Impact of postoperative intraocular pressure elevation on graft endothelial cells in non-preexisting glaucoma eyes undergoing descemet membrane endothelial keratoplasty: a cohort study.

BACKGROUND: Descemet membrane endothelial keratoplasty (DMEK) has become the dominant keratoplasty procedure. However, the impact of high intraocular pressure (IOP) on the DMEK prognosis in patients without preexisting glaucoma remains unknown. METHODS: Non-glaucoma patients who underwent DMEK in Peking University Third Hospital between July 2017 and March 2023 with a follow-up duration longer than six months were included in this cohort study. Eyes were divided into three groups: Group A) normal IOP; Group B) early IOP elevation (IOP ≥ 30 mmHg or increase of more than 10 mmHg from baseline within 3 days); Group C) intermediate-term IOP elevation (IOP > 21 mmHg or increase of more than 10 mmHg from baseline after 14 days postoperatively). The postoperative IOP, endothelial cell density (ECD), central corneal thickness (CCT), best-corrected visual acuity (BCVA) and rate of graft failure were analysed. RESULTS: Forty-seven eyes from forty-seven patients were included. Thirty-seven eyes were bullous keratopathy, and ten were Fuchs endothelial corneal dystrophy. Twenty-five eyes were classified as Group A, six as Group B and sixteen as Group C. The mean peak IOP was 49.00 ± 4.99 mmHg in Group B eyes and 31.89 ± 11.75 mmHg in Group C eyes. The postoperative BCVA significantly differed from that before surgery (P < 0.001). The ECD at 3 months after surgery in eyes with intermediate-term IOP elevation was lower (P = 0.032). Four eyes with intermediate-term IOP elevation developed graft failure (P = 0.001). CONCLUSIONS: Intermediate-term IOP elevation after DMEK may reduce the graft ECD and lead to graft failure within six months after surgery. However, early IOP elevation had no effect on the prognosis. Careful IOP monitoring and intermediate-term IOP management should be conducted for graft protection.

Efficacy and Safety of the Modified Cretan Protocol in Patients with Post-LASIK Ectasia

Objectives: To investigate the clinical efficacy and safety of the modified Cretan protocol in patients with post-laser in situ keratomileusis ectasia (PLE). Materials and Methods: In this retrospective study, 26 eyes of 16 patients with PLE were treated with the modified Cretan protocol (combined transepithelial phototherapeutic keratectomy and accelerated corneal collagen cross-linking). Visual, refractive, tomographic, and aberrometric outcomes and point spread function (PSF) were recorded preoperatively and at 6, 12, and 24 months after treatment. Results: Both uncorrected and best corrected visual acuity were stable at 24 months postoperatively compared to baseline (from 0.89±0.36 to 0.79±0.33 logarithm of the minimum angle of resolution [LogMAR] and 0.31±0.25 to 0.24±0.19 LogMAR, respectively, p>0.05 for all values). The mean K1, K2, Kmean, thinnest corneal thickness, and spherical aberration at baseline were 45.76±5.75 diopters (D), 48.62±6.17 D, 47.13±5.89 D, 433.16±56.86 µm, and -0.21±0.63 µm respectively. These values were reduced to 42.86±6.34 D, 45.92±6.74 D, 44.21±6.4 D, 391.07±54.76 µm, and -0.51±0.58 µm at 24 months postoperatively (p<0.001, p=0.002, p<0.001, p=0.001, and p=0.02, respectively). The mean spherical equivalent, manifest cylinder, Kmax, central corneal thickness, other corneal aberrations (root mean square, trefoil, coma, quatrefoil, astigmatism), and PSF remained stable (p>0.05 for all variables), while anterior and posterior elevation were significantly improved at 24 months postoperatively (p<0.001 and p=0.02, respectively). No surgical complications occurred during the 24-month follow-up. Conclusion: The modified Cretan protocol is a safe and effective treatment option for PLE patients that provides visual stabilization and significant improvement in topographic parameters during the 24-month follow-up. Further studies are needed to support our results.

Research progress on measurement methods and clinical applications of corneal elastic modulus.

