Immunohistochemical Findings in Retrocorneal Membranes of Eyes with Corneal Decompensation after Complicated Intraocular Surgery.

BACKGROUND: Retrocorneal membranes (RCMs) may result from epithelial ingrowth, stromal keratocytic downgrowth, fibrous metaplasia of the corneal endothelium, or a combination of these processes. In an institutional case series, the clinical history, ocular findings, and immunohistochemical staining results of RCMs were analysed in patients with unilateral corneal decompensation after complicated intraocular surgery. METHODS AND PATIENTS: Between January 2021 and September 2022, six retrocorneal membranes were excised during Descemet's stripping automated endothelial keratoplasty (DSAEK) and Descemet membrane endothelial keratoplasty (DMEK) procedures and classified after screening with haematoxylin and eosin, periodic acid-Schiff, elastic van Gieson staining, and immunohistochemical screening with cytokeratin 7 (CK7), anti-cytokeratin (CAM5.2 and AE1/3), cell surface glycoprotein CD34, smooth muscle actin (α-SMA), and vimentin. RESULTS: On the basis of the immunohistochemical screening, the majority of excised RCMs (5 of 6) could histopathologically be classified as membranes originating from fibrous metaplasia of the corneal endothelium. All these RCMs were positive for CK7, α-SMA, and vimentin and negative for CAM5.2 and CD34. In one patient, an RCM had developed after 18 days of corneal contact to a free-floating dexamethasone implant in the anterior chamber and was classified as originating from stromal keratocyte downgrowth (α-SMA- and vimentin-positive, all others negative). All eyes in this series had a previous history of complicated cataract surgery, partially with subsequent intraocular lens exchange. No eyes after previous penetrating keratoplasty were in this series. CONCLUSIONS: In this series of eyes with previous complicated intraocular interventions (in most cases cataract surgery and revisions), the dominating RCM belonged to the type originating from fibrous metaplasia of the corneal endothelium.

The Clinical Characteristics of Unilateral Placoid Pigment Epitheliopathies.

Purpose: Placoid-pigment-epitheliopathies like Acute-Posterior-Multifocal-Placoid-Pigment Epitheliopathy (APMPPE) and Relentless-Placoid-Choroidopathy (RPC) usually show bilateral involvement. This retrospective case series describes the clinical features with unilateral disease onset.Methods: 21 patients from 9 tertiary referring institutions were collected and evaluated.Results: Seventeen patients were included: 11 (65%) had unilateral placoid-pigment-epitheliopathy consistent with APMPPE, 6 (35%) with RPC (mean age: 28.82 ± 9.1 years). Mean follow-up time was 45 ± 48 months. Forty-one percent fellow-eyes had initial inflammatory signs including vitreous-cells, vascular-sheathing, and ONH swelling. Thirty-five percent developed chorioretinal lesions during follow-up after 19.5 ± 16.9 months. Initial inflammation in fellow-eye was not associated with fellow-eye involvement (p = .5). However, subfoveal choroidal-thickness (SCT) at baseline was significantly thicker in fellow-eyes who developed chorioretinal lesion compared to fellow-eyes who did not (400 ± 70 µm versus 283 ± 127 µm,p = .047).Conclusion: Unaffected fellow-eyes may have inflammatory signs at initial disease-onset and may develop lesions over time. They should be carefully monitored, particularly if they present with an increased SCT.

A Short Review on the Safety of Bromphenol Blue for Dye-Assisted Vitreoretinal Interventions.

Bromphenol blue was approved for the intraoperative staining of the vitreous, epiretinal membranes, and internal limiting membrane of the retina several years ago. It has been marketed as a combined dye formulation of bromphenol blue (1.3 mg/mL) and brilliant blue G (0.25 mg/mL). So far, comprehensive information on preclinical and clinical safety data of bromphenol blue is lacking. A PubMed analysis of available literature was performed. Ten relevant publications on preclinical and clinical evaluations of bromphenol blue were found. It is striking that almost no safety data is available on the presently used clinical product. Current clinical use seems not completely be justified by scientific safety data.

A Simple, Inexpensive, and Precise Photographic Method for Intraoperative Toric IOL Alignment.

