En face optical coherence tomography detection of Schlemm's canal in primary open angle glaucoma.

Purpose: To compare the morphological characteristics of Schlemm's canal (SC) in patients with primary open-angle glaucoma (POAG) and healthy controls, using swept-source optical coherence tomography (SS-OCT) with en face reconstruction. Methods: In this Prospective comparative study, we included 100 eyes from 50 patients diagnosed with POAG and 50 healthy controls. Three-dimensional cube and line scans of the temporal and nasal quadrants of the anterior segment of the limbus were acquired using SS-OCT. SC was identified using en face and cross-sectional images. The diameter and area of SC in cross-sectional images and the visible percentage and area of SC in en face images were measured using ImageJ. Results: SC was observed in 84% of en face images and 81% of cross-sectional images in eyes with POAG but in 92% of en face images and 86% of cross-sectional images in control eyes. Significant differences between the POAG and normal control eyes were found in the en face area (0.35 ± 0.14 mm2 vs. 0.56 ± 0.22 mm2 in the temporal quadrant and 0.36 ± 0.14 mm2 vs. 0.58 ± 0.23 mm2 in the nasal quadrant; both p < 0.001) and visible percentage of SC (85.71% vs. 94.91% and 87.10% vs. 95.52% in the temporal and nasal quadrant respectively, both p < 0.001) in en face images as well as the cross-sectional area (2790.9 ± 942.2 µm2 vs. 4138.6 ± 2027.8 µm2 in the temporal quadrant and 2805.7 ± 947.2 µm2 vs. 4224.0 ± 2002.2 µm2 in the nasal quadrant, both p < 0.001) and diameter of SC (123.1 ± 25.4 µm vs. 149.5 ± 34.7 µm in the temporal quadrant and 126.3 ± 28.9 µm vs. 155.3 ± 36.0 µm in the nasal quadrant, both p < 0.001) in cross-section images. In addition, the mean intraocular pressure (IOP) significantly correlated with the en face area, visible percentage of SC, and cross-sectional area in the temporal and nasal quadrants. Conclusion: SS-OCT can obtain high-quality en face images of SC without post-acquisition processing. Eyes with POAG had a decreased en face SC area compared with normal eyes. A correlation between SC area, visible percentage of en face images, and IOP was also observed.

In vivo CRISPR gene editing in patients with herpetic stromal keratitis.

In vivo CRISPR gene therapy holds large clinical potential, but the safety and efficacy remain largely unknown. Here, we injected a single dose of herpes simplex virus 1 (HSV-1)-targeting CRISPR formulation in the cornea of three patients with severe refractory herpetic stromal keratitis (HSK) during corneal transplantation. Our study is an investigator-initiated, open-label, single-arm, non-randomized interventional trial at a single center (NCT04560790). We found neither detectable CRISPR-induced off-target cleavages by GUIDE-seq nor systemic adverse events for 18 months on average in all three patients. The HSV-1 remained undetectable during the study. Our preliminary clinical results suggest that in vivo gene editing targeting the HSV-1 genome holds acceptable safety as a potential therapy for HSK.

Femtosecond laser-assisted Descemet's stripping endothelial keratoplasty: a prospective study of 6-month visual outcomes, corneal thickness and endothelial cell loss.

PURPOSE: To report 6-month outcomes of visual acuity, the corneal thickness and endothelial cell density (ECD) in patients undergoing femtosecond laser-assisted Descemet's stripping endothelial keratoplasty (FS-DSEK). METHODS: This prospective, consecutive, interventional series examined 25 eyes of 25 patients who underwent FS-DSEK for Fuchs endothelial dystrophy and bullous keratopathy. The pre-cut corneal endothelial graft thickness (CET) was 150 µm. Best-corrected visual acuity (BCVA), central corneal thickness (CCT), donor CET, recipient corneal stromal thickness (CST) and ECD were assessed at 1 week and 1, 2, 3 and 6 months postoperatively. RESULTS: The mean BCVA at 6 months was 0.76 ± 0.35 logMAR units, improving from 1.54 ± 0.52 logMAR. CCT decreased significantly, from 759.8 ± 152.4 µm at 1 week to 631.7 ± 79.7 µm at 6 months (P = 0.001) postoperatively. CET recovered to 153.4 ± 33.7 µm (P = 0.076) at 6 months as pre-cut status. The CST decreased from 561.5 ± 96.3 µm at 1 week to 479.7 ± 57.9 µm at 6 months (P < 0.001). Preoperatively, the donor ECD was 2747.6 ± 255.4 cells/mm2, and the ECD decreased to 1729.1 ± 562.9 cells/mm2 at 6 months, for a peak ECD loss of 36.86%. A greater decrease in CST observed from 1 week to 6 months postoperatively correlated with a lower ECD loss (P = 0.019) and a lower preoperative ECD (P = 0.012). However, a thinner CET correlated with a higher preoperative ECD (P = 0.028). CONCLUSIONS: FS-DSEK is a safe and effective surgical alternative for corneal endothelial decompensation. The donor ECD and its changes could be used as predictive factors for the improvement of CST and CET.

Malapposition of graft-host interface after penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK): an optical coherence tomography study.

BACKGROUD: Previous studies of internal graft-host malappositions have not dealt with the precise ways in which each malapposition affected post-penetrating keratoplasty (post-PK) visual outcomes. In this study, we reviewed our post-PK and post-deep anterior lamellar keratoplasty (post-DALK) keratoconic patients and used anterior segment optical coherence tomography (AS-OCT) to evaluate the associations between graft-host interface (GHI) characteristics and visual outcomes. METHODS: Novel GHI metrics included: mean graft-host touch (GHT), total prevalence of malapposition proportion (Pm), frequency of apposition (F), size of malapposition (Sm), junctional graft thickness (Tg), junctional host thickness (Th) and the absolute value of difference between Tg and Th (|Tg-Th|). We connected the external and internal junction points of GHI (GHT) and drew a straight line through the central point, perpendicular to both sides of the cornea. Tg and Th were the thicknesses at cross-points 1 mm away from the meeting point on the external side of the graft and host, respectively. Linear regression analysis was used to describe associations between GHI metrics and postsurgical visual outcomes [logarithm of minimum angle of resolution best-corrected visual acuity (logMAR BCVA), spherical equivalent diopter (SE), diopter of spherical power (DS), diopter of cylindrical power (DC) and keratometric astigmatism (Astig value)]. RESULTS: We enrolled 22 post-PK and 23 post-DALK keratoconic patients. Compared with the regular-apposition results, GHT was decreased in step and gape patterns, and increased in hill and tag patterns. SE increased averagely by 6.851, 5.428 and 5.164 diopter per 1% increase in: F (step) [ß = 6.851; 95% Confidence interval (CI) = 2.975-10.727; P = 0.001]; F (graft step) [ß = 5.428; 95% CI = 1.685-9.171; P = 0.005]; and Pm [ß = 5.164; 95%CI = 0.913-9.146; P = 0.018], respectively. SE increased averagely by 0.31 diopter per 10-µm increment in |Tg-Th| [ß = 0.031; 95% CI = 0.009-0.054; P = 0.007]. LogMAR BCVA increased (on average) by 0.01 per 10-µm increment in both GHT [ß = 0.001; 95% CI = 0-0.002; P = 0.030]. and Tg [ß = 0.001; 95% CI = 0.001-0.002; P = 0.001]. Astig value increased on average by 0.17 diopter per 10-µm increment in Sm [ß = 0.017; 95% CI = 0-0.033; P = 0.047]. CONCLUSION: This investigation of GHI characteristics suggests explanations for varied ametropia in keratoconic eyes and has potential significance as a reference for promoting pre-surgical planning and technology for corneal transplantation.

Hard Palate Mucoperiosteal Transplantation for Defects of the Upper Eyelid: A Pilot Study and Evaluation.

PURPOSE: To use hard palate mucoperiosteum to reconstruct the upper eyelid wisely and to evaluate its function and outcome. METHODS: In this case series, medial or lateral defects of the upper eyelid were reconstructed with a hard palate mucoperiosteum graft and a bandage contact lens to protect the cornea. Slit-lamp examinations, in vivo confocal microscopy, patient surveys, and pathologic examinations were performed as evaluations. RESULTS: Seven patients were included in this study. The average follow-up time was 21.9 months. Postoperatively, all patients maintained their preoperative corneal transparency, and the best-corrected visual acuities remained stable. Postoperative corneal examination by in vivo confocal microscopy was similar to the normal contralateral eye in all cases. All hard palate mucoperiosteal grafts merged smoothly with the normal tarsoconjunctiva. The mean ratio of the graft length to the upper eyelid decreased from 48.6% during the operation to 32.2% during the follow-up; the average shrinkage rate was 16.3% ± 7.1%. Both in vivo confocal microscopy and the pathologic examinations showed that stratified squamous epithelium comprised the main part of the hard palate graft. All patients could blink normally and had a relatively normal appearance. All patients were satisfied with the overall outcome of this therapy. Main complications included loss of eyelashes (100%), abnormal curvature of the eyelid (28.5%), mild lagophthalmos (14.3%), trichiasis (14.3%), and slight exfoliation of the corneal epithelium (42.8%). CONCLUSIONS: not only effectively reconstructs the upper eyelid but also provides protection for the cornea.

Assessment of Bulbar Redness with a Newly Developed Keratograph.

PURPOSE: To determine the validity and reliability of the clinical assessment of bulbar redness (BR) using a newly developed corneal topographer. METHODS: This is a cross-sectional diagnostic evaluation study. The BR scores [Oculus Index (OI)] from 30 eyes of 26 patients with different degrees of conjunctival hyperemia were assessed and scored automatically using a new method: a keratograph equipped with scanning and scoring software. The values obtained via this system were correlated with three image-based comparative subjective scales: the Institute for Eye Research (IER), the Efron, and the Validated Bulbar Redness (VBR) grading scales. The IER and Efron scores were interpolated to 0.1 unit, and the VBR scores were interpolated to 1 unit. We also evaluated the repeatability of each method and the level of agreement between the OI score and the scores achieved using the three other image-based methods. RESULTS: There was a significant correlation between the OI score and the scores obtained with the IER (r = 0.921, p < 0.001), Efron (r = 0.958, p < 0.001), and VBR (r = 0.965, p < 0.001) scales. The intraobserver intraclass correlation coefficients were 0.947, 0.874, 0.810, and 0.920 for the OI, IER, Efron, and VBR, respectively, and the intraobserver coefficients of repeatability were 13.924, 16.111, 17.684, and 16.900, respectively. Furthermore, the interobserver intraclass correlation coefficients were 0.889, 0.880, 0.884, and 0.881 for the OI, IER, Efron, and VBR, respectively, and the interobserver coefficients of repeatability were 15.934, 16.366, 22.059, and 21.373, respectively. CONCLUSIONS: The OI is an objective and reliable method for scoring BR. Its reproducibility was the highest of all the four modalities. The keratograph is recommended, therefore, as a suitable alternative for BR assessment.