Herpes Simplex Keratitis as a Complication of Pterygium Surgery.

BACKGROUND Infectious keratitis after pterygium surgery is a rare but potentially devastating complication. The present study presents 5 cases of herpes simplex keratitis (HSK) after pterygium surgery. CASE REPORT This study was conducted in our clinic in a 5-year period from February 2017 to September 2021. The 5 patients were men, aged between 42 and 73 years, with no prior history of herpes simplex virus (HSV) infections. Symptoms appeared near 1 month (median 30 days, range 10 to 70 days) after primary pterygium surgery. Diagnosis was based on clinical symptoms and laboratory test results, such as tear HSV-sIgA, corneal tissue polymerase chain reaction, and next-generation sequencing of metagenomics. The epithelial (1/5) and stromal (4/5) subtypes of HSK were identified. The patients received topical ganciclovir gel, immunosuppressive eyedrops, and oral acyclovir tablets, along with additional surgical interventions if necessary. Three were healed with conservative therapy, 1 eye required amniotic membrane transplantation due to corneal melt, and 1 was perforated and followed by corneal grafting. Finally, a literature review of previous publications on HSK after ocular surgeries was conducted. CONCLUSIONS HSK is a rare but serious complication that can arise after uneventful pterygium surgery. It is worthy of attention that both epithelial and stromal forms can occur. Timely diagnosis and treatment are crucial to prevent unfavorable outcomes. Consequently, routine corneal fluorescein staining, tear sIgA examination, and corneal scraping for polymerase chain reaction or next-generation sequencing of metagenomics should be performed in any suspected cases.

Comparison of the Meibomian Gland Openings by Optical Coherence Tomography in Obstructive Meibomian Gland Dysfunction and Normal Patients.

PURPOSE: The aim of this study was to use swept-source anterior segment optical coherence tomography (OCT) to explore imaging the meibomian gland openings and to identify their in vivo characteristics in patients with obstructive meibomian gland dysfunction (MGD) and healthy participants. METHODS: We enrolled 49 patients with MGD and 54 health controls in this case-control study. Each participant underwent slit-lamp examination, meibography, and OCT scanning. Sixteen patients with MGD underwent a repeat OCT examination after eyelid massage. The outcome measures included determinations of meibomian gland openings (orifices and terminal ducts) from OCT images and comparisons of the meibomian openings between patients with MGD and normal controls before and after meibomian gland massage. RESULTS: Using the same OCT scanning model, the number of visible orifices of the meibomian glands was similar between eyes with MGD and normal eyes (9.2 ± 2.3 vs. 9.7 ± 2.4). The mean diameter of the terminal ducts in patients with MGD was larger (120.22 ± 27.92 µm vs. 100.96 ± 20.30 µm) than in the normal controls, and had a larger coefficient of variation. Significant differences were observed in the mean diameter of the terminal ducts of patients with MGD before and after meibum gland massage (133.73 ± 27.81 µm vs. 102.26 ± 24.30 µm, p < 0.001). CONCLUSIONS: Patients with MGD have more diversified orifices and larger meibomian gland terminal duct diameters than normal subjects. In addition, meibomian gland terminal duct diameters seem to decrease in patients with MGD after meibum gland massage.

Correlation Between Anterior Chamber Volume and Corneal Biomechanical Properties in Human Eyes.