Various corneal diseases are strongly associated with corneal biomechanical characteristics, and early measurement of patients' corneal biomechanics can be utilized in their diagnosis and treatment. Measurement methods for corneal biomechanical characteristics are classified into ex vivo and in vivo. Some of these methods can directly measure certain corneal biomechanical parameters, while others require indirect calculation through alternative methods. However, due to diversities in measurement techniques and environmental conditions, significant differences may exist in the corneal mechanical properties measured by these two methods. Therefore, comprehensive research on current measurement methods and the exploration of novel measurement techniques may have great clinical significance. The corneal elastic modulus, a critical indicator in corneal biomechanics, reflects the cornea's ability to return to its initial shape after undergoing stress. This review aims to provide a comprehensive summary of the corneal elastic modulus, which is a critical biomechanical parameter, and discuss its direct, indirect, and potential measurement methods and clinical applications.

Co-existence of Neurotrophic Keratopathy in Eyes With Limbal Stem Cell Deficiency.

PURPOSE: To investigate whether neurotrophic keratopathy is present in limbal stem cell deficiency (LSCD), by measuring corneal sensation and characterizing corneal subbasal nerve plexus. DESIGN: Prospective, cross-sectional, case-control comparative study. METHODS: A total of 46 eyes with LSCD and 14 normal eyes were recruited from 2019 to 2022. Corneal sensation was measured using a Cochet-Bonnet esthesiometer, and subbasal nerve plexus was imaged using in vivo confocal microscopy (IVCM) at the central cornea and 4 limbal regions. Subbasal nerve density (SND, number of nerves/mm2), subbasal nerve length (SNL, total length of nerves/mm2) and subbasal nerve branch density (SNBD, number of branches/mm2) were quantified. LSCD was graded to stage 1, 2, and 3 using a previously established staging method consisting of clinical scores, basal cell density, central corneal epithelial thickness, and SNL. RESULTS: The mean (±SD) cornea sensation in the central cornea and limbus were 29.2 ± 21.5 and 33.6 ± 15.1 mm in the LSCD group and 57.6 ± 5.8 and 54.3 ± 4.7 mm in the control group, respectively (all P < .001). In sectoral LSCD, the corneal sensation in the affected regions (29.1 ± 17.6 mm) decreased significantly compared to the unaffected regions (41.4 ± 18.2 mm, P < .001). Central corneal SND, SNL, and SNBD were reduced by 84.6%, 82.6%, and 89.2%, respectively, in LSCD compared to controls (all P < 0.05). The central corneal sensation negatively correlated with the severity of LSCD (rho = -0.64, P < .0001) and positively correlated with SND, SNL, and SNBD (rho = 0.63, 0.66, and 0.56, respectively; all P < .001). CONCLUSIONS: Corneal sensation was reduced in eyes with LSCD. The degree of corneal sensation reduction positively correlated with the severity of LSCD. This finding demonstrated the coexistence of neurotropic keratopathy in LSCD.

The outcomes of corneal sight rehabilitating surgery in Stevens-Johnson syndrome: case series.

PURPOSE: To summarize the outcomes of corneal sight rehabilitating surgery in Stevens-Johnson syndrome (SJS). METHODS: This is a retrospective analysis of a consecutive case series. Twenty-four eyes of 18 SJS patients were included in this study. The ocular parameters, surgical procedures, postoperative complications, and additional treatments of the cases were reviewed. RESULTS: A total of 29 corneal sight rehabilitating surgeries, which consists of 9 keratoplasties, 8 Keratolimbal allograft (KLAL) and 12 combined surgeries (keratoplasty and KLAL simultaneously) were performed on the 24 eyes. All patients were treated with glucocorticoid eyedrops and tacrolimus eyedrops for anti-rejection treatment without combining systemic immunosuppression, except two patients who were prescribed prednisone tablets for the management of systemic conditions. The mean follow-up period was 50.6 ± 28.1 months. The optimal visual acuity (VA) (0.74 ± 0.60 logarithm of the minimum angle of resolution [logMAR]) and endpoint VA (1.06 ± 0.82 logMAR) were both significantly better than the preoperative VA (1.96 ± 0.43 logMAR) (95% CI, p = 0.000). 57.1% patients (8/14) were no longer in the low vision spectrum, and 88.9% patients (8/9) were no longer blind. The mean epithelialization time was 7.1 ± 7.6 weeks. The success rate was 86.7%. Additional treatments for improving epithelialization included administration of serum eyedrops (n = 10), contact lens (n = 15), amniotic membrane transplantation (n = 6), and tarsorrhaphy (n = 8). Complications included delayed epithelialization (n = 4, over 12 weeks), glaucoma (n = 11), and severe allograft opacity (n = 4). Only one graft rejection was observed. CONCLUSIONS: Keratoplasty and KLAL can remarkably enhance VA and improve low vision or even eliminate blindness for ocular complications of SJS. The outcome of the surgeries was correlated with the preoperative ocular situation and choice of operative methods.

