Transcriptomics and network analysis highlight potential pathways in the pathogenesis of pterygium.

Pterygium is a common ocular surface condition frequently associated with irritative symptoms. The precise identity of its critical triggers as well as the hierarchical relationship between all the elements involved in the pathogenesis of this disease are not yet elucidated. Meta-analysis of gene expression studies represents a novel strategy capable of identifying key pathogenic mediators and therapeutic targets in complex diseases. Samples from nine patients were collected during surgery after photo documentation and clinical characterization of pterygia. Gene expression experiments were performed using Human Clariom D Assay gene chip. Differential gene expression analysis between active and atrophic pterygia was performed using limma package after adjusting variables by age. In addition, a meta-analysis was performed including recent gene expression studies available at the Gene Expression Omnibus public repository. Two databases including samples from adults with pterygium and controls fulfilled our inclusion criteria. Meta-analysis was performed using the Rank Production algorithm of the RankProd package. Gene set analysis was performed using ClueGO and the transcription factor regulatory network prediction was performed using appropriate bioinformatics tools. Finally, miRNA-mRNA regulatory network was reconstructed using up-regulated genes identified in the gene set analysis from the meta-analysis and their interacting miRNAs from the Brazilian cohort expression data. The meta-analysis identified 154 up-regulated and 58 down-regulated genes. A gene set analysis with the top up-regulated genes evidenced an overrepresentation of pathways associated with remodeling of extracellular matrix. Other pathways represented in the network included formation of cornified envelopes and unsaturated fatty acid metabolic processes. The miRNA-mRNA target prediction network, also reconstructed based on the set of up-regulated genes presented in the gene ontology and biological pathways network, showed that 17 target genes were negatively correlated with their interacting miRNAs from the Brazilian cohort expression data. Once again, the main identified cluster involved extracellular matrix remodeling mechanisms, while the second cluster involved formation of cornified envelope, establishment of skin barrier and unsaturated fatty acid metabolic process. Differential expression comparing active pterygium with atrophic pterygium using data generated from the Brazilian cohort identified differentially expressed genes between the two forms of presentation of this condition. Our results reveal differentially expressed genes not only in pterygium, but also in active pterygium when compared to the atrophic ones. New insights in relation to pterygium's pathophysiology are suggested.

Postsurgery Classification of Best-Corrected Visual Acuity Changes Based on Pterygium Characteristics Using the Machine Learning Technique.

INTRODUCTION: Early detection of visual symptoms in pterygium patients is crucial as the progression of the disease can cause visual disruption and contribute to visual impairment. Best-corrected visual acuity (BCVA) and corneal astigmatism influence the degree of visual impairment due to direct invasion of fibrovascular tissue into the cornea. However, there were different characteristics of pterygium used to evaluate the severity of visual impairment, including fleshiness, size, length, and redness. The innovation of machine learning technology in visual science may contribute to developing a highly accurate predictive analytics model of BCVA outcomes in postsurgery pterygium patients. AIM: To produce an accurate model of BCVA changes of postpterygium surgery according to its morphological characteristics by using the machine learning technique. Methodology. A retrospective of the secondary dataset of 93 samples of pterygium patients with different pterygium attributes was used and imported into four different machine learning algorithms in RapidMiner software to predict the improvement of BCVA after pterygium surgery. RESULTS: The performance of four machine learning techniques were evaluated, and it showed the support vector machine (SVM) model had the highest average accuracy (94.44% ± 5.86%), specificity (100%), and sensitivity (92.14% ± 8.33%). CONCLUSION: Machine learning algorithms can produce a highly accurate postsurgery classification model of BCVA changes using pterygium characteristics.