Purpose: To investigate the correlation between anterior chamber volume (ACV) and corneal biomechanical properties in healthy and primary angle closure (PAC) eyes. Methods: A total of 79 eyes from 55 participants were enrolled in this study, including 24 eyes from 17 PAC patients and 55 eyes from 38 normal subjects. Anterior chamber volume was detected via swept-source anterior segment optical coherence tomography (OCT), and the cornea biomechanical data were obtained via corneal visualization Scheimpflug technology (Corvis ST). A student's t-test, Chi-square test, Pearson's correlation coefficients, and linear regression were used in the statistical analysis. Results: Anterior chamber volume was significantly associated with a lower deformation altitude (DA) (p = 0.033), higher stiffness parameter (SP-A1) (p = 0.005), younger age (p = 0.001), and higher biomechanical intraocular pressure (bIOP) (p = 0.001). PAC patients were suspected to have a much shallower anterior chamber than healthy participants. In the PAC group, the mean ACV (p < 0.01), SP-A1 (p < 0.01), and bIOP values (p = 0.01) were significantly reduced as compared to the normal group, and DA values (p = 0.02) and age (p = 0.01) were increased as compared to the normal group. Conclusions: Bigger ACV was associated with lower DA values and age, as well as higher SP-A1 and bIOP values. Reduced corneal stiffness was more commonly found in the PAC suspects as compared to their normal counterparts, indicating a protective physiological mechanism for people with shallower anterior chambers that protects against potential elevations of IOP.

TSLP Protects Corneas From Pseudomonas aeruginosa Infection by Regulating Dendritic Cells and IL-23-IL-17 Pathway.

Purpose: We sought to determine the role of epithelium-produced thymic stromal lymphopoietin (TSLP) and its underlying mechanisms in corneal innate immune defense against Pseudomonas (P.) aeruginosa keratitis. Methods: The expression of TSLP and TSLPR in cultured human corneal epithelial cells (HCECs) and mouse corneas was determined by PCR, Western, and/or ELISA. Cellular localization of TSLP receptor (TSLPR) was determined by whole mount confocal microscopy. TSLP-TSLPR signaling was downregulated by neutralizing antibodies and/or small interfering (si)RNA; their effects on the severity of P. aeruginosa-keratitis and cytokine expression were assessed using clinical scoring, bacterial counting, PMN infiltration, and real-time PCR. The role of dendritic cells (DCs) in corneal innate immunity was determined by local DC depletion using CD11c-DTR mice. Results: P. aeruginosa-infection induced the expression of TSLP and TSLPR in both cultured primary HCECs and in C57BL/6 mouse corneas. While TSLP was mostly expressed by epithelial cells, CD11c-positive cells were positive for TSLPR. Targeting TSLP or TSLPR with neutralizing antibodies or TSLPR with siRNA resulted in more severe keratitis, attributable to an increase in bacterial burden and PMN infiltration. TSLPR neutralization significantly suppressed infection-induced TSLP and interleukin (IL)-17C expression and augmented the expression of IL-23 and IL-17A. Local depletion of DCs markedly increased the severity of keratitis and exhibited no effects on TSLP and IL-23 expression while suppressing IL-17A and C expression in P. aeruginosa-infected corneas. Conclusions: The epithelium-expressed TSLP plays a protective role in P. aeruginosa keratitis through targeting of DCs and in an IL-23/IL-17 signaling pathway-related manner.

IL-24 Promotes Pseudomonas aeruginosa Keratitis in C57BL/6 Mouse Corneas.

The aim of this study was to elucidate the expression and functions of IL-24 in C57BL/6 mouse corneas in response to Pseudomonas aeruginosa infection. Among IL-20R cytokines, only IL-24 was induced at both mRNA and protein levels by infection at early time points. The upregulation of IL-24 was dampened by flagellin pretreatment, which protects the corneas from microbial infection. Time course studies revealed bimodal early and later peaks of IL-24 expression, a pattern shared with suppressor of cytokine signaling (SOCS)3 but not IL-1ß or IL-6. Silencing of IL-24 enhanced S100A8/A9 expression and suppressed SOCS3, IL-1ß, IL-1RN, and matrix metalloproteinase 13 expression at 6 h postinfection. Downregulation of the IL-24 signaling pathway significantly reduced the severity of keratitis, whereas rIL-24 exacerbated P. aeruginosa-mediated tissue destruction. In vitro, rIL-1ß induced the expression of SOCS3, IL-24, IL-1ß, and IL-6 in primary cultured human corneal epithelial cells. rIL-24, alternatively, stimulated the expression of SOCS3, but not the others. In conclusion, IL-24 promotes P. aeruginosa keratitis through the suppression of early protective mucosal immunity, culminating in increased severity of P. aeruginosa keratitis.

