Search

Purpose: To compare the reliability of the whorl-like region with that of the central cornea for accurate assessment of corneal subbasal nerve plexus (SNP) by analyzing the parameter variability of these two anatomical regions in repeated measurements. Methods: Participants were scanned in the central cornea and whorl-like region with in vivo confocal microscopy on three occasions by two examiners within a time span of one week. Coefficients of repeatability (CoR), intra-class correlation coefficient (ICC), and Bland–Altman scatter plots with 95% limits of agreement (LOA) in the central cornea and whorl-like region were calculated, respectively, based on the nerve fiber length, then the inter-observer and intra-observer agreement were compared between these two anatomical regions. Results: The inter-observer ICC was 0.945, the inter-observer CoR was 0.052, the intra-observer ICC was 0.936, and the inter-observer CoR was 0.046, with narrow 95% LOA within 1 standard deviation in the whorl-like region, whereas the inter-observer ICC was 0.600, the inter-observer CoR was 0.207, the intra-observer ICC was 0.206, and the intra-observer CoR was 0.253, with 95% LOA nearly threefold wider than the standard deviation in the central cornea. Conclusions: Nerve parameter in the whorl-like region showed higher inter-observer and intra-observer agreement than that of the central cornea. The whorl-like region is a more reliable site for accurate assessment of SNP. [ABSTRACT FROM AUTHOR]

Background: Keratolimbal allograft (KLAL) transplantation has been proved to be a useful surgical procedure for limbal stem cell deficiency patients. However, information about in vivo ocular surface changes in those patients is limited, due to the lack of a reliable and non-invasive technique for closely monitoring the changes of KLAL grafts. The aim of this study is to characterize the cellular changes in the limbus and central cornea after KLAL in patients with severe ocular chemical injury, using in vivo laser scanning confocal microscopy (LSCM). Methods: This is a prospective, noncomparative, observational case series. Twenty-three patients (23 eyes) with total limbal stem cell deficiency due to ocular chemical injury were recruited. KLAL with or without other concurrent surgery were performed. LSCM and slit-lamp examination were performed on the limbus and the central cornea before surgery and at 6 and 12 months postoperatively. Presence of palisades of Vogt, limbal basal epithelial cell density within the palisades of Vogt (LEC), limbal dendritic cells (DC) density, and central corneal basal epithelial cell (CEC) density were assessed by LSCM. Results: All patients completed 12 months of follow-up. Twenty-one patients were male and two were female, with a mean age of 39.5 ± 12.5 years. Six cases were due to acid burns, and the others were alkali burns. Palisades of Vogt were observed in all surviving grafts but were absent in graft failure. The epithelial cells in the central cornea of the failed graft had lost the classic polygonal morphology of the normal corneal basal epithelial cells. The cell density of LEC and CEC decreased significantly, whereas DC density increased in the failed grafts over time. Conclusions: In vivo LSCM is a useful tool for monitoring the cellular changes in KLAL grafts, and has the potential to diagnose the failure of KLAL grafts at the cellular level. [ABSTRACT FROM AUTHOR]

Introduction: The aim of this work is to evaluate the effect of mesenchymal stem cell transplantation (MSCT) and cultivated limbal epithelial transplantation (CLET) therapies on the limbus of patients suffering from limbal stem cell deficiency (LSCD). Methods: A sub-analysis of a phase I–II randomized, controlled, and double-masked clinical trial was performed to assess the changes in the anatomical structures of the limbus. In vivo confocal microscopy (IVCM) analysis was carried out in LSCD eyes before and 12 months after allogeneic MSCT or CLET. Epithelial phenotype of the central cornea, as well as the presence of transition zones and palisades of Vogt in the limbus, were assessed using Wilcoxon test. Results: Twenty-three LSCD (14 MSCT and nine CLET) eyes were included. The epithelial phenotype of the central cornea improved significantly (p < 0.001) from 15 (eight MSCT, seven CLET) and eight (six MSCT, two CLET) LSCD eyes showing conjunctival and mixed phenotypes, respectively, to eight (five MSCT, three CLET), five (two MSCT, three CLET), and ten (seven MSCT, three CLET) eyes showing conjunctival, mixed, and corneal phenotypes, respectively. Transition areas and palisades of Vogt were observed in at least one quadrant in nine (five MSCT, four CLET) and 16 (nine MSCT, seven CLET), and in four (two MSCT, two CLET) and six (three MSCT, three CLET) LSCD eyes before and after surgery, respectively. Changes in the transition zones and palisades were solely significant (p = 0.046) for the nasal and inferior quadrants, respectively. Conclusions: MSCT and CLET improved the central corneal epithelial phenotype despite only minor changes in the anatomical structures of the limbus, as detected by IVCM technology. Trial Registration: ClinicalTrials.gov identifier, NCT01562002. [ABSTRACT FROM AUTHOR]

Purpose: To compare short-term changes in corneal endothelial cells after gonioscopy-assisted transluminal trabeculotomy(GATT). Methods: This retrospective comparative study included 138 patients(138 eyes), and 98 of these patients underwent GATT procedure and 40 underwent SLT procedure as a control group. Changes in the corneal endothelium in patients who underwent GATT and SLT were analyzed retrospectively. Endothelial changes in the central cornea were examined using specular microscopy before and 6 months after the GATT and SLT procedure. Intraocular pressure(IOP), number of glaucoma medications, and side effects were evaluated at visits before and after two methods. Results: One hundred and thirty-eight eyes of 138 patients with a mean age of 62.9±12.7 years in the SLT group and 62.5±11.8 years in the GATT group were included in this study. Pre-procedure mean ± SD IOP was 27.7±3.6 mmHg and 27.4±5.3 mmHg (p=0.173) 2.8±0.5 and 2.9±0.8 (p=0.204) glaucoma drugs are in the SLT and GATT group, respectively. The mean corneal endothelial cell density (CECD) in the SLT group was 2433.1±581.4 cells/mm2 before the procedure and 2435.1±585 cells/mm2 6 months after the procedure, a change of 0.1±0.6% which was not statistically significant (p>0.967).The mean CECD at baseline in the GATT group was 2443.4±508.2 cells/mm2 and decreased to 2290.2±527.7 cells/mm2 6 months after this procedure, representing a cell loss of 6,2±9,1% (p<0.001). Conclusion: GATT caused more CECD damage than SLT at the sixth month after the procedure. Considering the loss of CECD in candidates for GATT, sufficient number of endothelial cells in the central cornea is recommended. [ABSTRACT FROM AUTHOR]