Expression of Vitamin D Receptor and Vitamin D Receptor Gene Polymorphisms (BsmI, FokI, and TaqI) in Patients with Pterygium / Expressão do gene do receptor da vitamina D e de seus polimorfismos (BsmI, FokI e TaqI) em pacientes com pterígio

ABSTRACT Purpose: This study aimed to determine the role of vitamin D receptor in the pathogenesis of pterygium. The vitamin D receptor eexpression levels in pterygium tissue, blood vitamin D levels, and frequency of selected vitamin D receptor gene polymorphisms (BsmI, FokI, and TaqI) were compared between patients with pterygium and healthy participants. Methods: The study included patients with pterygiumeee (n=50) and healthy volunteers (n=50). The serum vitamin D levels were measured for both groups. Immunohistochemical staining for vitamin D receptor ewas performed on sections obtained from the pterygium and adjacent healthy conjunctival tissues of the same individuals. The genomic existence of vitamin D receptor epolymorphisms (BsmI, FokI, and TaqI) were analyzed in DNA obtained from venous blood of participants using polymerase chain reaction and restriction fragment length polymorphism methods. Results: There was no difference found between the serum vitamin D levels of patients with pterygium and healthy controls. However, tissue expression of vitamin D receptor was higher in the pterygium endothelial cells of micro-vessels (p=0.002), subepithelial stromal (p=0.04), and intravascular inflammatory cells (p=0.0001), in comparison with the adjacent healthy conjunctival tissue. Moreover, while the BBtt haplotype was 2-fold higher, the bbTt haplotype was 2.5-fold lower, and the BbTT haplotype was 2.25-fold lower in the control group than in the pterygium group (p<0.001). Conclusions: Vitamin D serum levels did not differ between the healthy and pterygium groups. Vitamin D receptor expression was increased in the pterygium tissue versus the adjacent healthy tissue. However, vitamin D receptor polymorphism analysis in patients with pterygium did not reveal any significant difference in BsmI, FokI, or TaqI polymorphisms in comparison with the healthy volunteers.(AU)

RESUMO Objetivo: Determinar o papel do receptor da vitamina D na patogênese do pterígio. Os níveis de expressão do receptor da vitamina D no tecido do pterígio, os níveis sanguíneos de vitamina D e a frequência de alguns polimorfismos do gene do receptor da vitamina D (BsmI, FokI e TaqI) foram comparados entre pacientes com pterígio e participantes saudáveis. Métodos: Foram incluídos pacientes com pterígio (n=50) e voluntários saudáveis (n=50). Os níveis séricos de vitamina D foram medidos em ambos os grupos. Foi feita uma coloração imuno-histoquímica para o receptor da vitamina D em cortes obtidos do pterígio e dos tecidos conjuntivais saudáveis adjacentes dos mesmos indivíduos. A existência de polimorfismos do receptor da vitamina D (BsmI, FokI e TaqI) no genoma foi analisada em DNA obtido do sangue venoso dos participantes, usando métodos de Polymerase chain reaction (PCR) e RFLP. Resultados: Não foi observada nenhuma diferença entre os níveis séricos de vitamina D dos pacientes com pterígio e os dos controles saudáveis. Entretanto, a expressão tissular do receptor da vitamina D foi maior nas células endoteliais dos microvasos do pterígio (p=0,002), nas células estromais sub-epiteliais (p=0,04) e nas células inflamatórias intravasculares (p=0,0001), quando comparada à expressão no tecido conjuntival saudável adjacente. Além disso, embora o haplótipo BBtt tenha sido duas vezes mais frequente, o haplótipo bbTt foi 2,5 vezes menos frequente e o haplótipo BbTT foi 2,25 vezes menos frequente no grupo de controle do que no grupo com pterígio (p<0,001). Conclusões: Os níveis séricos de vitamina D não apresentaram diferenças entre o grupo de pessoas saudáveis e o com pterígio. A expressão do receptor da vitamina D mostrou-se maior no grupo com pterígio do que no tecido saudável adjacente. Entretanto, a análise dos polimorfismos do receptor da vitamina D nos pacientes com pterígio não revelou qualquer diferença significativa nos polimorfismos BsmI, FokI ou TaqI em comparação com os voluntários saudáveis.(AU)

The Effect of a Novel Strategy in Treating Primary Pterygium: A Prospective Randomized Clinical Study.

