Use of Botulinum Toxin in Ophthalmology.

Botulinum toxin is an important treatment for many conditions in ophthalmology, including strabismus, nystagmus, blepharospasm, hemifacial spasm, spastic and congenital entropion, corneal exposure, and persistent epithelial defects. The mechanism of action of botulinum toxin for both strabismus and nystagmus is the neuromuscular blockade and transient paralysis of extraocular muscles, but when botulinum toxin is used for some forms of strabismus, a single injection can convey indefinite benefits. There are two unique mechanisms of action that account for the long-term effect on ocular alignment: (1) the disruption of a balanced system of agonist-antagonist extraocular muscles and (2) the reestablishment of central control of alignment by the binocular visual system. For other ocular conditions, botulinum toxin acts through transient paralysis of periocular muscles. Botulinum toxin is a powerful tool in ophthalmology, achieving its therapeutic effects by direct neuromuscular blockade of extraocular and periocular muscles and by unique mechanisms related to the underlying structure and function of the visual system.

Management of a Large Congenital Hemangioma Obstructing Visual Axis: A Case Report and Review of Literature.

Congenital hemangiomas comprise a subset of vascular tumors with clinicopathologic features that are distinct from the more common infantile hemangioma. The authors present a patient with a large congenital hemangioma involving the forehead and brow which obstructed the visual axis and created significant risk for deprivational amblyopia. Management of the congenital hemangioma involved customized headgear to clear the visual axis and early vascular embolization of feeder vessels with the subsequent successful surgical resection at 23 days of life.A large amblyogenic congenital hemangioma required a multidisciplinary approach involving early vascular embolization of feeder vessels and subsequent surgical resection at 23 days of life.

Validation of preloaded DMEK donor tissues: a laboratory-based study on endothelial cell viability and comparison of two F-mark inks.

OBJECTIVE: To investigate endothelial cell loss (ECL) associated with Descemet membrane endothelial keratoplasty (DMEK) donor tissues preloaded in the DMEK RAPID transport system after 1 and 5 days and to compare prestamping with 2 different F-mark inks. METHODS: DMEK donor tissues were stripped, marked with gentian violet dye applied as an F-mark, trephined, stained with trypan blue, and then preloaded into the DMEK RAPID transport system by an eye bank technician. Preloaded DMEK tissues were then unfolded and stained with calcein AM after 1 or 5 days of storage. Tissues were imaged, analyzed for total tissue ECL, and immunostained for corneal endothelium markers zonular occludens-1 and xCD166. Additionally, ECL and the intensity of an F-mark caused by 2 different inks were quantified. RESULTS: Preloaded DMEK tissues displayed an average ECL of 11.9% ± 4.5% (n = 8) at 1 day and 9.9% ± 4.2% (n = 9) at 5 days. No difference was found between the 2 groups. Zonular occludens-1 and activated leukocyte cell adhesion molecule (ALCAM; also know as CD166) staining showed that the corneal endothelial monolayer remained intact on preloaded tissues. On 5-day preloaded DMEK tissues, the average ECL and mean grayscale caused by the Keir Surgical ink F-mark and the Cardinal Health ink F-mark were 4.3% ± 0.8% and 158.5 ± 13.9% and 5.0% ± 1.1% and 142.9% ± 20.0%, respectively. No difference was found between the F-mark inks. CONCLUSION: Preloaded DMEK donor tissues resulted in an acceptable ECL range after 1 and 5 days of storage and were deemed suitable for transplantation. Both F-mark inks are acceptable for prestamping preloaded DMEK tissues prior to surgical transplantation with comparable ECL and intensities.

Retrocorneal fibrous membrane after phacoemulsification in an eye with pseudoexfoliative glaucoma.