Introduction: Herpes zoster ophthalmicus (HZO) results from the reactivation of varicella zoster virus (VZV) in the ophthalmic branch of the trigeminal nerve. The inflammation caused by VZV involves multiple tissues in the eyes. Our goal is to evaluate pattern electroretinogram (PERG) changes and their relationship with corneal sub-basal nerve changes in patients with HZO. Methods: Twenty-two patients with herpes zoster keratitis or conjunctivitis and 20 healthy volunteers were recruited for this cross-sectional study. A PERG test was performed on both eyes of HZO patients and one eye of the healthy controls. In vivo confocal microscopy (IVCM) was also performed on both eyes of the HZO patients to detect corneal nerve damage. Results: Our results showed changes in the PERG parameters in both eyes of HZO patients compared to the healthy controls. Affected eyes showed delayed N95 peak time and decreased P50 and N95 amplitude compared to the unaffected eyes (p < 0.05, respectively). Both affected and unaffected eyes in HZO patients showed delayed P50 peak time and decreased N95 amplitude (p < 0.05, respectively) compared to controls. In HZO patients, no significant differences in each PERG parameter were found between eyes with and without corneal lesions or between eyes with and without increased Langham's cells in the corneal epithelial sub-basal layer. The IVCM images showed decreased total nerve length and number at the sub-basal layer of the epithelial cornea in affected eyes compared to unaffected eyes (p < 0.05). No significant correlation was found between total nerve length and PERG changes. Conclusions: Our results showed that VZV-affected eyes without central cornea involvement displayed reduced N95 amplitude and prolonged P50 peak time in bilateral eyes compared to the healthy controls. Larger studies are needed to further explore the effect of HZO on the electrophysiological response of the eye and the posterior segment. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the epithelial and stromal thicknesses of conjunctiva and cornea in psoriatic patients with anterior segment optical coherence tomography (AS-OCT), Methods: In this cross-sectional study, 61 patients with psoriasis and 42 age-matched, healthy individuals were enrolled. The epithelial and stromal thicknesses of both inferotemporal bulbar conjunctiva and central cornea were measured using AS-OCT. Results: Both the tear breakup time and Schirmer-1 test values were significantly lower in the psoriasis group compared with the controls (p < 0.05). The epithelial thickness of conjunctiva and cornea did not differ between psoriasis and control groups (p > 0.05). The central corneal stroma was significantly thicker in the psoriasis group (p = 0.04). PASI was positively correlated with the thickness of central cornea stroma (r = 0.442, p = 0.006) in the nail psoriasis group. Conclusions: Psoriasis is not associated with altered epithelial thicknesses of the cornea and conjunctiva. It is accompanied by the stromal thickening of the cornea without conjunctival stromal involvement. [ABSTRACT FROM AUTHOR]

Purpose: To report the intra-familial phenotypic variation of granular corneal dystrophy (GCD) across different age groups. Method: Two cases of GCD belonging to the same family (mother and daughter) were assessed and clinical findings were noted. Result: An 18-year-old female with complaint of glare, on examination showed brownish granules involving bowman's layer and superficial corneal stroma suggesting a diagnosis of Bowman layer dystrophy. Screening of her mother revealed multiple diffuse white granular opacities with snowflake appearance involving the central cornea. The intervening cornea was clear and limbus was not involved. Focal illumination showed deep stromal involvement. All these findings were typical of GCD. Genetic analysis revealed mutation of TGF beta-1 located on 5q31 which was consistent with our clinical diagnosis of GCD. Conclusion: Variable clinical presentation of GCD in different age groups can lead to diagnostic dilemma. Screening of family members can be helpful especially when dealing with early cases of GCD. [ABSTRACT FROM AUTHOR]

Copyright of Die Ophthalmologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: This study aimed to evaluate the consistency of preoperative keratometric values, anterior segment, and intraocular lens (IOL) power measurements in patients with cataract and no comorbidities using the Sirius topography device (CSO, Italy) and Lenstar LS 900 (Haag–Streit AG, Köeniz, Switzerland). Methods: Patients with grade 2 and 3 cataracts who applied to Ophthalmology Clinic of Dışkapı Yıldırım Beyazıt Education and Research Hospital, University of Health Sciences and planned for cataract surgery were included the study. Forty eyes with cataract from 40 patients were taken in the study. All patients underwent preoperative assessment using a combined Scheimpflug–Placido disc-based tomography device (Sirius) and Lenstar before cataract surgery. Keratometric measurements, such as flat keratometry (K1), steep keratometry (K2), and maximum keratometry (Kmax), and anterior segment parameters, white-to-white (WTW) distance, IOL power, astigmatism (AST), anterior chamber depth (ACD), aqueous depth (AD), and central cornea thickness (CCT), were recorded. Results: There were significant differences between K1Lenstar and K1Sirius, K2Lenstar and K2Sirius, KmaxLenstar and KmaxSirius, WTWLenstar and WTWSirius, and IOL powerLenstar versus IOL powerSirius. However, there were insignificant differences between ASTLenstar and ASTSirius, ACDLenstar versus ACDSirius, ADLenstar and ADSirius, and CCTLenstar and CCTSirius variables. Furthermore, it was found that Sirius measured significantly higher than Lenstar, especially in terms of IOL power. Conclusion: Significant differences were observed between Lenstar and Sirius in terms of keratometric values, WTW distance, and IOL power. The IOL power value measured with Sirius was found to be higher than the IOL power value measured with Lenstar. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to investigate the relation of the corneal ink mark size, shape, and location with the corneal perimeter in terms of the corresponding corneal axis. Material and methods: This study was designed both prospective experimental and literature search. Contact lenses were used to demonstrate the spreading effect of the surgical ink mark. Open-access published corneal images with corneal ink marks were reviewed. Mark size and perimeter of both contact lenses and corneal images were performed in Image J software. Results: Twenty contact lenses and 15 corneal images with 32 corneal marks, which were obtained from the literature, were included in the study. Mean degree corresponding to the ink size for the group 1 was 8.3° ± 1.2° (range 5.5–10.3), for group 2 was 11° ± 1.1° (range 8–12), for group 3 was 4.2° ± 0.7° (range 3.2–5.5), for group 4 was 4.2° ± 0.7° (range 3.2–5.5), and for group 5 was 6.3° ± 2.5° (range 2–11.5). Discussion: Theoretically, it is wise to target further located ink mark from central cornea based on the 360/2π × (r2 − r1)/(r1 × r2) × M formula. It has been experimentally shown that the smaller corneal perimeter and closer mark to the central cornea may lead the more significant deviation from the targeted axis. Preoperative manual corneal marking may be more responsible for residual astigmatism than it is thought. [ABSTRACT FROM AUTHOR]

In vivo confocal microscopy (IVCM) imaging of the corneal subbasal nerve plexus (SBNP) is a clinical imaging modality gaining popularity for the diagnosis and follow-up of corneal neuropathy in various conditions such as diabetes mellitus. There remain, however, major limitations to the method, hindering its widespread clinical use. Finding the same exact area of the central cornea to standardize image acquisition is difficult without a reference point. Alternatively, creating wide-area mosaics of the SBNP is resource-intensive and has not yet been developed for routine clinical use. Here, we investigated whether IVCM analysis of the corneal SBNP in a predetermined, anatomically standardized region of interest (ROI) could be applied as an equivalent substitution for wide-area SBNP mosaic generation and analysis. Furthermore, we investigated nerve patterns outside the central corneal region for a possible relationship to type 2 diabetes mellitus status using a publicly available dataset. We found that corneal nerve fibre length density (CNFL) based on the ROI underestimated the mosaic-based CNFL by an average of 34% in 90% of cases (150 eyes), and did not exhibit a significant reduction with diabetes, as seen in the full SBNP. Outside the central cornea, nerve orientation differed depending on the anatomic region (left, central or right superior plexus, P < 0.001). Moreover, in long-term type 2 diabetes mellitus (≥ 10 years, 28 subjects), nerve density in the left superior sector of the SBNP was decreased (P < 0.001) while that in the central superior SBNP increased (P = 0.01) relative to 35 age-matched healthy subjects with normal glucose tolerance. These results indicate that subbasal nerve degeneration in type 2 diabetes mellitus can vary according to anatomic location, and regions with potential diagnostic value outside the central SBNP may warrant further investigation. [ABSTRACT FROM AUTHOR]