OBJECTIVE: We sought to compare the efficacy and safety of conjunctival autograft (CAG), amniotic membrane transplantation (AMT) with postoperative interferon alfa-2b (IFN alfa-2b), and modified conjunctival autograft plus amniotic membrane transplantation (mCAG plus AMT) with postoperative IFN alfa-2b for primary pterygium. DESIGN: Randomized controlled clinical trial. METHODS: Eyes with nasal and primary pterygia were randomized in a 1:1:1 ratio to receive CAG, AMT with IFN alfa-2b, or mCAG plus AMT with IFN alfa-2b. Subjects were followed up for 12 months. Primary outcomes included recurrence rate and complications. Secondary outcomes included corneal epithelium status, ocular surface symptom score, and visual acuity change. RESULTS: Eighty-five subjects (30 in the CAG group, 25 in the AMT group, and 30 in the CAG+AMT group) completed the 12-month follow-up. No complication or grade 4 recurrence was found. There was no significant difference among the 3 groups in recurrence grade, corneal epithelium status, and visual acuity change. Compared with mCAG+AMT, CAG has a negative effect (ß = -0.62, P = .001), and AMT has a negative effect (ß = -2.02, P < .001) on postoperative symptom scores. Compared with AMT, CAG has a positive effect (ß = 1.28, P < .001) on postoperative symptom scores. CONCLUSIONS: All 3 strategies had good safety and clinical efficacy in the study. Compared with conjunctival autograft, the 2 surgeries using no autograft or limited autograft was less traumatic and gave more flexibility for future ocular surface condition changes.

Long-Term Results of P.E.R.F.E.C.T. for PTERYGIUM.

PURPOSE: To identify the recurrence rate, complication rate, cosmetic results, and patient satisfaction after P.E.R.F.E.C.T. for PTERYGIUM more than 10 years after surgery. METHODS: This is a prospective cohort study with 312 patients (351 surgeries). All patients underwent pterygium removal using P.E.R.F.E.C.T. for PTERYGIUM in 1 eye or both eyes by the author. The main parameters studied were recurrence rate, complication rate, esthetic outcomes, and patient satisfaction. RESULTS: Two hundred twenty-nine patients (77% of surviving cohort group) were able to be followed up with 16 patients deceased. The basic biographical data of the group followed up and those lost to follow-up were not different. The follow-up period was 153 ± 20 months. Twenty-five percent of the surgeries were for recurrent pterygia. The recurrence rate was zero, and there were no serious complications. Ninety-four percent of patients were graded as having normal or excellent cosmetic appearance by the surgeon, and 95% of the patients graded the appearance of their eye as greater than 8 of 10. Ninety-four percent of the patients gave more than 8 of 10 as their satisfaction with the service and surgery. CONCLUSIONS: P.E.R.F.E.C.T. for PTERYGIUM provides long-term and stable results for primary and recurrent pterygium patients with a zero recurrence rate and excellent cosmetic appearance of the eye and no serious complications. P.E.R.F.E.C.T. for PTERYGIUM should be considered as the standard by which other pterygium surgeries should be compared. Cosmetic outcomes after pterygium surgeries are now a more sensitive measure of success than recurrence rate alone.

Systematic Review: Effects of Pterygium and Pingueculum on the Ocular Surface and Efficacy of Surgical Excision.

PURPOSE: This systematic review examines the specific effects of pingueculum and pterygium on the ocular surface and evaluates the efficacy of surgical excision in reversing those effects. METHODS: A systematic review was performed according to the Preferred Reporting Items for the Systematic Review and Meta-Analyses statement and included 59 articles studying the effects of pterygium and pingueculum on the ocular surface as measured by tear break-up time (TBUT), Schirmer testing, tear osmolarity, Ocular Surface Disease Index (OSDI), and the effects of surgical removal on these ocular surface parameters. RESULTS: In most studies, eyes with pterygium or pingueculum when compared with control eyes had a statistically significantly lower TBUT (average 3.72 s), lower Schirmer I without anesthesia (average 3.01 mm), lower Schirmer II (average 4.10 mm), higher tear osmolarity (average 12.33 mOsm/L), and higher OSDI (average 6.82 points). Moreover, excision of pterygium and pingueculum led to a statistically significantly higher TBUT (average 3.15 s higher at 1 mo postexcision), lower tear osmolarity (average 3.10 mOsm/L lower at 3 mo postexcision), and lower OSDI score (average 2.86 points lower 1 mo postexcision) in most of the studies. The effect of excision on Schirmer test scores was equivocal because most studies did not reach significance. CONCLUSIONS: Our data confirm the relationship between pterygium and pingueculum and abnormal tear function and symptoms of dry eye disease. Furthermore, the data suggest that tear film parameters might improve after surgical removal of pterygium or pingueculum. Future studies would be helpful in exploring the potential role of pterygium and pingueculum excision in the management of dry eye disease.