Vitamin A Palmitate and Carbomer Gel Protects the Conjunctiva of Patients With Long-term Prostaglandin Analogs Application.

PURPOSE: To investigate the protective effects of vitamin A palmitate and carbomer gel on the morphology of conjunctival epithelium and density of goblet cells (GCs) in patients on long-term prostaglandin analogs (PGAs) application. METHODS: In this prospective cohort study, 23 primary open-angle glaucoma patients and 7 normal-tension glaucoma patients prescribed PGAs for >1 year were enrolled into 3 identical clinical trials and randomized into 3 groups (10 per group). Patients were treated twice daily with vitamin A palmitate eye gel 0.1%, or carbomer eye gel 0.2%, or no additional application of these 2 drugs. Ocular surface disease index questionnaires, Schirmer 1 test without anesthesia, tear break-up time test, and GCs density assessment by in vivo confocal microscopy and conjunctival impression cytology analysis were performed at baseline and at months 1, 3, and 6 of the study. RESULTS: Both vitamin A palmitate and carbomer gel led to a significant improvement in ocular surface disease index questionnaires score and prevented the gradual decline in tear break-up time. Vitamin A palmitate significantly increased the GC density after treatment. The GC density assessed by in vivo confocal microscopy positively correlated with that measured by conjunctival impression cytology. CONCLUSIONS: Vitamin A palmitate and carbomer eye gel can effectively relieve dry eye symptom caused by long-term application of PGAs by increasing the GCs density and thereby reducing the toxicity to the conjunctiva. Vitamin A palmitate and carbomer eye gel may be valuable alternatives for glaucoma patients who prescribed long-term PGAs.

Limitations of Keratoplasty in China: A Survey Analysis.

PURPOSE: Each year, over 8,000 corneal transplantation surgeries are performed in China. Unlike developed countries, which have established standard requirements for operative experience for corneal specialists, little information exists on surgical training for keratoplasty in China. The aim of this study was to assess the keratoplasty experience of Chinese corneal specialists and to characterize their surgical patterns. METHODS: One hundred and twenty-one corneal specialists in 16 provinces (65 cities) in China were invited to complete an anonymous survey at the 2014 Chinese Corneal Society annual meeting, which consisted of questions with single or multiple-choice answers. Demographics, the number and type of keratoplasties performed, and the perceived limiting factors for performing keratoplasties were analyzed. RESULTS: An overwhelming 89% response rate was achieved. Of the 108 respondents, 76% worked in tertiary centers, and only 23% held a medical doctorate degree. Furthermore, 69% of the participants had received corneal fellowship training of less than one year. Only 71% were capable of keratoplasties. Among those doing keratoplasty, 68% performed less than 50 keratoplasties each year. Of the same group of keratoplasty surgeons, 88% of corneal specialists capable of keratoplasties had performed penetrating keratoplasties, 87% had performed lamellar keratoplasties, 12% had performed deep anterior lamellar keratoplasties, and 5% had performed Descemet's stripping endothelial keratoplasties. When questioned on the reasons for the low number of keratoplasties performed in China, the respondents deemed the following factors most important: lack of surgical training (71%), a shortage of donor supply (52%), and a lack of curricula (42%). A multivariate logistic regression analysis showed that corneal transplantation capabilities are significantly associated with responders' education levels and training time. CONCLUSION: Keratoplasty surgery experience is suboptimal for Chinese corneal specialists. Penetrating and lamellar keratoplasties are the preferred surgical patterns. Our findings raise concerns about the adequacy of keratoplasty training in China.

Assessment of Bulbar Redness with a Newly Developed Keratograph.

