Michèle Mabon’s research while affiliated with Université de Montréal and other places

Purpose To report a rare case of conjunctival neuroma after a successful corneal neurotization surgery. Methods The clinical file and histopathology slides of this patient who underwent surgical corneal neurotization for a neurotrophic keratopathy in the right eye were reviewed. Results A 70-year-old man with a history of severe herpetic (varicella zoster) neurotrophic keratopathy and keratouveitis in the right eye developed a corneal perforation, which required tectonic keratoplasty (May 2020). Corneal neurotization was performed 1 year later without complication, using the ipsilateral supraorbital and supratrochlear nerves to reinnervate the right cornea (April 2021), followed by repeat penetrating keratoplasty (September 2021). Three months later, a superonasal conjunctival mass was observed with a contiguous corneal delle and melt at the corneal-host junction. In vivo confocal microscopy showed numerous nerve fibers within the conjunctival mass, suggesting a diagnosis of conjunctival neuroma. The mass was surgically debulked, and the diagnosis was confirmed by histopathology and immunohistochemistry. The delle and corneal melt were successfully treated with an amniotic membrane. Conclusions To the best of our knowledge, this is the first case of confirmed conjunctival neuroma reported after corneal neurotization. Confocal microscopy, histopathology, and immunohistochemistry have proven to be highly useful tools for the prompt recognition and accurate diagnosis necessary for the proper management of this rare complication.

Purpose To validate a French version of the Visual Function and Corneal Health Status (V-FUCHS) instrument in Fuchs endothelial corneal dystrophy (FECD) and to correlate questionnaire scores with objective measurements of best-corrected visual acuity (BCVA) and intraocular straylight. Methods The original V-FUCHS 15-item instrument was designed to assess VA and glare in patients with FECD. It was translated from English to French and back translated to English by independent translators. The questionnaire was administered on 2 occasions (4 weeks apart), and BCVA, modified Krachmer grade, and straylight were measured. Construct validity, internal consistency, test–retest reliability, and predictive validity were assessed. Results A total of 159 subjects, aged 41 to 86 years, were prospectively recruited from July 2019 to October 2020 and classified into 6 groups: mild, moderate, or advanced FECD; unilateral or bilateral Descemet membrane endothelial keratoplasty for FECD; and healthy controls (n = 35). Construct validity was confirmed by item response theory model. Cronbach alpha demonstrated excellent internal consistency (VA: 0.91, glare: 0.88), and intraclass correlations showed good test–retest reliability (VA: 0.75 and glare: 0.82). Significant correlations were observed between both VA and glare factors and the modified Krachmer grade, BCVA, and straylight. Conclusions The proposed French version of the V-FUCHS instrument provides a valid and reliable tool for the assessment of visual disability in patients with FECD. This questionnaire bridges the gap between self-reported FECD symptoms and objective clinical measurements, which may prove useful to optimize the timing of surgery and to assess postoperative improvement in symptoms.

Purpose: To assess the efficacy of the prestorage corneal swab (PCS) culture to screen for corneal graft contamination after storage in Optisol-GS. Methods: A retrospective analysis of all PCS cultures was performed at the Eye Bank of Québec in Hôpital Maisonneuve-Rosemont from September 2013 to June 2016. Whole corneal culture was performed on rejected grafts because of a positive PCS, and a contamination rate was calculated. In addition, contamination rates of corneoscleral rims were compared between corneas tested with PCS and those of imported corneas which did not have PCS. Results: Among the 1966 PCS cultures performed, 814 (41.4%) were positive for growth. Pathogenic bacteria were present in 144 (7.3%) corneas, including Staphylococcus aureus (n = 96, 11.8% of all positive cultures), Enterobacteriaceae (n = 14, 1.7%), and Pseudomonas aeruginosa (n = 6, 0.7%). After preservation in Optisol-GS, only 7 (6.9%) corneas remained contaminated (95% confidence interval 5.1-9.3). The sensitivity of the PCS culture was 87.5% (95% confidence interval 47.4-99.7). There was no significant difference in corneoscleral rim contamination between corneas tested with PCS (1/388; 0.2%) compared with imported, nonswabbed corneas (3/214; 1.4%) (P = 0.131). Therefore, the cost to recover the loss of tissue rejected because of false-positive PCS by purchasing corneal tissue was calculated to be $142,884 (CAD) per year. Conclusions: Despite the high sensitivity of PCS cultures, there was no significant reduction of infection after corneal transplantation using this technique. In consequence, 93% of the corneas possibly suitable for transplantation were rejected. This suggests that the PCS culture alone is a poor test for detecting clinically relevant corneal contamination.

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.

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.

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.

The goal of this study was to determine the changes in surgical techniques and leading indications for corneal transplantations performed in the last decade. The impact of administrative changes of corneal banking in Quebec was also evaluated. The records of all corneal transplantations performed between January 2000 and December 2011 in the territory subserved by the Quebec Eye Bank and Héma-Québec (Quebec, Canada) were retrospectively reviewed. A total of 3459 corneal transplantations were performed between 2000 and 2011. The rate of corneal transplantation more than doubled from 234 grafts per year in 2000 to 592 grafts per year in 2011. Imported tissue represented 40% of grafted corneas. Increases in tissue importation were seen in 2003 and 2009 to address local tissue shortage and peaks in wait time. The average wait time decreased from 434 ± 456 days (2000-2008) to 418 ± 551 days (2009-2011) (P = 0.01). The leading surgical indications were Fuchs endothelial corneal dystrophy (27%), pseudophakic corneal edema (26%), keratoconus (13%), and viral keratitis (8%). Regrafts represented 25% of procedures. Descemet stripping automated endothelial keratoplasty became the preferred technique for endothelial diseases, surpassing penetrating keratoplasty in 2011. The surgical indications and techniques used for corneal transplantation in Quebec reflected those of the literature. However, long wait times and corneal tissue shortages mandated significant changes in the organization of the Quebec Eye Bank. Partnering with a larger agency responsible for tissue and blood donation coordination (Héma-Québec) had a positive impact on yearly transplantation rates and wait times.

Corneal tattooing is a technique that has been used for centuries to improve either cosmesis or clinically significant anomalies.1 These anomalies include diplopia, glare and halos secondary to peripheral iridotomies (PI), and sector or total iris defects. The most commonly performed tattoo techniques are either by transepithelial intrastromal micropuncture or tattooing the anterior stroma after epithelial debridement.1 2 However, these techniques are known to be associated with several complications, including intra-operative microperforations, recurrent erosions, pigment non-homogeneity and fading of pigment over time.1 2 A newer procedure has been described, termed the intrastromal lamellar pocket technique. Several studies have investigated the use of this technique for aesthetic purposes in non-seeing …