BACKGROUND: It was the aim of this study to analyse the refractive outcome of toric intraocular lens (t-IOL) implantation guided by a newly developed method of photographic alignment. MATERIAL AND METHODS: Fourteen eyes of 10 patients (6 females, 4 males, age 63.4 ± 6.7 (40.6 - 68.0) years [mean ± 1 SD (range)]) were included in this retrospective study. All eyes received an Oculentis Tplus LS-313 (Oculentis, Berlin, Germany) t-IOL after standard phacoemusification (n = 4) or femtocataract laser-assisted surgery (n = 10). Image-guided t-IOL alignment included: (1) calculation of t-IOL parameters (combination of different biometric methods) and plotting a layout drawing of the target lens position, (2) capture of an anterior segment slit lamp photograph in the upright position, (3)  superposition of the photographs by the t-IOL target plot and a gradual scale, (4) drawing of marker lines on the photograph and removal of the IOL target coordinates, (5) transfer of the final image to a tablet PC, and (6) marking of the target axis at the corneal limbus with an ink pen in the surgical room. RESULTS: Preoperative corneal astigmatism was 2.50 ± 0.97 (1.38 - 4.34) diopters (D) (mean ± 1 SD, range). In all eyes, intraoperative alignment could easily be performed using the photographic target layout. Surgical interventions and postoperative follow-up were without complications in all cases. Residual postoperative astigmatism was 0.16 ± 0.24 (0.00 - 0.75) D (p < 0.001 compared to preoperative astigmatism). In 64% of patients, residual subjective astigmatism was zero, in 93% ≤ 0.5 D, and in 100% ≤ 0.75 D. Postoperative uncorrected logMAR visual acuity (0.05 ± 0.07, range 0.00 - 0.20) and best-corrected visual acuity (0.03 ± 0.05, 0.00 - 0.10) were significantly better (each p < 0.001) than best-corrected preoperative visual acuity (0.21 ± 0.14, 0.00 - 0.49). CONCLUSIONS: Results of this clinical series clearly indicate that the newly developed photographically guided technique of toric lens alignment leads to highly accurate postoperative results for astigmatic correction.

The Assessment of Blood Flow Velocities in Retinal Collaterals in Diabetic Retinopathy.

PURPOSE: Diabetic retinopathy (DR) is a microvascular disease characterized by capillary dropout and resultant retinal ischemia which then leads to retinal vascular remodeling. Our goal was to assess blood flow velocities in retinal collateral vessels in healthy and diabetic subjects with various stages of DR. METHODS: In our pilot study, we enrolled five eyes of five healthy subjects (H), five eyes of four subjects with diabetes and no retinopathy (DM), three eyes of three subjects with mild non-proliferative diabetic retinopathy (MDR), and five eyes of four subjects with proliferative diabetic retinopathy (PDR). Following routine ophthalmic examination, all subjects were imaged using a retinal function imager (RFI; Optical Imaging Inc., Rehovot, Israel). The built-in software of the RFI was used to identify and segment retinal collaterals with measurement of the blood flow velocities (BFV). One-way ANOVA was performed for BFV, followed by Newman-Keuls post hoc test. The level of significance was set at 5%. RESULTS: The total number of collateral segments involved in the study was 30, 31, 21, and 39 in the H, DM, MDR, and PDR groups, respectively. The BFVs in the collaterals were significantly lower in PDR (H: 1.86 ± 0.67, DM: 1.91 ± 0.71, MDR: 1.71 ± 0.53, PDR: 1.37 ± 0.58 mm/s). The PDR group showed a statistically significant difference in the comparisons to all groups (p = 0.012, p = 0.008, and p = 0.043 for the H, DM, and MDR groups, respectively), while no other comparisons between the groups were significant. CONCLUSION: We observed decreased BFV in retinal collaterals in PDR that may be due to the extensive capillary dropout and retinal ischemia. Further studies are needed for the noninvasive functional assessment of retinal microvascular changes in DR to better understand the underlying pathophysiology.

Safety and Feasibility of a Novel Sparse Optical Coherence Tomography Device for Patient-Delivered Retina Home Monitoring.

PURPOSE: To study a novel and fast optical coherence tomography (OCT) device for home-based monitoring in age-related macular degeneration (AMD) in a small sample yielding sparse OCT (spOCT) data and to compare the device to a commercially available reference device. METHODS: In this prospective study, both eyes of 31 participants with AMD were included. The subjects underwent scanning with an OCT prototype and a spectral-domain OCT to compare the accuracy of the central retinal thickness (CRT) measurements. RESULTS: Sixty-two eyes in 31 participants (21 females and 10 males) were included. The mean age was 79.6 years (age range, 69-92 years). The mean difference in the CRT measurements between the devices was 4.52 µm (SD ± 20.0 µm; range, -65.6 to 41.5 µm). The inter- and intrarater reliability coefficients of the OCT prototype were both >0.95. The laser power delivered was <0.54 mW for spOCT and <1.4 mW for SDOCT. No adverse events were reported, and the visual acuity before and after the measurements was stable. CONCLUSION: This study demonstrated the safety and feasibility of this home-based OCT monitoring under real-life conditions, and it provided evidence for the potential clinical benefit of the device. TRANSLATIONAL RELEVANCE: The newly developed spOCT is a valid and readily available retina scanner. It could be applied as a portable self-measuring OCT system. Its use may facilitate the sustainable monitoring of chronic retinal diseases by providing easily accessible and continuous retinal monitoring.