Plastic vs. glass: the effect of the synthetic material in contact with DMEK tissue during staining on endothelial cell loss.

PURPOSE: Endothelial cell loss (ECL) during Descemet membrane endothelial keratoplasty (DMEK) graft preparation has been shown to affect graft survival and the need for re-grafting. The purpose of this study was to quantitatively assess the impact of the plastic and glass mediums in contact with DMEK donor tissue during intra-operative graft staining on ECL. METHODS: Retrospective study that included patients who underwent DMEK surgery between January 2019 and June 2021 at Hôpital Maisonneuve-Rosemont and the Jewish General Hospital in Montreal, Canada. DMEK grafts were stained with 0.06% Trypan blue ophthalmic solution (VisionBlue®, Dutch Ophthalmic, USA, Exeter, NH) for 120 s in either a plastic or glass medium prior to delivery into the recipient's eye. The ECL was compared between the two groups 12-30 months post-operatively. RESULTS: ECL at 12-30 months was significantly less in the eyes that had received grafts stained in a plastic medium compared to those stained in a glass medium. Graft survival and re-bubbling was higher in the glass group however this difference was not statistically significant. CONCLUSION: Staining of the DMEK graft in a plastic medium caused less ECL compared to the glass medium.

Intracameral Fibrinous Reaction During Descemet's Membrane Endothelial Keratoplasty.

PURPOSE: To determine the outcomes and predisposing factors of Descemet's membrane endothelial keratoplasty (DMEK) complicated by intraoperative fibrinous reaction. METHODS: Retrospective cohort study of 346 DMEKs. Medical charts were reviewed for recipient demographics, surgical indications, donor characteristics, and potential predisposing ocular and systemic factors. For DMEKs complicated by fibrin, surgeons' notes on events leading to fibrin formation and on its intraoperative management, occurrence of graft detachment, primary failure, re-bubbling or regrafting, time to graft clearing, and endothelial cell density were additionally collected. RESULTS: Fifteen (4.3%) DMEKs were complicated by fibrin, which interfered with and protracted graft unfolding in all cases. Median surgical time was longer than for uncomplicated DMEKs (p = 0.001). Graft positioning at the end of surgery was suboptimal in seven eyes (47%) and failed in three (20%). Re-bubbling, primary failure, and regraft rates were of 40%, 33% and 53%, respectively. The corneas that cleared did so in three to eight weeks, with median endothelial cell loss of 53% at 12 months. Use of anticoagulants was a preoperative risk factor (p = 0.01). Surgeon-identified intraoperative factors included beginner surgeons (87%), prolonged AC shallowing (47%) and graft manipulations (33%), intraocular bleeding (27%), new injector (20%), tight donor scroll (13%), and floppy iris (13%). CONCLUSION: Fibrinous reaction is a rare intraoperative complication of DMEK that interferes with graft unfolding and results in poor outcomes. Anticoagulant use appears to be a risk factor and may be compounded by surgical trauma to vascular tissues and prolonged surgical maneuvers.

Rare Case of Thygeson Superficial Punctate Keratitis After COVID-19 Vaccination.

PURPOSE: The aim of this study was to elucidate a rare corneal association of the coronavirus disease 2019 (COVID-19) vaccine. Although cases of corneal involvement after vaccination have been reported, we present the first case of Thygeson superficial punctate keratitis (TSPK) linked to the COVID-19 vaccine. METHODS: This study is a case report. RESULTS: A 25-year-old woman was assessed in the ophthalmology clinic for recurrent ocular surface symptoms after receiving the COVID-19 vaccine. She was followed in clinic and was found to have a remitting and recurring pattern of bilateral intraepithelial corneal opacities with associated subepithelial haze primarily overlying the pupillary area. These corneal lesions responded well to topical corticosteroid ophthalmic drops. Based on the clinical appearance, the response to treatment, negative herpes simplex virus serology, and the temporal relationship between vaccination and ocular findings, a diagnosis of COVID-19 vaccine-induced TSPK was suspected. CONCLUSIONS: Although the COVID-19 vaccine remains overwhelmingly safe, clinicians should be aware of possible corneal side effects, including TSPK. Prompt ophthalmic assessment in those presenting with ocular symptoms after vaccination is encouraged.

Poor Long-Term Outcomes of Keratopigmentation With Black Ink for the Treatment of Dysphotopsia Secondary to Laser Peripheral Iridotomies.

