Comparison of repeat penetrating keratoplasty, DSAEK and DMEK for the management of endothelial failure of previous PK.

PURPOSE: To compare the clinical outcomes of repeat PK, DSAEK-on-PK or DMEK-on-PK for the management of endothelial failure of previous penetrating keratoplasty. DESIGN: Retrospective, interventional consecutive case series. PARTICIPANTS: 104 consecutive eyes of 100 patients requiring a second keratoplasty for endothelial failure of their primary penetrating keratoplasty performed between September 2016 and December 2020. INTERVENTION: Repeat keratoplasty. MAIN OUTCOME MEASURES: Survival and visual acuity at 12 and 24 months, rebubbling rate and complications. RESULTS: Repeat PK was performed in 61/104 eyes (58.7%), DSAEK-on-PK was performed in 21/104 eyes (20.2%) and DMEK-on-PK was performed in 22/104 eyes (21.2%). Failure rates in the first 12 and 24 months were 6.6% and 20.6% for repeat PKs compared to 19% and 30.6% for DSAEK and 36.4% and 41.3% for DMEK. For those grafts surviving 12 months, the chances of surviving to 24 months were greatest for DMEK-on-PK at 92% vs 85% each for redo PK and DSAEK-on-PK. Visual acuity at one year was logMAR 0.53 ± 0.51 in the redo PK group, 0.25 ± 0.17 for DSAEK-on-PK and 0.30 ± 0.38 for DMEK-on-PK. 24-month outcomes were 0.34 ± 0.28, 0.08 ± 0.16, and 0.36 ± 0.36 respectively. CONCLUSIONS: DMEK-on-PK has a greater failure rate in the first 12 months than DSAEK-on-PK which has a greater failure rate than redo PK. However, the 2-year survival rates in our series for those already surviving 12 months were greatest for DMEK-on-PK. There was no significant difference in visual acuity at 12 or 24 months. Careful patient selection is needed by experienced surgeons to determine which procedure to offer to patients.

Safety and clinical outcomes of omitting same and next day review after DMEK performed with an inferior peripheral iridotomy.

BACKGROUND/OBJECTIVES: To determine the incidence of day one postoperative complications after Descemet Membrane Endothelial Keratoplasty (DMEK) performed with intraoperative inferior peripheral iridotomy (PI), and whether their early detection influences postoperative intervention. SUBJECTS/METHODS: 70 eyes of 70 consecutive patients that underwent DMEK from August 2019 to August 2021 at a single UK centre were retrospectively analysed. Cases that did not have an inferior PI were excluded. Any action taken at day one and week one postoperative review was noted. RESULTS: No pupil block or other major adverse events were found at day one review. At one week, 14 eyes (20%) required re-bubbling, all of which had been fully attached at the day one review. CONCLUSIONS: This series suggests that inferior PI performed alongside DMEK alone or triple DMEK effectively minimizes the risk of pupil block. Since no early complications occurred in this cohort requiring immediate intervention, it may be safe to defer review of these patients to a later time point.

Analysis of microbial keratitis incidence, isolates and in-vitro antimicrobial susceptibility in the East of England: a 6-year study.

BACKGROUND/OBJECTIVES: To report the incidence, microbiological profile and in-vitro antimicrobial susceptibilities of microbial keratitis (MK) in the East of England (EoE) over a 6-year period. SUBJECTS/METHODS: A retrospective study of patients diagnosed with MK who underwent corneal scraping at participating trusts, within the EoE, between 01/01/2015-01/07/2020. Analysis was performed on MK isolate profiles, in-vitro anti-microbial sensitivities and trends over time. RESULTS: The mean incidence of IK, in the EoE, was estimated at 6.96 per 100 000 population/year. 1071 corneal scrapes were analysed, 460 were culture positive (42.95%) of which 87.2% were bacteria (50.3% gram-positive and 49.7% gram-negative), 2.4% polymicrobial, 9.3% fungi and 1.1% acanthamoeba. The most common organisms were pseudomonas spp (29.57%). There was a non-statistically significant trend (NST) in increasing incidence of pseudomonas spp, staph aureus and serratia (p = 0.719, p = 0.615, and p = 0.099 respectively) and a declining NST in Fungi (p = 0.058). Susceptibilities in-vitro to, penicillin classes, fluoroquinolone and aminoglycosides were 76.7% and 89.4%, 79.2% and 97.2% and 95.4 and 96.1% to gram-positive and gram-negative bacteria respectively. Gram-negative organisms were increasingly resistant to cephalosporins with a 19.2% reduction in sensitivity over time. (p = 0.011). Ceftriaxone showed the greatest decrease in sensitivity of 41.67% (p = 0.006). CONCLUSION: In the EoE, MK is relatively prevalent though likely underestimated. Profiles are similar to other UK regions with the exception of a higher fungal and lower acanthamoeba incidence. Common first and second-line antimicrobial selection provides, on the whole, good coverage. Nevertheless, anti-microbial resistance, to cephalosporins, was observed so selection should be carefully considered when treating MK empirically.

A lack of an association between COVID-19 vaccination and corneal graft rejection: results of a large multi-country population based study.

PURPOSE: The aim of the study was to present the rates of corneal transplant rejection from 2018 to 2022 at both Moorfields Eye Hospital UK, and Ospedali Privati Forli (OPF) "Villa Igea", Italy and evaluate the purported association between COVID-19 vaccination and rejection. METHODS: We performed a retrospective review of rejection cases presenting to the two units. Monthly rates were correlated against regional vaccination programme rates. At OPF, conditional Poisson regression model was employed to estimate the incidence risk ratio (IRR) of graft rejection following COVID-19 vaccination risk period compared with the control period. RESULTS: Between January 2018 and March 2022, there were 471 (Moorfields), 95 (OPF) episodes of rejection. From the start of vaccination programme in the UK in late January 2021, the median number of graft rejections per month at Moorfields was 6 (range: 5-9), which was not significantly different to post-lockdown, pre-vaccination programme (March 2020-January 2021), p = 0.367. At OPF, the median rates of rejection before and after initiation of the vaccination programme were not significantly different (p = 0.124). No significant increase in incidence rate of rejection in the risk period following COVID-19 vaccination was found (IRR = 0.53, p = 0.71). CONCLUSION: No notable increase in rates of transplant rejection was noted in year 2021 when COVID-19 vaccination was broadly implemented. The apparent temporal relationship between COVID-19 vaccination and corneal graft rejection highlighted in several case reports may not represent a causative association.

'Posture-Less' DMEK: Is Posturing After Descemet Membrane Endothelial Keratoplasty Actually Necessary?

PURPOSE: To evaluate the clinical results of Descemet membrane endothelial keratoplasty (DMEK) without any intraoperative or postoperative posturing. DESIGN: Retrospective, noncomparative, and interventional case series. METHODS: One hundred thirty-four (134) consecutive eyes of 101 patients requiring DMEK for any cause of endothelial failure were included. Descemet membrane endothelial keratoplasty was performed with an intraoperative inferior PI. After unscrolling and centration of the graft, the anterior chamber was near completely filled with 20% SF6. After filling the eye with gas there was no intraoperative tamponade time, and patients did not posture postoperatively. Main outcome measures were: graft detachment rate, rebubbling rate, primary and secondary failure rates, rejection rate, intraoperative and postoperative complications, and visual acuity 3 and 12 months after surgery. RESULTS: Five of 134 (3.7%) developed graft detachment greater than one-third of the graft area, and 19 of 134 (14.2%) developed graft detachment less than one-third of the graft area. A rebubble procedure was performed in 19 of 134 (14.2%); of those, the average number of rebubbling procedures performed was 1.13 (range, 1-2). Primary failure occurred in 6 of 134 (4.5%).Twelve-month graft survival occurred in 122 of 134 eyes (91.0%), with secondary failure within the first 12 months accounting for failure of 6 of 134 (4.5%). Nine of 134 (6.7%) cases had a recorded episode of endothelial rejection. The average time for rejection episode was 9.5 months (range, 1-20 months) after surgery. CONCLUSIONS: A total of 134 'posture-less' DMEKs did not suffer very high rates of graft detachment, rebubbling, or other postoperative complications, even with immediate erect posturing after surgery.

Sutureless Tectonic Mini-Descemet's Stripping Automated Endothelial Keratoplasty ("mini-DSAEK") for the management of corneal perforations.

PURPOSE: To report the outcomes of a new technique, pull-through sutureless 'mini-DSAEK', to manage corneal perforations secondary to different aetiologies including trauma, neurotrophic ulcer following penetrating keratoplasty (PK), herpes simplex keratitis and microbial keratitis. METHODS: In this retrospective case series, we report the clinical outcomes of five cases of sutureless tectonic mini-DSAEK performed in patients presenting with large corneal perforations to Southend University Hospital between November 2019 and October 2020. One corneal perforation was sufficiently peripheral for the tectonic mini-DSAEK graft to be successfully positioned outside of the central visual axis. Four corneal perforations were central or paracentral for which the tectonic grafts involved the visual axis. RESULTS: Anterior chambers remained deep and formed with no evidence of leak in all subsequent follow ups in all patients representing 100% tectonic success. All tectonic grafts remained attached except one partially detached graft. One patient underwent uneventful phacoemulsification with intraocular lens implant 8 months after the primary intervention with excellent visual outcome. Two patients underwent two-piece mushroom PK and one patient underwent triple procedure (cataract extraction + intraocular lens + PK) for visual rehabilitation 2-6 months after the primary intervention with good visual outcome. CONCLUSION: Sutureless tectonic pull-through mini-DSAEK is a useful technique in the management of corneal perforations, with a number of advantages compared with conventional techniques.

Early Endothelialization of Ab Interno Stromal Tectonic Patch in the Management of Corneal Perforation Secondary to Bacterial Keratitis.

PURPOSE: The purpose of this study was to describe a novel surgical technique using an ab interno stromal patch to treat corneal perforation and to present the histological findings of the patch after its removal during definitive mushroom keratoplasty. METHODS: The endothelium had already been removed with the submerged cornea using backgrounds away (SCUBA) technique. RESULTS: The patient was managed successfully with a sutureless ab interno stromal tectonic patch. Two months later, definitive mushroom keratoplasty was performed and the patch was sent for histological examination. Immunohistochemistry revealed a reactive endothelium covering the posterior surface of the graft. Nine months later, her best-corrected visual acuity was 6/9. CONCLUSIONS: This is the first case to our knowledge demonstrating that stromal tectonic grafts without the endothelium can successfully attach to the host tissue and seal a perforation. The stroma may undergo reendothelialization and begin to restore vision, even before penetrating keratoplasty.

Tectonic Mini-DSAEK Facilitates Closure of Corneal Perforation in Eyes With Healthy Endothelium.

PURPOSE: The purpose of this study was to report a surgical technique for closure of a traumatic corneal perforation in a patient with healthy endothelium. METHODS: A 69-year-old male patient presented to Southend University Hospital with a 2.5 mm round temporal corneal perforation caused by a metallic foreign body from an industrial accident. Best-corrected visual acuity at presentation was 6/36. The patient received a tectonic small diameter Descemet stripping automated endothelial keratoplasty (mini-DSAEK) to close the perforation. The patient subsequently developed traumatic cataract and underwent cataract surgery 8 months later. Clinical outcomes at 1 week, 1 month, 3 months, 6 months, and 9 months were evaluated. The primary outcomes of interest were successful sustained closure of the perforation and surgical complications, with secondary outcomes of best-spectacle corrected visual acuity (BSCVA, Snellen) and keratometric astigmatism (KA, Pentacam). RESULTS: The anterior chamber was reformed by the graft, restoring the globe's mechanical integrity. The bare stroma reepithelized by 1 week. Neither intraoperative nor postoperative surgical complications were reported. The anterior chamber remained deep and formed during subsequent follow-ups through 9 months. At the 9-month follow-up, final best spectacle-corrected visual acuity was 6/6-1 (Snellen fraction). Keratometric astigmatism was 1.1 diopters. CONCLUSIONS: Tectonic mini-Descemet stripping automated endothelial keratoplasty is a safe technique in the management of corneal perforations too large for tissue adhesives, with a low astigmatic profile and rapid visual recovery.

Negative polymerase chain reaction for SARS-CoV-2 in aqueous sample of patient with confirmed SARS-CoV-2 and recurrence of herpetic stromal keratitis.

This case report describes a negative result for antigen testing for the SARS-CoV-2 virus in an aqueous sample taken during the management of suspected herpes simplex keratitis from a patient with confirmed SARS-CoV-2 based on antigen testing of high nasal swab. The implications of no viral load detectable in the aqueous sample are discussed in context of routine phacoemulsification surgery during the SARS-CoV-2 pandemic.

A matched case-control study of the clinical, economic, and patient-reported outcomes of cystoid macular edema complicating phacoemulsification surgery.

PURPOSE: To assess the visual outcomes of pseudophakic cystoid macular edema (CME) as compared with age- and copathology-matched control subjects, the costs of treatment and follow-up, and the patient-reported outcomes using the new Cat-patient-reported outcome measures (PROM) 5 questionnaire. SETTING: West Suffolk Hospital NHS Foundation Trust, United Kingdom. DESIGN: Matched case-control study. METHODS: Fifty-two eyes of 49 patients developed CME over an 18-month period. Age- and copathology-matched patients were identified from clinical records over the same time period in a 2:1 ratio (90 eyes). Postoperative clinical outcomes were recorded including treatments received, costs of treatments, and patient-reported outcome measures using the Cat-PROM5. RESULTS: Patients with CME reported a significantly worse outcome from surgery than control subjects. Furthermore, patients with CME had significantly worse visual acuity postoperatively than control subjects (CME: logarithm of the minimum angle of resolution 0.40 ± 0.33, n = 37; control subjects: 0.30 ± 0.33; P < .05) despite there being no difference in preoperative visual acuity. In patients with epiretinal membrane (ERM), notably those with CME had worse patient-reported outcomes than control subjects with ERM, and only 18% received prophylactic corticosteroid injection at surgery compared with 63.6% of control subjects. CME resulted in an excess of 266 outpatient appointments, with 388 weeks of topical therapy, 18 orbital floor injections, 6 intravitreal steroid injections, 5 intravitreal antivascular endothelial growth factor injections, and 1 intravitreal dexamethasone implant with an excess expenditure of £216.81 per case. CONCLUSIONS: Patients developing CME after cataract surgery had reduced visual acuity at 4 to 6 weeks, patient-reported visual outcomes, and increased number of hospital appointments, treatments, and costs.

Femtosecond laser-assisted cataract surgery: A review.

PURPOSE: Review scientific literature concerning femtosecond laser-assisted cataract surgery. METHODS: Following databases were searched: CENTRAL (Cochrane Eyes and Vision Trials Register; Cochrane Library: Issue 2 of 12, June 2019), Ovid MEDLINE® without Revisions (1996 to June 2019), Ovid MEDLINE® (1946 to June 2019), Ovid MEDLINE® Daily Update June 2019, MEDLINE and MEDLINE Non-Indexed Items, Embase (1980-2019), Embase (1974 to June 2019), Ovid MEDLINE® and Epub Ahead of Print, in-Process & Other Non-Indexed Citations and Daily (1946 to June 2019), Web of Science (all years), the metaRegister of Controlled Trials ( www.controlled-trials.com ), ClinicalTrials.gov ( www.clinicaltrial.gov ) and World Health Organization International Clinical Trials Registry Platform ( www.who.int/ictrp/search/en ). Search terms/keywords included 'Femtosecond laser' combined with 'cataract', 'cataract surgery'. RESULTS: Based on quality of their methodology and their originality, 121 articles were reviewed, including randomised controlled trials, cohort studies, case-controlled studies, case series, case reports and laboratory studies. Each step of the femtosecond laser-assisted cataract surgery procedure (corneal incisions, arcuate keratotomies, capsulotomy and lens fragmentation) has been discussed with relevance to published outcomes, as well as complication rates of femtosecond laser-assisted cataract surgery, and what we can learn from the larger studies/meta-analyses and the economics of femtosecond laser-assisted cataract surgery within different healthcare settings. CONCLUSION: Studies suggest that the current clinical outcomes of femtosecond laser-assisted cataract surgery are not different to conventional phacoemulsification surgery and it is not cost effective when compared with conventional phacoemulsification surgery. In its current technological form, it is a useful surgical tool in specific complex cataract scenarios, but its usage has not been shown to translate into better clinical outcomes.

Risk-Adjusted CUSUM Analysis of the Learning Curve of Femtosecond Laser Assisted Cataract Surgery.

Objectives: To determine the length of the learning curve of femtosecond laser-assisted cataract surgery (FLACS) by a risk-adjusted cumulative sum method. Materials and Methods: This was a retrospective review of the first 288 FLACS performed by three surgeons over a 12-month period. The learning curves were analyzed separately for each surgeon and as pooled data via risk-adjusted cumulative sum methods. Change-point analysis was performed to estimate the length of the learning curve. Results: Rates of complications were as follows: anterior capsular tear (ACT) (3.4%), posterior capsular rupture (PCR) (0.7%), vitreous loss (0.3%), iris trauma (0.7%), Descemet's membrane tear (0.3%). There was a strong confidence level (96%) that there was a stable performance in terms of PCR after case 16 for the pooled data. Surgeon 1 did not have any cases of PCR, surgeons 2 and 3 exhibited change points at case 5 and 16, respectively (confidence levels = 99%, 98%). There was a strong confidence level (99.8%) that there was stable performance in terms of ACT after case 14 for the pooled data, however the individual surgeons demonstrated individual change points at case 1 (surgeon 1, confidence 99%), case 14 (surgeon 2, confidence 99%), and case 49 (surgeon 3, confidence 96%). Conclusions: The results suggest that there is an increased risk of ACT and PCR in FLACS within a surgeon's first 14 and 16 operations, respectively. Measures should be adopted to minimize harm to patients during this phase. However, overall rates of complications were safe.

A randomized controlled trial comparing femtosecond laser-assisted cataract surgery versus conventional phacoemulsification surgery.

PURPOSE: To compare the clinical results of conventional phacoemulsification surgery (CPS) with femtosecond laser-assisted cataract surgery. SETTING: Guy's & St Thomas' NHS Foundation Trust, London, United Kingdom. DESIGN: Single-center prospective randomized interventional case-controlled trial. METHODS: Patients undergoing cataract surgery were randomized to receive either CPS or femtosecond laser-assisted cataract surgery. The surgery was performed with a femtosecond laser (Lensx), and all operations were performed with a gravity-fluidics torsional phacoemulsification machine (Infiniti). The visual acuity, refraction, central corneal thickness (CCT), central foveal thickness (CFT), endothelial cell loss, and rates of intraoperative and postoperative events were recorded. Quality of life outcomes were measured with the EuroQOL 5 dimensions questionnaire (EQ-5D) and patient-reported quality of vision was assessed with a cataract surgery patient-reported outcome measures questionnaire (Cat-PROM5). RESULTS: The study comprised 400 eyes of 400 patients who had CPS (n = 200) or femtosecond laser-assisted cataract surgery (n = 200). Seven patients (3.5%) in the femtosecond laser-assisted group were not able to complete the treatment and received CPS. The mean uncorrected distance visual acuity (logarithm of the minimum angle of resolution [logMAR]) 0.15 ± 0.21 (SD) and 0.15 ± 0.19 logMAR after CPS and femtosecond laser-assisted surgery, respectively (P = 1.0); the pinhole-corrected visual acuity was 0.04 ± 0.12 and 0.04 ± 0.12, respectively (P = 1.0); the increase in CCT was 13 ± 19 µm and 15 ± 25 µm, respectively (P = .5); and the endothelial cell loss was 9.7 ± 13.7 % and 10.2% ± 13.7, respectively (P = .76). The manifest refraction spherical equivalent error was -0.14 ± 0.60 diopters (D) after CPS and -0.12 ± 0.60 D after femtosecond laser-assisted surgery (P = .74); the mean change in CFT was 9 ± 35 µm and 6 ± 35 µm, respectively (P = .55); and the rate of posterior capsule rupture was 3% and 0%, respectively (P = .03). CONCLUSIONS: This study confirms the nonsignificant differences between 2 treatment modalities, notwithstanding a significant reduction in posterior capsule ruptures in the femtosecond laser-assisted surgery group.

Refractive outcomes after limbal relaxing incisions or femtosecond laser arcuate keratotomy to manage corneal astigmatism at the time of cataract surgery.

PURPOSE: To compare the results of manual limbal relaxing incisions (LRIs) performed during conventional phacoemulsification surgery with those of nonpenetrating femtosecond laser arcuate keratotomies performed during femtosecond laser-assisted cataract surgery to manage corneal astigmatism. SETTING: Guy's and St. Thomas' NHS Foundation Trust, London, United Kingdom. DESIGN: Randomized case-controlled trial. METHODS: This was a secondary outcome of a randomized controlled trial comparing 400 patients treated with conventional phacoemulsification surgery or femtosecond laser-assisted cataract surgery. All patients with corneal astigmatism greater than 0.9 diopter (D) were offered LRIs or femtosecond laser arcuate keratotomy based on the original randomization. Visual acuity, postoperative refraction, and corneal topography were recorded 4 weeks postoperatively. Vector analysis was performed using the Alpins method. RESULTS: Fifty-one eyes of 51 patients received LRIs, and 53 eyes of 53 patients received femtosecond arcuate keratotomies. The mean target induced astigmatism was 1.50 D and 1.38 D, respectively, with 1.02 D and 1.23 D surgically induced astigmatism (P = .21), resulting in the femtosecond arcuate keratotomy group having a smaller difference vector (1.17 D versus 0.89 D; P = .02) and a greater correction index (0.48 versus 0.73; P = .02). Forty-four percent of patients in the femtosecond arcuate keratotomy group and 20% in the LRI group attained a postoperative cylinder of less than 0.50 D (P = .01). CONCLUSIONS: The femtosecond arcuate keratotomy group achieved a higher correction index and a smaller difference vector. The femtosecond arcuate keratotomy patients showed less postoperative cylinder than LRI patients.

Evaluation of a hub-and-spoke model for the delivery of femtosecond laser-assisted cataract surgery within the context of a large randomised controlled trial.

AIMS: To test a hypothesis that cataract operating room (OR) productivity can be improved with a femtosecond laser (FL) using a hub-and-spoke model and whether any increase in productivity can offset additional costs relating to the FL. METHODS: 400 eyes of 400 patients were enrolled in a randomised-controlled trial comparing FL-assisted cataract surgery (FLACS) with conventional phacoemulsification surgery (CPS). 299 of 400 operations were performed on designated high-volume theatre lists (FLACS=134, CPS=165), where a hub-and-spoke FLACS model (1×FL, 2×ORs=2:1) was compared with independent CPS theatre lists. Details of operative timings and OR utilisation were recorded. Differences in productivity between hub-and-spoke FLACS and CPS sessions were compared using an economic model including testing hypothetical 3:1 and 4:1 models. RESULTS: The duration of the operation itself was 12.04±4.89 min for FLACS compared with CPS of 14.54±6.1 min (P<0.001). Total patient time in the OR was reduced from 23.39±6.89 min with CPS to 20.34±5.82 min with FLACS (P<0.001)(reduction of 3.05 min per case). There was no difference in OR turnaround time between the models. Average number of patients treated per theatre list was 9 for FLACS and 8 for CPS. OR utilisation was 92.08% for FLACS and 95.83% for CPS (P<0.001). Using a previously established economic model, the FLACS service cost £144.60 more than CPS per case. This difference would be £131 and £125 for 3:1 and 4:1 models, respectively. CONCLUSION: The FLACS hub-and-spoke model was significantly faster than CPS, with patients spending less time in the OR. This enabled an improvement in productivity, but insufficient to meaningfully offset the additional costs relating to FLACS.

Time and motion studies of National Health Service cataract theatre lists to determine strategies to improve efficiency.

AIM: To provide a quantitative assessment of cataract theatre lists focusing on productivity and staffing levels/tasks using time and motion studies. METHODS: National Health Service (NHS) cataract theatre lists were prospectively observed in five different institutions (four NHS hospitals and one private hospital). Individual tasks and their timings of every member of staff were recorded. Multiple linear regression analyses were performed to investigate possible associations between individual timings and tasks. RESULTS: 140 operations were studied over 18 theatre sessions. The median number of scheduled cataract operations was 7 (range: 5-14). The average duration of an operation was 10.3 min±(SD 4.11 min). The average time to complete one case including patient turnaround was 19.97 min (SD 8.77 min). The proportion of the surgeons' time occupied on total duties or operating ranged from 65.2% to 76.1% and from 42.4% to 56.7%, respectively. The correlations of the surgical time to patient time in theatre was R2=0.95. A multiple linear regression model found a significant association (F(3,111)=32.86, P<0.001) with R2=0.47 between the duration of one operation and the number of allied healthcare professionals (AHPs), the number of AHP key tasks and the time taken to perform these key tasks by the AHPs. CONCLUSIONS: Significant variability in the number of cases performed and the efficiency of patient flow were found between different institutions. Time and motion studies identified requirements for high-volume models and factors relating to performance. Supporting the surgeon with sufficient AHPs and tasks performed by AHPs could improve surgical efficiency up to approximately double productivity over conventional theatre models.

Late Stromal Rejection in Deep Anterior Lamellar Keratoplasty: A Case Series.

PURPOSE: To report a series of 4 cases (3 patients) with late stromal graft rejection 32 to 46 months after an uneventful deep anterior lamellar keratoplasty (DALK). METHODS: Three patients (4 eyes), who had undergone an uneventful DALK for keratoconus (3 eyes) and infectious keratitis (1 eye) 32 to 46 months previously presented with a history of ocular discomfort and redness, with reduced visual acuity in 3 eyes. In all cases, all sutures had been removed at least 18 months previously. On examination, there was superficial and in 2 eyes deep neovascularization. In 2 eyes, the vessels extended within the interface between the donor and host corneas. The stroma of the donor cornea adjacent to the areas of vascularization was edematous. A diagnosis of stromal graft rejection was made, and the patients were administered intensive topical corticosteroids. RESULTS: All eyes responded well to treatment, becoming more comfortable, with decreasing redness, reversal of corneal edema, and return of prerejection best corrected visual acuity with up to 18 months follow-up. The patients continued to receive tapering dosage of topical corticosteroid for 12 months. In 1 eye topical steroids were reintroduced at 13 months because of a further rejection episode. CONCLUSIONS: These cases of late stromal rejection after DALK provide clinical evidence that donor keratocytes may persist in such lamellar grafts for extended periods and that patients should be warned that rejection may occur years after surgery.

Visual Outcomes and Graft Thickness in Microthin DSAEK--One-Year Results.

PURPOSE: To evaluate visual outcomes, endothelial graft thickness, and complications in microthin Descemet stripping automated endothelial keratoplasty (DSAEK). METHODS: A prospective interventional cohort of 130 eyes of 114 consecutive patients underwent microthin DSAEK. Endothelial graft preparation included pachymetry-controlled stromal dehydration to reduce donor thickness between 550 and 530 µm by a custom airflow device, before a single-pass microkeratome dissection with a uniform cutting head of 350 µm to achieve microthin endothelial grafts (<130 µm). Data on visual acuity, graft thickness, endothelial cell loss, and complication rates were analyzed. RESULTS: Pachymetry-controlled donor preconditioning reduced donor thickness on average by 67 µm (range 0-186, SD 44.7) from 590 µm (range 485-806, SD 53) to 528 µm (range 480-620, SD 23), P < 0.01, and allowed graft preparation without any case of intraoperative graft loss or perforation. The resultant mean graft thickness was 94 µm (SD 25) intraoperatively, 94 µm (SD 26) at 1 month, and 90 µm (SD 19) at 12 months. Of note, 98.2% of eyes without significant visual comorbidity achieved best-corrected Snellen acuity of 6/9 or more at 12 months. There was a 35.8% and 41% reduction in endothelial cell density at 3 and 12 months, respectively. Postoperative graft detachment occurred in 5% of cases (1.7% in uncomplicated eyes). There was no graft loss during preparation, and none developed immune rejection during the study period. CONCLUSIONS: The microthin DSAEK procedure offers a simple and safe technique to prepare thin endothelial grafts with a low risk of graft wastage, low risk of postoperative detachment, and visual results that are comparable to those of other thin endothelial keratoplasty procedures.

The Peterborough scheme for community specialist optometrists in glaucoma: results of 4 years of a two-tiered community-based assessment and follow-up service.

AIMS: To report on results of an innovative glaucoma shared-care scheme based in Peterborough, UK. METHODS: A retrospective review of all new appointments with 11 community-based specialist optometrists in glaucoma (SOG) was conducted. There are two tiers of SOG, whereby tier 2 SOGs have increased levels of autonomy. All optometrist assessments were reviewed by a consultant ophthalmologist, and levels of agreement were calculated for assessment of optic nerve head appearance, Humphrey visual field test interpretation, diagnosis and outcome. RESULTS: 1639 new patients were assessed by SOGs over a 4-year period. The median waiting time for patients from referral to SOG assessment was 0 days (IQR 0-56), and from SOG assessment to consultant review in a virtual clinic was 12 days (IQR 8-18days). After first appointment, over 60% of patients were classified as low-risk and remained within the SOG scheme. Rates of frank disagreement between SOG and consultant regarding diagnosis and proposed outcome were 5.6 and 10.4%, respectively, for tier 2 SOGs and 15.3 and 28.6%, respectively, for tier 1 SOGs. CONCLUSIONS: The SOG scheme demonstrates acceptable levels of accuracy between SOG and glaucoma consultant. This scheme allows many stable low-risk patients to remain out of hospital eye department outpatient clinics.