Metabolic signatures of tear extracellular vesicles caused by herpes simplex keratitis.

PURPOSE: Herpes simplex keratitis (HSK), caused by type 1 herpes simplex virus (HSV) reactivation, is a severe infectious disease that leads to vision loss. HSV can trigger metabolic reprogramming in the host cell and change the extracellular vesicles (EV) cargos; however, little is known about the EV metabolic signatures during ocular HSV infection. Here, we aimed to depict the EV-associated metabolic landscape in HSK patients' tears. METHODS: We collected 82 samples from 41 participants with unilateral HSK (contralateral unaffected tears were set as negative control), including subtype cohorts of 13 epithelial, 20 stromal, and 8 endothelial HSK. We isolated tear EVs via our previously established platform and conducted metabolic analysis using LC-MS/MS. The metabolic signatures for recognizing HSK and subtypes were assessed through differential analysis and machine learning algorithms. RESULTS: Hypopsia and increased extracellular CD63 levels were observed in affected eyes. We identified 339 metabolites based on sEVs isolated from tears. Differential analysis revealed alterations in energy and amino acid metabolism, as well as the infectious microenvironment. Furthermore, we observed dysregulated metabolite such as methyldopa, which is associated with inappropriate neovascularization and corneal sensation loss, contributing to the HSK severity particularly in the stromal subtype. Moreover, machine learning classification also suggested a set of EV metabolic signatures that have potential for pan-keratitis detection. CONCLUSIONS: Our findings demonstrate that tear EV metabolites can serve as valuable indicators for comprehending the underlying pathological mechanisms. This knowledge is expected to facilitate the development of liquid biopsy means and therapeutic target discovery.

Dissolvable hybrid microneedle patch for efficient delivery of curcumin to reduce intraocular inflammation.

Intraocular inflammation seriously impairs vision, and the effectiveness of intraocular drug delivery is hampered by various physiological barriers, such as the corneal barrier. In this paper, we present a simple approach to fabricating a dissolvable hybrid microneedles (MNs) patch for the efficient delivery of curcumin to treat intraocular inflammatory disorders. Water-insoluble curcumin was first encapsulated into polymeric micelles with high anti-inflammatory capacities, and then were combined with hyaluronic acid (HA) to create a dissolvable hybrid MNs patch using a simple micromolding method. Curcumin was amorphously dispersed within the MNs patch as indicated by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD) analyses. According to an in vitro drug release study, the proposed MNs patch provided sustainable drug release over 8 h. Following its in vivo topical application, the MNs patch demonstrated an extended pre-corneal retention time over 3.5 h and exhibited great ocular biocompatibility. Additionally, such MNs patch could reversibly penetrate the corneal epithelium, generating an array of microchannels on the corneal surface, thereby increasing ocular bioavailability. Of greater significance, the use of MNs patch demonstrated the improved therapeutic effectiveness in treating endotoxin-induced uveitis (EIU) in a rabbit model compared to curcumin eye drops via a significant reduction in the infiltration of inflammatory cells such as CD45+ leukocytes and CD68+ macrophages. Overall, the topical application of the MNs patch as an efficient ocular drug delivery system could potentially serve as a promising approach for treating different types of intraocular disorders.

Role of tear exosomes in the spread of herpes simplex virus type 1 in recurrent herpes simplex keratitis.

BACKGROUND: Herpes simplex keratitis (HSK) is the most common but serious infectious keratitis with high recurrence. It is predominantly caused by herpes simplex virus type 1 (HSV-1). The spread mechanism of HSV-1 in HSK is not entirely clear. Multiple publications indicate that exosomes participate in the intercellular communication process during viral infections. However, there is rare evidence that HSV-1 spreads in HSK by exosomal pathway. This study aims to investigate the relationship between the spread of HSV-1 and tear exosomes in recurrent HSK. METHODS: Tear fluids collected from total 59 participants were included in this study. Tear exosomes were isolated by ultracentrifugation, then identified by silver staining and western blot. The size was determined by dynamic light scattering (DLS). The viral biomarkers were identified by western blot. The cellular uptake of exosomes was studied using labelled exosomes. RESULTS: Tear exosomes were indeed enriched in tear fluids. Collected exosomes own normal diameters consistent with related reports. The exosomal biomarkers existed in tear exosomes. Labelled exosomes were successfully taken up by human corneal epithelial cells (HCEC) in large numbers in a short time. After cellular uptake, HSK biomarkers were detectable by western blot in infected cells. CONCLUSIONS: Tear exosomes should be the latent sites of HSV-1 in recurrent HSK and might be involved in the spread of HSV-1. Besides, this study verifies HSV-1 genes can be indeed transferred between cells by exosomal pathway, providing new inspiration for the clinical intervention and treatment as well as the drug discovery of recurrent HSK.

