Deep learning-accelerated image reconstruction in MRI of the orbit to shorten acquisition time and enhance image quality.

BACKGROUND AND PURPOSE: This study explores the use of deep learning (DL) techniques in MRI of the orbit to enhance imaging. Standard protocols, although detailed, have lengthy acquisition times. We investigate DL-based methods for T2-weighted and T1-weighted, fat-saturated, contrast-enhanced turbo spin echo (TSE) sequences, aiming to improve image quality, reduce acquisition time, minimize artifacts, and enhance diagnostic confidence in orbital imaging. METHODS: In a 3-Tesla MRI study of 50 patients evaluating orbital diseases from March to July 2023, conventional (TSES ) and DL TSE sequences (TSEDL ) were used. Two neuroradiologists independently assessed the image datasets for image quality, diagnostic confidence, noise levels, artifacts, and image sharpness using a randomized and blinded 4-point Likert scale. RESULTS: TSEDL significantly reduced image noise and artifacts, enhanced image sharpness, and decreased scan time, outperforming TSES (p < .05). TSEDL showed superior overall image quality and diagnostic confidence, with relevant findings effectively detected in both DL-based and conventional images. In 94% of cases, readers preferred accelerated imaging. CONCLUSION: The study proved that using DL for MRI image reconstruction in orbital scans significantly cut acquisition time by 69%. This approach also enhanced image quality, reduced image noise, sharpened images, and boosted diagnostic confidence.

Impact of OCT scan-patterns in identifying morphological features of lamellar macular holes and macular pseudoholes.

AIM: To evaluate the impact of the optical coherence tomography (OCT) scan patterns on the detection of the features associated with lamellar macular hole (LMH) and macular pseudohole (MPH). METHODS: This is a retrospective analysis of 100 consecutive eyes with LMH (n=41) and MPH (n=59) having at least three of the following OCT features, which include mandatory criteria for the diagnosis of LMH and MPH: Epiretinal membrane, epiretinal proliferation, verticalization, intraretinal cystoid spaces, foveoschisis, irregular foveal contour, foveal cavity with undermined edges, and ellipsoid line disruption. Primary outcome measurement was the detection frequency of the features in three different OCT scan patterns: 1) volume scan; 2) six radial scans (R6); and 3) vertical and horizontal radial scans (R2). RESULTS: Of the total eight features, the maximal detection frequency was found as 4.45±1.45, 4.35±1.47, and 3.70±1.59, by the volume, R6 and R2, respectively. R2 was inferior to the other patterns in detection of the total features (P<0.001), whereas R6 and volume patterns were found comparable (P=0.312). CONCLUSION: The physician should be aware that the selection of the OCT-scan pattern may influence the detection of mandatory morphological criteria for the diagnosis of LMH and MPH.

Impact of keratoconus stage on outcome after corneal crosslinking.

BACKGROUND: This study aimed to analyze if the outcome after corneal crosslinking (CXL) in progressive keratoconus patients depends on the stage at which the procedure is performed. This knowledge would help to improve success of CXL and to define surgery indications in those patients. METHODS: In this retrospective study, 124 consecutive eyes of 100 patients with progressive keratoconus undergoing corneal CXL at the University Eye Hospital Tübingen were included. The eyes were graded according to modified Krumeich stages depending on induced myopia or astigmatism, corneal radii, minimum corneal thickness, and morphological changes. The observation period covered November 2008 to September 2018. Preoperatively, 12 and 24 months after CXL, the best corrected visual acuity (BCVA) was determined and astigmatism as well as tomographic parameters (Kmax, Kmin, central corneal thickness (CCT), minimum corneal thickness (MCT)) were measured by means of a Scheimpflug camera system. RESULTS: BCVA results showed significant differences between the modified Krumeich stages at 12 months (p = 0.014) and at 24 months postoperatively (p = 0.032). Also, astigmatism differed significantly among the stages at 24 months after CXL (p = 0.023). However, no significant differences regarding astigmatism were detectable after 12 months. In terms of Kmax, Kmin, CCT, and MCT, no significant differences between the Krumeich stages were observed. CONCLUSIONS: BCVA showed a significantly higher improvement after CXL in the early stage of keratoconus compared to a higher stage. However, the postinterventional tomographic values did not differ significantly between the different modified Krumeich stages. The significantly higher improvement in BCVA after CXL in the early stage might indicate that earlier intervention provides a higher subjective benefit to the individual. Further studies with larger sample sizes are needed to confirm these findings.