PURPOSE: To report outcomes of keratopigmentation (KP) with commercial black ink in the treatment of dysphotopsia secondary to laser peripheral iridotomies (LPI) using manual anterior stromal puncture (ASP) and manual lamellar pocket (LP). METHODS: This is a retrospective case series of eyes that underwent KP for treatment of dysphotopsia secondary to LPI. Patients' postoperative symptoms were categorized as resolved, improved, no change, or worse. Any intraoperative and postoperative complications were noted, as well as the need for further treatments. RESULTS: Five eyes in 4 patients underwent ASP, and 14 eyes in 13 patients underwent LP. Only 1 patient had improvement in symptoms in the AK group. Four patients had a complete resolution of symptoms after LP, whereas 7 had symptomatic improvement and 3 did not notice any change. Fifty-five percent of patients in the LP group experienced late-onset depigmentation between 3 and 5 years postoperatively. One patient who underwent 2 LP re-treatments experienced irregular corneal steepening with nonprogressive corneal thinning. Overall, there were no serious adverse reactions to the pigment used. CONCLUSIONS: ASP was not suitable for the treatment of dysphotopsia secondary to LPI. In the short term, LP had good outcomes, but commercial black ink was prone to depigmentation at 3 to 5 years postoperatively. We therefore do not recommend the use of such pigment for long-term management of dysphotopsia secondary to LPI.

Successful management of severe post-LASIK Mycobacterium abscessus keratitis with topical amikacin and linezolid, flap ablation, and topical corticosteroids.

This is a case report of post-laser in situ keratomileusis (LASIK) multidrug-resistant Mycobacterium abscessus keratitis managed with combined topical amikacin and linezolid, flap amputation, and corticosteroids. A 34-year-old woman presented with a corneal interface infiltrate 3 weeks after LASIK. Cultures isolated mycobacteria. The infiltrate did not improve under intensive topical therapy and interface irrigation with empiric antibiotics over 5 weeks, and the infiltrate progressed to severe inflammation and stromal neovascularization. After identification of M abscessus susceptible only to amikacin and linezolid, antimicrobials were adjusted and the flap was ablated. Cultures repeated 1 week later came back negative. However, stromal inflammation and neovascularization persisted. Topical steroids achieved regression of the inflammation within 1 week. Identification of the mycobacterial pathogen and its susceptibilities is essential given the possibility of multidrug resistance. Topical linezolid can be effective in susceptible species. Corticosteroids can be helpful in cases with severe inflammation.

Crystalline Keratopathy in Post-LASIK Ectasia: A Case Report.

PURPOSE: To report an unusual case of bilateral crystalline keratopathy presenting several years after a laser in situ keratomileusis (LASIK) procedure. METHODS: Case report and review of the literature. RESULTS: A healthy 42-year-old woman with post-LASIK ectasia, treated with long-term corneoscleral contact lenses, developed new-onset crystalline keratopathy in both eyes. Anterior segment optical coherence tomography demonstrated bilaterally symmetric paracentral rings of hyperreflectivity, involving the LASIK corneal flaps. There was good clearance of the corneoscleral contact lenses with no corneal-lens touch in all quadrants. There was no evidence of infectious or systemic etiologies. Genetic testing for the UBIAD1 gene for Schnyder corneal dystrophy was negative. Continued clinical observations have exhibited progressive corneal crystalline deposition, yet the patient has remained visually asymptomatic. CONCLUSIONS: This is the first known reported case of significantly delayed progressive noninfectious crystalline keratopathy in post-LASIK ectasia. The pathophysiology of this condition remains elusive to date and highlights the challenges of noninvasive diagnostic techniques and yet the utility of molecular genetic analysis in elucidating the etiology of this unique clinical presentation.

The role of novel DMEK graft shapes in facilitating intraoperative unscrolling.