Discovering the Secret of Diseases by Incorporated Tear Exosomes Analysis via Rapid-Isolation System: iTEARS.

Nanoscale small extracellular vesicles (sEVs, exosomes) in tears allow us to investigate the multisignatures of diseases. However, the translations of tear sEVs for biomarker discovery and clinical diagnostics are practically limited by low recovery, long processing time, and small sample volume. Here, we report an incorporated tear-exosomes analysis via rapid-isolation system (iTEARS) via nanotechnology to discover the secrets of ocular disorders and systemic diseases. We isolate exosomes rapidly with high yield and purity from a few teardrops (∼10 µL) within 5 min via nanoporous membrane-based resonators for the quantitative detection and biomarker discovery through proteomic and transcriptomic analysis. We have identified 904 proteins, among which 228 proteins are discovered, 426 proteins are detected from exosomes of dry eye disease, and demonstrate CALML5, KRT6A, and S100P for the classification of dry eye disease. We have also investigated 484 miRNAs in tear exosomes and show miR-145-5p, miR-214-3p, miR-218-5p, and miR-9-5p are dysregulated during diabetic retinopathy development. We believe iTEARS can be used for improving molecular diagnostics via tears to identify ocular disorders, systemic diseases, and numerous other neurodegenerative diseases and cancer.

Detection of Tear Components Using Matrix-Assisted Laser Desorption Ionization/Time-of-Flight Mass Spectrometry for Rapid Dry Eye Diagnosis.

The tear is a biological fluid that has the diagnostic potential for ocular diseases. Extracellular vesicles (EVs), widly detected in various biofluids including tears, are nanoparticles released by living cells and considered as promising detection sources for noninvasive liquid biopsy. Understanding the roles of tears and tear-EVs in ocular diseases such as dry eye can facilitate the studies of clinical diagnosis, which usually entails detecting such liquid objects with a rapid and effective method. In this study, we used a mass spectrometry-based strategy to analyze peptidome/proteome profiles of tears and EVs for rapid dry eye diagnosis. Nanosized EVs were isolated from tears of both healthy control (HC) individuals and dry eye syndrome (DES) patients, and the tear compositions were further analyzed by tracking their fingerprints with matrix-assisted laser desorption ionization/time-of-flight mass spectrometry. The fingerprints of tear-EVs could be observed in a dose-dependent manner and tears, allowing for comparison of the discriminant peaks between tears and EVs. By analyzing these peaks, the fingerprints of both tear and tear-EVs were showed to have the capability of distinguishing patients with DES from HC donors and providing an efficient way for screening potential DES biomarkers. The proposed tear and EV fingerprinting approach is expected to be a potential tool in the rapid diagnosis of ocular diseases and in-depth research on pathogenesis. Data are available via ProteomeXchange with identifier PXD020217.

Thymic Stromal Lymphopoietin-Related Allergic Pathway in Patients With Vernal Keratoconjunctivitis.