Clinical features and comprehensive treatment of persistent corneal epithelial dysfunction after cataract surgery.

OBJECTIVE: Evaluation of clinical efficacy and safety of tobramycin/dexamethasone eye ointment in treating persistent corneal epithelial dysfunction (PED) after cataract surgery. METHODS: 26 cases diagnosed as PED after cataract surgery accept the tobramycin/dexamethasone ophthalmic ointment and intense pulse light treatment in the Xiamen University of Xiamen eye center between September 2016 and April 2022 were retrospectively analyzed, mainly including clinical manifestations, characteristics of morphological changes imaged by in vivo confocal microscopy, meibomian glands infrared photography, lipid layer thickness (LLT), management and therapeutic effects. RESULTS: There were 26 eyes, include 8(35%) males and 15(65%) females with an average age of 69.6 ± 5.2 years(50 to 78 years). The mean hospitalization time was (18.4 ± 7.5) days after cataract surgery. Twenty patients had meibomian gland dysfunction. Infrared photography revealed varying loss in the meibomian glands, with a mean score of 3.8 ± 1.2 for gland loss. The mean LLT was 61.6 ± 8.4 nm. After treatment, 20 patients were cured, and 3 received amniotic membrane transplantation. After treatment, the uncorrected visual acuity (UCVA) and best-corrected vision activity (BCVA) improved (P < 0.001), and there was no significant difference in intraocular pressure (IOP) before and after treatment (P > 0.05). CONCLUSIONS: The early manifestation of PED after surgery is punctate staining of the corneal epithelium. Tobramycin and dexamethasone eye ointment bandages have a good repair effect. The meibomian gland massage combined with intense pulse light treatment can effectively shorten the course of the disease.

Transepithelial phototherapeutic keratectomy for treatment-resistant recurrent corneal erosion syndrome.

BACKGROUND: To evaluate the efficacy and safety of trans-epithelial phototherapeutic keratectomy (TE-PTK) as a treatment for recurrent corneal erosion syndrome (RCES) in patients with symptoms refractory to conventional treatments. METHODS: All patients who received TE-PTK treatment for RCES had failed 3 or more conventional treatments and were reviewed, and if met criteria, approved by healthcare workers of the British Columbia public health authority (Medical Services Plan (MSP). A retrospective chart review and telephone survey were conducted at the Pacific Laser Eye Centre (PLEC). Exclusion criteria were ocular co-morbidities potentially affecting treatment efficacy. RESULTS: This study included 593 eyes of 555 patients (46.2% male; 50.9 ± 14.2 years old) who underwent TE-PTK. The leading identified causes of RCES were trauma (45.7%) and anterior basement membrane dystrophy (44.2%). The most common pre-PTK interventions were ocular lubricants (90.9%), hypertonic solutions (77.9%), and bandage contact lenses (50.9%). Thirty-six eyes had undergone surgical interventions such as stromal puncture, epithelial debridement, or diamond burr polishing. Post-PTK, 78% of patients did not require any subsequent therapies and 20% required ongoing drops. Six patients (1.1%) reported no symptom improvement and required repeat TE-PTK for ongoing RCES symptoms after initial TE-PTK. All 6 eyes were successfully retreated with TE-PTK (average time to retreatment was 11.3 ± 14.9 months). There was no significant difference in best corrected visual acuity pre- vs. post-operatively. The mean post-operative follow-up was 60.5 months (range: 5-127 months). CONCLUSION: TE-PTK has a good efficacy and safety profile for treatment-resistant RCES. The third-party public health-reviewed nature of this study, the low recurrence rate of RCES, and the low PTK retreatment rate suggest that TE-PTK might be considered for wider use in the management of RCES.