Outcomes of Ipsilateral Simple Limbal Epithelial Transplantation, Tenonectomy, Mitomycin and Amniotic Membrane Transplantation for Treatment of Recurrent Pterygium.

PURPOSE: To report on the outcomes of recurrent pterygium treated by ipsilateral simple limbal epithelial transplantation (SLET), mitomycin, tenonectomy, and amniotic membrane transplantation. METHODS: A retrospective, interventional study was conducted including all patients with recurrent pterygium who underwent SLET surgery under a single surgeon using ipsilateral donor tissue with a minimum 6-month follow-up at Toronto Western Hospital, Canada. Outcome measures included the following: recurrence rates, best spectacle-corrected visual acuity, and postoperative complications. RESULTS: Ten eyes of 10 patients, aged 60.7 ± 18.5 years (range 23-79) with a mean follow-up time of 15.2 ± 10.0 months of which 50% (n = 5) were men, were included. Eight eyes (80%) had a history of 2 or less pterygium operations. Two patients had 3 and 5 previous pterygium operations, respectively. Concurrent limbal stem cell disease was noted in 6 eyes (60%). Average number of pterygium recurrences per eye was 1.9 ± 1.3 (range 1-5). Mean pre-op best-corrected visual acuity was 0.5 LogMAR (Snellen equivalent 20/60, range 20/20 to counting fingers). Best-corrected visual acuity remained the same or improved in 6 eyes (60%). Recurrence was noted in 1 eye (10%) with a history of 5 previous pterygium excisions and remained stable at the last follow-up. No patients required a second operation. CONCLUSIONS: Ipsilateral SLET with mitomycin, tenonectomy, and amniotic membrane transplantation is a novel technique to address recurrent pterygium. Concurrent limbal stem cell diseases are often present. Initial results demonstrate low recurrence. Visual improvement is modest. Stabilization of the ocular surface to improve vision is possible.

Evaluation of the Safety and Efficacy of a Low-Temperature Plasma Surgical System for Pterygium.

PURPOSE: Surgical excision is the standard treatment for pterygium. This study was conducted to evaluate the safety and efficacy of a novel technique using low-temperature plasma (LTP) for excision and hemostasis in pterygium surgery. METHODS: A prospective, comparative, and randomized clinical trial was conducted on 60 patients (60 eyes) undergoing pterygium excision with conjunctival autografts using fibrin glue. Patients were equally divided into the following 2 groups: a control group and a LTP group. Postoperative follow-up visits were scheduled on day 1, week 1, and months 1 and 3, and recurrence was evaluated at 1 year. Patients were examined for operative time, best corrected visual acuity, conjunctival autograft inflammation (CAI), graft stability (GS), pain, recurrence, and final appearance. Factors related to pterygium recurrence and final appearance were analyzed. RESULTS: Mean operative times were shorter in the LTP group (16.7 ± 3.4 min) than those in the control group (20.1 ± 4.7 min, P = 0.002). LTP eyes had milder CAI than control eyes at postoperative day 1 (P = 0.000) and week 1 (P = 0.000). Patients in the LTP group exhibited better GS (P = 0.01) and milder pain (P = 0.04) than those in the control group on day 1. Two control patients (6.7%) and no (0%) LTP patients experienced recurrence (P = 0.08). GS and CAI were the significant factors contributing to recurrence (GS: R = 0.425, P = 0.001; CAI: R = 0.309, P = 0.016). CONCLUSIONS: LTP to replace surgical blades and disposable cautery for ablation and hemostasis is safe and efficient for pterygium surgery, resulting in shorter operative time, milder inflammation, and better graft stability without increasing complication risk.

BMP6 Regulates Corneal Epithelial Cell Stratification by Coordinating Their Proliferation and Differentiation and Is Upregulated in Pterygium.

