Corneal Epithelial Cell Density Is Reduced in Young Adults With Conjunctival Ultraviolet Autofluorescence

PURPOSE

The aim of this study was to investigate the effects of chronic ultraviolet (UV) radiation exposure on the corneal microstructure using conjunctival UV autofluorescence (CUVAF) as a marker of exposure.

METHODS

Young healthy adults aged 18 to 35 years were recruited. Participant's demographics and sun exposure behavior were recorded using questionnaires. Images of the bulbar conjunctiva from the right eye were captured and analyzed for the CUVAF area. Corneal microstructure was assessed by in vivo confocal microscopy and anterior segment optical coherence tomography. The presence of palisades of Vogt in all 4 limbal quadrants was recorded.

RESULTS

CUVAF was observed in 31 of 52 eyes (60%), with a mean (±SD) nasal, temporal, and total CUVAF area of 5.39 ± 4.16 mm 2 , 4.29 ± 4.27 mm 2 , and 9.67 ± 7.01 mm 2 , respectively. Individuals with CUVAF were significantly more likely to report undertaking moderate-intensity to high-intensity outdoor exercise ( P = 0.021). Individuals with CUVAF were less likely to have visible nasal and temporal palisades of Vogt ( P = 0.011). Corneal basal cell densities anterior to the nerve whorl ( P < 0.001) and nasally ( P = 0.005) were lower in individuals with CUVAF. Wing cell density anterior to the nerve whorl was lower in individuals with CUVAF ( P = 0.011). No significant changes in the central and limbal corneal epithelial thickness were observed.

CONCLUSIONS

Significant reductions in corneal epithelial cell density were observed in individuals with CUVAF, a biomarker of chronic UV exposure. This observation suggests that chronic UV exposure is damaging to the corneal microstructure.

Noninvasive Imaging of Conjunctival Goblet Cells as a Method for Diagnosing Dry Eye Disease in an Experimental Mouse Model

Purpose

The purpose of this study was to evaluate a noninvasive conjunctival goblet cell (GC) imaging method for assessing dry eye disease (DED) in an experimental mouse model.

Methods

Moxifloxacin-based fluorescence microscopy (MBFM) was used to examine GCs noninvasively in 56 mice. Forty-two (42) DED-induced mice were divided into 2 groups and treated topically for 14 days with cyclosporine (CsA) or normal saline (NS). In vivo MBFM imaging and clinical DED evaluations were performed and goblet cell density (GCD) and goblet cell area (GCA) were obtained and compared with histological GCD using periodic acid-Schiff (PAS) staining. Correlation and receiver operating characteristic (ROC) analyses showed MBFM's high diagnostic value.

Results

The GCD and GCA of the DED mice obtained from in vivo MBFM imaging were highly correlated with clinical DED parameters and GCD obtained from PAS histology. The therapeutic effect of CsA, as observed by in vivo MBFM, was significant with respect to that of NS treatment. The ROC curves derived from in vivo MBFM showed high diagnostic value in assessing DED.

Conclusions

The proposed noninvasive method has high diagnostic value in assessing the severity of DED and the effect of treatment for this disease.

Translational Relevance

A noninvasive imaging method using moxifloxacin-based fluorescence microscopy was evaluated for assessing DED in an experimental mouse model. The method showed high diagnostic value in assessing the severity of DED and the effect of treatment, bridging the gap between basic research and clinical treatment. The study provides a promising tool for diagnosing and monitoring DED.

Non-invasive hemoglobin estimation from conjunctival images using deep learning

Hemoglobin, a crucial protein found in erythrocytes, transports oxygen throughout the body. Deviations from optimal hemoglobin levels in the blood are linked to medical conditions, serving as diagnostic markers for certain diseases. The hemoglobin level is usually measured invasively with different devices using the blood sample. In the physical interpretation, some signs are traditionally used. These signs are the palms, face, nail beds, pallor of the conjunctiva, and palmar wrinkles. Studies have shown that conjunctival pallor can yield more effective results in detecting anemia than the pallor of the palms or nail beds. This study is aimed to predict the hemoglobin level by deep learning method, non-invasive, cheap, fast, high accuracy, and without creating medical waste. In this context, conjunctival images and age, weight, height, gender, and hemoglobin values were collected from 388 people who donated blood to the Turkish Red Crescent. A dataset was generated by augmenting the gathered data with body mass index data. Within the scope of this investigation, the limits of agreement (LoA) value at a 95% confidence interval was computed to be 1.23 g/dL, while the bias was established as 0.26 g/dL. The mean absolute percentage error (MAPE) values were determined to be 3.4%, and the root mean squared error (RMSE) was calculated to be 0.68 g/dL. These findings exhibit a successful outcome compared to similar investigations, signifying that this non-invasive method can be employed for hemoglobin level estimation. Furthermore, the estimated hemoglobin levels could aid in diagnosing several hemoglobin-related ailments.

Lymphangiectasia Hemorrhagica Conjunctivae Regression with Bleomycin Sclerotherapy on Anterior-Segment Optical Coherence Tomography

This case report discusses treatment of lymphangiectasia hemorrhagica conjunctivae with bleomycin sclerotherapy in a patient aged 47 years with a history of recurrent subconjunctival hemorrhage.

Moxifloxacin-Based Extended Depth-of-Field Fluorescence Microscopy for Real-Time Conjunctival Goblet Cell Examination

Conjunctival goblet cells (CGCs) are mucin-secreting cells in the eye and play essential roles for ocular surface homeostasis. Since various ocular surface pathologies are related to CGC dysfunction, CGC examination is important for the evaluation of ocular surface conditions. Recently we introduced moxifloxacin-based fluorescence microscopy (MBFM) for non-invasive CGC imaging. However, the imaging speed was up to 1 frame per second (fps) and needed to be improved for clinical applications. In this study, we developed a high-speed moxifloxacin-based, extended depth-of-field (EDOF) microscopy system that operates at a maximum imaging speed of 15 fps. The system used a deformable mirror for the high-speed axial sweeping of focal plane during single-frame acquisitions. The acquired images contained both in-focus and out-of-focus information, and deconvolution was used to filter the in-focus information. The system had a DOF of 800 [Formula: see text], field-of-view of 1.2 mm ×1.2 mm, and resolution of [Formula: see text]. Its performance was demonstrated by real-time, breathing-motion-insensitive CGC imaging of mouse and rabbit models, in vivo. High-speed EDOF microscopy has potentials for non-invasive, real-time CGC examinations of human subjects.

Quantification of Blood Flow Velocity in the Human Conjunctival Microvessels Using Deep Learning-Based Stabilization Algorithm

The quantification of blood flow velocity in the human conjunctiva is clinically essential for assessing microvascular hemodynamics. Since the conjunctival microvessel is imaged in several seconds, eye motion during image acquisition causes motion artifacts limiting the accuracy of image segmentation performance and measurement of the blood flow velocity. In this paper, we introduce a novel customized optical imaging system for human conjunctiva with deep learning-based segmentation and motion correction. The image segmentation process is performed by the Attention-UNet structure to achieve high-performance segmentation results in conjunctiva images with motion blur. Motion correction processes with two steps—registration and template matching—are used to correct for large displacements and fine movements. The image displacement values decrease to 4–7 μm during registration (first step) and less than 1 μm during template matching (second step). With the corrected images, the blood flow velocity is calculated for selected vessels considering temporal signal variances and vessel lengths. These methods for resolving motion artifacts contribute insights into studies quantifying the hemodynamics of the conjunctiva, as well as other tissues.

Incidence and progression of trachomatous scarring in a cohort of children in a formerly hyper-endemic district of Tanzania

Background

Trachoma is the leading infectious cause of blindness. Repeated or persistent ocular infection with Chlamydia trachomatis in childhood leads to conjunctival scarring, usually in adulthood but often earlier in areas with greater disease burden. There are limited longitudinal data examining change in scarring in children, especially where trachoma rates are low.

Methodology/Principal findings

A cohort of children, ages 1–9 years, were randomly selected at baseline from 38 communities in Kongwa, Tanzania and followed for 2 years. Rates of trachomatous inflammation—follicular (TF) were <5% over the survey period. At baseline, 1,496 children were recruited and 1,266 (85%) were followed-up. Photographs were obtained at baseline and follow-up and graded for the presence and severity of scarring using a four-point scale ranging between S1-S4. In children without scarring at baseline, 1.6% (20/1,246) were found to have incident scarring, and incident scarring was more common among girls compared to boys. Among children with scarring at baseline, 21% (4/19) demonstrated progression.

Conclusions/Significance

In this formerly hyper-endemic district, the incidence of new scarring in children ages 1–9 years is low, although 21% of those who had scarring at baseline progressed in severity over the 2-year follow-up period. These data provide support for the thesis that while incident scarring more closely reflects ongoing exposure, progression may involve factors independent of ongoing transmission of trachoma.

Trachoma is the leading infectious cause of blindness. The disease is caused by repeated eye infection with the bacterium Chlamydia trachomatis and characterized clinically in its active stage by follicles (TF) and/or severe inflammation (TI). Scarring of the inner surface of the eyelid results from repeated exposure to infection during childhood, and while active trachoma is mostly observed in childhood, scarring and late complications are often only seen in adulthood. In areas with heavy burden of trachoma, scarring may be observed among children, particularly among those with constant, severe trachoma and/or infection. Few studies have examined the incidence and progression of scarring in children in areas where the prevalence of trachoma has been substantially reduced. In this study, we examined the 2-year incidence and progression of scarring in Kongwa district, Tanzania where the prevalence of TF was about 5%. Incidence of new scarring was 0.8%/year and more common among girls. Progression of scarring was 21% in our cohort of children ages 1–9 years. Incidence in children was low in this formerly hyper-endemic area, but a substantial fraction of those with scarring at baseline demonstrated progression over the follow-up period. These data provide support for the thesis that without repeated exposure to trachoma, incident scarring is low, but other mechanisms for progression of scarring apart from ongoing transmission are operating, at least in children.

Angiographic biomarkers of filtering bleb function after XEN gel implantation for glaucoma: an optical coherence tomography-angiography study

PURPOSE

To evaluate, using optical coherence tomography-angiography (OCT-A), the vascular features of good bleb function after XEN gel implantation (XGI) for uncontrolled glaucoma.

METHODS

Forty-three patients (43 eyes), who underwent XGI, were enrolled. According to the intraocular pressure (IOP) reduction, patients were classified into Group 1 (21 eyes; success) and Group 2 (22 eyes; failure). Optical coherence tomography-angiography (OCT-A) was performed to image the vascularization of the conjunctival bleb-wall. The main outcomes were as follows: vessel displacement areas (VDAs), major vessel displacement area (MVDA; mm2 ), non-flow whole area (NFWA; mm2 ) and bleb-wall vessel density (BVD; %). Co-registered B-scans were also considered to evaluate the bleb-wall cyst-like structure density and area (BCSD, cysts/mm2 ; BCSA, mm2 ), and the bleb-wall thickness (BT, µm).