Neurotrophic keratopathy: General features and new therapies.

Neurotrophic keratopathy is an uncommon degenerative corneal disorder characterized by compromised corneal sensory innervation resulting in the formation of epithelial defects and nonhealing corneal ulcers. Various treatment modalities are available to stabilize disease progression, improve patient well-being, and prevent vision loss. For eligible patients, medical and surgical reinnervation have emerged as pioneering therapies, holding promise for better management. We present a comprehensive review of the disorder, providing an update relevant to ophthalmologists on pathogenesis, diagnosis, treatment options, and novel therapies targeting pathophysiological pathways.

Long-Term Corneal Endothelial Parameters of COVID-19 Patients With Ocular Surface Symptoms.

PURPOSE: This study aimed to investigate the long-term effects of COVID-19 on corneal endothelial cell morphology in patients with ocular symptoms to assess possible corneal involvement in patients who recovered. METHODS: The COVID-19 group included patients diagnosed and treated at Istanbul University Cerrahpasa Medical Faculty with confirmed SARS-CoV-2 infection and ocular irritation symptoms. The control group was comprised of age- and sex-matched individuals. The controls had no ocular pathologies. Noncontact specular microscopy (Konan Cell Check SL, Hyogo, Japan) was performed using the center method after 156 ± 16 days of COVID-19 diagnosis. Parameters such as endothelial cell density (ECD), hexagonality (HEX), coefficient of variation, and central corneal thickness were analyzed. RESULTS: Specular microscopy results of 54 COVID-19 patients with ocular irritation symptoms and 72 controls were evaluated. Ocular symptoms in COVID-19 patients included conjunctival hyperemia, foreign body sensation, tearing, ocular secretion, and chemosis. Mean (±SD) ECD was 2770 ± 31 (cells/mm 2 ) in the COVID-19 group and 2897 ± 26 in the control group, and mean (±SD) HEX was 46.52 ± 6.38 in the COVID-19 group and 58.22 ± 13.94 in the control group. COVID-19 patients exhibited significantly lower endothelial ECD and HEX levels than controls ( P = 0.003 and P < 0.001, respectively). Coefficient of variation and central corneal thickness analyses did not reach statistical significance. CONCLUSIONS: COVID-19 can cause long-term alterations in the corneal endothelial cells, leading to decreased ECD and HEX. Future research should focus on the long-term implications of COVID-19 on the corneal health and visual outcomes.

Corneal neuropathic pain: a review to inform clinical practice.

Corneal neuropathic pain (CNP) is a poorly defined disease entity characterised by an aberrant pain response to normally non-painful stimuli and categorised into having peripheral and central mechanisms, with the former responding to instillation of topical anaesthetic. CNP is a challenging condition to diagnose due to numerous aetiologies, an absence of clinical signs and ancillary tests (in vivo confocal microscopy and esthesiometry), lacking the ability to confirm the diagnosis and having limited availability. Symptomatology maybe mirrored by severe and chronic forms of dry eye disease (DED), often leading to misdiagnosis and inadequate treatment. In practice, patients with suspected CNP can be assessed with questionnaires to elicit symptoms. A thorough ocular assessment is also performed to exclude any co-existent ocular conditions. A medical and mental health history should be sought due to associations with autoimmune disease, chronic pain syndromes, anxiety and depression. Management begins with communicating to the patient the nature of their condition. Ophthalmologists can prescribe topical therapies such as autologous serum eyedrops to optimise the ocular surface and promote neural regeneration. However, a multi-disciplinary treatment approach is often required, including mental health support, particularly when there are central mechanisms. General practitioners, pain specialists, neurologists and psychologists may be needed to assist with oral and behavioural therapies. Less data is available to support the safety and efficacy of adjuvant and surgical therapies and the long-term natural history remains to be determined. Hence clinical trials and registry studies are urgently needed to fill these data gaps with the aim to improve patient care.

