VISUMAX 800 was introduced to improve the patient experience and clinical outcomes of small incision lenticule extraction (SMILE). This was a retrospective, matched, and case-control study (1:2) controlled for preoperative central corneal thickness and refractive error that compared early refractive and visual outcomes after SMILE using VISUMAX 800 and VISUMAX 500 to treat myopia. We included 50 eyes that underwent the VISUMAX 800 SMILE and 100 eyes that underwent the VISUMAX 500 SMILE. SMILE using VISUMAX 800 was performed using the CentraLign aid for vertex centration. Cyclotorsion was controlled by an OcuLign assistant in the VISUMAX 800 group after corneal marking. Corneal higher-order aberrations (HOAs) were evaluated using a Pentacam 1 month after surgery. No differences were observed in the pre- and post-operative refractive and visual outcomes at 1 day, 1 month, and 6 months after surgery. VISUMAX 800 induced less total HOAs than VISUMAX 500 (P = 0.036). No statistically significant differences were observed in the amounts of induced spherical aberrations or vertical and horizontal comas. No differences were observed in the 1 month and 6 months refractive and visual outcomes between two SMILE procedures, except for VISUMAX 800, which resulted in lower postoperative total HOAs than VISUMAX 500.

This review explores contemporary challenges in penetrating keratoplasty (PK), focusing on technical intricacies, technological advancements, and strategies for preventing graft rejection. A systematic literature search from January 2018 to July 2023 was conducted across PubMed, Cochrane, Web of Science, Scopus, and EMBASE. The inclusion criteria comprised studies on PK and its comparison with other corneal pathologies, with emphasis on keratoconus (KC). Two independent reviewers screened studies, extracting relevant data. The review covers PK evolution, highlighting infra-red femtosecond lasers\' impact on graft shapes, minimizing astigmatism, and enhancing wound healing. Graft rejection, a primary complication, is examined, detailing risk factors and preventive measures. Preoperative considerations, diagnostic techniques for rejection, and PK in KC are discussed. Postoperative care\'s significance, including intraocular pressure monitoring and steroid administration, is emphasized. The paper concludes with a comprehensive approach to prevent graft rejection, involving topical and systemic medications. An outlook on evolving monoclonal antibody research is presented. As the field progresses, personalized approaches and ongoing therapeutic exploration are expected to refine strategies, enhancing PK outcomes.

In this review, we presented the principles of radial keratotomy (RK), its evolution, enhancement, and complications, and strategies to manage the consequences of RK in the present day. It is essential to understand the RK procedure f, the theoretical background that supported this surgery, the current effect on the cornea, and how to approach patients needing vision improvement. These patients are developing cataracts that need to be handled well, from the IOL calculation to the surgical procedure. Guided keratorefractive surgery is the most accurate procedure to improve these patient\'s vision and life. Nevertheless, some patients may need other approaches, such as sutures, penetrating keratoplasty, corneal rings, and pinhole implants, depending on the degree of irregularity of the cornea, ablation depth for guided surgery or if the sutures are open.

Intraocular lens (IOL) power calculation after corneal refractive surgery (CRS) becomes an expanding challenge for ophthalmologists as more and more cataract surgeries after CRS are required. These patients typically also have high expectations as to visual performance. Conventional IOL power calculation schemes frequently provide inaccurate results in these cases. This review aims to summarize and recommend currently available IOL power calculation methods for eyes with the most common CRS methods: radial keratotomy (RK), photorefractive keratectomy (PRK), laser in situ keratomileusis (LASIK), and small incision lenticule extraction (SMILE). To this end, biometry measuring methods and IOL formulas will be explained and combinations of both are proposed. In synopsis, it is evident that the latest generation of vergence formulas exhibit favorable IOL power prediction accuracy in post-CRS eyes, even though the predictive precision of methods in eyes without CRS is not attained. Ray tracing computation, intraoperative aberrometry, and machine learning-based formulas hold potential to further improve refractive outcomes in post-CRS eyes.