Corneal oxygen demands, expressed as ratios of uptake rate relative to baseline rates derived from unstressed corneas, were determined with a micropolarographic system for central (closed eye) and superior (open eye) locations of one cornea of each of seven human subjects. The closed-eye central corneal measurements were repeated during two additional experimental sessions. Intrasubject variability of the three mean closed-eye central corneal rate ratios ranged as high as 23%, possibly representing effects of homeostatic mechanisms on the palpebral conjunctival capillaries of some subjects. For the open-eye superior cornea, which was covered by the upper eyelid of every subject prior to measurement, oxygen demand was found to have a greater intersubject range, but was diminished in magnitude relative to the demand associated with the closed-eye central cornea. Superior corneal oxygen demand was not found to be predictable from closed-eye central corneal oxygen demand or extent of eyelid overlap onto the cornea and thus indicated localized open-eye superior corneal environments that were significantly different from those of the corresponding closed-eye central corneas. Such localized environments may be critically important when gauging the susceptibility of particular eyes to superior corneal pathology during contact lens wear. [ABSTRACT FROM AUTHOR]

Aims/hypothesis: Non-invasive in vivo corneal confocal microscopy is gaining ground as an alternative to skin punch biopsy to evaluate small-diameter nerve fibre characteristics. This study aimed to further explore corneal nerve fibre pathology in diabetic neuropathy. Methods: This cross-sectional study quantified and compared corneal nerve morphology and microneuromas in participants without diabetes (n=27), participants with diabetes but without distal symmetrical polyneuropathy (DSPN; n=33), participants with non-painful DSPN (n=25) and participants with painful DSPN (n=18). Clinical and electrodiagnostic criteria were used to diagnose DSPN. ANCOVA was used to compare nerve fibre morphology in the central cornea and inferior whorl, and the number of corneal sub-epithelial microneuromas between groups. Fisher's exact tests were used to compare the type and presence of corneal sub-epithelial microneuromas and axonal swelling between groups. Results: Various corneal nerve morphology metrics, such as corneal nerve fibre length and density, showed a progressive decline across the groups (p<0.001). In addition, axonal swelling was present more frequently (p=0.018) and in higher numbers (p=0.03) in participants with painful compared with non-painful DSPN. The frequency of axonal distension, a type of microneuroma, was increased in participants with painful and non-painful DSPN compared to participants with diabetes but without DSPN and participants without diabetes (all p≤0.042). The combined presence of all microneuromas and axonal swelling was increased in participants with painful DSPN compared with all other groups (p≤0.026). Conclusions/interpretation: Microneuromas and axonal swelling in the cornea increase in prevalence from participants with diabetes to participants with non-painful DSPN and participants with painful DSPN. [ABSTRACT FROM AUTHOR]

Purpose: To report on a keratoconus (KC) patient with Axenfeld-Rieger syndrome (ARS) who developed sterile keratitis after accelerated corneal collagen cross-linking (CXL). Methods: An 18-year-old patient with ARS and KC who had previously undergone intrastromal ring segment implantation underwent accelerated CXL (9 mW/cm2 UVA intensity for 10 min). Results: After uneventful surgery, the patient presented with severe photophobia, redness of the eye, and decreased vision 72 h following the procedure. Slit-lamp examination showed anterior multiple superficial stromal infiltrates in the central cornea with an overlying epithelium defect. Due to the lack of pain and absence of any pathogen from corneal samples, a diagnosis of sterile keratitis was considered. A combination of topical antibiotic and corticosteroid regimen was administered. Three months after CXL slit-lamp examination showed a mild stromal scar overlying the central cornea, which did not decrease visual acuity. Conclusions: The mechanism by which the sterile keratitis occurs following CXL remains unclear. For our case, the reason of post-CXL sterile keratitis could be considered as an immune response due to the staphylococcal antigens. Furthermore, the possible developmental disturbance of corneal stroma in ARS might have contributed to the development of post-CXL sterile keratitis. [ABSTRACT FROM AUTHOR]

Purpose: Altered corneal biomechanics in patients with diabetes may affect intraocular pressure (IOP) measurements. Although a relationship between IOP and glucose levels has been reported in diabetic and nondiabetic patients, the mechanism by which hyperglycemia influences IOP is unclear. The aim of this study was to determine the effects of hyperglycemia on IOP, corneal biomechanics, and anterior segment parameters during the oral glucose tolerance test (OGTT) in nondiabetic patients. Methods: Twenty-one patients without DM who underwent OGTT were included in this study. A complete ophthalmologic examination was performed before the test. Blood glucose, insulin level, IOP (iCare rebound tonometer), Ocular Response Analyzer, and corneal topography (Pentacam) measurements were obtained at 0, 1, and 2 h during the OGTT. Data from the patients' right eyes were included in the analysis. Results: The mean age of the patients was 46.9 ± 11.0 years. There was a statistically significant difference in IOP between 1 and 2 h (p = 0.03) and a clinically significant difference between 0 and 1 h (p = 0.06). Corneal resistance factor was lower at 2 h than 1 h (p = 0.03), while central cornea thickness was increased at 1 h (p = 0.01) and 2 h (p = 0.05) compared to 0 h. There was positive partial correlation between hyperglycemia and IOP at 1 h (p = 0.049, r = 0.67). Conclusion: The positive partial correlation between IOP and glucose level suggests that acute hyperglycemia may lead to increased IOP. However, further research is needed to explain the mechanism of IOP elevation in the hyperglycemic phase during OGTT. [ABSTRACT FROM AUTHOR]

Purpose: We investigated the relationship between central and peripheral corneal astigmatism in elderly patients.Methods: Seventy-six eyes of 76 elderly subjects (mean age = 72.6 ± 3.0 years) were included in the study. Corneal shape was evaluated using the Pentacam HR (Oculus, Wetzlark, Germany), which is comprised of a rotating Scheimpflug camera and a short-wavelength slit light. The power distribution map was selected and corneal astigmatism was calculated using front K-Readings in zones centered on the pupil. Analyzed zones were 2.0-6.0 mm in diameter.Results: Corneal astigmatism decreased as diameter increased, similar to what was observed in eyes with with-the-rule astigmatism and against-the-rule astigmatism (ANOVA, p < 0.01). This effect was more pronounced in eyes with a large central corneal astigmatism (Spearman’s rank-correlation coefficient test, r = 0.51, p < 0.01). There was no change as to axis of corneal astigmatism (ANOVA, p = 0.98).Conclusion: These results suggest that the relationship between central and peripheral corneal astigmatism should be taken into consideration to optimize vision when astigmatic correction is needed. [ABSTRACT FROM AUTHOR]