PURPOSE: To investigate the expression of thymic stromal lymphopoietin (TSLP) and the relevant signaling pathways in the giant papillae obtained from patients with vernal keratoconjunctivitis (VKC) and to study the potential functional role and molecular mechanism of TSLP. METHODS: Giant papillae from VKC patients and control samples were used to perform immunohistochemical staining and analyze the mRNA expression of TSLP and related pathway by real-time polymerase chain reaction. RESULTS: TSLP was markedly expressed in the epithelial cells and some inflammatory cells of giant papillae, but not in the control conjunctival tissue. TSLP mRNA expression in the giant papillae of VKC was increased by 9.63 ± 0.99 (mean ± SD) fold compared with controls (P < 0.01). CD11c and OX40L immunoreactive cells largely infiltrated the giant papillae as observed by immunohistochemical staining. CD4Th2 cell infiltration was observed through high immunoreactivity of CD4. Th2 cytokines (IL-4, IL-5 and IL-13) and OX40 in the VKC specimens showed increased expression. Augmented gene expression levels of CD4 (6.88 ± 1.84), OX40L (7.60 ± 1.79), OX40 (7.25 ± 1.38), IL-4 (6.89 ± 1.46), IL-5 (8.42 ± 1.55), and IL-13 (9.69 ± 1.94) were significantly different from controls (P < 0.05). CONCLUSIONS: Our observations provide strong evidence that TSLP may be a crucial factor that contributes to the development and progression of allergic conjunctivitis. The results also demonstrated that TSLP activates dendritic cells to prime CD4T cells to differentiate into Th2 type and triggers Th2-dominant allergic inflammation through the TSLP/OX40L/OX40 signaling as part of immunopathogenesis of VKC.

Comparative Evaluation of Silicone Hydrogel Contact Lenses and Autologous Serum for Management of Sjögren Syndrome-Associated Dry Eye.

PURPOSE: To comparatively evaluate the efficacy of a bandage contact lens (BCL) and autologous serum (AS) eye drops in the management of severe dry eye caused by Sjögren syndrome (SS). METHODS: In this prospective randomized study, 40 patients with SS were enrolled. Patients were divided into 2 treatment groups: BCL and AS. RESULTS: A total of 37 patients were included, 18 patients (35 eyes) in the AS group and 19 patients (36 eyes) in the BCL group. At the end of 6 weeks, the best-corrected visual acuity improved significantly in the BCL group (0.5 ± 0.3 vs. 0.3 ± 0.2, P = 0.003) but not in the AS group (0.4 ± 0.3 vs. 0.3 ± 0.3, P = 0.11). The best-corrected visual acuity remained stable up to 6 weeks after discontinuation of the BCL (0.5 ± 0.3 vs. 0.4 ± 0.2, P = 0.03). Although the Ocular Surface Disease Index scores decreased significantly after treatment in both groups, patients in the BCL group had lower Ocular Surface Disease Index scores than those in the AS group (53.4 vs. 41.8 at week 3, 47.1 vs. 31.0 at week 6, 52.7 vs. 32.0 at week 12; P = 0.014, <0.001, <0.004, respectively). The "faces" scores showed improved quality of life in both groups. Tear break-up time improved significantly in both groups except at 6 weeks after discontinuation of the AS. Patients in the BCL group had lower corneal staining scores than those of the AS group after 6 weeks of treatment and 6 weeks after discontinuation of treatment (P < 0.01). There was no significant change in Schirmer I test scores between or within groups. CONCLUSIONS: Balafilcon A silicone hydrogel contact lenses as a BCL were effective in the management of SS-associated dry eye. Clinical Trial Registration­URL: http://www.clinicaltrials.gov. Unique identifier: NCT02147509.

Prevalence and risk factors of dry eye disease among a hospital-based population in southeast China.

OBJECTIVE: To investigate the prevalence of dry eye disease (DED) and distribution of associated risk factors among a hospital-based population. METHODS: In this cross-sectional study, we collected detailed information of clinically defined moderate-to-severe patients with dry eye among a consecutive hospital-based population, including age trend, gender structure, frequency of symptoms, and distribution of associated environmental/occupational risk factors. RESULTS: Of 6,657 consecutive outpatients aged older than 20 years, symptomatic dry eye presented in 635 subjects (9.54%). Five hundred thirty-two of these 635 subjects (7.99%) were clinically diagnosed as defined DED that combined with positive signs. Women (10.41%) were significantly higher than men (5.21%) (P<0.001). Overexposure to visual display terminal was a major risk factor for DED among young men and women (56.2%). Our study also found occupational conditions with the risk of exposure to adverse environment made up over half of all 532 patients with dry eye. The use of contact lenses was closely associated with DED in young women, and history of ocular surgeries might be another factor associated with DED in old people. One hundred sixty-three of 371 female patients with dry eye (43.9%) were associated with hormonal changes. The incidence of meibomian gland dysfunction-related DED increased gradually with age. There were only 10 patients with dry eye (1.9%) associated with Sjögren syndrome, and all of them were women. CONCLUSIONS: Environmental and occupational factors were strongly associated with DED and constituted the major proportion in a hospital-based population. A classification of DED based on the distribution of risk factors was recommended for clinical use.