RESULTS

Mean postoperative follow-up was 7.5 ± 0.14 months; Group 1 and 2 IOP were 14.0 ± 2.5 and 25.3 ± 2.1 mmHg, respectively (p < 0.001). Greater VDA (p < 0.001), MVDA (p = 0.046) and NFWA (p = 0.001) values, and lower BVD (p < 0.001) was found in Group 1 compared to Group 2. Group 1 showed higher BSCD, BSCA and BT values compared to Group 2 (p < 0.001). Postoperative IOP positively correlated with BVD (r = 0.567; p = 0.003), but negatively with VDAs, MVDA (r = -0.581, p = 0.002; r = -0.619, p = 0.001, respectively), BCSD, BCSA (r = -0.580; p = 0.002; r = -0.664; p < 0.001) and BT (r = -0.627, p = 0.001).

CONCLUSION

Successful filtration blebs after XGI present numerous and large areas of vessel displacement within the bleb-wall, along with a rarefied vascular network. These OCT-A features can be considered angiographic biomarkers of a good aqueous humour percolation through the bleb-wall layers.

Corneo-pterygium total area measurements utilising image analysis method

PURPOSE

To describe an objective method to accurately quantify corneo-pterygium total area (CPTA) by utilising image analysis method and to evaluate its association with corneal astigmatism (CA).

METHODS

120 primary pterygium participants were selected from patients who visited an ophthalmology clinic. We adopted image analysis software in calculating the size of invading pterygium to the cornea. The marking of the calculated area was done manually, and the total area size was measured in pixel. The computed area is defined as the area from the apex of pterygium to the limbal-corneal border. Then, from the pixel, it was transformed into a percentage (%), which represents the CPTA relative to the entire corneal surface area. Intra- and inter-observer reliability testing were performed by repeating the tracing process twice with a different sequence of images at least one (1) month apart. Intraclass correlation (ICC) and scatter plot were used to describe the reliability of measurement.

RESULTS

The overall mean (N=120) of CPTA was 45.26±13.51% (CI: 42.38-48.36). Reliability for region of interest (ROI) demarcation of CPTA were excellent with intra and inter-agreement of 0.995 (95% CI, 0.994-0.998; P<0.001) and 0.994 (95% CI, 0.992-0.997; P<0.001) respectively. The new method was positively associated with corneal astigmatism (P<0.01). This method was able to predict 37% of the variance in CA compared to 21% using standard method.

CONCLUSIONS

Image analysis method is useful, reliable and practical in the clinical setting to objectively quantify actual pterygium size, shapes and its effects on the anterior corneal curvature.

Progression of scarring trachoma in Tanzanian children: A four-year cohort study

Background

Trachoma is a progressive blinding disease initiated by infection of the conjunctiva with Chlamydia trachomatis. Repeated infections are thought to cause chronic inflammation, which drives scarring, leading to in-turning of the eyelids. The relationship between C. trachomatis, clinical inflammation and scarring development in children is not fully understood due to a paucity of longitudinal studies with infection data at frequent follow-up.

Methods and findings

This longitudinal cohort study took place in northern Tanzania. Children aged 6–10 years at baseline were eligible for inclusion. Participants were visited every three months for four years. Clinical signs and conjunctival swabs for C. trachomatis detection by qPCR were collected at each time-point. Conjunctival photographs from baseline and final time-points were graded and compared side-by-side to determine scarring incidence and progression.

Of the 666 children enrolled in the study, outcome data were obtained for 448. Scarring progression was detected in 103/448 (23%) children; 48 (11%) of which had incident scarring and 55 (12%) had progression of existing scarring. Scarring was strongly associated with increasing episodes of trachomatous papillary inflammation (TP). Weaker associations were found between episodes of C. trachomatis infection and follicular trachoma (TF) with scarring progression in unadjusted models, which were absent in multivariable analysis after adjusting for inflammation (multivariable results: C. trachomatis p = 0.44, TF p = 0.25, TP p = <0.0001, age p = 0.13, female sex p = 0.05). Individuals having TP at 30% or more of the time-points they were seen had an odds ratio of 7.5 (95%CI = 2.7–20.8) for scarring progression relative to individuals without any TP detected during the study period.

Conclusions

These data suggest that the effect of infection on scarring progression is mediated through papillary inflammation, and that other factors contributing to the development of inflammation, in addition to C. trachomatis infection, may be important in driving conjunctival scarring progression in children. The addition of TP as a measure in trachoma control programs would provide an indication of the future risk of developing scarring sequelae.

Trachoma is the leading cause of preventable blindness worldwide and is targeted for elimination as a public health problem by 2020. The natural history of trachoma is not completely understood however. We conducted a four-year longitudinal study in a trachoma-endemic area of northern Tanzania with detailed follow up every three months. In the four-year study period, nearly one quarter of children developed progression of conjunctival scarring, despite three rounds of annual mass drug administration (MDA) for trachoma control. Disease progression was strongly associated with increasing proportion of episodes with conjunctival papillary inflammation (TP), and only weakly associated with Chlamydia trachomatis infection and trachomatous inflammation–follicular (TF). Analysis revealed that associations between infection and TF with scarring progression were mediated through TP, and that other factors causing individual differences in TP were also contributing to scarring progression. These data have significant implications for trachoma control. We hypothesise that in individuals who have previously experienced ocular C. trachomatis infection, TP is the primary driver of scarring progression. The addition of TP to trachoma surveillance programs would provide an indicator for active disease progression in the community and a more accurate guide to the need for future trichiasis interventions.