PURPOSE: To evaluate whether the preparation of Descemet membrane endothelial keratoplasty (DMEK) grafts into various shapes affect their propensity to scroll as compared with the conventional circular graft design. METHODS: Prospective randomized laboratory-based study, using nine pre-stripped DMEK corneal grafts unfit for transplantation. Each graft was trephinated into a standard circular 8-mm shape, stained with trypan blue, and then immersed in balanced salt solution (BSS). The width of the DMEK graft scroll was measured, and photographs were obtained. The graft was then cut into one of three pre-selected shapes (four peripheral punches, four radial cuts, Maltese cross). These newly shaped grafts were then replaced in BSS and again photographed. The scroll widths, as well as pre- and post-preparation scroll width-to-height ratios, were calculated and compared. RESULTS: Nine pre-stripped DMEK corneal grafts (mean donor age ± SD 73.1 ± 9.3 years, range 58-85 years) were included. The mean pre-cut scroll widths for the three selected shapes were statistically similar. Following graft preparation into their assigned shapes, the mean post-preparation scroll widths (and corresponding change from pre-preparation measurements) were 1.73 ± 0.16 mm (- 3.6%) for the 4-peripheral punches, 2.59 ± 0.35 mm (+ 0.2%) for the 4-radial cuts and 4.13 ± 0.63 mm (+ 20.1%) for the Maltese cross (P = 0.0013). Therefore, the Maltese cross design resulted in a wider scroll than its pre-preparation control. CONCLUSIONS: Certain DMEK graft shapes may be less prone to scrolling than others. The Maltese cross graft design scrolled less tightly than the other experimental graft shapes. Future studies may elucidate intraoperative scrolling behavior of these DMEK graft shapes within the anterior chamber.

Association between unilateral quiescent stromal herpetic keratitis and bilateral dry eyes.

PURPOSE: According to our clinical observation, patients with quiescent herpes simplex virus (HSV) stromal keratitis often seem to present with signs of dry eye in the contralateral eye. Our goal was to compare dry eye signs and symptoms in both eyes of patients with quiescent HSV stromal keratitis with those of age- and sex-matched control subjects with healthy corneas. METHODS: A case-control study with 24 subjects per group. RESULTS: The average age of 10 men and 14 women in each group was 58 years. The HSV eye of cases was first compared with the contralateral eye with a healthy cornea. As expected, the HSV eye had a significantly lower corneal sensation threshold (P = 0.001); no significant difference was however found for Schirmer tests done with anesthesia (basal tear secretion) and without anesthesia, tear breakup time, mucus and debris in the tear film, and eyelid margin redness or swelling. Then, the HSV eye of cases was compared with the right eye of controls, whereas the healthy eye of cases was compared with the left eye of controls. Patients with unilateral quiescent HSV stromal keratitis had significantly lower bilateral Schirmer tests both with anesthesia (P = 0.001) and without anesthesia (P = 0.02). Dry eye symptoms of the healthy cornea of cases and those of controls did not differ significantly. CONCLUSIONS: Both eyes of patients with quiescent HSV stromal keratitis in our population were dry even if many patients with HSV stromal keratitis did not have symptoms in their fellow eye.

Use of telemedicine in screening for diabetic retinopathy.

BACKGROUND: A diabetic retinopathy screening program was introduced in September 2000 at a university-affiliated hospital in Montreal to meet the demands of an overburdened health care system. In this article we describe our initial experience with this program. METHODS: A Canon CR6-45NM nonmydriatic 45 degrees camera was installed in the outpatient endocrinology clinic of the hospital. All patients who visited the clinic between September 2000 and January 2001 agreed to participate in the program. For each patient, a short questionnaire (age, sex, type of diabetes mellitus, time since diagnosis, prior retinal laser therapy and presence of end-organ involvement) was filled in. Subsequently at least two photographs were obtained of each eye. The photographs were sent via the hospital intranet to a retinal specialist within the hospital. The specialist reviewed the images unchanged and sent a report (grading of the level of diabetic retinopathy, presence or absence of macular hard exudates, quality of the images obtained and follow-up recommendations) via the hospital intranet to the endocrinology service. If the images were judged to be of poor quality and could not be read by the retina specialist, the patient was asked to see his or her regular ophthalmologist. RESULTS: Images of 830 eyes of 415 patients (211 men and 204 women with a mean age of 57.5 years) were obtained. Most (83.6%) had type 2 diabetes. The average duration of disease was 13.3 years. Macular hard exudates were observed in 50 eyes (6.0%). Nonproliferative diabetic retinopathy was noted in 117 eyes (14.1%) and proliferative diabetic retinopathy in 15 eyes (1.8%). Unexpected findings included epiretinal membranes (in three eyes), macular holes (in two), bilateral cotton-wool spots (in one patient) and central retinal vein occlusion (in one eye). Overall, 10% of the patients were referred to a retina specialist based on the screening photographs. The main difficulty encountered with the screening program was image inconsistency. Overall, 35% of the images graded were felt to be of poor quality, the most common reason being poor exposure (84.4%). The quality of the images improved significantly over the study period (p < 0.01). Images obtained from patients aged 65 years or more were consistently poorer than those obtained from patients less than 65 years of age (p < 0.001). INTERPRETATION: Despite the imperfections of such a system, our experience was favourable, allowing us to screen large numbers of patients in a cost-effective, reliable manner.