In situ covalently cross-linked PEG hydrogel for ocular drug delivery applications.

Avastin(®) has been clinically proved to be effective in the treatment of intraocular neovascularization diseases. However, the short half-life of Avastin(®) need frequent administration to maintain its therapeutic efficiency. In this paper, we attempted to develop an in situ PEG hydrogels with great biocompatibility for sustained release of Avastin(®) to inhibit the corneal neovascularization. PEG hydrogels was formed via thiol-maleimide reaction using 4-arm PEG-Mal and 4-arm PEG-SH. The transparent hydrogel was rapidly formed under physiological conditions. By varying the concentration of 4-arm PEG-SH, PEG hydrogel with different gelling time, pore size, swelling ratio and mechanical property could be obtained. In vitro cytotoxicity indicated that the developed PEG hydrogel had no apparent cytotoxicity on L-929 cells after 7 days of incubation. In vitro release study showed the encapsulated Avastin(®) was sustained release from PEG hydrogels within a period of 14 days study. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis further confirmed that the released Avastin(®) did not undergo apparent hydrolysis within 14 days. As a conclusion, we could conclude that the developed PEG hydrogels as an injectable hydrogels might be suitable for extended Avastin(®) release to treat the corneal neovascularization.

Deep anterior lamellar keratoplasty using precut anterior lamellar cap for herpes simplex keratitis: a long-term follow-up study.

PURPOSE: To evaluate the feasibility, safety and efficacy of deep anterior lamellar keratoplasty (DALK) using precut anterior lamellar cap (ALC) for patients with herpes simplex keratitis. METHODS: In this single-centre retrospective study, 48 consecutive patients with herpes simplex keratitis and having undergone DALK using either big bubble technique or manual lamellar dissection, between February 2009 and March 2010, were included. Each patient received DALK using either a precut ALC or a full-thickness stroma (FTS), and completed a minimum follow-up time of 36 months. RESULTS: There were no significant differences in the age, sex, eyes and sizes of trephination between two groups. Postoperative best spectacle-corrected visual acuity of 0.3 logarithm of the minimum angle of resolution or better at the last follow-up visit was achieved in 74.1% of eyes in the FTS group and 71.4% in the ALC group (p=0.84). The mean central corneal thickness and corneal volume were significantly higher in the FTS group (550.7 ± 34.3 µm and 61.21 ± 4.12 mm(3)) than the ALC group (393 ± 45.7 µm and 54.68 ± 4.55 mm(3); p<0.0001). The mean simulated keratometry value was lower in the ALC group as compared with the FTS group (p=0.03; 44.51 ± 2.60 vs 46.06 ± 2.31). There was no difference in biomechanical behaviour of two types of corneal tissues after DALK. Corneal curvature remained stable in the ALC group, and no signs of corneal ectasia were observed during follow-ups. CONCLUSIONS: DALK using precut ALC should be considered as a selective surgical approach. A postoperative subnormal central corneal thickness of about 400 µm would not influence corneal curvature and refractive status.

[Effects of silicone punctal plugs for tear deficiency dry eye patients].