Purpose: Proper balance between cell proliferation and differentiation is essential for corneal epithelial (CE) stratification and homeostasis. Although bone morphogenetic protein-6 (BMP6) is known to be expressed in the CE for over 25 years, its function in this tissue remains unknown. Here, we test the hypothesis that BMP6 promotes CE cell stratification and homeostasis by regulating their proliferation and differentiation. Methods: We employed postnatal day-12 (PN-12), PN-14, PN-20, and PN-90 mouse eyes; human corneal limbal epithelial (HCLE) cells; and ocular surface fibrovascular disease pterygium tissues to evaluate the role of BMP6 in CE proliferation, differentiation, and pathology by RT-qPCR, immunoblots, and/or immunofluorescent staining. Cell proliferation was quantified by immunostaining for Ki67. Results: Coincident with the mouse CE stratification between PN-12 and PN-20, BMP6 was significantly upregulated and the BMP6 antagonist Noggin downregulated. Mature CE retained high BMP6 and low Noggin expression at PN-90. BMP6 and its receptors BMPR1A and BMPR2 were upregulated during in vitro stratification of HCLE cells. Consistent with its anti-proliferative role, exogenous BMP6 suppressed HCLE cell proliferation, downregulated cyclin-D1 and cyclin-D2, and upregulated cell-cycle inhibitors Krüppel-like factor 4 (KLF4) and p21. BMP6 also upregulated the desmosomal cadherins desmoplakin and desmoglein in HCLE cells, consistent with its pro-differentiation role. Human pterygium displayed significant upregulation of BMP6 coupled with downregulation of Noggin and cell-cycle suppressors KLF4 and p21. Conclusions: BMP6 coordinates CE stratification and homeostasis by regulating their proliferation and differentiation. BMP6 is significantly upregulated in human pterygium concurrent with downregulation of Noggin, KLF4, and p21.

Femtosecond Laser-assisted Preparation of Conjunctival Autograft for Pterygium Surgery.

Femtosecond laser-assisted conjunctival autografts (CAG) preparation was recently proposed. This study reports the outcomes of the first clinical trial on the use of laser to prepare CAG in pterygium surgery, and to compare the outcomes with those of manual technique. Forty eyes undergoing primary pterygium excision with laser-assisted CAG transplantation were prospectively included (L group). Two historical matched cohorts whose CAGs were prepared manually were compared (n = 78 eyes by the same experienced surgeon, M group; n = 78 eyes by trainees; TM group). We found the laser-created CAGs had only 11 µm deviation from the targeted thickness. The best-corrected visual acuity improved, and the astigmatism significantly decreased after surgery, with comparable efficacy across 3 groups. The 1-year recurrence rate was 2.5%, 3.8% and 7.7% in the L, M and TM groups, respectively (P = 0.12). There was no significant difference between the L and M groups in the complication rate (5.0% and 1.3%, respectively), surgical time (19.4 ± 5.1 and 19.1 ± 6.2 minutes, respectively), and postoperative discomfort scores (0.1 ± 0.3 and 0.2 ± 0.3, respectively), but these outcomes were significantly less favorable in the TM group. The results of this first comparative clinical trial suggest that femtosecond laser-assisted CAG preparation can be considered as an alternative technique for CAGs preparation.

Management of primary pterygium with intra-lesional injection of 5 flurouracil and bevacizumab (Avastin).

BACKGROUND: To assess the efficacy of combined 5FU and Avastin injections in the treatment of primary pterygium METHODS: Sixteen eyes with primary pterygium received intralesional 5 fluorouracil and Avastin (2.5-5 mg) injections every 2 weeks for a maximum of five injections. Fourteen eyes of 14 patients received five injections, one eye received three injections and one eye received two injections. All eyes were followed at monthly intervals for 3 months after last injection. Tissue was obtained by surgical excision of primary pterygium from four eyes who received injections and three eyes with primary pterygium who did not receive injections (control) and subjected to immunohistological examination for beta fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), von-Willebrand factor (vWF), lymphatic vessel endothelial hyaluronan receptor (LYVE-1) and collagen-I. RESULTS: Pterygium progression was arrested in all patients. Sixty-two percent of patients had improvement of redness while 89% had reduced thickness of the lesion. VEGF, bFGF, EGF, vWF, LYVE-1 and collagen-I were all reduced in the injected samples. CONCLUSIONS: The injection of 5 fluorouracil and Avastin act synergistically to arrest progression and induce atrophy in primary pterygium. This is related to the effect of agents on fibroblasts, collagen, and vascular tissues. Such medical intervention is a safe and viable option in the management of primary pterygium though excision of residual tissue is still required in some cases. Longer follow up is needed to ascertain whether this will reduce the recurrence rate following excision.

