Pterygium Group Research Articles

Impacts of Matrix Metalloproteinase-11 Genotypes on Pterygium Risk.

The dysregulation of matrix metalloproteinase (MMP) proteins has been reported to be involved in the etiology of pterygium. However, studies about the role of matrix metalloproteinase-11 (MMP-11) are lacking. This study is the first to examine the genomic role of MMP-11 in pterygium. The genotypes of MMP-11 rs738791, rs2267029, rs738792, and rs28382575 were determined in 140 pterygium cases and 280 non-pterygium controls by utilizing polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and direct sequencing. The genotypic frequencies of MMP-11 rs738792 TT, CT and CC were 40.0%, 50.7%, and 9.3% in the pterygium group, significantly different from those in the non-pterygium group (55.0%, 37.1%, and 7.9%, respectively; p for trend=0.0139). Specifically, individuals carrying the variants CT and CC had a 1.88- and 1.63-fold odds ratio of pterygium risk [95% confidence interval (CI)=1.22-2.89 and 0.77-3.44, p=0.0054 and 0.2834, respectively]. In the dominant model, individuals carrying CT+CC had significantly higher pterygium risk (odds ratio=1.83, 95%CI=1.21-2.77, p=0.0052). No association was found for other MMP-11 polymorphisms. Allelic analysis showed that MMP-11 rs738792 C allele was significantly associated with pterygium risk (odds ratio=1.48, 95%CI=1.08-2.01, p=0.0169). for the variant alleles of other MMP-11 polymorphisms were not associated with pterygium risk. The MMP-11 rs738792 genotypes can serve as a predictive marker for pterygium risk in Taiwanese. Additionally, elucidating the role of MMP-11 in the pathogenesis of pterygium could inform targeted therapies based on MMP-11 modulation.

Inflammation due to ocular surface homeostasis imbalance caused by pterygia: tear lymphotoxin-alpha study and a literature review

ObjectiveTo estimate the pterygium ocular surface state, and compare with healthy eyes and dry eyes. To investigate the inflammation due to pterygia growth by tear Lymphotoxin-alpha (LT α) test.DesignProspective, single-center study.Participants400 patients, divided into 100 pterygium group, 100 mild dry eye group, 100 moderate dry eye group, and 100 age-and sex-matched normal controls.MethodsThe non-invasive break-up time (NIBUT), tear meniscus height (TMH) test, corneal fluorescein staining (CFS), meibomian gland loss score (MGs), and lipid layer thickness (LLT) were evaluated in all patients. Pterygium status and ocular status in the pterygium group were collected. The tear LT α test was conducted in the pterygium patients group.ResultPterygium can affect the ocular surface, leading to decreased tear film stability. The TMH, NIBUT, CFS, MGs, and lipid layer thickness can provide insights into this phenomenon. The presence of pterygium can change the structure and condition of the ocular surface. Tear LT α testing shows an abnormal decrease in LT α levels in pterygium patients. This indicates an immune-inflammation microenvironment that causes tissue repair deficiency.ConclusionThe dry eye triggered by the growth of pterygium may originate from the tear film instability due to pterygia. As an inflammatory index, LT α in the development of pterygium and the aggravation of dry eye patients can indicate that the ocular surface is in different inflammatory states. Future tear testing in LT α may be a potential indicator to assess the inflammatory status of the dry eye.

Expression of CD44, PCNA and E-cadherin in pterygium tissues.

Pterygium is a common ocular surface disease defined by fibrovascular conjunctival growth extending onto the cornea. However, its pathogenesis remains unclear. This study aimed to determine the role of CD44, proliferating cell nuclear antigen (PCNA), and E-cadherin in pterygium formation and recurrence. Sixty patients with pterygium participated in the study, and we collected conjunctival samples from 30 patients to form a control group. CD44, PCNA, and E-cadherin expressions in surgically excised pterygium were compared with tissue samples from the control group. We observed that the percentages of CD44 and PCNA were statistically higher in the primary pterygium group and recurrent pterygium group than in the control group (P < 0.001 and P < 0.001, respectively). Conversely, E-cadherin values were statistically higher in the control group than in the primary and recurrent pterygium groups (P = 0.013 and P < 0.001, respectively). Cell proliferation and cell adhesion factors may play important roles in the pathogenesis of pterygium.

The effect of pterygium on front and back corneal astigmatism and aberrations in natural-light and low-light conditions

BackgroundTo investigate the effect of different sizes of pterygium on the front and back corneal topography, refractive changes and aberrations in natural-light and low-light conditions.MethodsSixty subjects with unilateral primary nasal pterygium were enrolled in this study. All the patients’ uncorrected, best spectacle-corrected visual acuity, corneal topographic aberration data in 3 mm and 7 mm areas were collected. The pterygium size was evaluated by the slit-lamp photography and Sirius Scheimpflug Analyzer.ResultsThe front topographic astigmatism values, corneal total aberrations, and higher-order aberrations in 3 mm and 7 mm areas were higher in the pterygium group than those in the control group. The pterygium horizontal length and thickness were moderately to strongly correlated with astigmatism and RMS of aberrations, while pterygium vertical length showed no or just mild correlation with the corneal astigmatism and aberrations. Compared to the readings in 3 mm area, the front and back corneal astigmatism and aberrations were larger in 7 mm area.ConclusionsPterygium led to visual impairment by inducing astigmatism and aberrations. In low-light condition, the visual function worsened due to increased corneal astigmatism values and aberrations.

Contribution of Matrix Metalloproteinase-2 Genotypes to Taiwan Pterygium Risk.

In the literature, the studies about the role of matrix metalloproteinase-2 (MMP-2) in pterygium diagnosis are mainly based on its protein expression. The role of MMP-2 variants has never been examined. The aim of this study was to examine the association of MMP-2 genotypes with pterygium risk. MMP-2 rs243865 and rs2285053 were genotyped in 140 pterygium cases and 280 non-pterygium controls by typical polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) genotyping technology. The genotypic frequency of MMP-2 rs243865 CC, CT and TT were 86.4%, 12.9% and 0.7% in the pterygium group and 81.1%, 17.1% and 1.8% in the non-pterygium group (p for trend=0.3389). The variant CT and TT carriers had a 0.70- and 0.38-fold pterygium risk (95%CI=0.39-1.26 and 0.04-3.25, p=0.2982 and 0.6686, respectively). As for MMP-2 rs2285053, the genotypic frequency of CC, CT and TT were 67.1%, 28.6% and 4.3% in the pterygium group, non-significantly different from those in non-pterygium group (p for trend=0.7081). The CT and TT carriers had a 0.88- and 0.71-fold pterygium risk (95%CI=0.56-1.38 and 0.27-1.88, p=0.6612 and 0.6456, respectively). The allelic analysis results showed that MMP-2 rs243865 variant T allele was not associated with pterygium risk (7.1% versus 10.4%, OR=0.67, 95%CI=0.39-1.13, p=0.1649). As for MMP-2 rs2285053, the T allele was not associated with pterygium risk either (18.6% versus 21.1%, OR=0.85, 95%CI=0.59-1.23, p=0.4136). The genotypes at MMP-2 rs243865 or rs2285053 played minor role in determining individual susceptibility for pterygium among Taiwanese.

Contribution of Radiation Sensitive Protein 51 Genotypes to Pterygium Risk in a Taiwanese Population.

In current literature, there is a notable lack of studies investigating the role of radiation-sensitive protein 51 (RAD-51) in pterygium diagnosis. Nevertheless, reports indicate elevated expression levels of RAD-51 among recurrent pterygium cases compared to those with primary pterygium. However, the genomic involvement of RAD-51 has yet to be explored in any population. This study aimed to assess the contribution of RAD-51 genotypes to pterygium risk in a representative Taiwanese population. RAD-51 rs1801320 genotyping was successfully conducted in a Taiwanese cohort comprising 140 pterygium cases and 280 non-pterygium controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology. The distribution of RAD-51 rs1801320 genotypes (GG, CG, and CC) in the pterygium group (70.0%, 25.7%, and 4.3%, respectively) did not significantly differ from that in the non-pterygium group (73.6%, 23.6%, and 2.8% for GG, CG, and CC genotypes, respectively; p for trend=0.6337). Carriers of the variant CG and CC RAD-51 rs1801320 genotypes exhibited 1.15- and 1.58-fold increased pterygium risk, respectively (95%CI=0.72-1.84 and 0.53-4.67, p=0.6552 and p=0.5914, respectively). In the dominant model, there appeared to be a slight association between variant genotypes CG and CC and pterygium risk (OR=1.19, 95%CI=0.76-1.87, p=0.0223). Allelic analysis revealed that the RAD-51 rs1801320 variant C allele was not significantly linked to pterygium risk (17.1% versus 14.6%, OR=1.20, 95%CI=0.82-1.78, p=0.3991). Variant genotypes at RAD-51 rs1801320 were firstly identified to associate with susceptibility to pterygium among Taiwanese individuals. Nonetheless, these findings warrant validation in larger and more diverse populations.

Expression of placental growth factor, neuropilin-1, and neuropilin-2 in primary pterygium tissue.

The aim of this study was to evaluate the expression of placental growth factor (PLGF), neuropilin-1 (NP-1), and neuropilin-2 (NP-2) molecules in primary pterygium tissue compared with normal conjunctival tissue. The records of 42 patients who underwent excision surgery with autografts for primary pterygium (pterygium group) and 20 patients who underwent conjunctival nevus excision surgery (control group) in the same period were reviewed retrospectively. The samples obtained from the pterygium tissues in the pterygium group and the clean conjunctival tissues adjacent to the nevus in the control group were collected from the archive. Immunohistochemical stains of the primary antibodies-1/100 diluted PLGF, NP-1, and NP-2 (Abcam Cambridge Science Park, UK)-were applied to all groups. Staining intensities and the percentage of positive cells in epithelial, endothelial, stromal, and inflammatory cells were analyzed by an experienced pathologist. The positivity rates of PLGF and NP-2 expression in epithelial, endothelial, stromal, and inflammatory cells were found to be higher in the pterygium group than in the control group (PLGF: p < 0.001, p < 0.001, p = 0.001, and p < 0.001, respectively; NP-2: p < 0.001 for all). Staining intensities for PLGF and NP-2 were higher in the pterygium group than in the control group (PLGF: p < 0.001, p < 0.001, p = 0.005, and p < 0.001, respectively; NP-2: p < 0.001, p < 0.001, p = 0.001, and p < 0.001, respectively). However, no significant differences were found in any cell type in terms of NP-1 expression positivity rates (p = 0.730, p = 0.121, p = 0.524, and p = 0.624, respectively) or staining intensity (p = 0.716, p = 0.147, p = 0.147, and p = 0.780, respectively). PLGF and NP-2 levels were found to be higher in pterygium tissue, while there was no difference in NP-1. These results indicate the possible roles of NP-2 and PLGF in primary pterygium.

The influence of pterygium on corneal densitometry evaluated using the Oculus Pentacam system.

To assess the effect of pterygium on corneal densitometry (CD) values. One hundred and nine patients (155 eyes) with primary pterygium were divided into a severe pterygium group (79 eyes) and a mild-to-moderate pterygium group (76 eyes) according to pterygium severity. Among them, 63 patients had monocular pterygium; and 25 patients (38 eyes) underwent pterygium excision combined with conjunctival autograft follow-up. A Pentacam anterior segment analyzer was used to obtain the CD values and corneal morphological parameters, including central corneal thickness (CCT), flat-axis keratometry (K1), steep-axis keratometry (K2), corneal astigmatism, irregular astigmatism, and spherical aberration. CD was subdivided into four concentric radial regions based on corneal diameter and three layers according to depth. CD values at 0-12 mm of the anterior 120 μm layer, 0-10 mm of the center layer and full thickness, and 2-6 mm of the posterior 60 μm layer were significantly higher in eyes affected by pterygium than in the contralateral unaffected eyes (all P < 0.05). CD values were significantly higher in the severe pterygium group than in the mild to moderate pterygium group (all P < 0.05). Corneal astigmatism, irregular astigmatism, K1, K2, CCT, and spherical aberration correlated with CD values in eyes with pterygium (all P < 0.05). CD values at 6-10, 0-12 mm in the anterior 120 μm layer and full thickness, 10-12 and 0-12 mm in the center layer were significantly decreased 1 month after pterygium surgery compared with those before surgery (all P < 0.05). Patients with pterygium had increased CD values, particularly in the anterior and central layers. CD values were correlated with pterygium severity grading and corneal parameters. Pterygium surgery partially reduced the CD values.

Alterations in Macular Microvasculature in Pterygium Patients Measured by OCT Angiography.

Previous studies have reported an association between pterygia and maculopathy, yet the underlying mechanisms and alterations to the macular microvasculature in pterygium patients have yet to be fully elucidated. Our study conducted an analysis of macular superficial vessel length density (VLD) and vessel perfusion density (VPD) to establish associations between the conjunctival and macular microvasculature in patients with unilateral and bilateral pterygia. We revealed a loss of macular microvasculature in the outer nasal (ON) region in both unilateral and bilateral pterygium patients. VLD was significantly decreased in both pterygium groups in the ON region, and VPD was notably lower in bilateral pterygium patients in the same area. Furthermore, in unilateral pterygium patients, the vessel percent pixel coverage (PPC) of the pterygium and the area of the pterygium exhibited a negative correlation with VLD in the ON region. Multiple stepwise linear regression models indicated that the PPC could best predict VLP in the ON region. Taken together, our findings suggest that patients with pterygia may be more susceptible to macular diseases, and this may be due to a compensatory increase in blood perfusion via the anterior ciliary artery. These results underscore the importance of managing maculopathy in patients with pterygia.

Study of Corneal Curvature with Pterygium Morphology in Tertiary Care Center in Central India

Purpose: To evaluate the correlation between corneal astigmatism and pterygium morphology by anterior segment optical coherence tomography. Methods: Patients diagnosed with unilateral pterygium were included in this prospective crosssectional study. A thorough history was taken and each patient underwent detailed ocular examination including demographic data, subjective refraction with best corrected visual acuity using a Snellen’s chart, anterior and posterior segment examination with slit lamp biomicroscopy , keratometric measurements using an autorefractometer. The vertical width and horizontal length of the pterygium was measured manually with the millimetric scale of the slit lamp biomicroscope. Results: The study consisted of 45 patients with a mean age of 54.58 years. Mean Horizontal pterygium length, vertical width and percentage extension of pterygium was 2.71 mm, 4.56 mm, 50.22% respectively. Mean anterior corneal astigmatism was 2.11±1.69. Analysing the correlation separately, a statistically significant correlation was present between horizontal length and percentage extension and the anterior corneal astigmatism. Conclusion: Anterior corneal astigmatism was higher in pterygium group as compared to the contralateral eye without pterygium.

The Influence of Pterygium on Meibomian Glands and Dry Eye Parameters.

Mechanical factors are also associated with meibomian gland dysregulation in patients with pterygium. Dry eye parameters were assessed, and the results support the association between pterygium and dry eye disease. This study aimed to investigate how meibomian gland dysfunction and dry eye parameters relate to the existence of pterygium. Patients with pterygium and healthy volunteers of similar age and demographic characteristics were included. Schirmer 1 test, Ocular Surface Disease Index score, fluorescein tear film breakup time, and ocular surface staining scores (Oxford score) were recorded. Meiboscores were estimated based on meibomian gland loss rate on infrared meibography (SL-D701; Topcon, IJssel, the Netherlands). The symmetry of meibomian gland loss with respect to eyelid midline was assessed. Fifty-four eyes with pterygium (group 1) and 50 eyes of healthy volunteers (group 2) were included. The mean ages were 54.0 ± 12.3 and 52.3 ± 8.0 years, respectively. Schirmer 1 test results and tear film breakup time were lower in group 1 ( P = .007, P < .001). Oxford and Ocular Surface Disease Index scores were significantly higher in group 1 ( P = .009, P < .001). The mean meiboscores were significantly higher in group 1 ( P < .001). There was meibomian gland depletion in 90.7% (49 of 54) of group 1 and 32% (16 of 50) of group 2 ( P < .001). Meibomian gland loss region was distributed asymmetrically in 75.5% (37 of 49) of the eyes in group 1, but not in any of the eyes in group 2. The asymmetry was located on the side where the pterygium was detected in 94.5% (35 of 37) of these eyes. Meibomian glands are influenced morphologically and functionally in eyes with pterygium. The overlap of the pterygium location and meibomian gland abnormality suggests a direct mechanical relationship. In managing pterygium patients, the possibility of meibomian gland dysfunction and associated evaporative dry eye should be considered.

Measurement of Pterygium Tissue Dry Weight Using Two Different Tissue Preparation Techniques in Freeze-Dry Method

Due to pterygium tissue compression on the corneal surface, it has been hypothesised that the degree of corneal astigmatism caused by pterygium can vary. This study aims to develop a freeze-dried method for estimating net pterygium tissue mass (NPTM) as dry weight. A single surgeon (KMK) excised 60 primary pterygium using the controlled partial avulsion technique and divided them into two groups: formalin-fixed (n=30) and unfixed (n=30). After determining the weight of each sterile container, 5 mL of 5% buffered formaldehyde was added to the formalin-fixed group and stored for one week, while 5 mL of distilled water was added to the non-fixed pterygium group. Each container was pre-frozen for 12 hours before being freeze-dried (-24 hours at -80 degrees Celsius). The result is referred to as the net pterygium tissue mass (NPTM). Using an independent T-test, a comparison of wet and dry weight and percentage of NPTM was conducted between groups. Wet weights for formalin-fixed and non-fixed pterygium were 253.33 82.17 g and 255.17 63.52 g, respectively, while dry weights were 184.92 84.31 g and 179.54 72.85 g. Formalin-fixed pterygium tissue revealed a slightly higher percentage of NPTM than non-fixed pterygium tissue (69.39 13.29% vs. 67.75 13.29%, p = 0.792), but this difference was not statistically significant. The freeze-dried method can be utilised to quantify the NPTM of pterygium fibrovascular tissue and investigate the influence of pterygium translucency on predicting induced-corneal astigmatism.

Evaluation of Tear Secretion and Tear Film Stability in Patients with Pterygium and Normal Individuals

Introduction: Abnormalities of any of the components of lacrimal function unit can lead to dysfunctional tear film and development of dry eye. Dry eye is a commonly encountered problem in general population.&#x0D; Materials and Methods: A hospital-based, case-control study was conducted at National Medical College and Teaching Hospital, Nepal from 1st August 2018 to 30th July 2019. A total of 279 participants: 93 cases of pterygium (Group A: case) and186 (Group B: control) normal individuals with no ocular surface disorder were enrolled. Objective analysis was done by Schirmer’s (SCH) without and with anesthesia and Tear Break up Time (TBUT). Dependent t test was used to analyze the data. P value &lt;0.05 was considered statistically significant.&#x0D; Results: The mean age of the patients was 47.82 ±11.09 years (range 26-71) with male being 48 (51.6%) in Group A and in Group B, 101 (54.3%) were male with mean age being 42.16 ±13.13 years (range 32-75). The mean SCH without and with anesthesia and TBUT values were 16.94±5.61mm, 13.81±5.06mm, 10.14± 4.06 sec in Group A whereas in Group B, 20.39 ±6.08mm, 16.74 ±5.25mm and 13.05 ±4.32 sec respectively which was statistically significant (p &lt; 0.05). Patients with pterygium had higher risk of having dry eye than normal individuals (Odd ratios: 2.69, 2.44 and 2.27 respectively).&#x0D; Conclusion: Pterygium is a common ocular surface disorder which could result in instability of tear film indices, dysfunctional tear film and thus dry eye.

Tear film cytokines as prognostic indicators for predicting early recurrent pterygium

Cytokine profiles in tears have become a noninvasive biomarker for various ocular surface diseases. Therefore, the preoperative profile of cytokines in tear samples of 89 primary pterygium patients were obtained from Zhongshan Ophthalmic Center during 2015–2017. Compared to the tear cytokines in primary groups, the concentrations of IL-8, MMP-1, MMP-9, bFGF and VEGF were generally higher in recurrent pterygium group. The five cytokines were used to build diagnostic models by multiple machine learning algorithms, which can accurately distinguish non-recurrent and recurrent samples of primary pterygium patients. Besides, these cytokines were significantly associated with Recurrent-free survival (RFS) time in pterygium patients and further applied to develop a prognostic model which can estimate the prognosis of pterygium after resection. Afterward, a novel nomogram combined risk score of cytokines related biomarker and clinical characteristics was constructed, which manifested ideal accuracies to predict the 1 and 2 years’ probability of pterygium recurrent events. Thus, our finding provides a more simple and accurate prediction for early pterygium recurrence after resection. It also affords a useful tool for ophthalmologists to choose the optimal treatment strategies for pterygium patients.

Decreased Macular Retinal Thickness in Patients With Pterygium

PurposeTo explore alterations in macular retinal thickness (RT) and analyze correlation between macular RT and pterygium area, length in pterygium patients.MethodsTotally 13 patients with pterygium (left eye) and 13 healthy controls (left eye) were recruited. OCTA was applied to scan each eye to generate three-dimensional images. Based on the Early Treatment Diabetic Retinopathy Study (ETDRS) method, each image was divided into nine subregions for the ETDRS: central (C); inner superior (IS); outer superior (OS); inner nasal (IN); outer nasal (ON); inner inferior (II); outer inferior (OI); inner temporal (IT); and outer temporal (OT). The macular RT in each subregion was measured. Furthermore, the correlation between RT and the area, length of pterygium was analyzed.ResultsThe visual acuity of pterygium patient was different from that of the control (P < 0.05). Besides, decreased intraretinal thickness of the IN and ON, increased intraretinal thickness of OT, decreased extraretinal thickness of OT, IN, ON, OS, and decreased retinal full layer thickness of medial superior, OS, IN, ON, and II subregions in pterygium group were observed. There was a negative correlation between RT of the IN and ON subregions and the length of pterygium (r = −0.5803 and r = −0.6013, P = 0.0376 and P = 0.0297). The RT of IN subregion was negatively correlated with pterygium area (r = −0.5844, P = 0.0359). According to the receiver operating characteristic analysis, in the ON subregion, the areas under the curve of the inner retinal thickness, outer retinal thickness and the whole retinal thickness were 1.0 (95% CI: 1.0), 0.882 (95% CI: 0.715 and 0.963), and 1.0 (95% CI: 1.0). The smallest area under the curve of retinal thickness in OT subregion was 0.018 (95% CI: 0–0.059).ConclusionRT of pterygium patients was significantly decreased, and the main alterations occurred in the temporal side suggesting there might exist retinal structural alterations in pterygium.

NLRP3 and NLRP6 expression in pterygium and normal conjunctiva and their relationship with pterygium formation and recurrence.

This study aimed to explore the pterygium formation and recurrence, by detecting the expression of Nod-like receptor pyrin domain 3 (NLRP3) and Nod-like receptor pyrin domain 6 (NLRP6) in pterygium and evaluate the correlation between NLRP3 and NLRP6 in pterygium. In this prospective study, the expression levels of NLRP3 and NLRP6, with their related effectors, were evaluated in primary pterygium (n = 40) and recurrent pterygium (n = 32) tissue samples and compared with normal conjunctiva (n = 11) tissue samples by immunohistochemistry. Compared to the normal conjunctiva group, the expression levels of NLRP3, caspase-1, IL-18, and IL-1β, were significantly higher, and NLRP6 showed an expression that was significantly lower in pterygium tissue samples (P < 0.05, respectively). Compared to the primary pterygium group, the expression levels of NLRP3, caspase-1, IL-18 and IL-1β were significantly higher, and NLRP6 showed an expression that was significantly lower in recurrent pterygium tissue samples (P < 0.05, respectively).There was a negative correlation between NLRP3 expression and NLRP6 expression in normal conjunctival (r = -0.739, P = 0.009) and pterygium (r = -0.533, P = 0.000). NLRP3 and NLRP6 may be involved in the formation and recurrence of pterygium. NLRP6 may play an anti-inflammatory role in normal conjunctival tissue to maintain conjunctival homeostasis.

Decreased retinal microvasculature densities in pterygium.

To investigate the retinal vascular network alterations in eyes of patients with pterygium. Totally 18 left eyes from 18 female pterygium patients and 18 left eyes from 18 female healthy control subjects were enrolled. Optical coherence tomography angiography (OCTA) images were generated of the superficial retinal layer and deeper retinal layer of the macular retina for each eye. The microvascular (MIR) and macrovascular (MAR) densities were calculated and MIR, MAR, and total microvascular (TMI) density was compared in the healthy control and pterygium groups. In pterygium group, in the superficial retinal layer, the vascular density in superficial MIR, superior right (SR), inferior right (IR), right (R), superficial central annuli (SC)1, SC2, and SC3 decreased significantly in the macular area (P<0.05). Furthermore, the vascular density in all those decreased regions except R, was significantly and negatively correlated with the disease course (r=-0.6038 to -0.7762, P=0.0008), and the area size of pterygium (r=-0.6043 to -0.9508, P<0.05). For the deeper retinal layer, the density of deep total microvessel (DTMI), deeper MIR, SR, IR, R, DC2, and DC3 decreased significantly in macular area of pterygium patients (P<0.05). Furthermore, the vascular density in all those decreased regions was significantly and negatively correlated with the disease course (r=-0.6901 to -0.7795, P=0.0015), and the area size of pterygium (r=-0.6043 to -0.9563, P<0.05). No statistically significant differences and correlation was found in other region density (|r|<0.47, P>0.05). OCTA findings suggest that pterygium patients present with decreased retinal MIR density, and the major vascular alterations occurr mainly on the bitamporal side. The vascular density of the superficial SC1, SC2, SC3 adjacent to the foveal and deep layer of DC2, DC2 regions, significantly decreased.

Dynamic thiol disulphide homeostasis in patients with surfer's eye: a case-control study.

The role of oxidative stress in the pathogenesis of pterygium is still unclear. However, abnormal thiol disulfide homeostasis levels are involved in the pathogenesis of various systemic or ocular diseases. We aim to analyze dynamic thiol disulphide homeostasis in patients suffering from conjunctival pterygium using a contemporary technique. Thirty-eight subjects suffering from pterygium and 35 age-gender matched healthy volunteers were recruited for the study. For each case, total thiol, disulfide and native thiol levels in blood were obtained. Additionally, the ratio of disulfide over total thiol, native thiol over total thiol and disulfide over native thiol were computed. The level of median native thiol was lower in pterygium group (318.2µmol/L vs. 333.4µmol/L) and median disulfide was slightly higher in pterygium group (24.3µmol/L vs. 22.8µmol/L) compared to control group. Both disulfide over total thiol and disulfide over native thiol ratios were higher in pterygium group, ratio of native thiol over total thiol was found to be higher in control group. Nevertheless, none of those differences were statistically significant at 95% confidence level. Notably, correlation test pointed to a negative correlation both between pterygium grade and native thiol and between total thiol and pterygium grade in pterygium group (P = 0.03 and 0.02, respectively). A negative correlation hinting that slightly weakened dynamic thiol disulphide homeostasis in subjects with pterygium, a local ocular disease. Further studies with larger sample sizes may shed light on this potential relationship and justify systemic antioxidant therapies in these cases.

Corneal epithelial mapping in different corneal conditions

Abstract Background Cataract surgery is traumatic to the corneal epithelium,scarring and opacity is the commonest cause of blindness. Objective To study the corneal epithelial thickness in different corneal conditions using anterior segment optical coherence tomography (AS-OCT). Patients and Methods A case-control study including 80 eyes divided equally into 4 groups; group 1:controls,group 2:corneal scarring ,group 3:cataract patients and group 4:pterygium. using AS-OCT epithelial mapping to document changes in epithelial thickness in controls, cataract patients pre and 1 month after phacoemulsification, patients with corneal scarring and patients with pterygium. Results In phacoemulsification group; we found that epithelial thickness became thinner in area (0_2) and thicker in area (7_9) mm in the map with no significant change in areas (2_5),(5_7) mm in the map. In corneal scarring group; we found that epithelial thickness became thicker compared to control group in all zones. In pterygium group; we found that epithelial thickness became thicker compared to control group in, areas (2_5), (5_7) &amp; (7_9) mm in the map with no significant change in area (0_2) mm in the map. Conclusion The corneal epithelium thickness becomes thinner or thicker to compensate for changes in stromal thickness.

Comparison of Corneal Irregularity After Recurrent and Primary Pterygium Surgery Using Fourier Harmonic Analysis.

PurposeTo the best of our knowledge, few detailed investigation of astigmatism with recurrent pterygium currently exists. We aimed to evaluate corneal irregularity after recurrent pterygium surgery.MethodsThis observational study included consecutive patients who underwent recurrent pterygium surgery and were observed for >12 months postoperatively via corneal examination. Patients who underwent primary pterygium surgery during the same period served as controls. Pterygium size and corneal irregularity evaluated with Fourier harmonic analysis (spherical component, regular astigmatism, asymmetry component, and higher-order irregularity) were compared between groups preoperatively and at 1, 3, 6, and 12 months postoperatively.ResultsOverall, 203 eyes of 203 patients (age, 66.5 ± 9.5 years) were included, of which 44 eyes had recurrent pterygium and 159 had primary pterygium. Regular astigmatism in the recurrent pterygium group was higher than that in the primary pterygium group preoperatively and at 1 and 3 months postoperatively. The asymmetry component and higher-order irregularity in the recurrent pterygium group were higher than those in the primary pterygium group at all observation points.ConclusionsFourier harmonic analysis showed that larger corneal irregularity that could not be corrected with spectacles persisted for a long time after recurrent pterygium excision than after primary pterygium excision. Thus, recurrence prevention is critical for primary pterygium surgery.Translational RelevanceWe demonstrated that larger corneal irregularity that could not be corrected with spectacles remained long after excision of recurrent pterygium compared with excision of primary pterygium; thus, the prevention of recurrence is clinically important for primary pterygium surgery in terms of corneal irregularity.