Pattern noise (PANO): a new automated functional glaucoma test.

PURPOSE: To present a newly developed visual field device (pattern noise: PANO) designed to be sensitive to glaucoma defects, cost-effective, material-practical and easy to repair and therefore particularly suited for low-income countries, where glaucoma can be highly prevalent (e.g. sub-Saharan Africa). METHODS: This is primarily a descriptive paper, but it also includes a prospective matched case-control pilot study. Hardware, stimulus, target configuration, testing strategy and result sheet are described. The main outcome measure is the contrast level (range 2-64). Targets are composed of bright/dark pixels flickering with 18 Hz and have a size of 5°. Pixel size is approximated to the hill of vision. Average luminance of targets is constant and equals background luminance.The study was performed in the West Region in Cameroon. Twenty eyes of 20 newly presenting patients with glaucomatous optic disc cupping on funduscopy were compared with 20 eyes of 20 normal patients matched in age and laterality of eye. RESULTS: Mean age was 32.9 ± 18.8 years for glaucoma patients and 32.2 ± 15.6 years for healthy subjects. Mean contrast threshold was significantly higher in eyes with abnormal disc (16.2 ± 14.3 vs. 4.4 ± 0.8, P = 0.002). Correlation of mean contrast thresholds and cup-to-disc ratio was significant (r = 0.59; P = 0.006). Average examination time was significantly longer for glaucoma eyes compared to healthy eyes (8.2 vs. 6.1 min, P < 0.001), whereas error rate did not differ (4.8 ± 2.5% vs. 4.1 ± 1.8%, P = 0.33). CONCLUSION: PANO demonstrated visual field defects in patients with glaucomatous optic disc. Defects correlated significantly with glaucomatous optic nerve head morphological alterations. Healthy eyes obtained normal results. More studies are needed to establish PANO.

Corneal Neurotization-Indications, Surgical Techniques and Outcomes.

Corneal neurotization is a promising surgical approach for the treatment of moderate to severe neurotrophic keratopathy. This technique aims to restore corneal sensation by transferring healthy nerves, either directly or via a conduit, to the anesthetic cornea. This review provides a report on the current state of development, evidence, and experience in the field. We summarize the data available from clinical reports and case series, placing an emphasis on the diversity of the surgical techniques reported. While these data are encouraging, they also highlight the need for a consensus in reporting outcomes and highlight how the next step will involve validating putative outcome parameters when researching and reporting corneal neurotization surgery.

DMEK surgical training: An instructional guide on various wet-lab methods.

Descemet membrane endothelial keratoplasty (DMEK) is a partial-thickness corneal transplantation procedure that involves selective transplantation of the Descemet membrane and endothelium. DMEK offers significant advantages over other keratoplasty techniques, such as faster visual rehabilitation, better final visual acuity due to minimal optical interface effects, lower risk of allograft rejection, and less long-term dependence on topical steroids. Despite all its advantages, DMEK has been found to be more challenging than other corneal transplantation techniques, and its steep learning curve appears to be an obstacle to its widespread use and adoption by corneal surgeons worldwide. DMEK surgical training laboratories (wet labs) provide a window of opportunity for surgeons to learn, prepare, manipulate, and deliver these grafts in a risk-free environment. Wet labs are a significant learning tool, especially for those institutions that have limited tissue availability in their local centers. We provide a step-by-step guide for preparing DMEK grafts using different techniques on human and nonhuman models with instructional videos. This article should eventually help the trainees and the educators understand the requirements for performing DMEK and conducting a DMEK wet lab and develop their skills and interests from a wide variety of available techniques.

Intraocular bag-in-the-lens exchange: indications, outcomes, and complications.

PURPOSE: To report the indications, outcomes, and complications regarding bag-in-the-lens (BIL) intraocular lens (IOL) exchange over a period of 13 years in a tertiary ophthalmologic center. SETTING: Department of Ophthalmology of the University Hospital of Antwerp, Belgium. DESIGN: Observational retrospective study. METHODS: Between 2003 and 2020, 12 176 patients were operated using the BIL technique. Adult patients who underwent an intraocular BIL exchange were included, and the demographics, indications, outcomes, and complications were recorded. RESULTS: 59 eyes (0.48%) of 59 patients who underwent a BIL exchange between 2007 and 2020 were included. The mean age was 61.15 ± 13.53 years. The mean time between primary surgery and IOL exchange was 25.73 ± 41.88 months. The main indication for explantation was refractive surprise mostly related to patient risk factors, for example, preoperative corneal and refractive surgery. The mean preoperative uncorrected (UDVA) and corrected (CDVA) distance visual acuity were 0.36 ± 0.24 and 0.79 ± 0.24, respectively. The postoperative 1-month UDVA and CDVA were 0.66 ± 0.28 and 0.86 ± 0.19, respectively. The improvement in UDVA was statistically significant (<0.0001). The most common intraoperative complication was damage to the anterior hyaloid in 9 eyes (15%), which did not prohibit reimplantation of a secondary BIL. CONCLUSIONS: BIL to BIL exchange was a viable and successful technique that provides good refractive results with few, manageable complications. Because of the tertiary profile of the study center with referral of complex cases, BIL was the preferred IOL in patients at risk for postoperative refractive surprise.

Wave-like calcification on the posterior surface of an acrylic hydrophilic bag-in-the-lens (BIL) implant.

Purpose: To report secondary opacification of a hydrophilic bag-in-the-lens (BIL) which is a rare manifestation that can happen years after initial surgery. Observations: We describe a case of a prominent wave-like, rippled opacification on the posterior surface of the BIL. The opacification was composed of calcium deposits and seems to start in the periphery as a ring and progresses to the centre of the posterior surface. Due to the specific design of the BIL, there is direct contact between the BIL and the posterior chamber, both with the space of Berger, and the anterior hyaloid, particularly in this very hyperopic eye. Conclusions and importance: Abnormal fluid flow and stagnation in an unusual retrolenticular space is a possible explanation for this unusual pattern of posterior surface opacification.