PURPOSE: To determine the validity and reliability of the clinical assessment of bulbar redness (BR) using a newly developed corneal topographer. METHODS: This is a cross-sectional diagnostic evaluation study. The BR scores [Oculus Index (OI)] from 30 eyes of 26 patients with different degrees of conjunctival hyperemia were assessed and scored automatically using a new method: a keratograph equipped with scanning and scoring software. The values obtained via this system were correlated with three image-based comparative subjective scales: the Institute for Eye Research (IER), the Efron, and the Validated Bulbar Redness (VBR) grading scales. The IER and Efron scores were interpolated to 0.1 unit, and the VBR scores were interpolated to 1 unit. We also evaluated the repeatability of each method and the level of agreement between the OI score and the scores achieved using the three other image-based methods. RESULTS: There was a significant correlation between the OI score and the scores obtained with the IER (r = 0.921, p < 0.001), Efron (r = 0.958, p < 0.001), and VBR (r = 0.965, p < 0.001) scales. The intraobserver intraclass correlation coefficients were 0.947, 0.874, 0.810, and 0.920 for the OI, IER, Efron, and VBR, respectively, and the intraobserver coefficients of repeatability were 13.924, 16.111, 17.684, and 16.900, respectively. Furthermore, the interobserver intraclass correlation coefficients were 0.889, 0.880, 0.884, and 0.881 for the OI, IER, Efron, and VBR, respectively, and the interobserver coefficients of repeatability were 15.934, 16.366, 22.059, and 21.373, respectively. CONCLUSIONS: The OI is an objective and reliable method for scoring BR. Its reproducibility was the highest of all the four modalities. The keratograph is recommended, therefore, as a suitable alternative for BR assessment.

Prevalence and associated factors of pinguecula in a rural population in Shanghai, Eastern China.

PURPOSE: To determine the prevalence and associated factors of pinguecula in a rural Chinese population aged ≥ 50 years in Eastern China. METHODS: This cross-sectional, population-based survey included an age-stratified random sample of 1108 residents living in Lvxiang Town of Jinshan District. Participants were requested to complete a comprehensive questionnaire to collect demographic data, history of systemic diseases and lifestyle details. The presence of pinguecula on slit lamp examination was recorded. The prevalence of pinguecula and its associated factors were investigated by logistic regression models. RESULTS: Among 1108 eligible subjects, 959 participated in the study, with an average age of 65.1 ± 9.2 years (range 50-89 years). The overall age-adjusted prevalence of pinguecula in this population was 75.57% (95% confidence interval 71.79-79.35%). Logistic regression analysis revealed that age (p = 0.002) and working outdoors (daily sunlight exposure ≥ 2 hours; p = 0.001) were independent risk factors for pinguecula. In addition, sex, education level, alcohol intake, smoking and decreased tear break-up time did not have associations with the development of pinguecula after adjusting for age and outdoor work occupations. CONCLUSIONS: The prevalence of pinguecula was 75.57% in this Chinese population aged ≥ 50 years from a coastal rural area of Shanghai, Eastern China, which was higher than the majority of previous findings. Age and working outdoors were independent risk factors for pinguecula.

Meibomian Gland Alteration in Patients with Primary Chronic Dacryocystitis: An In vivo Confocal Microscopy Study.