Outcomes and Complications of Limbal Stem Cell Allograft Transplantation: A Report by the American Academy of Ophthalmology.

PURPOSE: To review the published literature on the safety and outcomes of keratolimbal allograft (KLAL) transplantation and living-related conjunctival limbal allograft (lr-CLAL) transplantation for bilateral severe/total limbal stem cell deficiency (LSCD). METHODS: Literature searches were last conducted in the PubMed database in February 2023 and were limited to the English language. They yielded 523 citations; 76 were reviewed in full text, and 21 met the inclusion criteria. Two studies were rated level II, and the remaining 19 studies were rated level III. There were no level I studies. RESULTS: After KLAL surgery, best-corrected visual acuity (BCVA) improved in 42% to 92% of eyes at final follow-up (range, 12-95 months). The BCVA was unchanged in 17% to 39% of eyes and decreased in 8% to 29% of eyes. Two of 14 studies that evaluated the results of KLAL reported a notable decline in visual acuity over time postoperatively. Survival of KLAL was variable, ranging from 21% to 90% at last follow-up (range, 12-95 months) and decreased over time. For patients undergoing lr-CLAL surgery, BCVA improved in 31% to 100% of eyes at final follow-up (range, 16-49 months). Of the 9 studies evaluating lr-CLAL, 4 reported BCVA unchanged in 30% to 39% of patients, and 3 reported a decline in BCVA in 8% to 10% of patients. The survival rate of lr-CLAL ranged from 50% to 100% at final follow-up (range, 16-49 months). The most common complications were postoperative elevation of intraocular pressure, persistent epithelial defects, and acute allograft immune rejections. CONCLUSIONS: Given limited options for patients with bilateral LSCD, both KLAL and lr-CLAL are viable choices that may provide improvement of vision and ocular surface findings. The studies trend toward a lower rejection rate and graft failure with lr-CLAL. However, the level and duration of immunosuppression vary widely between the studies and may impact allograft rejections and long-term graft survival. Complications related to immunosuppression are minimal. Repeat surgery may be needed to maintain a viable ocular surface. Reasonable long-term success can be achieved with both KLAL and lr-CLAL with appropriate systemic immunosuppression. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Neuropathic Corneal Pain: Tear Proteomic and Neuromediator Profiles, Imaging Features, and Clinical Manifestations.

PURPOSE: To investigate the tear proteomic and neuromediator profiles, in vivo confocal microscopy (IVCM) imaging features, and clinical manifestations in neuropathic corneal pain (NCP) patients. DESIGN: Cross-sectional study. METHODS: A total of 20 NCP patients and 20 age-matched controls were recruited. All subjects were evaluated by corneal sensitivity, Schirmer test, tear break-up time, and corneal and ocular surface staining, Ocular Surface Disease Index and Ocular Pain Assessment Survey questionnaires were administered, as well as IVCM examinations for corneal nerves, microneruomas, and epithelial and dendritic cells. Tears were collected for neuromediator and proteomic analysis using enzyme-linked immunosorbent assay and data-independent acquisition mass spectrometry. RESULTS: Burning and sensitivity to light were the 2 most common symptoms in NCP. A total of 188 significantly dysregulated proteins, such as elevated metallothionein-2, creatine kinases B-type, vesicle-associated membrane protein 2, neurofilament light polypeptide, and myelin basic protein, were identified in the NCP patients. The top 10 dysregulated biological pathways in NCP include neurotoxicity, axonal signaling, wound healing, neutrophil degradation, apoptosis, thrombin signaling mitochondrial dysfunction, and RHOGDI and P70S6K signaling pathways. Compared to controls, the NCP cohort presented with significantly decreased corneal sensitivity (P < .001), decreased corneal nerve fiber length (P = .003), corneal nerve fiber density (P = .006), and nerve fiber fractal dimension (P = .033), as well as increased corneal nerve fiber width (P = .002), increased length, total area and perimeter of microneuromas (P < .001, P < .001, P = .019), smaller corneal epithelial size (P = .017), and higher nerve growth factor level in tears (P = .006). CONCLUSIONS: These clinical manifestations, imaging features, and molecular characterizations would contribute to the diagnostics and potential therapeutic targets for NCP.

Nonpenetrating Foldable Intrastromal Keratoprosthesis: A Review of the Literature.

PURPOSE: To review the literature focusing on the clinical outcomes of KeraKlear (KK) (KeraMed), a foldable intrastromal keratoprosthesis. METHODS: We searched 6 databases using 4 keywords: KeraKlear, Foldable Keratoprosthesis, Intrastromal Keratoprosthesis, and Non-penetrating Keratoprosthesis. Included studies had to be conducted in vivo on humans, published until January 3, 2023, and had to investigate the implantation of the KK. Eyes were considered at high risk of keratoprosthesis retention failure whenever there was an active inflammatory ocular surface disorder or in case of previous KK failure. We aimed at recording the postoperative complications, rate of prosthesis retention, and mean improvements in visual acuity. RESULTS: We identified 144 publications, 6 of which (38 eyes) met the inclusion criteria. No randomized controlled trials were found, and some studies had significant limitations regarding sample size and follow-up duration. With a mean follow-up of 28 ± 18.8 months, postoperative complications of any kind occurred between 0% and 50% and 24% had an implant extrusion/needed a reoperation. The mean postoperative visual acuity improvement on the last follow-up was -0.83 ± 0.27 LogMAR, that is, -0.57 ± 0.3 for high-risk and -1.03 ± 0.25 for low-risk eyes, whereas 1 year after implantation, 50% of the prostheses were retained in the former and 81% in the latter group. None of the eyes developed glaucoma, endophthalmitis, or expulsive hemorrhages; none had to be eviscerated/enucleated. CONCLUSIONS: Despite the limited quality and quantity of evidence, the available literature seems to suggest the KK to be a valuable tool in the treatment of complicated corneal disorders. Because in many parts of the world, the access to corneal transplantation is limited, this prosthesis could represent a valid alternative.

Long-Term Outcomes of Keratoprosthesis With Biological Haptic: A Review of 25 Years of Single-Center Surgeries.

PURPOSE: To study the outcome of eyes that underwent surgery for keratoprosthesis with a biological haptic, osteo-odonto-keratoprosthesis (OOKP) or tibia keratoprosthesis, by a single surgeon over a time span of more than 25 years. METHODS: One hundred thirty eyes that had received a keratoprosthesis with a biological haptic between 1994 and 2022 by a single surgeon were included in this retrospective analysis. Main outcome parameters were postoperative best corrected visual acuity, postoperative refractive error, postoperative complications, anatomical and functional survival of the prosthesis as well as comparison of subgroups of the 2 different types (OOKP n = 78; tibia keratoprosthesis n = 52) of keratoprostheses, and subgroup analysis of different indications for surgery. Patients were examined every 6 months. RESULTS: The longest follow-up was 25.8 years. Reasons for implantation were graft-vs-host disease (6.9%), vascularized corneas and dry eye (22.9%), physical or chemical burns (29.8%), Stevens-Johnson syndrome (9.9%), and ocular cicatricial pemphigoid (30.5%). The functional success rate with postoperative visual acuity of better than 0.7 log MAR was achieved by 56.9%. The OOKP subgroup showed a better mean visual outcome. 14 keratoprostheses (10.7%) had to be explanted over the whole time span. In the time leading to explantation, refraction showed a statistically significant myopic shift when compared with the non-explanted prosthesis. Anatomical survival rates were better for the OOKP in the first 12 years after implantation. CONCLUSIONS: The study shows that keratoprosthesis with a biological haptic has favorable long-term outcomes. The retention rate stayed very high with excellent functional outcomes.

Retrospective Analysis of a New Intrastromal Dissection Technique Using the Retinal Reflex for Deep Anterior Lamellar Keratoplasty.

PURPOSE: The purpose of this study was to describe a new surgical technique for deep anterior lamellar keratoplasty. METHODS: All pupils in the recipient eyes were dilated preoperatively. Vertical grooving was performed using a crescent blade with a width of 5 mm and a depth of one-third to half corneal thickness on the temporal side of the limbus. Stromal dissection was performed as close as possible to Descemet membrane by observing the gap between the gold line by retinal reflex and the front edge of the crescent blade. Lamellar dissection was performed along the lamellar plane using corneal dissectors. The ophthalmic viscoelastic device was injected into the intrastromal pocket to separate the anterior and posterior stroma and an anterior corneal lamella was excised. A donor cornea was sutured into the recipient bed. RESULTS: In 18 eyes, none of the patients had Descemet membrane rupture during surgery. The mean postoperative residual stromal thickness was 80 ± 31 µm. The mean central corneal thickness after surgery was 660 ± 69 µm. At the last follow-up, the cornea was cleared in all 18 eyes on slit-lamp examination. CONCLUSIONS: We estimated the residual stromal thickness based on the gap between the gold line by the retinal reflex and crescent blade, and intrastromal lamellar dissection was performed using a smooth corneal dissector. Consequently, the surface of stromal dissection was smooth, and the residual stromal thickness was even.

The role of the JAK/STAT3 signaling pathway in acquired corneal diseases.

Acquired corneal diseases such as dry eye disease (DED), keratitis and corneal alkali burns are significant contributors to vision impairment worldwide, and more effective and innovative therapies are urgently needed. The Janus kinase/signal transducer and activator of transcription 3 (JAK/STAT3) signaling pathway plays an indispensable role in cell metabolism, inflammation and the immune response. Studies have shown that regulators of this pathway are extensively expressed in the cornea, inducing significant activation of JAK/STAT3 signaling in specific acquired corneal diseases. The activation of JAK/STAT3 signaling contributes to various pathophysiological processes in the cornea, including inflammation, neovascularization, fibrosis, and wound healing. In the context of DED, the hypertonic environment activates JAK/STAT3 signaling to stimulate corneal inflammation. Inflammation and injury progression in infectious keratitis can also be modulated by JAK/STAT3 signaling. Furthermore, JAK/STAT3 signaling is involved in every stage of corneal repair after alkali burns, including acute inflammation, angiogenesis and fibrosis. Treatments modulating JAK/STAT3 signaling have shown promising results in attenuating corneal damage, indicating its potential as a novel therapeutic target. Thus, this review emphasizes the multiple roles of the JAK/STAT3 signaling pathway in common acquired corneal disorders and summarizes the current achievements of JAK/STAT3-targeting therapy to provide new insights into future applications.

Boston Keratoprosthesis type 1 (KPro) without contact lens wearing in end-stage corneal disease: The APEC experience.

PURPOSE: To report the visual outcomes and survival analysis of keratoprosthesis without contact lens wearing in a tertiary eye care hospital in Mexico City, Asociación Para Evitar La Ceguera (APEC, Coyoacán, México). DESIGN: Retrospective cohort with survival analysis. PARTICIPANTS: Twenty-three eyes (22 patients) received KPro type 1 between 2015 and 2020 with a follow-up time of three years. METHODS: We included analyzed data about past medical history, preoperative diagnosis, best-spectacle visual acuity (BSCVA), postoperative complications and retention rate. Univariate, bivariate and survival analysis were performed and reported. RESULTS: The mean age was 58 ± 13.5 years (SD). 60.86% were male patients (14 eyes). Twelve-eyes (52%) achieved a BSCVA of 20/200 or better in the first and second year of follow-up. At 3 years, only 35% achieved 20/200 or better (BSCVA). Retention rate of Boston type 1 KPro was 87% (20 eyes) at 3 years follow-up. The most common complication was retroprosthetic membrane (RPM) which occurred in 9 eyes (39.1%), followed by corneal melting in 7 eyes (30.4%). CONCLUSIONS: We report the results of a retrospective cohort of twenty-three eyes (22 patients) who were implanted with a Boston type 1 KPro without contact lens wearing to treat corneal blindness. BSCVA improved significantly in most patients achieving 20/200 or better at the 2-year follow-up. Retention rate was 87%, with the presence of RPM as the most common complication.