Comparative studies between artificial eyeball phantoms and in-vivo human subjects were carried out to better understanding the structural deformation of the cornea under varying intraocular pressure (IOP). The IOP-induced deformation and the tension of the cornea were measured by using an optical coherence tomography and noncontact tonometer readings, respectively. The dependence of the central cornea thickness (CCT) and corneal radius of curvature (CRC) on the IOP differed significantly between the full eyeball phantom (FEP) and cornea eyeball phantom (CEP) models. While the CCT changes were very similar between the two models, the relation between the CRC and the IOP was dependent on the type of eye phantom. For the CEP, the CRC drastically decreased as internal pressure increased. However, we found that the changes in the CRC of FEP was dependent on initial CCT under zero IOP (CCT0). When CCT0 was less than 460 μm, the CRC slightly decreased as IOP increased. Meanwhile, the CRC increased as IOP increased if CCT0 was 570 μm. A constitutive mechanical model was proposed to describe the response of the cornea accompanied by the changes in IOP. In vivo measurements on human subjects under both noninvasive and invasive conditions revealed that the relation between the CRC on the IOP is much closer to those observed from FEP. Considering the observed structural deformation of human cornea, we found that FEP mimics the human eye more accurately than the CEP. In addition, the tonometry readings of IOP show that the values from the CEP were overestimated, while those from the FEP were not. For these reasons, we expect that the FEP could be suitable for the estimation of true IOP and allow performance testing of tonometers for medical checkups and other clinical uses. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the incidence of opaque bubble layer (OBL) in femtosecond laser-assisted in situ keratomileusis (LASIK) flaps created with the support of Visumax Carl Zeiss femtosecond laser, planned with different flap diameters (7.90, 8.0, and 8.20 mm) and the same laser energy and power settings. Incidence of intraoperative OBL in flaps of consecutive 108 patients (216 eyes) subjected to bilateral femtosecond-assisted LASIK was considered. Flap creation was performed with the same laser design parameters (spot distance and energy offset) and different presetting diameters of 7.90 mm (72 eyes, group 1), 8 mm (72 eyes, group 2), and 8.20 mm (72 eyes, group 3). The incidence of OBL was considered and its extension was reported measuring involvement of different four corneal flap quadrants in which was theoretically divided the entire flap area; based on these data, OBL presence was classified as none (no evidence of OBL), minimal (minimal presence in not more that one quadrants corneal flap), mild (OBL presence in almost two or three quadrants without tendency to invade central cornea), and moderate (OBL presence in almost three quadrants with tendency to invade central cornea). In group 1, the incidence of OBL was of 23.6 % (17 eyes) with a mild/moderate presence; in group 2, incidence was 20.8 % (15 eyes) with mild presence. Group 3 presented a reduced OBL incidence (4.1 %, 3 eye) with a minimal presence. No statistically significant difference was found between group 1 and 2 ( p = 0.8414).We found statistically significant differences between group 1 and group 3 ( p = 0.0012) and between groups 2 and 3 ( p = 0.0044). A significant reduction and extension of OBL incidence were evident when LASIK flap settings diameter was increased, and flap edge was closer to the contact glass border; this is probably consequent to a more effective gas dispersion outside of corneal flap. [ABSTRACT FROM AUTHOR]

To investigate metabolic differences between the central and peripheral cornea the latter including the limbal area, corneas were dissected and examined using phosphorus-31 (P) nuclear magnetic resonance spectroscopy. Since mostP signals originate from the epithelium,P spectra of the cornea primarily represent the metabolic state of the epithelium. The spectra of the peripheral cornea showed all phosphorus resonances detected in the whole cornea; in contrast, the central cornea showed no phosphocreatine and glycerophosrylethanolamine, and only low levels of ATP. These results indicate that there is a higher metabolic activity in the peripheral epithelium, especially in the limbal area, than in the central epithelium. To evaluate the metabolic state of corneal epithelium during regeneration, we also examined corneas reepithelializing after 7 mm of central epithelial tissue had been removed by mechanical scraping. Rabbits were killed 24 and 48 h after scraping. The reepithelializing corneas clearly showed an increase in ATP, phosphocreatine, and sugar phosphates with time, although phosphorylcholine remained depressed. These findings suggest that the reepithelializing cornea has an elevated level of energy production and that it may have reached a higher steady state, thereby indicating accelerated metabolism of the epithelium during regeneration. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the repeatability of Anterion and compare the agreement of ocular biometric measurements and predicted intraocular lens (IOL) powers with other three optical biometers. Methods: Flat keratometry (Kf), steep keratometry (Ks), J0 and 45 vectors, central cornea thickness (CCT), anterior chamber depth (ACD), and axial length (AL) from the Anterion, IOLMaster 700, Lenstar LS 900, and OA-2000 were recorded. The IOL powers were calculated with the Hoffer Q, Holladay 1, SRK/T, and Haigis formulas. The repeatability was evaluated using the within-subject standard deviation (Sw), repeatability coefficient (RC), coefficient of variation (COV), and intraclass correlation coefficient (ICC). Inter-device agreement between the four biometers was assessed with the 95% limits of agreement. Results: In total, 101 right eyes of 101 participants were enrolled. The Anterion showed good repeatability for all the included biometric parameters with all the CoV ≤ 0.30% and ICC ≥ 0.930 except for J45 with moderate repeatability (ICC was 0.849). Good agreement was found among the four devices for Kf, Ks, J0, J45, ACD, and AL. Generally, wide 95% LoA was found for the predicted IOL powers with the four IOL calculation formulas between the four devices. Conclusions: The Anterion showed good repeatability of biometric measurements for most parameters. Good agreement among the four optical biometers was achieved for all the parameters except for CCT and the predicted IOL power. The AL values exhibited the best repeatability with Anterion and the best agreement among the biometers in our study. [ABSTRACT FROM AUTHOR]

PurposeTo explore the in vivo morphological changes of cornea and limbus in aniridia-associated keratopathy (AAK).MethodsThree cases of AAK were examined with the application of in vivo confocal microscopy (IVCM).ResultsAbnormal structure of wing and basal layer of epithelium, the loss of subbasal nerves, and the presence of goblet cells at central cornea could be identified in the most severe case, along with the absence of Vogt palisades. The less extent of abnormalities in corneal epithelial cells, subbasal nerve, and Vogt palisades were visible in the moderate or mild cases.ConclusionsThe morphological changes of cornea and limbus vary in AAK, and IVCM is a promising tool to determine the degree of limbal stem cell deficiency in patients with AAK. [ABSTRACT FROM AUTHOR]

Purpose: To determine the recovery of structural and functional corneal sensory nerves within the LASIK flap in order to provide insight to more proximal corneal reinnervation and symptoms post-LASIK. Methods: Twenty participants underwent femtosecond LASIK with a superior flap hinge. Ocular Comfort Index in Chinese (OCI-C), Cochet-Bonnet esthesiometry, and in vivo confocal microscopy were conducted before surgery and 1 week, 1-, 3-, and 6-months post-LASIK to measure symptoms, corneal sensitivity, nerve fiber density, width, and the number of interconnections within the flap (central and mid-temporal regions), and next to the superior flap hinge. Linear mixed models were used to compare differences between corneal regions at each time point post-LASIK and changes over time post-LASIK. Spearman's correlation tests were used to examine the associations between variables post-LASIK. Results: The least reduction in sensitivity (P < 0.03) and in nerve fiber density (P < 0.02) was found near the flap hinge compared to other regions, but no regional differences were found in nerve fiber width and interconnections. Nerve fiber density and the number of interconnections at all regions within the flap recovered over time (P < 0.02). The recovery of corneal sensitivity and nerve fiber width was only seen at the central and temporal regions (P < 0.04). No association was found between sensitivity and nerve parameters, but a higher OCI-C score was associated with a lower nerve fiber density near the hinge (r = − 0.43, P = 0.003) over time post-LASIK. Conclusion: Corneal sensitivity and density are preserved in the hinge, but this preservation of the corneal nerve damage does not affect the nerve morphology. [ABSTRACT FROM AUTHOR]

Copyright of Spektrum der Augenheilkunde is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Der Ophthalmologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We report four patients with herpes zoster ophthalmicus who developed a dense pannus limited to a sector of the superior cornea that advanced to the central region of the cornea. The pannus appeared to develop in response to peripheral infiltrates in a subepithelial or anterior stromal location and not in association with disciform corneal edema, interstitial keratitis, or scleritis. The corneal pannus developed insidiously as a late complication without associated ulceration and with little or no anterior uveitis or conjunctival reaction. Additionally, all four patients developed anterior and mid-stromal infiltrates in a punctate or incomplete ring configuration at the leading border of the pannus that threatened the visual axis. In the three patients that were treated with topical corticosteroids, the infiltrates resolved with preservation of visual acuity. The other patient developed central scarring with a permanent reduction in vision. Patients with infiltrates and pannus in a sector of the cornea should be followed carefully and treated with topical corticosteroids when infiltrates appear to prevent progression to the central cornea. [ABSTRACT FROM AUTHOR]