PURPOSE: To evaluate meibomian gland (MG) alterations in patients with primary chronic dacryocystitis (PCD) by in vivo confocal microscopy (IVCM), and to correlate the finding with clinical presentation. METHODS: Twenty-eight eyes with the diagnosis of PCD and their contralateral unaffected eyes were studied and compared with 27 normal controls. All subjects completed an Ocular Surface Disease Index questionnaire (OSDI) and underwent slit-lamp biomicroscopy examination, tear break-up time (BUT) measurements, fluorescein staining, Schirmer test I, and an IVCM examination of the MG. IVCM parameters, including the MG acinar unit density (MGAUD), periglandular inflammatory cell density (ICD), MG acinar unit longest diameter (MGALD), and MG acinar unit shortest diameter (MGASD) and their correlation with clinical data were analyzed. RESULTS: The mean MG expressibility scores, BUT values, and staining scores were significantly worse in eyes with PCD compared with the contralateral clinically unaffected eyes and controls (p < 0.05). A significant decrease in MGAUD was observed in PCD eyes compared with the controls and the contralateral clinically unaffected eyes. Conversely, the mean ICD and MGASD values were significantly higher in the PCD eyes. There were no significant differences in mean MGALD value between the PCD eyes and the contralateral clinically unaffected eyes. In addition, there were significant changes in the IVCM parameters in the contralateral unaffected eyes compared with the controls, including MGAUD, ICD, MGALD, and MGASD. All IVCM parameters showed a strong, significant correlation with MG dropout grades, MG expressibility, fluorescein staining scores, and OSDI values (all p < 0.05). CONCLUSIONS: Patients with unilateral PCD demonstrated significant changes in MG as compared with the contralateral clinically unaffected eyes and controls. The MG function should be closely observed in these patients.

[The study of corneal epithelial change in keratoconic eyes with Fourier-domain optical coherence tomographic pachymetry].

OBJECTIVE: To compare the corneal epithelial thickness profile in keratoconic and normal eyes with advanced Fourier-domain optical coherence tomography (OCT) and to evaluate the diagnostic efficiency of pachymetry parameters. METHODS: Cross-sectional observational study. Twenty-five consecutive keratoconus patients (34 eyes) and 41 normal volunteers (41 eyes) in Eye & ENT Hospital of Fudan University between June 1 and July 31, 2013 were enrolled.Observations of corneal epithelial thickness and corneal thickness profiles were taken from all subjects. The epithelial pachymetry parameters were superior, inferior, inferior-superior (I-S), minimum (Min), maximum (Max), Min-Max, and central. The corneal pachymetry parameters were inferotemporal-superonasal (IT-SN), I-S, Min, Min-median, Min-Max, and central.Statistical analysis methods included Chi-square test, independent two-sample t-test, and Wilcoxon rank sum test. The diagnostic efficiency of all parameters were analyzed by receiver operating characteristic (ROC) curves and Youden index. RESULTS: The inferior, I-S, Min, Min-Max, and central epithelial thickness averages were (50.5 ± 4.8) µm, (-2.7 ± 7.5) µm, (35.9 ± 10.7) µm, (-33.6 ± 18.9) µm, and (50.1 ± 6.8) µm in keratoconic eyes.In normal eyes, they were (54.8 ± 2.5) µm, (0.9 ± 1.3) µm, (51.4 ± 2.6) µm, (-5.7 ± 1.8) µm, and (54.7 ± 2.2) µm. Among the epithelial pachymetry parameters, Min-Max and Min showed high diagnostic efficiency for keratoconus (AUC = 0.967, 0.968; Youden index = 0.882, 0.829); inferior, I-S, and central parameters showed moderate efficiency (AUC = 0.794, 0.728, 0.715; Youden index = 0.461, 0.564, 0.565). The IT-SN, I-S, Min, Min-median, Min-Max, and central corneal thickness averages were (-82.8 ± 65.2) µm, (-72.5 ± 55.6) µm, (401.2 ± 83.8) µm, (-83.4 ± 48.2) µm, (-169.7 ± 99.4) µm, and (453.4 ± 58.6) µm in keratoconic eyes.In normal eyes, these parameters were respectively (-23.7 ± 18.5) µm, (-20.5 ± 19.8) µm, (525.4 ± 28.1) µm, (-23.1 ± 4.8) µm, (-59.2 ± 23.3) µm, and (533.4 ± 28.8) µm. Min, Min-median, and Min-Max had preferable diagnostic efficiency (AUC = 0.952, 0.938, 0.924; Youden index = 0.784, 0.829, 0.721); central, IT-SN, and I-S parameters showed moderate efficiency (AUC = 0.891, 0.877, 0.862; Youden index = 0.643, 0.707, 0.580). CONCLUSIONS: In observation with Fourier-domain OCT, keratoconus was characterized by central and inferior epithelial thinning, increased epithelial thickness variation, central cornea thinning, increase in asymmetry, and gaps between corneal IT-SN and I-S thickness.Fourier-domain OCT was confirmed to have high speed, high resolution, and noninvasion. The pachymetry parameters showed specific strengths in diagnosis of keratoconus, especially epithelial pachymetry parameters of Min and Min-Max, and corneal pachymetry parameters of Min, Min-median and Min-Max.

Impact of conjunctivochalasis on visual quality of life: a community population survey.

Conjunctivochalasis (Cch) is a very common ocular disorder, which can cause an unstable tear film and ocular discomfort. The study of vision-related quality of life (VR-QoL) in a community population with Cch can provide a better understanding of the impact of Cch on common people than objective clinical examinations alone. This cross-sectional comparative study enrolled 360 participants ≥ 40 years old living in Sanle Community, Shanghai. In the study, 198 subjects were diagnosed with Cch and 86 with dry eye syndrome (DES) without Cch. The remaining 76 subjects were normal controls. Socio-demographical data were collected, and Cch and related ocular symptoms and signs were evaluated. In addition, all participants were required to complete the Chinese version of the 25-item National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25) and Ocular Surface Disease Index Questionnaire (OSDI). Main outcome measures include the comparison on the OSDI score and VFQ-25 score among the subgroups, and the correlation of these scores with the socio-demographical and clinical data. The results revealed that subjects with Cch had significantly decreased tear film stability even compared with those with DES (P = 0.001). The participants with either Cch or DES reported significantly higher OSDI scores and lower VFQ-25 composite scores than the normal controls (P<0.001 and 0.007 respectively). Further comparisons among the subgroups of Cch revealed that the following factors were associated with higher OSDI scores and lower VFQ-25 composite scores: nasal-side Cch, chalasis folds higher than tear meniscus height, punctal occlusion, or increased extent of chalasis on digital pressure. In conclusion, Cch was associated with an adverse impact on VR-QoL in a community population, and the impairment in VR-QoL had a significant correlation with disease severity and tear film abnormalities.

Assessment of corneal epithelial thickness in dry eye patients.

PURPOSE: To investigate the features of corneal epithelial thickness topography with Fourier-domain optical coherence tomography (OCT) in dry eye patients. METHODS: In this cross-sectional study, 100 symptomatic dry eye patients and 35 normal subjects were enrolled. All participants answered the ocular surface disease index questionnaire and were subjected to OCT, corneal fluorescein staining, tear breakup time, Schirmer 1 test without anesthetic (S1t), and meibomian morphology. Several epithelium statistics for each eye, including central, superior, inferior, minimum, maximum, minimum - maximum, and map standard deviation, were averaged. Correlations of epithelial thickness with the symptoms of dry eye were calculated. RESULTS: The mean (±SD) central, superior, and inferior corneal epithelial thickness was 53.57 (±3.31) µm, 52.00 (±3.39) µm, and 53.03 (±3.67) µm in normal eyes and 52.71 (±2.83) µm, 50.58 (±3.44) µm, and 52.53 (±3.36) µm in dry eyes, respectively. The superior corneal epithelium was thinner in dry eye patients compared with normal subjects (p = 0.037), whereas central and inferior epithelium were not statistically different. In the dry eye group, patients with higher severity grades had thinner superior (p = 0.017) and minimum (p < 0.001) epithelial thickness, more wide range (p = 0.032), and greater deviation (p = 0.003). The average central epithelial thickness had no correlation with tear breakup time, S1t, or the severity of meibomian glands, whereas average superior epithelial thickness positively correlated with S1t (r = 0.238, p = 0.017). CONCLUSIONS: Fourier-domain OCT demonstrated that the thickness map of the dry eye corneal epithelium was thinner than normal eyes in the superior region. In more severe dry eye disease patients, the superior and minimum epithelium was much thinner, with a greater range of map standard deviation.