OBJECTIVE: To document the effectiveness and outcome of corneal grafting using acellular porcine corneal stroma (APCS) for veterinary use (BioCorneaVet™ ) to restore corneal integrity in dogs.
METHODS: A review of medical records of patients that underwent keratoplasty with APCS graft to repair deep corneal defects, descemetoceles, and perforations between 2019 and 2021 was carried out. Only animals with intact dazzle reflex, consensual PLR before the surgery and a minimum follow-up of four weeks were considered for the study, with forty dogs (1 eye each) meeting the inclusion criteria.
RESULTS: Brachycephalic breeds were the most frequently represented, and 20 right eyes and 20 left eyes were affected with 25 perforations, 8 descemetoceles, and 9 deep stromal defects (1 eye had both perforation and descemetocele). Most of the patients had concurrent ocular diseases or had undergone previous surgery on the other eye. Two different thickness of xenograft was used (300 or 450 µm), and the diameter ranged from 3 to 10 mm. Postoperative complications included mild to severe corneal vascularization, partial dehiscence, melting, and glaucoma. Follow-up time ranged from 28 to 797 days (mean: 233 days). Ocular integrity was maintained in 37/40 cases (92.5%), and vision was preserved in 36 cases (90%).
CONCLUSIONS: The use of APCS (BioCorneaVet™ ) is an effective surgical treatment for deep stromal defects, descemetocele, and perforations in dogs, providing a good tectonic support and preserving anatomical integrity and vision. The cosmetic appearance was considered good in all the cases and continued to improve with time.

UNASSIGNED: Moorfields Eye Hospital sits as a major tertiary centre for ophthalmic care in the United Kingdom and became a central hub to provide safe and effective ophthalmic care across London and surrounding regions during the COVID-19 pandemic. We explore the impact on both the acute and elective corneal services during the first wave of this pandemic.
UNASSIGNED: A retrospective review of the proportion of corneal transplants and anterior segment trauma repairs was performed during the period of March 23rd to July 1st 2020 compared with an identical period in 2019. Data were acquired from our in-house electronic patient records.
UNASSIGNED: A 92% reduction in corneal elective work was observed during the lockdown period compared with an identical period in 2019, with only 10 elective cases in total being performed. In addition, 91 corneal cross-linking and 76 therapeutic lasers were cancelled. There were 15 cases of primary repair for anterior segment trauma compared with 6 cases pre-COVID-19. A similar scenario occurs with removal of foreign body (4 cases during COVID-19 period versus no cases during pre-COVID-19 era) and with traumatic lens aspirations (6 cases during COVID-19 compared with 2 pre-COVID-19). Interestingly, a statistical difference (p=0.03) was found in the time interval from presentation of symptoms to emergency corneal surgery. During the COVID-19 period, a delay of 1.5 days ± 2.29 (range 0-10 days) occurred compared with 0.8 days ± 1.54 (range 0-6 days) pre-COVID-19.
UNASSIGNED: Stringent risk stratification reduced elective corneal surgery capacity during the lockdown thereby preserving social distancing requirements. However, an apparent increase in emergency corneal surgery seen is likely attributed to centralisation of ophthalmic services during the pandemic crisis, alongside increased domestic injuries. Despite the challenges posed, successful delivery of corneal surgery occurred whilst helping to identify lessons in preparations for future pandemics and current inefficiencies in healthcare delivery.

The use of advanced therapies with stem cells to reconstruct the complex tissue of corneal stroma has gained interest in recent years. Besides, collagen-based scaffolds bioengineering has been offered as another alternative over the last decade. The outcomes of the first clinical experience with stem cells therapy on corneal stroma regeneration in patients with advanced keratoconus were recently reported. Patients were distributed into three experimental groups: Group 1 (G-1) patients underwent implantation of autologous adipose-derived adult stem cells (ADASCs) alone, Group 2 (G-2) received a 120 μm decellularized donor corneal stromal laminas, and Group 3 (G-3) received a 120 μm recellularized donor laminas with ADASCs. A follow up of 36 months of clinical data, and 12 months of confocal microscopy study was performed, the authors found significant clinical improvement in almost all studied mean values of primary and secondary outcomes. Corneal confocal microscopy demonstrated an increase in cell density in the host stroma, as well as in the implanted tissue. Using different approaches, allogenic small incision lenticule extraction (SMILE) implantation was applied in cases with advanced keratoconus. Some authors reported the implantation of SMILE intrastromal lenticules combined with accelerated collagen cross-linking. Others performed intrastromal implantation of negative meniscus-shaped corneal stroma lenticules. Others have compared the outcomes of penetrating keratoplasty (PKP) vs. small-incision Intralase femtosecond (IFS) intracorneal concave lenticule implantation (SFII). Femtosecond laser-assisted small incision sutureless intrasotromal lamellar keratoplasty (SILK) has been also investigated. The published evidence shows that the implantation of autologous ADASCs, decellularized or recellularized human corneal stroma, allogenic SMILE lenticules corneal inlay, and recombinant cross-linked collagen have shown initially to be potentially effective for the treatment of advanced keratoconus. In light of the present evidence available, it can be said that the era of corneal stromal regeneration therapy has been already started.