OBJECTIVE: To evaluate the efficacy of silicone punctual plug for treating aqueous tear deficiency dry eye patients. METHODS: Prospective consecutive cases study. Silicone punctal plugs (France Chirurgie Instrumentation) were inserted into lower canaliculus in 65 tear deficiency dry eye patients (65 eyes). The clinical data collected included sex and age of the patients, frequency of lubricant use, the Ocular Surface Disease Index (OSDI) scores, slit lamp microscope examination, Schirmer I test (SIT) (with anesthesia), tear break-up time (TBUT), and ocular surface staining with fluoresce in sodium. All examinations were recorded at baseline, 6 weeks and 6 months after punctal occlusion. RESULTS: There were 41 women and 24 men in this study, and their average age was 41.77 years old. The dry eye symptoms improved in 57 (87.69%) of 65 eyes at 6 months follow-up. The frequency of lubricant use was significantly decreased in these eyes (χ(2) = 81.97, P < 0.01). More importantly, the symptoms disappeared in 25 (38.46%) eyes, which did not need lubricant any more. At baseline, 6 weeks and 6 months after punctal occlusion, OSDI mean score was 37.32 ± 2.41, 19.60 ± 8.07 and 18.17 ± 7.93, respectively (F = 344.10, P < 0.01); mean SIT result was (3.03 ± 0.75) mm, (6.66 ± 2.10) mm and (6.75 ± 2.16) mm, respectively (F = 169.59, P < 0.01); mean TBUT was (2.91 ± 0.76) s, (7.02 ± 2.39) s and (7.57 ± 2.38) s, respectively (F = 242.00, P < 0.01). Compared with the baseline data, hyperemia of conjunctiva grading and ocular surface staining scores were also improved significantly after plug insertion, and all of these differences were statistically significant. Foreign body sensation was the most common complication in our study (12 eyes, 18.46%). Epiphora (4 eyes, 6.15%), partial extrusion (3 eyes, 4.62%), and total extrusion (3 eyes, 4.62%) were the other complications encountered. CONCLUSION: Silicone punctal plug insertion is a stable, effective and safety method for the treatment of tear deficiency dry eye.

A novel technique of modified continuous blanket suture for amniotic membrane fixation in severe ocular surface diseases.

The purpose of this article is to demonstrate a novel technique using modified continuous blanket suture (MCBS) to fix the amniotic membrane (AM) in different severe ocular surface disease lesions. The MCBS techniques were used to fix the AMs of 5 representative patients with different ocular surface lesions related to severe ocular surface diseases. In all cases, stable adherence of the AM was maintained until the epithelialization of the ocular surface was completed. No early detachment, dissolution, or dislocation of the AM patch was observed. During follow-up, all patients acquired a smooth and acceptable ocular surface without any persistent epithelial defect, infection, or ulceration. The MCBS method achieved good AM fixation on the ocular surface in cases of severe ocular surface lesions and could prevent the early detachment of the AM and promote the epithelialization of the ocular surface.

Clinical significance of tear menisci in dry eye.

PURPOSE: To determine the relationships among tear menisci variables and clinical tests used in the diagnosis of dry eye patients. METHODS: Dry eye patients (n=50; age, 35.2 years) and healthy subjects (n=48; age, 33.3 years) were recruited. Upper and lower tear menisci were imaged noninvasively by optical coherence tomography (OCT) immediately after normal and delayed blinking in both eyes. Tear meniscus heights, areas, and radius of curvatures were obtained by custom software. Tear film break-up time was measured by fluorescein (fluorescein film tear break-up time, FTBUT) and tearscope (noninvasive tear film break-up time), ocular surface vital staining was evaluated with fluorescein (FS), and secretion was measured by Schirmer I test without and with anesthesia. RESULTS: In dry eye patients, all lower tear meniscus variables during normal blinking were correlated with all clinical tests except Schirmer I test without anesthesia. Upper tear meniscus variables were correlated with FTBUT and Schirmer I test with anesthesia. During delayed blinking, upper and lower tear menisci variables were correlated with Schirmer I test without anesthesia and FS; however, there were no correlations between menisci variables and FTBUT or Schirmer I test with anesthesia. In healthy subjects, only lower meniscus variables were correlated with Schirmer I test with anesthesia during normal blinking. During delayed blinking, the lower meniscus variables were correlated with only the Schirmer I test without anesthesia. CONCLUSIONS: Lower tear menisci were correlated more strongly with the clinical tests than were upper menisci. The tear menisci were associated with the basic tear secretion during normal blinking. Delayed blinking may affect reflex tearing levels.

Upper and lower tear menisci in Sjögren's syndrome dry eye.

PURPOSE: To measure the tear menisci in Sjögren's syndrome dry eye (SSDE) by optical coherence tomography (OCT) and to determine its relationships with the clinical tests. METHODS: Twenty-six SSDE, 26 non-SSDE, and 26 control subjects completed the Ocular Surface Disease Index (OSDI) before OCT determination of upper tear meniscus volume (UTMV), lower tear meniscus volume (LTMV), and total tear meniscus volume (TTMV). These were followed by measurements of noninvasive tear breakup time (NITBUT), fluorescein tear breakup time (FTBUT), fluorescein staining, Schirmer test, and corneal confocal microscopy. RESULTS: UTMV, LTMV, and TTMV were the lowest in SSDE among the three groups (P < 0.05). High sensitivity and specificity of UTMV (1.0; 0.96), LTMV (0.92; 0.92), and TTMV (0.96; 0.96) were found in the diagnosis of SSDE. For SSDE, the areas under the UTMV, LTMV, and TTMV receiver operating characteristic curves were larger than those in NITBUT, FTBUT, and Schirmer test (P < 0.005). In the SSDE group, NITBUT was correlated with UTMV (R = 0.41) and TTMV (R = 0.39) (P < 0.05). Fluorescein staining score was significantly correlated with UTMV (R = -0.46), LTMV (R = -0.41), and TTMV (R = -0.53) (P < 0.05). Superficial epithelial cell density was correlated with UTMV (R = 0.18), LTMV (R = 0.51), and TTMV (R = 0.44) (P < 0.05). CONCLUSIONS: Tear menisci volumes estimated by OCT may have great potential in the diagnosis and monitoring of SSDE. They can also reflect ocular surface damage and tear film stability.

Deep anterior lamellar keratoplasty using acellular corneal tissue for prevention of allograft rejection in high-risk corneas.

PURPOSE: To determine whether deep anterior lamellar keratoplasty (DALK) using acellular glycerol-cryopreserved corneal tissue (GCCT) could prevent allograft rejection in high-risk corneas. DESIGN: Prospective, randomized, comparative study. SETTINGS: The Eye Hospital, Wenzhou Medical College, Zhejiang, China. STUDY POPULATION: All patients with herpes simplex virus keratitis, bacterial keratitis, fungal keratitis, or ocular burn, who were eligible as per study design, were invited to participate. OBSERVATION PROCEDURES: According to randomized block design, all patients received either GCCT or fresh corneal tissue (FCT) during DALK. Best-corrected visual acuity (BCVA), slit-lamp microscopy, and in vivo confocal microscopy examinations at 1 week and 1, 3, 6, 12, and 24 months after surgery were analyzed. Kaplan-Meier survival analysis was used to evaluate graft survival rate. MAIN OUTCOME MEASURES: Therapeutic success, 2-year rejection-free graft survival rate and 2-year graft survival rate, in vivo confocal microscopy results, BCVA, and endothelial cell density. RESULTS: Postoperative BCVA of 20/40 or better at the last follow-up visit was achieved in 57.6% (19/33) of eyes in the GCCT group and in 54.8% (17/31) of the FCT group. No graft rejection occurred in the GCCT group, while in the FCT group 10 episodes of stromal rejection developed in 7 eyes. Overall, the rejection-free graft survival rate at 2 years was significantly higher in the GCCT group as compared with the FCT group (100.0%, 78.8% respectively, P = .006). CONCLUSIONS: Deep anterior lamellar keratoplasty using acellular glycerol-preserved cornea could prevent allograft rejection and promote graft survival rate in high-risk corneas.

Tear dynamics and corneal confocal microscopy of subjects with mild self-reported office dry eye.

PURPOSE: To investigate changes in tear dynamics and corneal microstructure in mild self-reported office dry eye. DESIGN: Prospective laboratory investigation. PARTICIPANTS: Twenty healthy office workers, 20 office workers with mild self-reported dry eye, and 20 office workers with moderate to severe dry eye as determined by the Ocular Surface Disease Index (OSDI). METHODS: Real-time anterior segment optical coherence tomography was used to obtain upper (UTMV), lower (LTMV), tear meniscus volumes. The total tear meniscus volume (TTMV) was the sum of the UTMV and LTMV. This was followed by measurement of noninvasive tear breakup time (NITBUT), fluorescein tear breakup time (FTBUT), fluorescein staining, Schirmer I test, and in vivo confocal microscopy of cornea. MAIN OUTCOME MEASURES: Upper tear meniscus volume, LTMV, TTMV, NITBUT, fluorescein tear FTBUT, fluorescein staining, Schirmer I test, and in vivo confocal microscopy of cornea. RESULTS: There were no significant differences in UTMV and LTMV between the control and mild self-reported dry eye groups (P>0.05). These values in the moderate to severe dry eye group were significantly lower than those in the control and mild dry eye groups (P<0.01). Both mild and moderate to severe office dry eye groups had decreased NITBUT (P<0.05 each) and FTBUT (P<0.01 each) compared with controls. On the basis of receiver operating characteristic curves, the cutoff value for abnormal FTBUT was 3.3 seconds, yielding good diagnostic accuracy with a sensitivity of 0.75 and specificity of 0.80. For NITBUT, when the cutoff time was 9.7 seconds, the sensitivity was 0.90 and specificity was 0.50. The moderate to severe office dry eye group had decreased Schirmer I test values and increased subbasal nerve tortuosity compared with the mild office dry eye and control groups (P<0.05 each). Both the mild dry eye and moderate to severe dry eye groups had decreased cell densities in superficial, intermediate, and basal epithelial layers compared with the controls (P<0.05 each). CONCLUSIONS: Although the quantity of tears in patients with mild self-reported office dry eye was not decreased, ocular surface damage was present.