The process of corneal neovascularization induced by alkali burns was periodically observed with a newly developed macroscope. The central corneas were burned using filter discs measuring 6 mm in diameter that had been immersed in 1 N NaOH. At 0, 1, 3 and 7 days and at 2, 3 and 4 weeks after injury, the corneas were observed with the macroscope and then examined histologically. At 1 day post-burn, the limbal vascular plexus was engorged but no new vessel formation was detected. By 3 days, many vascular sprouts had arisen from the limbal vascular arcade. At 7 days, the vascular sprouts grew and became fine new vessels. At 2 weeks, the new vessels lengthened further to the central cornea. At 3 weeks, trunk vessels extended and branched like a vascular tree. Blood in the trunk vessels appeared to flow slowly to and fro. The ends of the vessels swelled in a fusiform shape on the application of slight pressure of the macroscope probe. Histological examination revealed that the ends of the vessels consisted of single vascular endothelial cells and the trunk vessels were covered by pericytes. By 4 weeks, the branch vessels around the burned lesion had degenerated and collapsed. Thus, our in vivo study using the new macroscope not only clarified the process of corneal neovascularization from the early to the regressive phases but also provided some valuable new information. [ABSTRACT FROM AUTHOR]

PurposeCharacterization of the biomechanical properties of the human eye has a number of potential utilities. One novel purpose is to provide the basis for development of suitable tissue-mimicking material. The purpose of this study was to determine the indentation and needle insertion characteristics on human eye globes and tissue strips.MethodsAn indenter assessed the elastic response of human eye globes and tissue strips under increasing compressive loads. Needle insertion determined the force (N) needed to penetrate various areas of the eye wall.ResultsThe results demonstrated that globes underwent slightly greater indentation at the midline than at the central cornea, and corneal strips indented twofold more than scleral strips, although neither difference was significant (P=0.400 and P=0.100, respectively). Significant differences were observed among various areas of needle insertion (P<0.001). Needle insertion through the anterior sclera (adjacent to the limbus) and posterior sclera (adjacent to the optic nerve) required the greatest amount of force (0.954 and 1.005 N, respectively). The force required to penetrate the central cornea (0.518 N) was significantly lower than all other areas except the midline sclera (0.700 N)ConclusionThese data form the basis for further research into the development of a tissue-mimicking human eye construct with potential utility as a model for use in ophthalmology research and surgical teaching. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to investigate the relationship between corneal decompensation following laser peripheral iridotomy (LPI) and iridocorneal endothelial contact. Study design: Retrospective observational case series. Methods: Specular microscopy images of LPI recipients with narrow angles were taken at the central cornea and the 8 midperipheral corneal regions at approximately 3 mm from the center. Eleven eyes of 11 patients had a minimum of ≤ 1600 cells/mm2 among 8 midperipheral corneal endothelial cell densities (ECDs). Radial scans of the angles in the 8 directions were taken with ultrasound biomicroscopy (UBM) in the supine and face-down positions. The minimum and maximum angle opening distance at 750 μm from the scleral spur of the 8 directions were defined as the narrowest and widest angles, respectively. The ECD of the narrowest angle direction was compared with the ECD of the widest angle direction. Results: When UBM was performed with the subject in the supine position, the iris and cornea at the narrowest angle were in contact in only 4 of 11 eyes, while in the face-down position, the iris and the cornea at the narrowest angle were in contact in 10 of the 11 eyes. In the face-down UBM, the midperipheral ECD of the narrowest angle direction was significantly smaller than the midperipheral ECD of the widest angle direction (P = 0.006). Conclusion: The ECD of the narrow angle direction can decrease after LPI. This suggests that corneal endothelial cell damage following LPI may be due to mechanical damage from iridocorneal endothelial contact. [ABSTRACT FROM AUTHOR]

KC keratoconus; Ctrl control; CSC corneal stromal cell; CEC corneal epithelial cell; ImC immune cell. In the schematic of diagram of the human cornea, the corneal epithelium and stroma (labeled in black) from the central cornea were subjected to downstream experiments, and the corneal endothelium (labeled in gray) was excluded (see Materials and Methods). b, c Anterior segment OCT (b) and Scheimpflug optical cross-sectional analysis (c) showed typical symptoms of keratoconus cornea. d UMAP representation of human corneal cells colored into 6 distinct clusters. e, f Expression levels (e) and distribution (f) of well-known representative cell markers across clusters. g The cell type proportions (top panel) and the number of detected genes per cell type (bottom panel). h Representative GO terms of specifically expressed genes in each cell type. i UMAP plot of human corneal cells colored by three major cell types in KC and Ctrl groups. j Bar plot representing the differences in relative proportion of major cell types between Ctrl and KC samples. ns, no significance (Student's t-test). [Extracted from the article]

Implantation of toric intraocular lenses (IOLs) has become standard in the correction of corneal astigmatism. The IOL selection is based on keratometric measurements of the central cornea. However, mid-peripheral corneal changes may yield suboptimal correction in patients with larger pupils. This study retrospectively analyzed corneal topography data collected using a Scheimpflug device during routine clinical examinations. Of 11,953 patients, 641 met the inclusion criteria. Total corneal astigmatism was compared between five concentric zones (2–6 mm) using vector analysis. The absolute difference between astigmatism at 2 mm and 6 mm was 0.30 D (− 0.36 to 0.64), which decreased to 0.10 D (0 to 0.20) between the 5- and 6-mm zone. With-the-rule astigmatism was the most prevalent (53%), 34% had against-the-rule (ATR), and 13% had oblique. The decrease of the cylinder power with the diameter differed significantly between the three types, with ATR and oblique astigmatism being associated with the steepest change. Patients with high corneal astigmatism tend to demonstrate larger differences between the center and mid-periphery than those with low and moderate astigmatism. In conclusion, we demonstrated that central corneal astigmatism differs from that measured at the mid-periphery and that a larger difference was found in patients with ATR, oblique and high astigmatism. [ABSTRACT FROM AUTHOR]

Scar formation as a result of corneal wound healing is a leading cause of blindness. It is a challenge to understand why scar formation is more likely to occur in the central part of the cornea as compared to the peripheral part. The purpose of this study was to unravel the underlying mechanisms. We applied RNA-seq to uncover the differences of expression profile in keratocytes in the central/peripheral part of the cornea. The relative quantity of mitochondrial RNA was measured by multiplex qPCR. The characterization of mitochondrial RNA in the cytoplasm was confirmed by immunofluoresence microscope and biochemical approach. Gene expression was analyzed by western blot and RT qPCR. We demonstrate that the occurrence of mitochondrial DNA common deletion is greater in keratocytes from the central cornea as compared to those of the peripheral part. The keratocytes with CD have elevated oxidative stress levels, which leads to the leakage of mitochondrial double-stranded RNA into the cytoplasm. The cytoplasmic mitochondrial double-stranded RNA is sensed by MDA5, which induces NF-κB activation. The NF-κB activation thereafter induces fibrosis-like extracellular matrix expressions and IL-8 mRNA transcription. These results provide a novel explanation of the different clinical outcome in different regions of the cornea during wound healing. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the early efficacy and safety of intrastromal injection of teicoplanin as the alternative treatment for the methicillin-resistant Staphylococcus aureus (MRSA) keratitis by comparing it with vancomycin. Materials and methods: Twenty-four eyes of 24 New Zealand white rabbits were included in the study. MRSA keratitis was induced in the right eye of each rabbit by injecting 0.1 mL MRSA suspension containing 1000 colony-forming units (CFU) intrastromally to the central cornea. The rabbits were divided into three treatment groups 24 h after the inoculation of MRSA. Eight rabbits received intrastromal teicoplanin therapy, eight received intrastromal vancomycin therapy, and eight received balanced salt solution and served as the control group. Nine hours after the treatment, all rabbits were sacrificed and corneal tissues were collected for microbiological analysis. We also examined and scored all the rabbits clinically before and after the treatment. Results: The control group scored higher with regard to conjunctival injection, iritis, fibrin, hypopyon, epithelial erosion, and corneal infiltrate than the vancomycin and teicoplanin groups (p = 0.031, 0.010, < 0.001, 0.029, 0.009, and < 0.001, respectively). Chemosis and corneal oedema were similar in all groups (p = 0.731 and 0.075, respectively). The severity of all clinical parameters was similar in both the vancomycin and teicoplanin groups after the treatment. The bacterial load was the highest (7.83 ± 0.71 log10 CFU/g) in the control group. The eyes treated with vancomycin and teicoplanin had similar bacterial loads (6.40 ± 0.69 vs. 6.31 ± 0.75 log10 CFU/g, p = 0.809). Conclusion: The efficiency of teicoplanin seems to be comparable to that of vancomycin when administered intrastromally in the early treatment of MRSA keratitis. The former may be preferred in the treatment of selected cases with vancomycin hypersensitivity or resistance. [ABSTRACT FROM AUTHOR]