Optical Coherence Tomography Angiography for Evaluation of Reperfusion After Pterygium Surgery.

PURPOSE: To describe the use of optical coherence tomography angiography (OCTA) to quantitatively monitor the conjunctival graft revascularization after pterygium excision and conjunctival autograft (CAG) transplantation. DESIGN: Prospective, interventional case series. METHODS: Ten patients undergoing pterygium excision and femtosecond laser-assisted CAG transplantation were included. OCTA was performed at 1 week, 1 and 3 months postoperatively at the CAG transplantation site and harvested area. The vessel density at three different depths: conjunctival epithelium or CAG epithelium, conjunctival stroma or CAG stroma, and episclera, was evaluated and quantified. The revascularization rate was assessed and correlated with the postoperative CAG thickness. RESULTS: No intraoperative and postoperative complications occurred. Reperfusion of the CAGs was observed at 1 week, and early reperfusion within the first month accounted for more than half of graft revascularization. The vessel regrowth density was 9.6±2.6 % and 11.1±2.8 % between 1 week and 1 month, and was 9.8±1.8 % and 11.9±1.9 % between 1 and 3 months, at the CAG and underlying episcleral levels, respectively. All the CAGs were well-perfused at 3 months. The vessel regrowth density was significantly and strongly correlated with the changes of CAG thickness in a negative relationship (γ = -0.94, P = 0.019). At the harvested site, the vascular network of episclera was not affected, and the conjunctival vascularization was restored at 1 month. CONCLUSIONS: OCTA is a promising tool to evaluate the vascularization or revascularization of conjunctiva, conjunctival graft and episclera, in a quantitative and serial manner, helping in diseases diagnosis and treatment monitoring. The graft revascularization rate was predictive of postoperative graft deswelling.

EFFECT OF SUN EXPOSURE DURATION ON CYCLOOXYGENASE-2 EXPRESSION IN THE CONJUNCTIVA.

Pterygium is a multifactorial proliferative pathologic change of bulbar conjunctiva. The purpose of this study was to determine the effect of the duration of exposure to solar radiation (expressed in years) on the incidence of positive cyclooxygenase-2 (COX-2) finding in conjunctival tissue in two groups of patients. Group 1 consisted of 68 patients with primary pterygium having undergone conjunctival autograft transplantation. Group 2 consisted of 43 patients with morphologically unchanged conjunctivae that were harvested during cataract surgery. All 111 specimens were submitted to immunohistochemical staining for monoclonal COX-2 antibody (1:100; M361701 MO A-HU, Dako, Santa Clara, California, USA). The immunostaining intensity in the surface epithelium was scored using the following grading system: 0 no immunostaining; + weak immunostaining (few cells being positive focally or scattered); ++ medium immunostaining; and +++ strong immunostaining (diffuse staining throughout the tissue). The analysis of COX-2 activity yielded 29 (42.6%) positive findings in group 1 and 27 (62.8%) positive findings in group 2. Group 2 consisted of statistically significantly older individuals with a history of considerably longer sun exposure. Statistical analysis proved the duration of exposure to solar radiation to be the most important factor in positive COX-2 findings.

Therapeutic contact lenses vs. tight bandage patching and pain following pterygium excision: a prospective randomized controlled study.

PURPOSE: The immediate postoperative management of patients undergoing pterygium excision usually includes eye patching in order to alleviate pain and prevent accidental tissue damage. Commonly applied tight patching with gauze bandages results in decreased field of monocular vision and discomfort. The aim of this study was to evaluate the patient-centered outcome of pterygium surgery when therapeutic contact lenses (TCL) are used instead of tight bandage patching in the first 24 postoperative hours. METHODS: Prospective randomized controlled study. Sixty patients with primary pterygium who underwent pterygium surgery consisting of conjunctival autografting with 10-0 Vicryl sutures were randomized into two groups, bandaged with TCLs and tight bandage patching. MAIN OUTCOME MEASURES: Degree of pain on an 0-10 scale, use of pain killers, level of patient discomfort, sleep quality, and visual acuity (VA). RESULTS: Sixty patients were studied. The pain level and pain duration during the first postoperative day was significantly lower in the tight bandage patching group compared with the TCL group (P = 0.034, P = 0.04 respectively). