A Novel Marking Technique for Descemet Membrane Endothelial Graft Using an Ophthalmic Viscoelastic Device.

PURPOSE: To describe the viscoelastic marking technique, a novel marking technique of Descemet membrane endothelial keratoplasty (DMEK) grafts that enables usage of a single donor cornea for 2 surgeries-one that uses Descemet membrane and endothelium (DMEK) and the other using the stroma and Bowman layer. METHODS: A retrospective case analysis was performed on 26 eyes of 26 consecutive patients who underwent DMEK using the "viscoelastic marking technique." In this novel technique, an ophthalmic viscoelastic device (Healon 5) is placed over the endothelial side. Descemet membrane is then folded in half over the ophthalmic viscoelastic device with the stromal side up, and the F mark is drawn on the stromal side of the folded Descemet membrane. Primary outcome was best spectacle-corrected visual acuity, and secondary outcomes included graft detachment and rebubble rate, graft failure, and endothelial cell density. RESULTS: Mean best spectacle-corrected visual acuity improved significantly from 1.0 ± 0.7 logarithm of the minimum angle of resolution (LogMAR) before the surgery to 0.9 ± 0.7 LogMAR, 0.5 ± 0.6 LogMAR, 0.4 ± 0.2 LogMAR, and 0.4 ± 0.4 LogMAR at 1, 3, 6, and 12 months after surgery, respectively. Seven eyes (27%) had partial graft detachment that required air injection. Primary failure occurred in 3 eyes (11%). There were no free-floating donors or recognized inverted donors. The endothelial cell density loss at 12 months after surgery was a cell-loss rate of 38.3%. CONCLUSIONS: The viscoelastic marking technique is a simple, approachable, and safe technique for marking DMEK grafts while preserving the anterior cornea for additional surgery.

Stepwise Guided Photorefractive Keratectomy in Treatment of Irregular Astigmatism After Penetrating Keratoplasty and Deep Anterior Lamellar Keratoplasty.

PURPOSE: To report the outcome of stepwise ablation using topography-guided photorefractive keratectomy to treat irregular astigmatism after either penetrating keratoplasty (PKP) or deep anterior lamellar keratoplasty (DALK). METHODS: This is a retrospective, interventional analysis including patients with irregular astigmatism after either PKP or DALK, who underwent topography-guided photorefractive keratectomy. The entire cohort was analyzed, as well as the PKP and DALK groups separately. Analysis of factors associated with a better outcome was also performed. RESULTS: Thirty-four eyes of 34 patients (20 PKP patients and 14 DALK patients) aged 47.4 ± 15.9 years were included. Twenty-one patients underwent more than 1 ablation. Refractive stability and a minimal period of 5 months were required before repeat ablation. The average follow-up duration was 17.0 ± 6.0 months. Corrected distance visual acuity (CDVA) improved significantly from 0.22 ± 0.14 logarithm of the minimum angle of resolution (logMAR) to 0.14 ± 0.12 logMAR at final follow-up (P = 0.035). Uncorrected distance visual acuity (UDVA) improved significantly from 0.90 ± 0.54 logMAR to 0.57 ± 0.40 logMAR at final follow-up (P = 0.004). CDVA and UDVA improved by ≥1 Snellen lines in 54.2% and 70.8% of the eyes, respectively, and by ≥3 Snellen lines in 16.7% and 54.2% of the eyes, respectively. Statistically significant improvement was seen in optical aberrometry indices (total root mean square, higher-order aberration root mean square, defocus, coma, trefoil, and spherical aberration). The difference between PKP and DALK in either CDVA (P = 0.562) or UDVA (P = 0.384) improvement was nonsignificant. CONCLUSIONS: The stepwise topography-guided photorefractive keratectomy approach in cases of irregular astigmatism after PKP or DALK can help improve visual acuity outcomes. Patients should be appropriately counseled that more than 1 treatment will likely be needed.

Simple Preoperative Ink Test as a Novel Adjunct to Intrastromal Keratopigmentation for Post-laser Peripheral Iridotomy Dysphotopsias.

PURPOSE: To describe a simple preoperative ink test as a novel adjunct to intrastromal keratopigmentation for post-laser peripheral iridotomy (LPI) dysphotopsias. METHODS: A surgical marking pen is applied to the area over a peripheral iridotomy before intrastromal keratopigmentation. The patient can then assess whether there is any improvement in their symptoms of dysphotopsias. Manual intrastromal keratopigmentation can then be performed using a crescent blade into the clear cornea at 50% depth and tunneled centrally to create a pocket ensuring that the peripheral iridotomy is fully occluded. The crescent blade is coated with an alcohol-based commercially available black tattoo pigment, and the pocket is filled. RESULTS: We have used the preoperative ink marker test on 5 eyes in patients with post-LPI (4 temporal and 1 superior) dysphotopsias before performing intrastromal keratopigmentation, with good patient satisfaction. Patients report immediate symptomatic relief after the procedure. This ink marking technique can also be extended to help identify which iris defect is symptomatic in patients with multiple iris defects. CONCLUSIONS: The preoperative ink test before intrastromal keratopigmentation is a novel adjunct to the treatment of post-LPI dysphotopsias.

Enhancing Descemet Membrane Endothelial Keratoplasty in Postvitrectomy Eyes With the Use of Pars Plana Infusion.

PURPOSE: To present a modified surgical technique to perform Descemet membrane endothelial keratoplasty (DMEK) in previously vitrectomized eyes and to analyze its safety and efficacy. METHODS: A retrospective analysis of previously vitrectomized eyes that underwent DMEK at Toronto Western Hospital was performed. The modified DMEK technique that was used included placement of a posterior pars plana infusion to reduce fluctuations in the anterior chamber depth and its excessive deepening. RESULTS: Twelve eyes of 12 patients (5 females and 7 males) aged 65.3 ± 21.5 years were included. Mean best-corrected visual acuity improved significantly from 1.72 ± 0.62 logMAR (mean Snellen ∼20/1040) preoperatively to 1.01 ± 0.64 logMAR (mean Snellen ∼20/200) at 6 months postoperatively (P = 0.017). Mean donor endothelial cell density was 2658 ± 229 cells/mm preoperatively and 1732 ± 454 cells/mm at 6 months after the procedure (mean percentage cell loss of 31.8%) (P = 0.046). There were no significant intraoperative complications, and no graft failures. One eye had graft detachment, which resolved after 2 rebubbling procedures. One eye had retinal detachment, which was corrected surgically. CONCLUSIONS: The use of posterior pars plana infusion in previously vitrectomized eyes stabilizes the anterior segment during DMEK, allowing for performance of DMEK surgery, and can potentially reduce intraoperative and postoperative complications.

Airsoft gun-related ocular injuries: novel findings, ballistics investigation, and histopathologic study.

PURPOSE: To describe the ocular injuries related to airsoft gun bullets, investigate the ballistics of airsoft bullets, record real-time impact of the bullets on an eye, and investigate the histopathologic changes within the cornea after being hit by an airsoft gun bullet. DESIGN: Retrospective, interventional case series and experimental animal study. METHODS: All consecutive cases of patients with airsoft gun-related ocular injuries during 2006 to 2008 were included in this study. Porcine eyes were used for high-speed video photographs of bullet impacts. Rabbit eyes were used for the histopathologic investigation. All patients were treated in the Department of Ophthalmology at Soroka University Medical Center, Beer-Sheva, Israel. Laboratory investigations were performed at Ben-Gurion University of the Negev, Beer-Sheva, Israel. The main outcome measures were ocular injuries of the patients, ballistics of the airsoft bullets, nature of corneal deformation upon impact, and corneal histopathologic changes after the hit. RESULTS: Fifty-nine patients with a mean age of 9.8 +/- 3.8 years (range, 2.8 to 26 years) were examined; 49 were male (83.1%). The ocular injuries included hyphema, corneal edema, corneal erosion, traumatic mydriasis, and posterior segment involvement. A novel, "donut" form of corneal erosion was seen and also demonstrated by the histopathologic investigation. Substantial anterior segment deformation was recorded in real-time using the high-speed video camera. CONCLUSIONS: Airsoft gun injuries affect mainly young men and can be visually threatening. Typical ocular injuries along with a unique form of corneal erosion can be seen.

The effect of Nd:YAG laser posterior capsulotomy on ocular wave front aberrations.

OBJECTIVE: To assess the effect of Nd:YAG laser posterior capsulotomy on ocular wave front aberrations. STUDY DESIGN: Retrospective comparative study. PARTICIPANTS: Twenty-four eyes of 24 consecutive pseudophakic patients with symptomatic PCO, who presented for Nd:YAG laser posterior capsulotomy at our clinic, were included in this study. METHODS: The wave front aberrations of the entire optical path of 24 pseudophakic eyes of 24 patients before, and 1 month after, Nd:YAG laser posterior capsulotomy were measured using the Nidek Optical Path Difference (OPD) scan aberrometer. Total, tilt, and high-order aberrations, and total coma, total trefoil, total tetrafoil, total spherical, and total high astigmatism aberrations were analyzed statistically. Secondary measures included changes in visual acuity and refraction, and repeatability of wave front measurements in the fellow eye. RESULTS: Before Nd:YAG laser posterior capsulotomy, the total higher-order aberrations root mean-square (RMS) wave front aberration was 2.08 (SD 2.20) microm, with total trefoil being a major contributor at 1.19 (SD 1.15) microm. One month after the procedure, significant decreases in total, tilt, and high-order aberrations, and total trefoil, total tetrafoil, total spherical, and total high astigmatism aberrations were noted (p< 0.05). No significant changes in total coma aberrations were found (p > 0.05). Additionally, significant improvement in visual acuity without significant change in refraction was observed. No statistically significant differences were detected in any of the RMS values of wave front measurements taken 1 month later in the fellow eye. CONCLUSIONS: Nd:YAG laser posterior capsulotomy causes significant decrease in ocular wave front aberrations measured using the Nidek-OPD scan aberrometer, which can account for a better optical quality after the procedure. Further research to examine the impact of wave front aberrations in visual function after Nd:YAG laser posterior capsulotomy is needed.