Sequential Customized Therapeutic Keratectomy in Patients With a History of Radial Keratotomy.

PURPOSE: To evaluate the outcome of sequential customized therapeutic keratectomy (SCTK) in reducing higher order aberrations (HOAs) and improving quality of vision in highly aberrated corneas consequent to previous radial keratotomy (RK). METHODS: A retrospective review of patients undergoing SCTK treatment from January 2012 to October 2020 was conducted in the Eye Center, Humanitas Clinical and Research Center (Rozzano, Italy). Indications for treatment in patients who had RK were significantly and/or progressively reduced corrected distance visual acuity (CDVA) combined with visual symptoms critically affecting quality of life. Preoperative and postoperative CDVA, corneal topography and aberrometry, Scheimpflug tomography, and anterior segment optical coherence tomography were registered. RESULTS: Thirty-four patients who underwent RK a mean of 26.62 ± 7.10 years before SCTK treatment were included. SCTK induced a significant improvement of CDVA from 0.44 ± 0.82 logMAR preoperatively to 0.15 ± 0.64 logMAR postoperatively (P < .001). No patient experienced worsening of CDVA, whereas 8 patients (23,50%) gained one line and 23 patients (67.65%) gained two lines or more. A significant decrease in corneal coma, trefoil, and spherical aberrations was also noted (P = .003, .003, and .004, respectively). CONCLUSIONS: SCTK proved to be a safe and effective option to treat highly aberrated eyes following RK. The authors suggest the use of SCTK as a first-line approach for the treatment of HOAs after RK and avoiding more invasive procedures such as corneal transplantation or intraocular lens implantation. [J Refract Surg. 2023;39(12):808-816.].

Sequential Custom Therapeutic Keratectomy for the Treatment of Granular Corneal Dystrophy Type 1: A Long-term Study.

PURPOSE: To evaluate the effectiveness of sequential custom phototherapeutic keratectomy (SCTK) for granular corneal dystrophy type 1 (GCD1). METHODS: Thirty-seven eyes of 21 patients with GCD1 were treated with SCTK to remove superficial opacifications, regularize the corneal surface, and decrease optical aberrations. SCTK is a sequence of custom therapeutic excimer laser keratectomies with step-by-step intraoperative corneal topography monitoring of results. Six eyes of 5 patients previously treated with penetrating keratoplasty received SCTK for disease recurrence. Pre-operative and postoperative corrected distance visual acuity (CDVA), refractive values, mean pupillary keratometry, and pachymetry were retrospectively analyzed. The mean follow-up period was 41.3 months. RESULTS: SCTK provided significant decimal CDVA improvement, from 0.33 ± 0.22 to 0.63 ± 0.24 (P < .0001) at the last available follow-up visit. One eye, initially treated with penetrating keratoplasty, showed visually significant disease 8 years after the first SCTK and was re-treated. Mean corneal pachymetry difference between preoperative and final follow-up values was 78.42 ± 62.26 µm. Mean corneal curvature and the spherical component did not show a statistically significant change or hyperopic shift. Astigmatism and higher order aberration reduction were statistically significant. CONCLUSIONS: SCTK is a powerful tool for the treatment of anterior corneal pathologies hindering vision and quality of life, such as GCD1. SCTK is less invasive and fosters more rapid visual recovery than penetrating keratoplasty or deep anterior lamellar keratoplasty. Providing significant visual improvement, SCTK can be the preferred initial treatment in eyes with GCD1. [J Refract Surg. 2023;39(6):422-429.].

Posterior lamellar keratectomy for recalcitrant deep stromal keratitis: A case report.