Vision-related quality of life in patients with infectious keratitis.

PURPOSE: To determine the vision-related quality of life (VR-QOL) in patients with infectious keratitis using the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25). METHODS: Sixty-five patients with infectious keratitis (IK) were enrolled in the study. The NEI VFQ-25 scores and clinical and demographic data, including age, gender, pathogen, best corrected visual acuity (BCVA), and duration of the disease, were collected from the subjects. The subscale and composite scores were calculated and analyzed. Correlations between the VFQ-25 scores and the clinical and demographic features were also explored. RESULTS: The mean age of enrolled subjects was 48.4 years (SD, 16.2), with 44 males (67.7%). The microbial pathogens were viruses (n = 48, 73.8%), fungi (n = 13, 20.0%), and bacteria (n = 4, 6.2%). The mean scores of each VFQ-25 subscale ranged from 31.9 (SD, 28.6) for role difficulties to 92.7 (SD, 13.1) for color vision; the mean composite score was 58.1 (SD, 19.2). Significant differences in scores were observed only in the subscale of dependency among educational levels and in the mental health subscale and the composite among the three pathogen groups. Multivariate regression analysis revealed that VFQ-25 composite score correlated significantly with the BCVA of the worse-seeing eye, duration of the disease, history of operation (for IK treatment), and gender. CONCLUSIONS: Infectious keratitis has extensive impacts on patients and VR-QOL. The BCVA of worse-seeing eye, duration, history of operation for IK treatment, and gender contributed independently to VR-QOL. Early treatment should be encouraged to obtain better visual prognosis and VR-QOL for patients with IK.

[Evaluation the change of corneal epithelium thickness after pterygium excision with conjunctival autograft transplantation by Fourier domain optical coherence tomography].

OBJECTIVE: To evaluate the change of corneal epithelial thickness after pterygium excision with conjunctival autograft transplantation by Fourier Domain Optical Coherence Tomography (FD-OCT) . METHODS: Twenty-two patients (24 eyes) with the diagnosis of primary pterygium were enrolled. They underwent pterygium excision combined with conjunctival autograft transplantation. Twenty-five volunteers (25 eyes) served as the normal control group. FD-OCT was performed preoperatively and 1, 2, 3, 5, 7 days postoperatively to measure the thickness of corneal epithelium at 1 mm and 2 mm anterior to the nasal or temporal scleral spur. Corneal fluorescein staining was performed simultaneously. Comparisons on the thickness of corneal epithelium were made between preoperative values and postoperative ones. RESULTS: The thickness of cornea epithelium at 1 mm anterior to the scleral spur was (43.81 ± 2.55) µm in normal subjects. At day 1 after surgery, corneal epithelial thickness at the same location was (21.28 ± 5.72) µm and then gradually increased to (39.94 ± 5.47) µm at day 7 postoperatively. All the difference on postoperative days had statistically significant (t = -17.69, -14.97, -10.63, -9.86, -3.15, P < 0.05) . The thickness of cornea epithelium at 2 mm anterior to the scleral spur was (40.50 ± 3.17) µm in normal subjects. At day 1 after surgery, corneal epithelial thickness at the same location was (24.02 ± 5.92) µm, and then gradually increased to (940.34 ± 5.69) µm at day 7 postoperatively. All the difference on postoperative days except day 7 had statistically significant (t = -12.08, -10.27, -6.18, -2.99, P < 0.05). Cornea epithelium at this location repaired sooner than that at 1 mm anterior to the scleral spur. At day 1 after surgery, corneal epithelium defect area were (39.31 ± 22.77) mm(2), and then decreased to (1.01 ± 1.72) mm(2) at 7 days (t = 6.68, 5.55, P < 0.05). At day 7 postoperative, 66.7% patients had a complete recovery of corneal epithelium with no fluorescein staining. CONCLUSIONS: FD-OCT was the effective instrument for observing the change of limbus-peripheral cornea epithelium thickness.Within 7 days postoperatively, cornea epithelium restored almost normal. After pterygium surgery, limbus-peripheral cornea epithelium restoration showed the tendency from the central to peripheral cornea.