Sensitivity and specificity of computer vision classification of eyelid photographs for programmatic trachoma assessment

Background/aims

Trachoma programs base treatment decisions on the community prevalence of the clinical signs of trachoma, assessed by direct examination of the conjunctiva. Automated assessment could be more standardized and more cost-effective. We tested the hypothesis that an automated algorithm could classify eyelid photographs better than chance.

Methods

A total of 1,656 field-collected conjunctival images were obtained from clinical trial participants in Niger and Ethiopia. Images were scored for trachomatous inflammation—follicular (TF) and trachomatous inflammation—intense (TI) according to the simplified World Health Organization grading system by expert raters. We developed an automated procedure for image enhancement followed by application of a convolutional neural net classifier for TF and separately for TI. One hundred images were selected for testing TF and TI, and these images were not used for training.

Results

The agreement score for TF and TI tasks for the automated algorithm relative to expert graders was κ = 0.44 (95% CI: 0.26 to 0.62, P < 0.001) and κ = 0.69 (95% CI: 0.55 to 0.84, P < 0.001), respectively.

Discussion

For assessing the clinical signs of trachoma, a convolutional neural net performed well above chance when tested against expert consensus. Further improvements in specificity may render this method suitable for field use.

Conjunctival melanocytic naevus: Diagnostic value of anterior segment optical coherence tomography and ultrasound biomicroscopy

Purpose

Conjunctival naevi are the most frequently diagnosed primary melanocytic lesions of the conjunctiva. The clinical manifestations are greatly variable which may result in diagnostic difficulties and differential diagnostic confusions. Therefore aims of the present study were: 1) to assess the morphologic features of conjunctival naevi; 2) to delineate the anterior segment optical coherence tomography (AS-OCT) characteristics of these lesions; 3) to compare AS-OCT and ultrasound biomicroscopy (UBM) as diagnostic tools in these alterations and 4) to correlate histological results with the AS-OCT pictures in case of surgically excised naevi.

Methods

All lesions were photo-documented. AS-OCT and UBM (over the age of 18 years) were performed. Surgically excised lesions were admitted to histological examinations.

Results

In our series of 57 conjunctival naevi, 54.4% were highly pigmented, 15.8% proved to be amelanotic. AS-OCT could detect intralesional cysts in 61.4% of the naevi, while slit-lamp and UBM proved to be less sensitive (40.3% vs. 28.5%). UBM could visualize the posterior margins of all naevi, while AS-OCT proved to be less sensitive with the detection of 89.4% of posterior naevus margins. Thickness of the conjunctival epithelial layer could be measured with AS-OCT in case of subepithelial naevi, while no distinct epithelial layer could be detected in compound and junctional naevi.

Conclusions

Superiority of AS-OCT over UBM was demonstrated in visualizing internal structures of conjunctival naevi. UBM proved to be a better tool in highly pigmented and remarkably elevated naevi. Correlation was found between the histological type of the naevus and the thickness of the epithelial layer covering the lesion.

Dry eye following cataract surgery: The effect of light exposure using an in-vitro model

PURPOSE

Cataract surgery can lead to the temporary development or worsening of dry eye symptoms. Contributing factors may include corneal incisions, agents used before, during or after surgery, light from the operating microscope, disruption of ocular surface tissues and inflammatory processes. The purpose of this study was to observe the effect of light exposure on conjunctival fibroblasts in order to determine whether light has an effect on wound healing closure, assuming that operating microscopes might have an effect on the ocular surface.

METHOD

An in vitro scratch assay was performed on porcine conjunctival fibroblasts. Ten minutes of light exposure from a light microscope with a halogen bulb was performed after the scratch assay. Fibroblasts were kept in culture for 48 hours post-exposure and the wound closure rates were visualized by live/dead staining. The fibroblasts which were exposed to light were compared to those without light exposure. Cell viability was also analysed by MTT assay.

RESULTS

A Slower wound closure rate was found when fibroblasts were exposed to light compared to the non-light exposed controls. Cell viability reduced by 20% with light exposure compared to controls in p3 cells (p = 0.04; however, the trend was not observed with p4 and p5 cells (p > 0.05).

CONCLUSIONS

These results suggest that light exposure might be one of the possible contributory factors for dry eye after ophthalmic surgery. Further evaluation of light effects should be carried out with different ocular surface cells.

A Kalman Filtering and Nonlinear Penalty Regression Approach for Noninvasive Anemia Detection with Palpebral Conjunctiva Images

Noninvasive medical procedures are usually preferable to their invasive counterparts in the medical community. Anemia examining through the palpebral conjunctiva is a convenient noninvasive procedure. The procedure can be automated to reduce the medical cost. We propose an anemia examining approach by using a Kalman filter (KF) and a regression method. The traditional KF is often used in time-dependent applications. Here, we modified the traditional KF for the time-independent data in medical applications. We simply compute the mean value of the red component of the palpebral conjunctiva image as our recognition feature and use a penalty regression algorithm to find a nonlinear curve that best fits the data of feature values and the corresponding levels of hemoglobin (Hb) concentration. To evaluate the proposed approach and several relevant approaches, we propose a risk evaluation scheme, where the entire Hb spectrum is divided into high-risk, low-risk, and doubtful intervals for anemia. The doubtful interval contains the Hb threshold, say 11 g/dL, separating anemia and nonanemia. A suspect sample is the sample falling in the doubtful interval. For the anemia screening purpose, we would like to have as less suspect samples as possible. The experimental results show that the modified KF reduces the number of suspect samples significantly for all the approaches considered here.

Fresh frozen amniotic membrane for conjunctival reconstruction after excision of neoplastic and presumed neoplastic conjunctival lesions

PurposeSuspicious neoplastic conjunctival lesions often require wide excision with tumour-free margins, leaving significant conjunctival defects requiring reconstruction. In this study we report the results of using fresh frozen amniotic membrane grafts (AMG) after wide excision of potentially malignant lesions.MethodsRetrospective review of 53 patients; between January 2011 and April 2014. Conjunctival lesions were excised with a non-touch technique (2 mm margin) and sent for histopathological analysis. The surgical margins were treated with cryotherapy and a fresh frozen AMG was used to cover the defect. The main features examined were for any signs of recurrence, the conjunctivalisation of the AMG, complications and cosmetic appearance.ResultsFifty-three patients; 35 males and 18 females. Mean age was 54.9 (range 19-88). The mean follow up to January 2015 for all lesions was 21.4 months (range 8-48 months). The most common lesions were invasive malignant melanoma. There were no local surgical complications in 77.3% of patients; minimal scarring (11.3%), symblepharon (11.3%), and granuloma (7.5%). Five patients with conjunctival melanoma developed in-transit metastasis and orbital extension, none of it was at the site of the AMG.ConclusionOur case series is the largest reported to date, with the largest number of melanomas. The use of fresh frozen AMG has improved the local surgical outcomes by improving healing and reducing scarring as well as allowing for a wider surgical margin.

Conjunctival Ultraviolet Autofluorescence as a Measure of Past Sun Exposure in Children

Background: Conjunctival ultraviolet autofluorescence (CUVAF) area detected from UVAF photographs is a recently developed potential marker for past sun exposure, but its relationship with sun-related factors has not been fully investigated.Methods: The study included 339 healthy children ages 5 to 15 years in Melbourne, Australia. Data were collected by questionnaire and examination at school. CUVAF area was measured using a computer program and analyzed as a continuous and dichotomous outcome (any/none).Results: Fifty-three children (15.6%) had detectable CUVAF, and the youngest age at which a child showed sun damage was 8 years. Compared with silicone skin cast score, there was good inter-grader agreement on CUVAF grading, with Cohen kappa 0.85 [95% confidence interval (CI), 0.65-1.00] for total CUVAF area using both eye photographs. Perfect intra-grader agreement was achieved. Fairer pigmentation, including medium/fair skin color [adjusted odds ratio (AOR), 3.42; 95% CI, 1.02-11.48 vs. dark/olive] and blue/gray eye color (AOR, 4.07; 95% CI, 1.73-9.55 vs. brown) was associated with increased odds of CUVAF. Increasing lifetime sunburn number (e.g., AOR, 2.89; 95% CI, 1.14-7.35 and 4.29; 1.04-17.76 for sunburns 2 to 4 and ≥ 5 times, respectively, vs. no sunburns, trend P = 0.004) and freckling by the end of last summer were associated with increased odds of CUVAF.Conclusions: CUVAF area can be an a priori objective measure of past sun exposure in pediatric populations for future research.Impact: To our knowledge, this is the first pediatric study that evaluated associations of sun-related risk factors with CUVAF. Cancer Epidemiol Biomarkers Prev; 26(7); 1146-53. ©2017 AACR.

Automated Assessment of Hemodynamics in the Conjunctival Microvasculature Network

The conjunctival microcirculation is accessible for direct visualization and quantitative assessment of microvascular hemodynamic properties. Currently available methods to assess hemodynamics in the conjunctival microvasculature use manual or semi-automated algorithms, which can be inefficient for application to a large number of microvessels within the microvascular network. We present an automated image analysis method for measurements of diameter and blood velocity in microvessels. The method was applied to conjunctival microcirculation images acquired in 15 healthy human subjects. Frangi filtering, thresholding, and morphological closing were applied to automatically segment microvessels, while variance filtering was used to detect blood flow. Diameter and blood velocity were measured in arterioles and venules within the conjunctival microvascular network, and blood flow and wall shear rate were calculated. Repeatability and validity of hemodynamic measurements were established. The automated image analysis method allows reliable, rapid and quantitative assessment of hemodynamics in the conjunctival microvascular network and can be potentially applied to microcirculation images of other tissues.

Image-Based Assessment of Allergic Inflammation under Conjunctival Provocation

Conjunctival redness is an objective allergy symptom which can be analyzed using objective computer imaging methods. To evaluate allergic inflammation of the eyes, a robust and precise image-based method was developed and applied to analyze allergic hyperemia under the conjunctival provocation test (CPT). High-resolution digital photos were taken and analyzed via digital analysis software to obtain and document conjunctival redness. The evaluations made using this newly developed image-based method concurred with the study investigators' assessments: the therapeutic effects of the highest doses were superior to the lowest dose.

Photodocumentation of Allergic Severity under Conjunctival Provocation

The aim of this work was to evaluate conjunctival redness as an objective allergy symptom during the conjunctival provocation test (CPT). The CPT is an instillation of ophthalmic solution containing an allergen into the ocular mucosa. Allergic severity using the CPT was evaluated in the multicenter, randomized, controlled, double-blind, dose-finding study of 159 patients with birch pollen allergy where the mucosal sensitivity of the eye was assessed based on subjective and objective symptoms such as itching and redness, respectively. High-resolution digital photos were taken, arranged in image matrices, and analyzed by an external central observer to assess conjunctival redness. The photodocumentation method described here was successfully applied in a dose-finding study using the CPT. The evaluations of allergic severity carried out by an external observer agreed with the investigators' assessments.

[Specifics of surgically created draining zone in children with glaucoma after intraoperative mitomycin C according to ultrasonographic data]

The results of ultrasound biomicroscopy of draining zone created by filtering procedures in children with glaucoma after intraoperative mitomycin C (MMC) are represented. 149 eyes of 129 children with glaucoma after surgery with and without MMC were studied. In 68 cases we created limbal-based conjunctival flap and in 81--fornix-based. Comparative analysis did not reveal influence of MMC on scleral and internal surgical zones. Significant difference after surgery with MMC consisted in forming of cystic bleb in 20.8% when limbal-based conjunctival flap was created. It was showed that fornix-based conjunctival flap not only prevents forming of "mitomycin" cystic bleb but maintains positive effects of citostatic medications as well.

Conjunctival pain at termination of cataract surgery

An explanation is proposed for the conjunctival pain at the conclusion of cataract surgery. Pain associated with injection of antibiotics under the conjunctiva is sometimes observed at the end of cataract surgery performed under retrobulbar block. Partial block of the sensory nerves of the eye has been proposed as a reason for this. Failure to block orbital-ciliary nerves, branches of the maxillary branch of the fifth cranial nerve is put forward as an additional explanation for the pain.

Do not try this at home: trash can intracapsular cataract extraction

The authors present a 39-year-old woman who sustained blunt trauma from a metal garbage can to her left eye and presented with her intact crystalline lens luxated subconjunctivally after expulsion through a scleral wound. External photographs show the lens found under intact conjunctiva and a computed tomography scan demonstrates the extrascleral lens. The patient had a ruptured globe repair and intraoperative photographs showed removal of the lens.

Ultrasound biomicroscopy study of direct and oblique 25-gauge vitrectomy sclerotomies

PURPOSE

To study 25-gauge sclerotomy healing process in vivo with ultrasound biomicroscopy (UBM) in direct and oblique incisions.

DESIGN

Prospective interventional case series report.

METHODS

At our institution, we performed UBM studies on 53 sclerotomies during the first 30 days after 25-gauge vitrectomy, looking for conjunctival bleb development, sclerotomy healing signs, and vitreous incarceration in the wound.

RESULTS

Echographical healing signs were completed in 77% of patients by day 15 with no differences between direct and oblique sclerotomies. By day 30, all but one sclerotomy were closed. Conjunctival blebs developed over 64% of direct sclerotomies, and 25% of oblique (P = .0059), but all resolved spontaneously by day 15. Vitreous incarceration appeared in 72% of sclerotomies.

CONCLUSIONS

Twenty-five gauge sclerotomies heal by day 15 in most cases with no difference between direct and oblique sclerotomy construction. Conjunctival blebs developed more frequently over direct than oblique sclerotomies.

Bilateral epibulbar granulocytic sarcomas: a case of an 8-year-old girl with acute myeloid leukaemia

PURPOSE

An 8-year-old girl with a history of acute myeloid leukaemia (AML) presented with bilateral ocular discomfort, conjunctival injection, photophobia, and epiphora.

METHODS

Clinical examination and high-frequency ultrasound showed bilateral epibulbar tumours.

RESULTS

Granulocytic sarcomas were suspected and leukaemic infiltration was confirmed by fine-needle aspiration biopsy based cytopathologic examination.

CONCLUSIONS

Epibulbar granulocytic sarcoma in AML is rare (particularly in a child). We describe the first high-frequency ultrasound images and illustrate the use of a minimally invasive fine-needle aspiration biopsy technique to confirm our diagnosis.

Filtering blebs imaging by optical coherence tomography

PURPOSE

To assess the ability of standard optical coherence tomography to visualize filtering blebs after glaucoma surgery.

METHODS

A prospective interventional case series was conducted in a private practice. Twenty-nine eyes of 24 patients (21 with good, 2 with fair and 6 with poor intraocular pressure [IOP] control) were investigated. After the focus was manually adjusted on the conjunctiva, blebs were scanned perpendicularly to the limbus.

RESULTS

Hyporeflective fluid-filled spaces were detected in 19 out of the 21 eyes with good IOP. Within this group, blebs were classified into three different categories according to their optical coherence tomography pattern: type A (featuring a thick wall and a single large fluid-filled space), type B (featuring a thin wall and multiple large fluid-filled spaces) and type C (featuring multiple, irregular and flattened fluid-filled spaces). Fluid-filled spaces were not observed in three out of the six eyes with poor IOP control. Trabeculectomy without antimetabolites was associated with type A blebs (P = 0.015, Fisher's exact test), mitomycin-C trabeculectomy with type B blebs (P = 0.0025) and mitomycin-C phacotrabeculectomy with type C blebs (P = 0.0173).

CONCLUSIONS

Although it was not developed to evaluate the anterior segment of the eye, standard optical coherence tomography can visualize filtering blebs and reveal interesting details of their morphology. Clinicians using optical coherence tomography to diagnose glaucoma can take advantage of this ability of the instrument to obtain more information about their patients in the postoperative course of trabeculectomy and phacotrabeculectomy.

[Ultrasound biomicroscopy of conjunctival lesions]

BACKGROUND

The value of ultrasound biomicroscopy in the diagnosis of conjunctival lesions is not well established.

PATIENTS AND METHODS

For the examination of conjunctival lesions, we used an ultrasound biomicroscope (Humphrey, Zeiss, Oberkochen) with a high frequency transducer (30 MHz). Between January 2000 and August 2001, 28 patients (16 female, 12-male) with conjunctival lesions, aged 9 to 81 years, were available for this study.

RESULTS

Histological examination of the excised tissue displayed the presence of a compound naevus (8/28), cysts (6/28), inflammatory processes (3/28), granulomatous processes (2/28), lymphomas (2/28), foreign bodies (2/28), a pterygium (2/28), a malignant melanoma (1/28), a primary acquired melanosis (1/28), and a conjunctival amyloidosis (1/28). Using ultrasound biomicroscopy we were able to demonstrate a cystic tumour in the six patients (21 %) with a cyst of the conjunctiva. In patients suffering from solid tumours of the conjunctiva the definite diagnosis could not be made with ultrasound biomicroscopy alone. The eight patients with compound naevus displayed a somewhat heterogeneous sonographic structure within the tumour. In the patient with a foreign body we were able to demonstrate posterior shadowing of the underlying tissue.

CONCLUSION

For evaluation of conjunctival lesions caused by a cyst or a solid tumour, ultrasound biomicroscopy may be an additional diagnostic tool, e. g. for assessing the margins of the tumour. However, up to now it is not possible to differentiate between different lesions solely by means of ultrasonography.

Downward extension of the lacrimal gland under the bulbar conjunctiva after trabeculectomy

PURPOSE

To describe two cases in which the lacrimal gland was considered to extend downward under the bulbar conjuctiva following trabeculectomy.

PATIENTS AND METHODS

We report two patients who complained of epiphora after trabeculectomy. A biopsy was performed on the tissue under the bulbar conjunctiva on the periphery of the bleb of case 1. The anatomical relationship between the holes and the avascular filtering bleb in case 2 was investigated using ultrasound biomicroscopy.

RESULTS

In case 1, a biopsy showed the lacrimal gland tissue filtrated with mononuclear cells. In case 2, ultrasound biomicroscopy revealed no connection between the multiple leaking holes and localized filtering bleb.

CONCLUSION

Following trabeculectomy at the superior temporal quadrant, we should consider downward extension of the lacrimal gland as a possible source of a patient's complaint of epiphora.

360 Degrees of epibulbar granulation tissue thirteen years after silicone circle buckle operation

To demonstrate a granulomatous reaction to silicone buckel thirteen years after retinal detachment surgery. We report on a 71-year-old man who developed a 360 degrees of epibulbar granulation tissue due to silicone circle buckel. The granulation tissue was demonstrated by a computer tomography and histologically. A granulomatous reaction to silicone circle buckel can be found many years from the first operation. Biopsy is always necessary to establish a definitive diagnosis. Treatment of 360 degrees of epibulbar granulation tissue causing ocular dysfunction is by surgical excision.

A rare case of both eyelids swelling: isolated conjunctival amyloidosis

Amyloid is an eosinophilic, amorphous protein that has been reported to deposit in virtually any tissue or organ and when extensive, may attain tumourous proportions. We present a rare case where both the upper and lower palpebral conjunctiva were affected by amyloid deposition.

Neodymium: YAG transconjunctival laser revision of late-failing filtering blebs

OBJECTIVE

To study the effectiveness of neodymium:YAG (Nd:YAG) laser transconjunctival revision of late-failing filtering blebs.

DESIGN

Retrospective, noncomparative case series.

PARTICIPANTS

Thirty consecutive patients from a glaucoma referral practice at the Ohio State University Department of Ophthalmology.

INTERVENTION

Transconjunctival Nd:YAG laser revision of blebs diagnosed as failing secondary to episcleral fibrosis.

MAIN OUTCOME MEASURE

Reduction in intraocular pressure (IOP) and survival of bleb.

RESULTS

Reduction in IOP was attained in 24 (80%) of 30 patients with a mean prelaser IOP of 21.21 mmHg and a mean 1-week postlaser IOP of 13.97 mmHg (P < 0.0001). These results were maintained at the 1-, 3-, and 12-month follow-up visits with mean IOPs of 16.31 mmHg (P = 0.0008), 14.81 mmHg (P < 0.0001), and 15.25 mmHg (P = 0.0003), respectively. Two-year data were available on a small number of patients (4) with a mean of 15.25 mmHg (P = 0.0085). Mean time interval between trabeculectomy and laser revision was 31 months.

CONCLUSION

Late-failing filtering blebs are often amenable to Nd:YAG transconjunctival revision.

Uveal lymphoid infiltration. Report of four cases and clinicopathologic review

PURPOSE

The purpose of the study was to report the clinicopathologic features of four patients with uveal lymphoid infiltration who were diagnosed by a conjunctival biopsy.

DESIGN

A case series.

PARTICIPANTS

Four patients at four institutions participated.

MEASURES

The histopathologic findings of the conjunctival and episcleral biopsy specimens from four patients with the diagnosis of uveal lymphoid infiltration were recorded. The conjunctival specimens were placed in 10% neutral buffered formaldehyde solution or B5 solution and processed routinely for light microscopic examination and immunohistochemical analysis for B cells and T cells and kappa and lambda light chains. The clinical and histopathologic findings were compared with 47 previously reported cases of uveal lymphoid infiltration.

RESULTS

Two men and two women (average age = 57 years) presented with diffuse punctate to coalescent yellow uveal infiltrates and epibulbar pink fleshy lesions. Ultrasonography of the lesions showed diffuse choroidal thickening and a lack of choroidal or scleral excavation. The conjunctival biopsy specimens showed diffuse infiltration of the substantia propria with B lymphocytes with variable kappa and lambda restriction. Scattered T lymphocytes also were present. Plasmacytoid cells and a prominent Grenz zone were present.

CONCLUSIONS

Patients with solitary or multiple yellow uveal infiltrates should have careful conjunctival evaluation for the presence of pink conjunctival lesions. Biopsy specimens of the conjunctival lesion may establish the diagnosis of uveal lymphoid infiltration.

Ultrasound biomicroscopy in the clinical evaluation of ab externo holmium:YAG laser sclerostomies

High-frequency ultrasound biomicroscopy (UBM) has extensive powers of resolution. This makes it possible to explore and study some areas of the anterior segment with a clarity close to that of histologic preparations. High-frequency UBM was used in the clinical evaluation of 10 glaucomatous eyes subjected to ab externo holmium:yttrium-aluminum-garnet (Ho:YAG) laser sclerostomy. The anatomic characteristics of the fistular paths were viewed and compared with echographic images. The authors demonstrated that in the 5 cases where the filtering bleb, fistular path, and internal ostium were present, there was a reduction of intraocular pressure. UBM is a high-definition diagnostic instrument in the follow-up of fistular paths and filtering blebs after Ho:YAG laser sclerostomy, making it possible to reoperate at an early stage before the onset of clinical manifestations.

Epithelial barrier function of the filtering bleb conjunctiva and the cornea after trabeculectomy with mitomycin C

PURPOSE

To evaluate epithelial barrier function of the filtering bleb conjunctiva and the cornea after trabeculectomy with adjunct, intraoperative mitomycin C, by using a newly developed slit-lamp fluorophotometer.

SUBJECTS AND METHODS

Thirteen patients with normal-tension glaucoma with a cystic filtering bleb who had undergone unilateral trabeculectomy with mitomycin C only once at least 1 year previously were subjected to the study. Epithelial barrier function of the bleb conjunctiva and the cornea in the operated eye was evaluated using an Anterior Fluorometer FL-500 to measure the uptake of topically applied fluorescein.

RESULTS

Fluorescein uptake (nanograms per milliliter, mean +/- standard error) by the bleb conjunctiva (1,857 +/- 380) was not significantly different from either the uptake by the superior bulbar conjunctiva in the operated eyes, located approximately 90 degrees C away from the filtering bleb (1,974 +/- 258), or the uptake by the conjunctiva in the intact eyes, located symmetrically against the bleb (1,913 +/- 248). The corneal uptake in the operated eye (56.1 +/- 10.2) was not significantly different from that in the intact eye (53.5 +/- 8.3).

CONCLUSIONS

Epithelial barrier function of the cystic filtering bleb conjunctiva and the cornea long after trabeculectomy with mitomycin C was demonstrated to be almost identical to that of the control.

Long-term dislocation of a hard contact lens

A 48-year-old female was fitted with hard contact lenses and lost the right lens the next day. She was asymptomatic for 62 months but then presented with a painful mass in the right superonasal orbital quadrant. Surgical exploration was non-diagnostic. Five months later the contact lens was found in the right upper fornix. This case emphasizes the importance of a thorough ocular examination, including double eversion of the lids and sweeping the fornices of patients with unidentified periocular masses or pain.

[Lymphographic and morphological studies of the conjunctiva in onchocerciasis patients in Liberia]

Conjunctival lymphographies in patients infected with Onchocerca volvulus in Liberia showed normal or only slightly dilated lymphatics. The light-microscopical studies of conjunctival specimens revealed microfilariae predominantly in edematous dilated interstitial channels. Microfilariae in lymphatics and interstitial channels without endothelium of the conjunctivae were demonstrated by scanning and transmission electron microscopy. No signs of inflammatory cellular reaction were found in the vicinity of the parasites. In conclusion, the dilatation of lymphatics and interstitial channels as well as the pathways along which the microfilarial penetrated the cornea and the anterior segments of the eye are discussed.

[Indirect lymphography at the eye and in the face- and neck-region with iotasul (author's transl)]

For the first time the lymphatic pathways of the conjunctiva and the eyelids of dogs could be presented in vivo with the water-soluble X-ray contrast medium iotasul. By means of indirect application the lymph flow could be demonstrated up to the truncus jugularis. Because of the simultaneous infusion of the contrast medium at different points the lymphography of the face- and neck-region is considerably facilitated.

A human and in vitro study on the exchange of water and solutes from soft contact lenses

Elimination of technetium (pertechnetate in normal saline solution) was studied from various types of contact lenses placed on normal human eyes by means of computer assisted gamma camera using "region of interest technique" with the designated area corresponding to the conjunctival sac. An elimination 4 times slower was found from a highly hydrophilic lens (Scanlens) than from a HEMA-lens (Softlens), 0,5% min and 2.0% min, respectively. From an ultrathin lens (U3-Softlens) was eliminated 2.4% min. Hard lenses did not absorb the isotope. In a laboratory study the lenses were pre-soaked in pertechnetate, blotted and washed at 2 min intervals in 0.5 ml saline. By this procedure 3% min of the technetium was eliminated from Scanlens, 16% min from Softlens and 28%/min from a thin, therapeutic lens (Plano-T). The ratio Softlens/Scanlens was in the human study 4.0 and in the laboratory study 4.9. Radioactivity was very rapidly eliminated from CAB-lenses. A similar study was carried out with radioactive water. More than 100% min was eliminated in the first 10 min followed by a slower elimination from 10-20 min. Then an increased elimination was seen for a few min. This increased elimination was in repeated studies constantly found after 20 min. It was not found in the studies with technetium and labelled leucine.