Microwave thermokeratoplasty (MTK) is a surgical procedure for the correction of pathologic corneal steepening. The purpose of this study was to examine the postoperative outcomes of eyes with advanced keratoconus that underwent femtosecond-laser zig-zag penetrating keratoplasty (z-PK) following MTK for reshaping of the central cornea. This study involved 32 eyes of 32 consecutive advanced keratoconus patients; i.e., 25 eyes of 25 patients who underwent MTK prior to z-PK (MTK + z-PK group), and 7 eyes of 7 patients who underwent z-PK alone (z-PK group). In all treated eyes, visual acuity (VA) and corneal topography were measured before surgery and at 6-months postoperative. At 6-months postoperative, the mean uncorrected distance VA (logarithm of the minimum angle of resolution) and surface regularity index (SRI) of the MTK + z-PK group was 0.62 ± 0.39 (mean ± standard deviation) and 1.26 ± 0.45, respectively, while that in the z-PK group was 1.02 ± 0.18 and 7.64 ± 3.22, respectively. Both variables were significantly better in the MTK + z-PK group than in the z-PK group (P < 0.05). The findings in this study reveal that MTK prior to z-PKP is effective for improving UDVA and reducing the irregularity of corneal topography in patients with advanced keratoconus. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the imaging features of corneal deposits and nerve alterations in Chinese patients with Bietti Corneoretinal Crystalline Dystrophy (BCD) using in vivo confocal microscopy (IVCM). Methods: Twenty patients with BCD and 20 age- and sex-matched healthy controls were enrolled in this retrospective, observational study. Corneal deposits and sub-basal nerve plexus (SNP) were observed by IVCM. Parameters of SNP including total nerve density/number, main nerve trunk density/number, and branch nerve density/number were analyzed by Neuron J. Results: Corneal deposits were observed in both eyes of all patients by IVCM. These crystals appeared as dot-shaped, needle-shaped, and rod-shaped hyperreflective bodies and were located not only in the sub-epithelium and stroma of cornea, but in endothelium which were not reported before. There was a decrease of total nerve density (P < 0.001), main nerve trunk density (P = 0.007), and branch nerve density (P = 0.001), in BCD compared to controls. The number of total nerves/frame (P = 0.001), main nerve trunks/frame (P = 0.005), and branch nerves/frame (P = 0.006) in BCD were lower than controls. Conclusion: New findings in locations of corneal crystals by IVCM expand the phenotype spectrum of BCD. Corneal deposits may be useful for diagnosis of BCD, especially ones without retinal deposits. Corneal nerve parameters were reduced in BCD, which may provide new insights to be further explored to contribute to our understanding of BCD. IVCM is a promising tool to evaluate corneal deposits and nerve alterations in BCD. [ABSTRACT FROM AUTHOR]

Copyright of Der Ophthalmologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: To establish the clinical features and outcomes of patients with chronically retained, feathery chestnut-burr spine-related corneal injury. Methods: The data of the patients who presented with chestnut-burr-related corneal injury between 2010 and 2018 were retrospectively evaluated. Nineteen eyes of 19 patients, with chronically retained corneal intrastromal feathery chestnut-burr spines, were included. Results: The mean age of the patients (11 male and 8 female) was 29.8 ± 19.9 years. Best-corrected visual acuity was 0.13 ± 0.23 logMAR at initial examination and increased to 0.0 ± 0.0 logMAR at last visit. Chestnut-burr spines were located in the peripheral cornea in 14 eyes (73.7%) and in the central cornea in 5 eyes (26.3%). Localized corneal edema surrounding the chestnut-burr spines were detected in all eyes. No eyes were Seidel positive. Three eyes (15.8%) had low-grade anterior chamber reaction. None of the patients had epithelial ulceration or any sign of infection at initial presentation. In order to control acute localized inflammation, all patients were put on topical steroid (loteprednol etabonate). The mean duration of topical steroid treatment was 3.8 ± 1.8 (range 2–7) months. During the follow-up period, inflammation was controlled and no sign of reinflammation occurred. Conclusion: Acute inflammation in intrastromal chestnut-burr spines can be well controlled with easy tapering of topical steroids. However, as the reinflammation possibility cannot be excluded, long-term follow-up of these patients is mandatory. [ABSTRACT FROM AUTHOR]

Purpose: Human corneal epithelial cell-transformed (HCE-T) cell line is used as a widely accepted barrier model for pharmacological investigations in the context of eye application. The differentiation of (limbal) corneal epithelial into mature corneal epithelium coincides with the expression of established differentiation markers. If these differentiation mechanisms are disturbed, it will lead to ocular surface disease. In this study, we want to compare the expression of differentiation markers in the HCE-T cell line to differentiated primary epithelial cells (pCECs) and primary limbal epithelial cell (LEC) culture. This is necessary in order to decide whether HCE-T cells could be a tool to study the differentiation process and its regulatory networks in corneal epithelium. Methods: Primary limbal epithelial cells (LECs) for cell culture and primary corneal epithelial cells (pCECs) as differentiated tissue samples were obtained from the limbus or central cornea region of corneal donors. HCE-T cell line was purchased from RIKEN Institute RCB-2280.Expression levels of conjunctival- and corneal-specific keratin and adhesion markers (KRT3, KRT12, KRT13, KRT19, DSG1), stem cell and differentiation markers (PAX6, ABCG2, ADH7, TP63, ALDH1A1), and additional (unvalidated) putative differentiation and stem cell markers (CTSV, SPINK7, DKK1) were analyzed with qPCR. Additionally, KRT3, KRT12, DSG1, and PAX6 protein levels were analyzed with Western blot. Results: KRT3, KRT12, DSG1, PAX6, ADH7, and ALDH1A1 mRNA expressions were higher in LECs and magnitudes higher in pCECs compared to HCE-T cells. KRT3, KRT12, PAX6, ALDH1A1, ADH7, TP63, and CTSV mRNAs have shown increasing mRNA expression from HCE-T < HCE-T cultured in keratinocyte serum-free medium (KSFM) < LEC < to pCEC.KRT3 and KRT12 protein expressions were only slightly increased in LEC compared to HCE-T samples, and the strongest signals were seen in pCEC samples. DSG1 protein expression was only detected in pCECs. PAX6 protein expression was hardly detected in HCE-T cells, and no difference could be seen between LECs and pCECs. Conclusions: The HCE-T cell line is even less differentiated than LECs regarding the investigated markers and therefore might also lack the ability to express differentiation markers at protein level. Hence, this cell line is not suitable to study corneal differentiation processes. Primary LECs in the way cultured here are not an ideal system compared to differentiated epithelium in organ culture but should be preferred to HCE-T cells if corneal differentiation markers are investigated. Other cell models or differentiation protocols should be developed in the future to gain new tools for research on ocular surface diseases. [ABSTRACT FROM AUTHOR]

Abstract Background  A rise in intraocular pressure (IOP) in upgaze is regarded as a diagnostic sign in Graves’ ophthalmopathy (GO). However, the question of erroneous IOP measurement due to applanation carried out on the peripheral cornea has never been addressed. Methods  In 22 healthy volunteers, as well as in 51 GO patients, applanation tonometry was performed in the primary position of gaze and at 20° of upgaze. In addition, applanation tonometry was repeated using a flexible chin rest to incline the head and produce 20° upgaze. This enabled applanation on the central cornea. Results  In healthy controls, mean IOP in conventional upgaze showed a significant rise compared to primary position (p p p = 0.7930). Mean IOP in GO patients was also significantly higher in conventional upgaze compared to primary position (p p p  Conclusion  In both normal volunteers and patients suffering from GO, a rise in IOP was observed in conventional upgaze tonometry. However, this increase in IOP was partially due to applanation on the peripheral cornea. Measurements in upgaze by head inclination on the central cornea led to a significant lowering of the gaze-dependent IOP change. The discriminating power of the IOP difference between upgaze and primary position to diagnose GO was found to be limited. The broad overlap of IOP between normal individuals and GO patients as detected by conventionally performed upgaze tonometry leads us to conclude that this sign may not be of relevant differential diagnostic value in patients with a clinically undetermined diagnosis. [ABSTRACT FROM AUTHOR]

Aim To investigate the effects of fibrovascular traction and the pooling of tears at the pterygium apex on the corneal topographic changes induced by pterygium. Methods A total of 16 eyes of 14 cases with primary pterygium were included in the study. A computerized corneal topography system was used for corneal topography examinations. Baseline keratographs were taken two times at straight gaze. A repeat corneoscope photograph was immediately obtained in temporal gaze. Then the tears at the pterygium apex were dried with a cellulose sponge, and a new corneoscope photograph was immediately obtained without allowing one to blink. Corneal topographic maps (numeric maps) were divided into 301 fields in 24 meridians. One colour was allocated to each field, representing its mean refractive power for all groups. In all eyes, keratometric astigmatism at the 3 mm central cornea and total mean corneal refractive power were found. Data were compared using paired-samples two-tailed t-tests. Results Keratometric astigmatism at the 3 mm central cornea was significantly reduced at the temporal gaze (3.10 ± 2.34 D, t = 3.40, P = 0.027) and dried eyes (2.12 ± 1.01 D, t = 4.74, P = 0.001) according to the first baseline measurement (4.31 ± 1.91 D) of the total mean corneal refractive power was found to be 43.45 ± 1.28 D (39.29-45.87) at the first baseline measurement. There was no change at the temporal gaze (43.54 ± 1.06 D, P > 0.05). However, the total corneal refractive power was significantly higher in dried eyes (44.26 ± 0.93 D, t = 34.92, P < 0.001). The steepest region of corneal topography was a superior quadrant, and the flattest area was a nasal quadrant at the baseline. At the temporal gaze, the cornea was significantly flatter in the superior and inferior sides of the pterygium meridian. After dried pooling of tears, topographic abnormalities returned, and the cornea became more uniform and symmetric. Conclusion We... [ABSTRACT FROM AUTHOR]

Introduction: Intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF) agents are a primary management option for retinal diseases. Acute elevation of intraocular pressure (IOP) is a complication associated with these injections that should be considered. This study investigated and compared the prophylactic effects of fixed combination anti-glaucoma medication on IOP spikes following intravitreal anti-VEGF injections. Methods: This randomized double-blind clinical trial included one eye of each participant indicated for treatment with intravitreal injection of anti-VEGF agents (bevacizumab, aflibercept, and ranibizumab) and randomly allocated to one of the three prophylactic anti-glaucoma medications, with each drug further divided into one- and two-drop regimens before intravitreal injection. Participants with allergies or contraindications to medications were excluded from the pretreatment groups and were invited to participate in the control group. Results: The study involved 308 participants: 89 in the dorzolamide/timolol group, 86 in the brimonidine/timolol group, 101 in the brinzolamide/brimonidine group, and 32 in the control group. Baseline characteristics and IOP were comparable across all groups. In the prophylactic premedication groups, mean IOP at 30 min were within 21 mmHg and returned to their baseline at 1 h. Mean IOP measurements between baseline and 30 min in the brimonidine/timolol two-drop regimen were not significantly different: 13.72 ± 4.63 vs 15.11 ± 4.39 mmHg, p = 0.096. In the control group, IOP significantly increased from baseline at 30 min and 1 h post-injection: 14.31 ± 4.10, 22.15 ± 8.64, and 18.36 ± 7.52 mmHg, respectively, p < 0.001. Conclusion: Topical fixed combination anti-glaucoma medication used as a prophylactic treatment before intravitreal anti-VEGF injections significantly prevented IOP spikes post-injection, with a comparable effect among three medications. Prophylactic treatment of IOP spikes should be considered as standard care to prevent further damage in patients with compromised retinal vascular and optic nerve perfusion. Trial Registration: TCTR20241005001, retrospectively registered. Plain Language Summary: Drug injection into the eye is a standard treatment for various eye diseases. However, an increase in eye pressure is often observed post-injection. This study focuses on the effect of prophylactic topical antiglaucoma eye drops on pressure of the eye elevation post-injection of drug into the eye. All medications in the study significantly prevented pressure of the eye spikes compared with no treatment. Prophylactic treatment of pressure of the eye spikes should be considered as standard care to prevent further damage to the eye. [ABSTRACT FROM AUTHOR]

Fuchs' endothelial corneal dystrophy (FECD) is a common sight-threatening condition characterised by pathological changes in the posterior cornea. Here we report observations by light, transmission and volume scanning electron microscopy on changes in the endothelium and matrix associated with the characteristic deformations of Descemet's membrane, termed guttae. Specimens were archived full-thickness human corneal tissue, removed during graft surgery, that had been fixed, stained and embedded by conventional processing methods for examination by transmission electron microscopy more than 40-years previously. Intact archived samples can be extremely valuable where, as with FECD, new cell-based methods of therapy now avoid excision of the full cornea thickness and any tissue excised is inferior for study. Volume electron microscopy, in particular serial block face scanning electron microscopy (SBF SEM), employing backscatter electron detection from resin-embedded specimens, has become an invaluable technique for 3D imaging of biological samples. However, archived specimens are normally considered unsuitable for imaging as conventional processing methods generate low backscatter electron yield. To overcome this for SBF SEM, we subjected epoxy resin-embedded specimens to de-plastination, then applied additional contrasting agents, uranyl acetate and lead acetate, prior to re-embedding. Selected regions of interest in the new resin blocks were examined in a scanning electron microscope equipped for SBF SEM and serial image datasets acquired. Enhanced contrast enabled 3D reconstruction of endothelium and guttae in Descemet's membrane over large tissue volumes. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the efficacy of in situ adeno-associated virus (AAV)-mediated gene delivery into the human corneal limbal region via targeted sub-limbal injection technique. Human cadaveric corneal tissues were fixed on an artificial anterior chamber. Feasibility of sub-limbal injection technique was tested using trypan blue and black India ink. An enhanced green fluorescent protein (eGFP) encoding AAV DJ was injected into sub-limbal region. After AAV injection, corneal tissues were incubated in air-lift culture and prepared for immunohistochemical analysis. Cell survivial and expression of eGFP, stem cell markers (p63α and cytokeratin 19 (KRT19)), and differentiation marker cytokeratin 3 (KRT3) were evaluated using confocal microscopy. Both trypan blue and black India ink stained and were retained sub-limbally establishing specificity of the injection technique. Immunohistochemical analysis of corneas injected with AAV DJ-eGFP indicated that AAV-transduced cells in the limbal region co-express eGFP, p63α, and KRT19 and that these transduced cells were capable of differentiating to KRT3 postitive corneal epithelial cells. Our sub-limbal injection technique can target cells in the human limbus in a reproducible and efficient manner. Thus, we demonstrate that in situ injection of corneal limbus may provide a feasible mode of genetic therapy for corneal disorders with an epithelial etiology. [ABSTRACT FROM AUTHOR]