OBJECTIVE: To evaluate the clinical course and outcome of canine SCCEDs treated with a combination of cotton-tip debridement (CTD), scalpel blade debridement (SBD), and superficial grid keratotomy (SGK).
METHODS: Medical records of dogs diagnosed with SCCED and treated by the same diplomate (FJO) from 2011 to 2019 were reviewed. Age, breed, sex, affected eye, time of onset before treatment, previous procedures performed, time to healing, need for a second treatment, and complications were reported.
RESULTS: A total of 308 eyes (291 dogs) met the inclusion criteria and were included in the study. All dogs received the same treatment (CTD + SBD + SGK) and the same topical medication (tobramycin 0.3% solution and sodium chloride 5% ointment). All eyes healed. Mean age at presentation was 9 years and 6 months (114.4 ± SD 28.0 months), and Boxer was the most common breed (93/308; 30.2%). Mean corneal healing time was 11.5 days (±SD 6.6). Complications occurred in 15/308 (4.9%) eyes. The three main complications observed were infected epithelial ulcer, infected stromal ulcer, and melting corneal ulcer, and 7/15 (46.7%) of the complications were diagnosed in Boston Terrier. Healing occurred after one treatment in 299/308 (97.1%) eyes, and the remaining cases needed a second treatment.
CONCLUSIONS: CTD + SBD + SGK is an inexpensive and efficient treatment for SCCED in dogs. Boston Terrier may be at higher risk of developing complications following this procedure.

OBJECTIVE: To report surgical and corneal clarity scores (CCSs) of corneo-limbo-conjunctival transpositions (CLCTs) in a large number of canine cases.
METHODS: Retrospective review of records that underwent CLCT to repair deep ulcers or perforations between 2002 and 2018. Signalment, concurrent eye disease, additional procedures, pathogenesis, medication, graft orientation, follow-up, and CCSs were recorded.
RESULTS: 418 eyes of 399 dogs were included. Brachycephalics were most commonly affected, comprising 325/418 (77.75%) of the eyes. The most commonly affected breeds were Pugs, Shih Tzus, Cavalier King Charles Spaniels, and French Bulldogs, with 116/418 (27.75%), 64/418 (15.31%), 34/418 (8.13%), and 34/418 (8.13%) ulcerated eyes, respectively. Mean age at surgery was 5.5 years (range 59 days-17.7 years), and median follow-up time was 100 days (range 3 days-7.64 years). The most common etiopathogenesis was spontaneous ulceration in 205/418 eyes (49.04%) of which 191 (93.17%) occurred in brachycephalics. Primary keratoconjunctivitis sicca affected 122/418 eyes (29.19%) and injury 39/418 eyes (9.33%). Mean ulcer width was 3.5 mm (0.5-10 mm). Success rate was 97.13% (406/418 eyes). Failure end points recorded included no menace response, secondary glaucoma, and endophthalmitis. Pre-existing perforation was found in 101/418 (24.16%) of the eyes and significantly increased failure rate (P < .001). The median CCS was G3 (G0-G4), which was lower for Pugs (G2). Graft orientation affected CCS, but did not reach statistical significance.
CONCLUSIONS: The high success rate and CCS for CLCT in dogs make it a good technique to treat deep ulcers but a less desirable outcome is anticipated when treating perforations and Pugs.

BACKGROUND: Optical coherence tomography (OCT) has recently been introduced in the operating theatre. The aim of this review is to present the actual role of microscope-integrated optical coherence tomography (MI-OCT) in ophthalmology.
METHODS: A total of 314 studies were identified, following a literature search adhering to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. After full-text evaluation, 81 studies discussing MI-OCT applications in ophthalmology were included.
RESULTS: At present, three microscope-integrated optical coherence tomography systems are commercially available. MI-OCT can help anterior and posterior segment surgeons in the decision-making process, providing direct visualization of anatomic planes before and after surgical manoeuvres, assisting in complex cases, and detecting or confirming intraoperative complications. Applications range from corneal transplant to macular surgery, including cataract surgery, glaucoma surgery, paediatric examination, proliferative diabetic retinopathy surgery, and retinal detachment surgery.
CONCLUSIONS: The use of MI-OCT in ophthalmic surgery is becoming increasingly prevalent and has been applied in almost all procedures. However, there are still limitations to be overcome and the technology involved remains difficult to access and use.