OBJECTIVE: To report a case of a retrocorneal fibrous membrane and corneal decompensation following uncomplicated phacoemulsification in an eye with pseudoexfoliative glaucoma. METHOD: Case report and literature review. RESULTS: A monocular 83-year-old female developed corneal decompensation 1 year after uncomplicated cataract extraction via phacoemulsification. She had a history of pseudoexfoliative glaucoma and had undergone 3 rounds of selective laser trabeculoplasty in the same eye 3 years prior. Given the resulting corneal edema, the patient underwent Descemet's membrane endothelial keratoplasty, at which time a retrocorneal fibrous membrane was identified. Peeling of the membrane was surgically challenging and resulted in an intraocular hemorrhage intraoperatively and a small iridodialysis because the membrane had extended over the angle and iris. Postoperatively, the cornea cleared well, and vision improved significantly. However, vision was ultimately limited by macular pathology. Pathologic examination demonstrated Descemet's membrane with an attached fibrocellular membrane. Immunostaining for smooth muscle actin was positive within the membrane compatible with a retrocorneal membrane. We also present a review of the literature on modern causes of retrocorneal fibrous membranes. CONCLUSIONS: Retrocorneal fibrous membranes are encountered most commonly following corneal transplantation and may be surgically challenging to remove. We present the first case of a pathologically proven retrocorneal fibrous membrane following uncomplicated cataract surgery via phacoemulsification and selective laser trabeculoplasty.

Clinical Outcomes of Transscleral-Sutured Intraocular Lens Combined With Descemet Membrane Endothelial Keratoplasty.

PURPOSE: The aim of the study was to report clinical outcomes of Descemet membrane endothelial keratoplasty (DMEK) combined with transscleral-sutured intraocular lens (IOL) compared with DMEK combined with phacoemulsification and posterior chamber IOL (Phaco-DMEK). METHODS: A retrospective chart review of all patients who underwent DMEK combined with transscleral-sutured intraocular lens fixation or combined with phacoemulsification for Fuchs endothelial corneal dystrophy from 2016 to 2021 at the Toronto Western Hospital or the Kensington Eye Institute (Toronto, ON, Canada) and had at least 18 months of follow-up was performed. Main outcomes were postoperative distance-corrected visual acuity, rebubbling rate, graft survival rate, and complications. RESULTS: Twenty-one cases of DMEK combined with transscleral-sutured IOL (DMEK-TSS-IOL) and 44 cases of Phaco-DMEK were evaluated. Twelve eyes (57.15%) had a foldable acrylic 3-piece IOL (AR40E) and 9 (42.85%) had a single-piece polymethylmethacrylate (PMMA) IOL (CZ70BD). LogMAR distance-corrected visual acuity improved significantly from 1.48 ± 0.62 (SD) to 0.86 ± 0.82 ( P = 0.01) 12 months after DMEK-TSS-IOL and from 0.41 ± 0.29 logMAR to 0.11 ± 0.11 logMAR ( P < 0.0001) after Phaco-DMEK. No statistically significant differences were observed in donor ( P = 0.97) or 1-year postoperative endothelial cell density ( P = 0.11) between the groups. Rebubbling was necessary in 33.33% of eyes in DMEK-TSS-IOL compared with 25% of Phaco-DMEK eyes ( P = 0.55). Graft survival rate was 76.19% in the DMEK-TSS-IOL group compared with 90.90% in the Phaco-DMEK group ( P = 0.13). CONCLUSIONS: Transscleral-sutured IOL combined with DMEK is an option for the management of endothelial diseases in aphakic eyes or those which require IOL exchange for the experienced surgeon. However, when compared with routine Phaco-DMEK, there are higher complication and lower survival rates at 18 months.

Five-Year Safety and Efficacy of Femtosecond Laser-Assisted Descemet Membrane Endothelial Keratoplasty.

PURPOSE: The purpose of this study was to evaluate 5-year safety and efficacy outcomes of femtosecond-enabled Descemet membrane endothelial keratoplasty (F-DMEK) in patients with Fuchs' endothelial dystrophy (FED). METHODS: This was a retrospective study, including patients with FED and cataract who underwent either F-DMEK (16 eyes of 15 patients) or manual DMEK (M-DMEK) (42 eyes of 37 patients) combined with cataract extraction. Outcome measures included visual acuity, graft detachment, graft survival, and endothelial cell loss. RESULTS: The average follow-up in F-DMEK and M-DMEK was 57.1 ± 12.4 months and 58.5 ± 17.3 months, respectively ( P = 0.757). The rates of primary failure (0% vs. 9.5%, P = 0.567), secondary failure (0% for both), and graft rejection (0% vs. 7.1%, P = 0.533) did not differ significantly between the groups. Improvement in best spectacle-corrected visual acuity was similar in F-DMEK and M-DMEK (0.32 ± 0.27 logarithm of the minimum angle of resolution and 0.35 ± 0.44 logarithm of the minimum angle of resolution, respectively, P = 0.165) and persisted at 2, 3, 4, and 5 years and at the last follow-up. The rates of graft detachment and rebubbling were significantly lower with 6.25% in F-DMEK and 33.3% in M-DMEK ( P = 0.035). Cell-loss rates were lower in F-DMEK compared with M-DMEK throughout the follow-up, significantly so up to 2 years with a difference of 8.6% at 1 year ( P = 0.023), 11.8% at 2 years ( P = 0.021), 7.6% at 3 years ( P = 0.088), 5.8% at 4 years ( P = 0.256), 13.6% at 5 years ( P = 0.169), and 7.1% at the final follow-up ( P = 0.341). CONCLUSIONS: F-DMEK had an excellent safety and efficacy profile which was maintained over 5 years of follow-up. Lower endothelial cell-loss rates in F-DMEK compared with M-DMEK may help extend the duration of graft survival.

Clinical features and management of keratoconjunctivitis associated with inadequate tear drainage.

OBJECTIVE: To describe clinical features and management of toxic keratoconjunctivitis associated with punctal and (or) canaliculus stenosis (toxic soup syndrome). DESIGN: Retrospective observational case series. METHODS: Electronic medical record database search for the keywords "toxic soup syndrome" and retrospective chart review were performed. Thirty-five eyes of 25 patients were seen at a tertiary cornea clinic between January 2017 and December 2021. Sex, age, distance-corrected visual acuity, topical medications, symptoms, clinical signs, and outcomes after medical and surgical interventions were analyzed. The main outcome measured was improvement in ocular surface signs and symptoms after interventions. RESULTS: Overall, 35 eyes of 25 patients with a mean age of 66.8 ± 12.8 years, of which 72% were female, were included. The primary complaint was hyperemia and epiphora in all patients. Rosacea or meibomian gland disease were present in all patients, 7 (28%) had glaucoma, and 7 (28%) developed limbal stem cell deficiency. Twenty-two patients (88%) were using topical medications on presentation. All eyes had either punctal plugs, cauterized puncta, or punctal and (or) canaliculus stenosis. Management of all patients consisted of suspension of all preserved topical medications and institution of some type of anti-inflammatory therapy. Nineteen patients (76%) improved after improvement of lacrimal drainage. One patient with severe resistance in the canaliculus required ongoing preservative-free topical steroids. CONCLUSIONS: Chronic drug-induced or pooled inflammatory mediators causing toxic conjunctivitis may be aggravated by punctal and (or) canaliculus stenosis, leading to toxic soup syndrome. Clearance of punctal obstruction leads to improvement in most patients.

Comparative evaluation of four Descemet membrane endothelial keratoplasty graft preparation techniques.

OBJECTIVE: To compare subjective and objective outcomes of 4 different Descemet membrane endothelial keratoplasty (DMEK) peeling techniques performed by novice surgeons at different stages in their surgical career. DESIGN: An ex vivo prospective study. METHODS: In the first round, 2 DMEK peeling techniques were pitched against each other: the peripheral scoring and Sinskey dissection technique with the peripheral scoring and microhoe dissection and the peripheral blunt microhoe dissection against the scleral spurectomy and microhoe dissection. Three surgeons with different operative experience performed the peeling. Outcome measures included graft peeling time, surgeon's peeling difficulty grading (on a scale of 1-10, 1 being the easiest and 10 the hardest), number of radial and circumferential tears before and after trephination, and tissue loss. The 2 techniques that performed the best from the first round proceeded to the final round to identify the best overall technique. RESULTS: In total, 90 tissues (45 pairs) were peeled by 3 surgeons. Following the first-round results, the peripheral scoring and Sinskey dissection and peripheral blunt microhoe dissection proceeded to the final round. There were no significant differences between the groups in terms of peeling times, subjective feeling of difficulty, post-trephination tears, and peeling success rates (P > 0.05 for all). However, the peripheral scoring and Sinskey dissection technique had significantly fewer pretrephination radial tears (1.3 ± 1.3 vs 6.1 ± 5.2, P = 0.007) and circumferential tears (0.6 ± 0.9 vs 1.8 ± 2.1, P = 0.02). CONCLUSIONS: This study demonstrates that the learning curve can be overcome quickly with appropriate DMEK peeling techniques. The peripheral scoring and Sinskey dissection peeling technique allows efficient peeling with fewer related tears.

Long-Term Stability of Femtosecond Astigmatic Keratotomy After Treatment of High Postkeratoplasty Astigmatism.

PURPOSE: The purpose of this study was to assess long-term stability and outcomes of femtosecond astigmatic keratotomy (FSAK) after treatment of high postkeratoplasty astigmatism. METHODS: This retrospective study included patients who underwent FSAK for high astigmatism (≥4 D) after penetrating keratoplasty or deep anterior lamellar keratoplasty. Main outcome measures were corneal astigmatism, uncorrected visual acuity, and best-corrected visual acuity (BCVA) at 1 month and 1, 5, and 10 years. RESULTS: Overall, 61 eyes of 61 patients (mean age 56 ± 19 years, 54.1% male) were included in this study. Preoperative corneal astigmatism ranged from 4 to 25 D. One month after FSAK, mean corneal astigmatism was significantly reduced from 9.02 ± 3.97 D to 4.86 ± 3.10 D ( P < 0.001). Thereafter, corneal astigmatism remained stable at all visits up to 10 years ( P < 0.05 for all compared with baseline). After FSAK, there was a significant improvement in logMAR uncorrected visual acuity from 1.21 ± 0.48 to 0.87 ±0.54 ( P < 0.001) and logMAR BCVA from 1.03 ± 0.55 to 0.49 ± 0.45 ( P < 0.001) which remained stable up to 10 years. A mild reduction in BCVA improvement was seen between 1 month and 1 year. CONCLUSIONS: Femtosecond astigmatic keratotomy was effective and stable at reducing very high magnitudes of postkeratoplasty astigmatism over the long term. The procedure also had a stable effect on visual acuity, albeit some reduction in the degree of BCVA improvement was seen over the early postoperative period.

The Effect of COVID-19 on Corneal Donor Volumes and Eye Bank Processes: An Analysis From the Eye Bank of Canada (Ontario Division).

PURPOSE: With the rise in COVID-19 cases, the Eye Bank of Canada (Ontario Division), the largest eye bank in Canada, was faced with challenges related to ocular donor suitability which resulted in tissue shortages after the first wave of COVID-19 cases in Ontario, Canada. This article aims to analyze the impact of COVID-19 on ocular tissue donation and transplant surgeries. METHODS: Trends in ocular donations in 2020 and the transplant rates were compared with the data from the previous year, as a benchmark of normal eye bank activity. RESULTS: Ocular donor volumes decreased during the first wave of the COVID-19 pandemic (March-June 2020) by 65% as compared to the same period in 2019. By the end of the year 2020, this had resulted in a total reduction of 29% of ocular donor volumes as compared to 2019. The ocular transplant surgery volumes in the year 2020 decreased by 32% compared to the previous year, mostly secondary to elective surgery shutdown during the first wave. Because of tissue shortages, the Eye Bank of Canada (Ontario Division) had to import 24 corneas from the United States and cancel 7 surgeries in the year 2020. CONCLUSIONS: The decline in ocular tissue donor volumes and transplant surgery was a result of an interplay of causes related to the COVID-19 pandemic. Most importantly, ruling out of COVID-19 carriers, lockdown measures affecting tissue retrieval processes, and shutdown of elective surgery were the 3 major factors accounting for tissue shortages and surgical volume reductions.

Outcomes of femtosecond laser-assisted cataract and refractive lens surgery in patients with prior radial keratotomy.

PURPOSE: To investigate outcomes of femtosecond laser (FL)-assisted cataract surgery (FLACS) and refractive lens exchange (RLE) in patients with prior radial keratotomy (RK). SETTING: Single clinical practice. DESIGN: Retrospective observational case series. METHODS: All patients with prior RK undergoing FLACS- or FL-assisted RLE surgeries over a 6-year period were reviewed. Inclusion criteria were diurnal stability and stable manifest refraction. Exclusion criteria were any other incisional corneal surgery, macular or glaucomatous pathology, or vision loss due to any other cause. Data collected included demographics, visual acuity, laser settings, and complications. Main outcome measures were intraoperative and postoperative complications and visual outcomes. Safety and efficacy indices were evaluated. RESULTS: 16 eyes of 9 patients were included. Mean age and follow-up time were 59.9 ± 9.9 years (range 44 to 75 years) and 3.3 ± 2.5 months, respectively. The mean number of RK cuts was 11.8 ± 5.3 (range 8 to 20). Mean preoperative uncorrected (UDVA) and corrected distance visual acuity (CDVA) were 0.9 ± 0.4 logMAR (Snellen 20/160) and 0.2 ± 0.3 logMAR (Snellen 20/30), respectively. 2 intraoperative anterior capsule tears were identified. 1 postoperative intraocular lens dislocation occurred. Postoperatively, the mean UDVA and CDVA were 0.2 ± 0.2 logMAR (20/30) and 0.1 ± 0.1 logMAR (20/25), respectively. The safety index was 1.6, and the efficacy index was 1.2. CONCLUSIONS: FLACS- or FL-assisted RLE surgery in RK patients has a high risk for anterior capsule tear and should be avoided. Thickened incisional scars are potential sources of incomplete laser penetrance. Toric lens implantation in RK eyes provide unpredictable astigmatic correction and should also be avoided.

Tape Splint Tarsorrhaphy for Persistent Corneal Epithelial Defects.

PURPOSE: To report outcomes of tape splint tarsorrhaphy (TST) for persistent corneal epithelial defects (PCED). DESIGN: Retrospective, interventional case series. METHODS: The study population was consecutive patients with a PCED (14 days or longer) treated at a tertiary cornea clinic with TST. Patients with a corneal epithelial defect that did not respond to treatment with a bandage contact lens were included. Patients with a follow-up time of less than 3 months were excluded. Time to PCED resolution was the main outcome measure. RESULTS: Thirty-four eyes of 33 patients (mean age 62.9 ± 17.8 years; range, 27-90 years) were included in this study. The main etiologies of the PCED were post keratoplasty (n = 15), herpes simplex virus (n = 4), superficial keratectomy (n = 3), neurotrophic cornea (n = 4), fungal keratitis (n = 2), exposure keratopathy (n = 2), failed graft (n = 1), peripheral ulcerative keratitis (n = 1), rosacea (n = 1), and stitch abscess (n = 1). Mean ± SD time from PCED presentation to TST was 58.9 ± 106.3 days (range, 14-390 days). The mean ± SD area of the PCED was 25.1 ± 15.7 mm2 (range, 0.50-42.0 mm2). After TST, resolution of the PCED was achieved in 29/34 eyes (85.3%) without the need for additional interventions within 22.5 ± 24.3 days (range, 2-105 days). The mean ± SD logMAR best-corrected visual acuity improved significantly from 1.11 ± 0.41 to 0.83 ± 0.70 (P = .02). There were no complications attributed to TST and 2 patients elected to discontinue due to discomfort. CONCLUSIONS: TST achieved resolution of PCEDs secondary to various etiologies in 85.3% of eyes, with significant improvement in vision demonstrated. This simple, inexpensive, noninvasive technique may be considered for patients with PCEDs.

Surgical Management of Fuchs Endothelial Corneal Dystrophy: A Treatment Algorithm and Individual Patient Meta-Analysis of Descemet Stripping Only.

PURPOSE: This study aims to determine predictive factors for success of Descemet stripping only (DSO) in Fuchs corneal endothelial dystrophy and propose a DSO treatment algorithm. METHODS: Ovid MEDLINE, Embase, and Cochrane CENTRAL databases were searched to evaluate DSO case series, including combined phacoemulsification and DSO, and the use of Rho-kinase inhibitors (ROC-i). Our primary outcome was success of corneal clearance. Secondary outcomes included the time to corneal clearance, the postoperative endothelial cell count (ECC), and the impact of ROC-i. RESULTS: Sixty-eight cases were evaluated with a mean follow-up of 12.4 months. DSO corneal clearance was achieved in 85% (n = 58) with a mean time of 4.9 weeks for the ROC-i group compared with 10.1 weeks in the observation group (P < 0.0001). The mean central ECC postoperatively was higher in the ROC-i group compared with the observation group 1151 ± 245 versus 765 ± 169 cells/mm2, respectively (P < 0.018). The postoperative best-corrected visual acuity (BCVA) improved in 61 eyes (90%), with mean final BCVA of 0.17 (0.26) logMAR (P = 0.001), which was statistically significant compared with preoperative BCVA. Factors influencing success were 4-mm descemetorhexis size, a clear peripheral ECC with no clinical sequelae of decompensation or guttae, and a low central corneal thickness. No intraoperative complications were noted. The commonest postoperative complication was deep corneal stromal scars noted at the descemetorhexis edge (n = 9). CONCLUSIONS: DSO has a role in the treatment of a subset of patients with Fuchs corneal endothelial dystrophy and that adjuvant treatment with ROC-i may lead to faster corneal clearance.

KAMRA presbyopic inlay refractive outcomes: a Canadian perspective.

OBJECTIVE: To retrospectively analyze the visual outcomes of KAMRA (AcuFocus Inc, Irvine, Calif.) inlay insertion in a cohort of patients reporting success of procedure, complications, patient satisfaction, and refractive outcomes. DESIGN: Retrospective trial at the TLC Laser Centre, Toronto. METHODS: A total of 5 surgeons at the practice inserted 35 KAMRA inlays in 35 patients between October 2012 and June 2014. Some patients had a sole KAMRA inlay insertion, whereas others had combined laser vision correction (LVC) and KAMRA inlay on either the same day or sequentially. There was a small cohort of patients who had previous unrelated LVC. Mean time of follow-up was 299 days. RESULTS: After KAMRA inlay insertion there was a significant improvement in uncorrected near visual acuity (p = 0.00009), uncorrected intermediate visual acuity (p = 0.00006), and uncorrected distance visual acuity (p = 0.02), but levels of patient dissatisfaction were 43%. The most common cause for dissatisfaction was requirements for readers (23%), followed by dysphotopsias (11%). The explantation rate was 11.42%, and 28.5% of patients required enhancements after inlay insertion. CONCLUSIONS: The KAMRA corneal inlay has significant improvements in uncorrected near visual acuity, uncorrected intermediate visual acuity, and uncorrected distance visual acuity when used in isolation or combined with LVC. Appropriate patient selection is crucial. This procedure should not be used as first-line presbyopia management because of low levels of patient satisfaction, biocompatibility concerns, and explantation rates.

The "Two-Flaps" Technique for Descemet Stripping Only.

PURPOSE: The success of Descemet stripping only (DSO) is optimized by performing a well-centered, accurately sized diameter of descemetorhexis with a smooth curvilinear border. To achieve this success, we describe a repeatable and relatively straightforward technique to optimize this descemetorhexis for DSO. METHODS: The "two-flaps" technique uses the Gorovoy DSO forceps. The technique takes advantage of the flat and smooth surface of the forceps to create the desired 4-mm Descemet stripping with minimal stromal trauma along with a continuous curvilinear descemetorhexis, minimizing the risk of postoperative stromal scarring and extension of the rhexis beyond 4 mm. RESULTS: This technique has been used successfully in 11 cases performed by 1 surgeon or directly supervised by him. All cases achieved the desired 4-mm circumference without any residual tags or visually significant stromal scarring, with successful clearing of the central cornea and endothelial cells repopulating the central stripped area. CONCLUSIONS: This technique described provides a consistent, reproducible, and relatively trauma-free peeling of Descemet membrane and associated endothelial cells/guttae to optimize the success of DSO.

Four-Year Survival Comparison of Endothelial Keratoplasty Techniques in Patients With Previous Glaucoma Surgery.

PURPOSE: To compare 4-year survival outcomes of Descemet membrane endothelial keratoplasty (DMEK) and Descemet-stripping automated endothelial keratoplasty (DSAEK) in eyes with previous glaucoma surgery. METHODS: This is a retrospective, comparative case series, including patients with previous trabeculectomy or glaucoma drainage device implantation, who later underwent either DMEK (n = 48) or DSAEK (n = 41). Follow-up was limited to 12 to 60 months to prevent bias. Primary outcomes were graft survival and rejection. Secondary outcomes were best spectacle-corrected visual acuity (BSCVA), detachment/rebubble, endothelial cell loss, and intraocular pressure elevations. RESULTS: Baseline characteristics, follow-up duration, and preexisting glaucoma parameters did not differ significantly between the groups. Graft survival probability after DMEK and DSAEK was 75% and 75% at 1 year, 63% and 50% at 2 years, 49% and 44% at 3 years, 28% and 33% at 4 years, and 28% and 29% at 5 years, respectively (P = 0.899 between the groups). Graft rejection rates were 20.8% and 19.5%, respectively (P = 1.000). Primary failure, rebubbling, endothelial cell loss, and intraocular pressure elevation did not differ significantly between the groups. Preoperative BSCVA did not differ between the groups (P = 0.821). Postoperative BSCVA was significantly better in the DMEK group at 6, 12, and 24 months (P < 0.001, P = 0.022, and P = 0.047, respectively). In a multivariable model (R2 = 0.576), the type of surgery was the only significant factor affecting postoperative BSCVA, in favor of DMEK (coefficient value -0.518, P = 0.002). CONCLUSIONS: In eyes with previous glaucoma surgery, DMEK and DSAEK had comparably low survival and comparably high rejection rates. Postoperative visual acuity might be better after DMEK in this setting.

Comparison of Descemet Stripping Automated Endothelial Keratoplasty and Descemet Membrane Endothelial Keratoplasty in the Treatment of Failed Penetrating Keratoplasty.

PURPOSE: To compare the outcomes of Descemet stripping automated endothelial keratoplasty (DSAEK) with Descemet membrane endothelial keratoplasty (DMEK) for the treatment of failed penetrating keratoplasty (PKP). METHODS: This is a retrospective chart review of patients with failed PKP who underwent DMEK or DSAEK. The median follow-up time for both groups was 28 months (range 6-116 months). Data collection included demographic characteristics, number of previous corneal transplants, previous glaucoma surgeries, best-corrected visual acuity, endothelial cell density, graft detachment and rebubble rate, rejection episodes, and graft failure. RESULTS: Twenty-eight eyes in the DMEK group and 24 eyes in the DSAEK group were included in the analysis. Forty-three percent of eyes in the DMEK group and 50% of eyes in the DSAEK group had to be regrafted because of failure (P = 0.80). The most common reason for failure was persistent graft detachment (58%) in the DMEK group and secondary failure (58%) in the DSAEK group; hence, the time between endothelial keratoplasty and graft failure differed significantly between the groups (P = 0.02). Six eyes (21%) in the DMEK group and 7 eyes (29%) in the DSAEK group developed graft rejection (P = 0.39). Rejection was the cause of failure in 67% and 71% in the DMEK and DSAEK groups, respectively. The best-corrected visual acuity 6 months after surgery was better in the DMEK group compared with the DSAEK group (P = 0.051). CONCLUSIONS: Both DSAEK and DMEK have a role in treating PKP failure. Primary failure due to persistent graft detachment was significantly higher in the DMEK group, although the overall failure rate in the medium term was similar.