Comparison of fresh corneal tissue versus glycerin-cryopreserved corneal tissue in deep anterior lamellar keratoplasty.

PURPOSE: To compare the microstructural differences in fresh corneal tissue (FCT) with glycerin-cryopreserved corneal tissue (GCCT) used during deep anterior lamellar keratoplasty (DALK). METHODS: The medical records of 48 consecutive patients who underwent DALK for stromal opacity without endothelial abnormalities were retrospectively reviewed. Patients were divided into two groups: an FCT group (n = 22) and a GCCT group (n = 26), according to the corneal tissue used. The best corrected visual acuity (BCVA), slit lamp, corneal topography, pachymetry, and laser scanning in vivo confocal microscopy examinations at 2 weeks and 1, 3, 6, 12, and 24 months after surgery were analyzed. RESULTS: No graft rejection developed in the GCCT group, whereas stromal rejection developed in one eye in the FCT group. There were no significant differences in spherical equivalent (P = 0.37), astigmatism (P = 0.26), BCVA (P = 0.64), central corneal thickness (P = 0.73), or endothelial cell density (P = 0.49) between the two groups at 24 months. Confocal microscopy showed that GCCT was acellular, whereas dendritelike cells and keratocytes were found in the FCT group 2 weeks after surgery. The keratocyte density improved significantly in the GCCT group at 3 months after surgery, whereas it decreased significantly after surgery in the FCT group during follow-up. No significant difference in regeneration of nerve fibers was found in the subbasal layer and anterior stroma between the two groups at 24 months. CONCLUSIONS: DALK using GCCT provides clinical results comparable to FCT. GCCT can be used safely and effectively for DALK and may minimize stromal rejection after surgery.

Upper and lower tear menisci in the diagnosis of dry eye.

PURPOSE: To measure the upper and lower tear menisci in patients with aqueous tear deficiency (ATD) dry eye by real-time optical coherence tomography (OCT) and to determine the most effective meniscus variables for the diagnosis of dry eye. METHODS: Eyes of 48 pre-screened ATD patients were compared with those of 47 healthy subjects. Upper and lower tear menisci were imaged simultaneously by real-time OCT immediately after blinking. The height, radius, and cross-sectional area of upper and lower tear menisci were obtained. RESULTS: The tear meniscus radius, height, and cross-sectional area were significantly smaller in patients with dry eye than in healthy subjects (P < 0.01). The lower tear meniscus variables were higher than the upper menisci (P < 0.01) in normal subjects; however, no significant differences between menisci were found in ATD patients. In both groups, the upper and lower tear meniscus variables were strongly correlated with each other. Good dry eye diagnostic accuracies were obtained with cutoff values for an abnormal lower tear meniscus radius (LTMR) of 182 microm and a lower tear meniscus height (LTMH) of 164 microm. The LTMR diagnostic sensitivity and specificity were 0.92 and 0.87, respectively. The LTMH diagnostic sensitivity and specificity were 0.92 and 0.90. CONCLUSIONS: Upper tear meniscus variables in ATD patients were assessed by real-time OCT. The tear meniscus was smaller in ATD patients than in healthy subjects. LTMR and LTMH may have potential in the diagnosis of ATD.