLACS group than in the CCS group (P = 0.027, P = 0.012). CONCLUSIONS: The 1-month postoperative retinal changes were less pronounced in the FLACS group than in the CCS group.

Comparison of two different contrast sensitivity devices in young adults with normal visual acuity with or without refractive surgery.

This study investigated the reliability and correlation of two contrast sensitivity test (CST) devices in young adults with normal visual acuity, with or without refractive surgery. 57 patients aged 20-39 years who received both manual (OPTEC-6500) and automated CST (CGT-2000) examinations from June 19 to July 24, 2021 were retrospectively enrolled. Patients with corrected visual acuity under 20/20 or history of ocular surgery other than refractive surgery were excluded. 82 eyes of 41 patients (40 eyes with and 42 without history of refractive surgery) were enrolled. Mean time taken to complete each examination was 396.4 ± 20.4 and 286.8 ± 2.3 s using manual and automated CST, respectively (P < 0.001). Patients who underwent refractive surgery had significantly decreased area under the log contrast sensitivity formula (AULCSF) in mesopic compared with photopic conditions in automated CST examinations (AULCSF difference 0.415 vs. 0.323 in patients with and without refractive surgery, P < 0.001), but there was no significant difference in manual CST examinations. Patients who reported decreased subjective night vision had significantly decreased AULCSF in automated CST examinations, but there was no significant difference in manual CST examinations. Compared with manual CST, automated CST was quicker and correlated well with decrease in subjective night vision.

Analysis of keratometric measurements in accordance with axial length in an aged population.

To investigate keratometric measurements according to axial length in an aged population. Patients requiring cataract surgery with keratometric measurements from four different ophthalmic devices (autorefractor/keratometer, Scheimpflug imaging, corneal topography/ray-tracing aberrometry, and partial coherence interferometry) between January 2016 and March 2021 were reviewed retrospectively. Cases for which four ophthalmic devices were deployed in the same order a day were included in this investigation. The corneal curvature of the flattest and steepest meridian, mean corneal curvature, corneal astigmatism, steepest axis location, and axial length were evaluated. In total, 250 eyes (137 patients) were included in the analysis. A negative correlation was found between mean corneal curvature and axial length, with correlation coefficients of 0.587, 0.592, 0.588, 0.591, 0.588, and 0.562 for autorefractor/keratometer, Scheimpflug imaging, corneal topography/ray-tracing aberrometry, partial coherence interferometry, total corneal refractive power of Scheimpflug imaging, and simulated keratometry of corneal topography/ray-tracing aberrometry measurements, respectively. No statistically significant differences were found for corneal astigmatism according to axial length. In axial length group of less than 26.0 mm, negative correlation was found between axial length and mean frontal corneal curvature while no correlation was found between axial length and corneal astigmatism. All four ophthalmic devices showed good inter-device reliability for mean corneal curvature but not corneal astigmatism.

Use of roller compaction and fines recycling process in the preparation of erlotinib hydrochloride tablets.

This study focuses on improving the manufacturing process for a generic immediate-release tablet containing erlotinib hydrochloride by adding a fines recycling process during roller compaction. Due to the large fraction of small-sized API particles, the starting powder mixture was inconsistently fed into the roller compactor. Consequently, poorly flowing granules with a high ratio of fines were produced. A fines recycling step was, therefore, added to the existing roller compaction process to minimize the risks caused by the poor granule flow. A laboratory scale roller compactor and a tablet simulator were used to prepare granules at various process conditions. The effect of dry granulation parameters on size distribution, API distribution, powder flow, compaction properties, and dissolution profile was evaluated. The granule batch after fines recycling had markedly improved size distribution and flowability while maintaining acceptable tablet tensile strength and rapid dissolution profile. The application of the fines recycling process at commercial scale resulted in reliable dissolution performance and batch-to-batch consistency, which were further confirmed by bioequivalence to the reference product. Understanding how granule properties are impacted by the fines recycling process may enable fine-tuning of the dry granulation process for optimal product quality.