Successful Regression in Patients with Progressive Keratoconus by Corneal Crosslinking. / Erfolgreiche Regression durch Crosslinking bei Patienten mit fortschreitendem Keratokonus.

BACKGROUND: Since 2019, corneal collagen crosslinking (CXL) is included in the catalog of procedures covered by statutory health insurance in Germany. CXL is an established ophthalmological procedure for the last 20 years. The aim of this investigation was the measurement of progression before and after CXL. MATERIAL UND METHODS: 65 consecutive eyes with progressive keratoconus from 53 patients were included in the retrospective study, which were observed at the University Eye Hospital Tübingen at least two years before and at least two years after CXL. The time of observation took place from October 2009 until March 2018. Parameters of interest had been the best corrected visual acuity (BCVA) and the keratometric values from the elevation maps measured by a Scheimpflug camera. RESULTS: 65 eyes of 53 patients had been documented. The study population included 46 (86.8%) male and 7 (13.2%) female subjects. The mean age was 24 ± 8 years. The averaged observation time between the primary consultation and CXL showed 25 ± 15 months. Preoperatively the mean BCVA pointed out in a significant increase (0.13 ± 0.17 [first visit] vs. 0.23 ± 0.22 [preOP], p < 0.0001) while the mean Kmax resulted in a statistically significant increase (46.34 ± 3.33 dpt [first visit] vs. 48.78 ± 4.17 dpt [preOP], p < 0.0001). The mean thinnest point of the cornea showed a significant decrease (490.48 ± 34.23 µm [first visit] vs. 468.62 ± 29.84 µm [preop], p < 0.0001). Postoperatively the mean BCVA resulted in a significant improvement at the 12th postoperative month in comparison to the preoperative measurement (0.23 ± 0.22 [preOP] vs. 0.16 ± 0.14 [12 months], p = 0.04 respectively 0.17 ± 0.17 [24 months], p = 0.0006). The mean Kmax demonstrated in the 12th postoperative month a significant reduction (48.78 ± 4.17 dpt [preOP] vs. 47.91 ± 3.41 dpt [12 months], p = 0.0009 respectively 48 ± 4.56 dpt [24 months], p = 0.0051). The mean thinnest point of the cornea indicated a decrease at the 12th postoperative month (468.62 ± 29.84 µm [preOP] vs. 459.82 ± 35.88 µm [12 months], p = 0.0078 respectively 453.47 ± 43.39 µm [24 months], p = 0.0227). CONCLUSION: CXL is a successful procedure for the therapy of progressive keratoconus.

α5ß1-Integrin inhibitor (CLT-28643) effective in rabbit trabeculectomy model.

PURPOSE: Glaucoma filtration surgery (GFS) fails due to fibrosis. The α5ß1-integrin plays a pivotal role in fibrosis, angiogenesis and inflammation. This is the first experiment evaluating the prevention of fibrosis after GFS by a specific small molecule α5ß1-integrin inhibitor (CLT-28643). METHODS: Twenty-four rabbits received trabeculectomy on their right eyes. The rabbits were randomized into three groups of eight eyes each. CLT-28643 was given as a single subconjunctival injection intraoperatively to two of the right eye groups followed by postoperative vehicle eye drops (CLT+ group) or CLT-28643 eye drops 4 times daily (CLT++ group). A third group received mitomycin-C (MMC) intraoperatively (sponge application, 0.04%, 2 min) followed by vehicle eye drops postoperatively. The control-surgery group consisted of 12 left eyes having trabeculectomy with no adjunctive therapy. The remaining 12 left eyes formed the untreated group. Clinical assessment included intraocular pressure (IOP) measurement, slit-lamp examination (including bleb survival and morphology) and bleb photography. The rabbits were killed after four weeks for histology. RESULTS: Both CLT-28643-treated groups showed significantly prolonged bleb survival, and better bleb score compared to the control-surgery group. At end of the study, most functioning blebs were found in the MMC group (MMC group 75%; CLT+ group 12.5%, CLT++ group 25%; CLT+ group 12.5%, control-surgery group 0%). CLT-28643 was non-toxic and well tolerated. CONCLUSIONS: This rabbit GFS study indicates that inhibition of α5ß1-integrin by the novel α5ß1-integrin antagonist CLT-28643 significantly improved the outcome. The effect of a single intro-operative application of CLT-28643 seems to be inferior to 0.04% MMC.