A new tonometer--the Corvis ST tonometer: clinical comparison with noncontact and Goldmann applanation tonometers.

PURPOSE: To compare intraocular pressure (IOP) measurements obtained using the Topocon noncontact tonometer (NCT), the Goldmann applanation tonometer (GAT), and the Corvis ST (CST), a newly developed tonometer with features of visualization and measurement of the corneal deformation response to an air impulse. A secondary objective was to assess the agreement among the devices. METHODS: Fifty-nine participants, including glaucoma patients (36 cases) and control volunteers (23 cases), were enrolled. One eye was selected randomly for further study. IOP measurements were obtained with the CST, NCT, and GAT by two experienced clinicians. IOP values were compared. Intraobserver variability and interobserver variability were assessed by the coefficient of variation and intraclass correlation coefficient. Device agreement was calculated by Bland-Altman analysis. RESULTS: Mean IOP for all examined eyes was 18.9 ± 5.8 mm Hg for CST, 21.3 ± 6.8 mm Hg for NCT, and 20.3 ± 5.7 mm Hg for GAT. There was no statistically significant difference in IOP measurements among the tonometers except between the CST and NCT. Correlation analysis showed a high correlation between each pair of devices (all P < 0.001). The CST displayed the best intraobserver variability and interobserver variability. Bland-Altman analysis revealed a bias between CST and GAT, CST and NCT, and GAT and NCT of -1.3, -2.4, and -1.1 mm Hg, with 95% limits of agreement of -6.2 to 3.5 mm Hg, -10.1 to 5.2 mm Hg, and -8.3 to 6.2 mm Hg, respectively. CONCLUSIONS: The CST offers an alternative method for measuring IOP. IOP measurements taken with these devices may not be interchangeable.

Assessment of tear film stability in dry eye with a newly developed keratograph.

PURPOSE: To investigate the applicability of a newly developed corneal topographer in assessing tear film stability. METHODS: This is a prospective, case-control study. Forty-four Chinese dry eye patients and 41 normal subjects were recruited. Noninvasive tear film break-up time (NI-BUT) was measured using a new method based on a corneal topographer equipped with modified scan software. The reliability of the measurements was determined. Then, the correlations between the NI-BUT and the traditional fluorescein tear film break-up time, Schirmer I test values, and inferior tear meniscus height measurements were determined. The receiver operating characteristic curve technique was used to evaluate the NI-BUT examination in the diagnosis of dry eye. RESULTS: In total, a significant difference between the NI-BUT and the fluorescein tear film break-up time was found (3.2 ± 2.3 seconds vs. 5.2 ± 3.4 seconds; P < 0.001). The coefficient of variation and intraclass correlation coefficient values of NI-BUT were 12.8% and 0.93, respectively, for NI-BUT for intraobserver repeatability and 15.4% and 0.88, respectively for interobserver repeatability. The NI-BUT showed a good correlation with other dry eye examinations (all P < 0.05). In addition, the NI-BUT was significantly shorter in dry eye patients (2.0 ± 0.2 seconds) than in normal subjects (4.3 ± 0.3 seconds; P < 0.001). When the cutoff value was set at <2.65 seconds, the sensitivity and specificity of the test were 84.1% and 75.6%, respectively. CONCLUSIONS: Measurements of NI-BUT obtained with the newly developed corneal topographer may provide a simple, noninvasive screening test for dry eyes with acceptable sensitivity, specificity, and repeatability.