Purpose: To characterise the corneal deposits of macular corneal dystrophy and correlate with high-resolution optical coherence tomography (OCT). Methods: A total of 23 eyes of 15 patients were evaluated for clinical features on slit lamp biomicroscopy, and high-resolution OCT was performed to correlate the clinical findings. The deposits were characterised based upon their location and level in the corneal layers. Results: Mean age was 31.5 (Range 20–67) years. The stromal deposits were restricted to central 8 mm in 9 eyes; in the rest of the 14 eyes, the deposits were seen in both central and peripheral cornea. In one patient, no such distinction could be made due to diffuse nature of the deposits throughout the cornea with sparing of 1–2 mm of the cornea internal to the limbus. The central deposits were in the anterior stromal layers, while the peripheral deposits were in the deep stromal corneal layers and non-contiguous with the anterior stromal deposits. In one patient aged 67 years, the peripheral deposits in deep corneal layers were more prominent than the central anterior stromal deposits and were associated with a significant thickening of Descemet membrane. Conclusions: MCD exhibits a clinically diverse presentation as revealed on the clinical and optical coherence tomography study. Immunophenotype and genotype–phenotype correlation may further help in understanding various clinical presentations of MCD. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effect of metronidazole ophthalmic solutions on corneal neovascularization (CNV) in a rat model. Methods: A chemical burn was created in the right central cornea of 40 rats. Animals were randomized and distributed into four study groups (n = 10 rats per group) designated Met_0.1%, Met_0.5%, sham, and untreated groups. Chemical-burned corneas in the Met_0.1% and Met_0.5% groups received ophthalmic solutions of 0.1 and 0.5% metronidazole, respectively. Corneas in the sham group received phosphate-buffered saline (metronidazole diluent). All treated eyes received ophthalmic solution at intervals of 6 h, for up to 30 days. Untreated corneas received no treatment. CNV was evaluated postinjury using corneal photographs at different evaluation time points. The main CNV outcome measures were: burn intensity, index of CNV, and percentage of vascularized corneal area. Five rats from each group were euthanized, on days 15 and 30; the samples were collected for histological analyses. Differences with P < 0.05 were considered significant. Results: CNV was observed in the eyes from day 7 postinjury. However, the indices of CNV for the Met_0.1% and Met_0.5% groups were smaller than those for the sham and untreated groups (P < 0.05). Furthermore, corneas treated with 0.1 or 0.5% metronidazole had smaller vascularized areas compared to control corneas. On histological study, the presence of blood vessels confirmed clinical outcomes. Conclusions: Regular instillation of 0.1 or 0.5% metronidazole had a significant inhibitory effect for CNV on chemical burns induced in a rat model. [ABSTRACT FROM AUTHOR]

A 24-year-old male patient with bilateral high myopia presented to our outpatient department with sudden onset of pain and diminution of vision in his right eye. He had sequentially undergone bilateral trabeculectomy and photorefractive keratectomy at the age of 6 years in both eyes. This was followed by radial keratotomy in right eye at the age of 8 years. The slit lamp examination demonstrated the presence of infiltrates in central cornea with an underlying fluid cleft, along with 14 radial keratotomy scars. Anterior segment optical coherence tomography confirmed the presence of intrastromal cleft in communication with anterior chamber. Bacterial culture revealed coagulase-negative Staphylococcus. The patient was successfully treated with fortified antibiotics in conjunction with the sensitivity report. This case underlines the need for a cautious approach towards refractive surgery in paediatric age group and highlights the long-term sequelae of retreatments in these cases. [ABSTRACT FROM AUTHOR]

Background: To evaluate the feasibility of partial lamellar keratoplasty (LK) for treatment of peripheral corneal disease (PCD) using a graft from the corneoscleral rim preserved in glycerin. Methods: Patients who underwent LK for PCD at Shandong Eye Hospital from January 2006 to December 2012 were included. Corneoscleral rims of donor grafts, out of which the corneal buttons had been punched and used for penetrating keratoplasty, were preserved in glycerin and used for LK procedures. A trephine of 7.5-8.0 mm was used to mark the central cornea. An excision was made according to the size of the lesions, after which a partial ring-shaped corneoscleral graft was transplanted to repair the peripheral cornea. Visual acuity, refractive astigmatism, and complications were monitored. Results: There were 26 patients (28 eyes), including 15 patients with Terrien's marginal degeneration, eight with Mooren's ulcer, two with Wegener's granulomatosis, and one with peripheral corneal ulcer. The mean follow-up was 15 months (range, 6-36 months). Uncorrected visual acuity was improved by a mean of 3.17 Snellen chart lines ( P = 0.010), and best spectacle-corrected visual acuity was improved by a mean of 0.85 Snellen chart lines ( P = 0.045) at 6 months after surgery. The refractive astigmatism decreased by 5.1 ± 8.6 diopters ( P = 0.003). Two patients suffering graft ulcers (recurrence) were successfully treated by a second partial LK. No graft rejection occurred. Conclusions: Partial LK using a graft from the corneoscleral rim appears to be effective in the treatment of patients with PCD. This approach saves the donor graft, which is important in the countries or regions with scarcity of donor tissue. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate corneal endothelial cell parameters after a single session of selective laser trabeculoplasty (SLT) in pseudoexfoliative glaucoma (PEG) patients.Methods: Corneal endothelial cell parameters of 18 PEG patients were compared with 18 healthy subjects following SLT treatment. All patients underwent SLT treatment to 180 degrees of inferior trabecular meshwork. Corneal measurements were performed using specular microscopy (Noncon Robo SP8000, Konan Medical, Hyogo, Japan). Endothelial cell density (ECD), hexagonal cell ratio (HEX), coefficient of variation (CV) of the corneal endothelial cell layer and central corneal thickness of the patients were measured at each visit.Results: There was a statistically significant decrease in ECD (p = 0.004) and a statistically significant increase in CV (p = 0.041) at superior cornea 1 week after SLT. They returned to pre-SLT values at 1 month. One hour post-SLT HEX of inferior cornea was statistically significantly reduced (p = 0.01). At central cornea, there was a significant increase in HEX after 1 week (p = 0.001). Post-SLT IOP showed a significant positive correlation with CV and significant negative correlation with HEX at superior and inferior cornea. There was no correlation between total laser energy used and endothelial cell parameters.Conclusion: Effect of a single session of SLT on corneal endothelium of PEG patients appears to be transient, and superior cornea was more affected than central and inferior cornea. All parameters returned to pre-SLT values at 1 month after treatment. [ABSTRACT FROM AUTHOR]