PURPOSE: To describe a new technique for management of recalcitrant deep stromal keratitis using posterior lamellar keratectomy. METHODS: A 66-year-old pseudophakic male presented with deep stromal corneal infiltrates, extending from 2 to 4 o'clock in the vicinity of the limbus of the left eye, 3 months after phacoemulsification. The infiltrates failed to respond to empirical topical medications, anterior chamber wash and intrastromal injection. Posterior lamellar keratectomy was done to debulk the infectious load. In this technique the diseased posterior lamella was excised through a sclerocorneal lamellar pocket without a donor graft. RESULTS: The infection subsided within 2 weeks after posterior lamellar keratectomy. Patient achieved best corrected visual acuity (BCVA) of 20/60 with complete resolution of symptoms at 2 weeks follow up. Till the last follow-up at 6 months, the patient maintained BCVA of 20/60 with no sign of recurrence or corneal decompensation at the keratectomy site. CONCLUSION: Posterior lamellar keratectomy is a simple, effective and inexpensive technique for management of small, peripheral, deep-seated recalcitrant keratitis. It leads to radical treatment of the disease like therapeutic penetrating keratoplasty but in a less invasive manner and without a donor graft.

Disseminated idiopathic lipid keratopathy in a normolipemic cat.

OBJECTIVE: To report a case of idiopathic lipid keratopathy in a normolipemic cat. ANIMAL STUDIED: A 10-year-old neutered female European domestic cat. RESULTS: A cat was evaluated for bilateral white corneal deposits. Slit-lamp examination revealed multiple, well-defined, round, stromal, cream-colored deposits of different sizes associated with generalized superficial corneal vascularization. Blood lipids were normal, and no history of travel to tropical locations or ocular trauma was present. Topical betamethasone/gentamicin 0.1% suspension q 12 hours did not result in any improvement of clinical appearance after one week. Tomography following the initial therapy revealed dense, hyperreflective deposits with posterior shadowing in the anterior and mid stroma of both corneas. A four-week course of itraconazole 0.01% ophthalmic cream was prescribed q 12 hours with no improvement. Four months after the initial examination, a diagnostic superficial keratectomy and amniotic membrane implantation were performed. Histopathological analysis showed membrane bound vacuoles with infiltration of foamy macrophages suggesting a diagnosis of primary lipidosis. The post-surgical period was unremarkable, and ten days later, the patient was re-examined. Opacification from a corneal leukoma was observed in the excision site with mild fibrotic tissue. Two months post-keratectomy, no further changes were detected in the cornea, and the patient was managed only with topical lubricant. CONCLUSIONS: To our knowledge, this is the first report of idiopathic corneal lipidosis in a cat and may be considered as a differential diagnosis of corneal disease in felines.

Sequential intracorneal ring segment implantation followed by transepithelial phototherapeutic keratectomy and corneal cross-linking.

PURPOSE: To evaluate the safety and visual outcomes of intrastromal corneal ring segment (ICRS) implantation followed by transepithelial phototherapeutic keratectomy (te-PTK) and corneal cross-linking (CXL) in patients with mild keratoconus. METHODS: Patients with mild keratoconus and contact lens intolerance who underwent sequential ICRS implantation followed by phototherapeutic keratectomy and corneal CXL between April 2015 and July 2018 were retrospectively included in the study. Refractive and visual outcomes, satisfaction questionnaire and complications were recorded at the last follow-up (mean 9.5 months postoperatively). RESULTS: Twenty eyes of 17 patients were enrolled, including 5 women and 15 men. The mean time between the two procedures was 16 months. Based on values before the first procedure and 9.5 months after the second procedure, significant improvements were noted in uncorrected distance visual acuity (UDVA) (0.80±0.35 logMAR vs. 0.46±0.38 logMAR), corrected distance visual acuity (CDVA) (0.38±0.23 logMAR vs. 0.13±0.16 logMAR), maximal K (56.11±4 diopters [D] vs. 50.6±3.56 D), mean K (51.87±3.43 D vs. 48.45±2.91 D), cylinder (7.99±3.94 D vs. 4.23±3.49 D), and spherical equivalent (-3.84±3.36 D vs. -0.99±2.15 D) (P<0.01). Among the outcomes, we noted 5 (25%) superficial corneal scarring (haze); 75% of eyes gained>=1 logMAR line of CDVA. In all, 94.5% of patients reported that they were satisfied with their outcomes. CONCLUSION: Combining ICRS implantation followed by te-PTK and corneal CXL appears to be a safe and effective approach for improving visual outcomes and quality of life in keratoconus patients.

Corneal Neuro-Regenerative Effect of Transcutaneous Electrical Stimulation in Rabbit Lamellar Keratectomy Model.

Purpose: This study aimed to evaluate the effect of transcutaneous electrical stimulation (TES) on corneal nerve regeneration in rabbits injured from superficial lamellar keratectomy (SLK). Methods: New Zealand White rabbits were used in this experimental study. To induce corneal nerve damage, SLK was performed using a 7.0-mm trephine. TES was applied for 28 days after the corneal nerve injury. Corneal sensitivity, Western blotting, real-time polymerase chain reaction (PCR), and immunofluorescence were performed to observe changes in the corneal tissue. Results: In the 2-Hz and 20-Hz electrical stimulation groups, the degree of corneal wound healing increased by more than 10% compared to the control group, but no significant difference was observed. Conversely, the electrical stimulation (2-Hz or 20-Hz) group showed significantly increased corneal sensitivity compared to the control group. Western blot analysis revealed that small proline-rich protein 1A (SPRR1a), a regeneration-associated protein was significantly increased in the 2-Hz group on days 1 and 7 compared to that in the other groups. Once again, nerve regeneration in the 2-Hz group was supported by the results of PCR, in which a significant increase in the nerve growth factor (NGF) on day 1 was observed compared with the other groups. Moreover, immunofluorescence after 28 days of electrical stimulation showed significant nerve regeneration in the 2-Hz group. Conclusions: TES promoted corneal nerve regeneration in rabbit SLK model. The application of electrical stimulation of 2-Hz frequency was more effective than the 20-Hz frequency, showing potential clinical applications for corneal diseases. Translational Relevance: This study shows how application of TES to the eyes that exhibit corneal nerve damage can improve corneal nerve regeneration examined by histologic analysis.

Histological findings of corneal tissue after failed phototherapeutic keratectomy in macular corneal dystrophy - a case report.

BACKGROUND: Macular corneal dystrophy is a rare inherited disease of the cornea leading to deposits mainly in the stroma. Affected patients suffer from progressive loss of visual acuity which should be treated with penetrating keratoplasty. This is the first case report describing the clinical and histopathological findings of corneal tissue after failed phototherapeutic keratectomy (PTK) in a patient with macular corneal dystrophy. CASE PRESENTATION: A 32-year-old man presented with visual impairment, blurred vision and increasing glare sensitivity in both eyes in 2014. All symptoms had existed for several years and had recently increased sharply. A corneal dystrophy was diagnosed and penetrating keratoplasty was recommended but the patient was hesitant to undergo surgery. In 2018, in contrast to current guidelines, a PTK was performed in both eyes in Turkey for unknown reasons. In May 2019, he presented again in our clinic. Best corrected visual acuity was markedly reduced in both eyes. Slit-lamp examination revealed multiple dense, poorly circumscribed grey-white patchy changes in the stroma accompanied by corneal opacity in both eyes. In February 2020, the patient decided to have penetrating keratoplasty performed at the University Eye Hospital in Tübingen. The explanted cornea was stained for acid mucopolysaccharides (AMP) and periodic acid-Schiff staining (PAS). The histopathological examination revealed destruction of Bowman's layer and a subepithelial fibrosis band due to the PTK previously performed. The AMP staining demonstrated blue deposits typical of macular corneal dystrophy, mainly in the stroma but also in the endothelium. Interestingly, the acidic mucopolysaccharides were found increased in the PTK-induced subepithelial fibrosis band. The postoperative course after keratoplasty was favourable with a significant increase in visual acuity and a clear graft. CONCLUSIONS: This report presents the first case of a histologically evident exacerbation of macular corneal dystrophy after PTK and emphasizes the relevance of thorough pre-interventional diagnosis and patient selection to consider other therapeutic approaches, such as penetrating keratoplasty.

[Phototherapeutic keratectomy for recurrent corneal erosion of various epithelial origins: influence of depth of ablation on pachymetry and refraction]. / Phototherapeutische Keratektomie bei rezidivierenden Hornhauterosionen verschiedener epithelialer Genese: Einfluss der Ablationstiefe auf Pachymetrie und Refraktion.

BACKGROUND: Phototherapeutic keratectomy (PTK) is an established treatment method for patients suffering from either genetic corneal dystrophy or recurrent corneal erosion (RCE) without underlying basement membrane dystrophy, often caused by trauma. OBJECTIVE: This study aimed to describe the changes in manifest subjective refraction and pachymetry after PTK treatment in patients suffering from epithelial basement membrane dystrophy (EBMD) and traumatic or atraumatic RCE without underlying EBMD. MATERIAL AND METHODS: This was a retrospective, single-center study performed at the Department of Ophthalmology of the Ludwig-Maximilians University (Munich). Patient data were retrospective collected using the smart-eye database of the Department of Ophthalmology including diagnostic data from an autorefractometer and from the Pentacam HR. All laser treatments were performed with an ablation depth of 10 µm for EBMD patients and 6 µm for RCE patients without EBMD. RESULTS: Both collectives showed a decrease in pachymetry larger than the calculated ablation depths after a follow-up interval of 126 days (95% CI 104-147 days). While the EBMD collective receiving an ablation of 10 µm showed a decrease of 25.8 µm (N = 74; 95% CI 21.2-30.3; p < 0.001), the non-EBMD collective receiving an ablation of 6 µm showed a decrease of 12.3 µm (N = 44, 95% CI 7.0-17.7; p < 0.001). Both, total corneal refractive power (TCRP) as well as spherical equivalent (SE) offered no significant change in preoperative and postoperative comparison for the EBMD collective. On the other hand, patients without underlying EBMD showed a significant myopic decrease in SE of 0.4 dpt (±0.7 dpt SD, p < 0.05). The mean follow-up interval was 126 days (95% CI 104-147 days). CONCLUSION: PTK treatment offers an effective method for patients suffering from either EBMD dystrophy or RCE syndrome without underlying EBMD. The final ablation based on pachymetry at the apex can be estimated at 2.3 to 2.6 times higher compared to the original ablation depth. The reasons for this are on the one hand the laser ablation itself and the influence of the reactive wound healing of the corneal epithelium.

[Phototherapeutic keratectomy for epithelial basement membrane dystrophy : Impact of excimer laser systems used on the changes of visual acuity, refraction and astigmatism]. / Phototherapeutische Keratektomie bei Epithel-Basalmembran-Dystrophie : Einfluss verwendeter Excimerlaser-Systeme auf die Entwicklung von Visus, Refraktion und Astigmatismus.

BACKGROUND: Excimer laser-assisted phototherapeutic keratectomy (PTK) has become established as the gold standard in treatment of epithelial basement membrane dystrophy (EBMD), commonly also known as map-dot-fingerprint dystrophy (MDF). At the Department of Ophthalmology, Saarland University Medical Center in Homburg/Saar, systems from Zeiss Meditec and Schwind have been used. The outcomes of both were compared in this study. PATIENTS AND METHODS: The retrospective study included patients who underwent PTK with a diagnosis of MDF between 2007 and 2017. A total of 170 operations were performed using Zeiss Meditec MEL-70 (Carl Zeiss Meditec AG, Jena, Germany) and 98 using a Schwind eye-tech-solutions Amaris 750S laser (Schwind eye-tech-solutions GmbH, Kleinostheim, Germany). Preoperative and postoperative data for visual acuity, refraction and astigmatism as well as curvature data from the Pentacam and endothelial cell count were collected. The follow-up period averaged 8 months. RESULTS: In both groups visual acuity postoperatively was significantly better (Zeiss: p < 0.001, Schwind p < 0.004). The improvement in the Schwind group was less than in the Zeiss group, which is the reason why there was a significant difference between the laser systems postoperatively (p < 0.017). There were no significant changes regarding the spherical equivalent after PTK. Regarding astigmatism, there was a significant decrease in the Zeiss group (p < 0.042), while it did not change significantly in patients treated with Schwind laser (p < 0.217). Overall, this led to a significant postoperative difference between both laser systems (p < 0.014). CONCLUSION: The PTK can be recommended as an effective treatment method for patients with EBMD, regardless of the laser systems used. Patients benefit from long relief from recurrences with improved or constant visual acuity and stable refraction.

36-Month Outcomes of Mechanical and Transepithelial PTK Epithelium Removal Techniques Prior to Accelerated CXL for Progressive Keratoconus.

PURPOSE: To compare the 36-month visual, refractive, and topographic results and the optical quality of the cornea between mechanical and transepithelial phototherapeutic keratectomy (PTK) epithelium removal techniques prior to the accelerated corneal cross-linking (CXL) procedure in patients with progressive keratoconus. METHODS: Keratoconic eyes that received either mechanical epithelium removal or transepithelial PTK epithelium removal prior to accelerated CXL with 36 months of follow-up were included. The uncorrected (UDVA) and corrected (CDVA) distance visual acuity, spherical equivalent (SE), manifest astigmatism, flat keratometry (K1), steep keratometry (K2), maximum keratometry (Kmax) readings, thinnest corneal thickness (TCT), topographic astigmatism, point spread function (PSF), and aberrometric parameters including root mean square higher order aberrations (RMS HOAs), vertical coma, and spherical aberration (SA) were assessed preoperatively and 12, 24, and 36 months postoperatively. RESULTS: One hundred ten eyes of 110 patients with keratoconus were included (mechanical epithelium removal group: 69 eyes, transepithelial PTK epithelium removal group: 41 eyes). After the CXL procedure, the mean UDVA, CDVA, manifest astigmatism, RMS HOAs, SA, vertical coma, and PSF improved significantly throughout the follow-up visits in both groups (P < .05 for all variables). The improvement in the mean UDVA, CDVA, manifest astigmatism, K1, K2, Kmax, RMS HOAs, SA, vertical coma, and PSF were significantly better in eyes that underwent transepithelial PTK epithelium removal when compared to eyes that underwent mechanical epithelium removal during the follow-up period (P < .05 for all variables). CONCLUSIONS: Transepithelial PTK-assisted accelerated CXL seems to be more efficient in improving the visual acuity and the optical quality while stabilizing the cornea compared to the accelerated CXL with mechanical epithelium removal in patients with progressive keratoconus. [J Refract Surg. 2022;38(3):191-200.].

Transepithelial phototherapeutic keratectomy for post-traumatic recurrent corneal erosions.

Purpose: To evaluate the outcomes of transepithelial phototherapeutic keratectomy (transepithelial PTK) for treatment of posttraumatic recurrent corneal erosions. Methods: Twenty-four eyes of 22 patients with posttraumatic recurrent corneal erosions who were treated with transepithelial PTK from April 2018 to July 2020 were included in this retrospective study. The rates of recurrent erosions and complications were evaluated during the follow-up after surgery. Visual acuity and refraction were recorded preoperatively and 1 year after surgery. Total corneal astigmatism, total corneal irregular astigmatism, and total corneal spherical aberrations were recorded using corneal tomography preoperatively and 1 year after surgery. Results: Mean postoperative follow-up was 13 months (range: 12-32 months). None of the patients suffered from any complications or further erosions. Uncorrected distance visual acuity, best-corrected distance visual acuity, spherical equivalent, and cylinder remained stable at 1-year postoperatively compared with the baseline (P = 0.214, P = 0.461, P = 0.084, and P = 0.879, respectively). Moreover, there was no significant difference in total corneal astigmatism, total corneal irregular astigmatism, and total corneal spherical aberrations between baseline and 1-year postoperative visit (P = 0.938, P = 0.136, and P = 0.981, respectively). Conclusion: Transepithelial PTK was an effective treatment for patients with posttraumatic recurrent corneal erosions.

Recurrence and Visual Outcomes of Phototherapeutic Keratectomy in Lattice Corneal Dystrophy: A Cohort Study.

PURPOSE: To evaluate recurrence and visual outcomes of phototherapeutic keratectomy (PTK) in lattice corneal dystrophy. METHODS: Kaplan-Meier survival analyses were retrospectively performed. Recurrence was defined as central biomicroscopic findings of recurrence with decreased visual acuity: loss of at least two lines or visual acuity ≤ 20/40) at any time during the follow-up. RESULTS: Twenty-two virgin eyes and 10 with previous keratoplasty (20 patients; 13 women and 7 men) were studied during a mean of 4.7 ± 3.5 years (range: 11 months to 18 years). One and 5 years after the first PTK (PTK1), 1 of 32 and 12 of 32 eyes, respectively, recurred. The cumulative probabilities of recurrence were 3%, 48%, and 89% in the whole sample at 1, 5, and 10 years, respectively. All cases in the virgin group and 8 eyes in the previous keratoplasty group improved their visual acuity. There were no significant differences in recurrence probability between groups (log-rank test; P = .86). A second PTK (PTK2) was performed in 15 of 32 eyes, with 6 postoperative recurrences recorded. The cumulative probabilities of recurrence in the whole sample were 18%, 30%, and 44% at 1, 3, and 5 years, respectively. Visual acuity improved in 11 of 13 eyes in the virgin group and 2 of 2 eyes in the previous keratoplasty group. Recurrence probability after PTK1 and PTK2 was similar in the whole sample (log-rank test; P = .637). Persistent graft edema after PTK1 in one eye was the only complication found. CONCLUSIONS: PTK can be an effective, safe, and repeatable treatment to delay keratoplasty in symptomatic lattice corneal dystrophy. [J Refract Surg. 2022;38(1):43-49.].

Superficial keratectomy followed by intense pulsed light for Salzmann's nodular degeneration and coexisting meibomian gland dysfunction.

PURPOSE: To describe the clinical course of a case of bilateral Salzmann nodular degeneration (SND) treated with superficial keratectomy (SK) followed by intense pulsed light (IPL) for the treatment of coexisting meibomian gland dysfunction (MGD). CASE DESCRIPTION: A 54-year-old man who presented to us complaining of progressive blurred vision associated with foreign body sensation in both eyes because of SND and coexisting MGD. In view of symptoms and visual acuity (VA) deterioration, bilateral SK was performed. Two months after SK, IPL treatment to the face and meibomian gland expression (MGX) using the E-eye device (E-SWIN, Paris) on days 0, 15, and 45, were performed in both eyes with the aim to avoid recurrence and/or progression of MGD. One year after SK, the patient was asymptomatic and VA was 20/20 in both eyes; however because of worsening of non-invasive tear film break-up time measured on Sirius® Scheimpflug tomograph, IPL and MGX were promptly repeated and scheduled every 6 months. CONCLUSION: In our case, IPL was a safe and effective option to control MGD in a patient with SND requiring SK with no observed recurrence of SND 2 years after surgery.

Excimer laser-assisted phototherapeutic keratectomies combined to EDTA chelation for the treatment of calcific band keratopathy.

INTRODUCTION: Calcific band keratopathy (CBK) is a relatively common chronic corneal degeneration and various forms of treatment are mentioned in the literature. CASES DESCRIPTION: Two patients (89 and 37 yo, respectively) affected by diffuse long-standing CBK in one eye and complaining of ocular pain, foreign body sensation and decreased visual acuity are reported. An ethylenediaminetetraacetic acid (EDTA) application on the ocular surface was performed associated with a customized no-touch transepithelial phototherapeutic corneal remodeling in one patient and a standard phototherapeutic keratectomy (PTK) in the second patient. Corneal transparency progressively improved in both cases since the early follow-up visits and the cornea became clear 2 weeks after surgery. In both cases, a significant reduction of ocular discomfort was reported. CONCLUSIONS: Combining EDTA chelation and excimer laser-assisted PTK represents an useful treatment of band keratopathy even in challenging cases and may help regularize corneal surface and improve corneal clarity.

Thermo-Gelling Dendronized Chitosans as Biomimetic Scaffolds for Corneal Tissue Engineering.

Biomimetic scaffolds with transparent, biocompatible, and in situ-forming properties are highly desirable for corneal tissue engineering, which can deeply fill corneal stromal defects with irregular shapes and support tissue regeneration. We here engineer a novel class of corneal scaffolds from oligoethylene glycol (OEG)-based dendronized chitosans (DCs), whose aqueous solutions show intriguing sol-gel transitions triggered by physiological temperature, resulting in highly transparent hydrogels. Gelling points of these hydrogels can be easily tuned, and furthermore, their mechanical strengths can be significantly enhanced when injected into PBS at 37 °C instead of pure water. In vitro tests indicate that these DC hydrogels exhibit excellent biocompatibility and can promote proliferation and migration of keratocyte. When applied in the rabbit eyes with corneal stromal defects, in situ formed DC hydrogels play a positive effect for new tissue regeneration. Overall, this thermo-gelling DCs possess appealing features as corneal tissue substitutes with their excellent biocompatibility and unprecedented thermoresponsiveness.

The impact of the COVID-19 pandemic on microbial keratitis presentation patterns.

BACKGROUND: Microbial keratitis (MK) is the most common non-surgical ophthalmic emergency, and can rapidly progress, causing irreversible sight-loss. This study explored whether the COVID-19 (C19) national lockdown impacted upon the clinical presentation and outcomes of MK at a UK tertiary-care centre. METHODS: Medical records were retrospectively reviewed for all patients with presumed MK requiring corneal scrapes, presenting between 23rd March and 30th June in 2020 (Y2020), and the equivalent time windows in 2017, 2018 and 2019 (pre-C19). RESULTS: In total, 181 and 49 patients presented during the pre-C19 and Y2020 periods, respectively. In Y2020, concurrent ocular trauma (16.3% vs. 5.5%, p = 0.030) and immunosuppression use (12.2% vs 1.7%, p = 0.004) were more prevalent. Despite proportionately fewer ward admissions during the pandemic (8.2% vs 32.6%, p<0.001), no differences were observed in baseline demographics; presenting visual acuity (VA; median 0.6 vs 0.6 LogMAR, p = 0.785); ulcer area (4.0 vs 3.0mm2, p = 0.520); or final VA (0.30 vs 0.30 LogMAR, p = 0.990). Whilst the overall rates of culture positivity were similar in Y2020 and pre-C19 (49.0% vs. 54.7%, p = 0.520), there were differences in the cultures isolated, with a lower rate of poly-microbial cultures in Y2020 (8.3% vs. 31.3%, p = 0.022). CONCLUSIONS: Patient characteristics, MK severity and final visual outcomes did not appear to be affected in the first UK lockdown, despite fewer patients being admitted for care. Concurrent trauma and systemic immunosuppression use were greater than in previous years. The difference in spectra of isolated organisms may relate to behavioural changes, such as increased hand hygiene.

Long-Term Outcome After Superficial Keratectomy of the Abnormal Epithelium for Partial Limbal Stem Cell Deficiency.

PURPOSE: To investigate the etiology and long-term surgical prognosis of the abnormal epithelium for partial limbal stem cell deficiency (LSCD), following superficial keratectomy DESIGN: Retrospective, interventional case series METHODS: This single-center, retrospective study was conducted to assess the prognosis of consecutive patients who underwent superficial keratectomy, with or without amniotic membrane transplantation (AMT), for the treatment of partial LSCD, from 2010 to 2019. We analyzed the etiologies of partial LSCD, surgical success rate, prognosis for recurrent cases, and the improvement in visual acuity. RESULTS: We included 40 patients (51 eyes) with partial LSCD. All eyes were in clinical stage II without dense fibrovascular tissue. Idiopathy was the most common etiology (39%), followed by multiple surgeries involving the corneoscleral limbus (19%). All eyes attained corneal reepithelialization and transparency. Furthermore, the visual acuity improved or remained unchanged postoperatively. We observed recurrence in 19 eyes (37%) with a mean follow-up period of 26.3 months. Despite no significant difference in the recurrence rates among different etiologies, postoperative delayed epithelialization and extensive limbal involvement were identified as risk factors for recurrence (P < .001 and P = .013, respectively). Repeat surgeries were performed in 16 eyes. The final success rate was 84%. CONCLUSIONS: Superficial keratectomy is useful for the treatment of partial LSCD of varied etiologies, with an expected improvement in visual acuity postoperatively. Although the procedure can be repeated and have a high success rate, there have been several cases of recurrence in the long-term postoperative course.