Long-Term Follow-Up of Descemet Stripping Only: Data Up to 7 Years Postoperatively.

PURPOSE: The aim of this study was to report long-term follow-up of eyes undergoing Descemet stripping only (DSO). METHODS: This was a retrospective study including 26 eyes of 20 patients undergoing DSO between December 2015 and November 2022. Eligibility criteria included peripheral endothelial cell count (ECC) >1000 cells/mm 2 and symptoms caused by central guttata. Patients underwent a central circular 4-mm descemetorhexis using a reverse Sinskey hook and a pair of descemetorhexis forceps using a peeling technique. Three parameters were measured before surgery and at last follow-up: best-corrected visual acuity (BCVA), central corneal thickness (CCT), and ECC measured centrally and at the periphery. RESULTS: The mean age was 73 ± 9 years [52-90 years]. The average follow-up period was 23.7 ± 24.8 months [3-84]. Twenty-two eyes responded to DSO with 20 female eyes (91%) and 2 male eyes (9%). The mean postoperative BCVA improved from 0.3 ± 0.17 logMAR to 0.09 ± 0.13 logMAR ( P value <0.05). The mean postoperative CCT decreased from 588 ± 41 µm to 546 ± 50 µm ( P -value <0.05). The mean postoperative central ECC was 780 ± 257 cells/mm 2 [484-1500]. Peripheral ECC decreased postoperatively (1837 ± 407 cells/mm 2 preoperatively to 864 ± 340 cells/mm 2 postoperatively, P value >0.05). Peripheral endothelial cell polymegathism was stable (average of 26.8% ± 6.8% preoperatively and 30.2% ± 14% postoperatively). Average peripheral endothelial cells polymorphism decreased postoperatively (63.1 ± 20.5% preoperatively to 33% ± 25% postoperatively, P value >0.05). Four eyes did not show improvement after DSO and underwent Descemet membrane endothelial keratoplasty surgery. There were 3 men (75%) and 1 women (25%). The preoperative trend was for nonresponders to have lower BCVA, higher CCT, more abnormal peripheral polymorphism, and polymegathism. CONCLUSIONS: The results of this study, with up to 7 years follow up, demonstrate the durability of DSO.

Labial mucosal epithelium grafting in an ex vivo human donor cornea model.

The purpose of the study was to establish a simple ex vivo corneal re-epithelization model and study the labial mucosal epithelium grafting as a potential approach for ocular surface reconstruction. Four human donor corneal buttons were overstored in a corneal cold storage solution at 4 °C for 32-52 days. Four labial oral mucosa strips were dissected from four patients during fornix reconstruction after they signed informed consent. The substantia propria was trimmed off, and the resulting graft was sutured near the corneal limbus with running sutures (thus forming the tissue construct). Constructs were cultured under the standard conditions with the anterior corneal side outwards. After 3 weeks of culture, constructs were removed, washed, and fixed. Sections were stained with hematoxylin and eosin (HE), anti-keratins 4, 13, 19, and p63. Nuclei were counterstained with Hoechst. After the cultivation, all constructs were integral with the attached graft and non-loosened sutures. The native cells were absent in all donor corneas. Histological evaluation demonstrated that the labial mucosal grafts were attached to the Bowman's membrane (BM), and its cellular outgrowths were found to be transit from the graft to the BM over the anterior surface in all constructs. Cells expressed mucosal epithelial keratins 4, 13, and 19, and several were p63-positive in nuclei. In the study, a simple ex vivo corneal re-epithelization model was successfully established. The model was potent in studying the labial mucosal epithelium grafting as an option for autologous ocular surface reconstruction in patients with bilateral limbal stem cell deficiency.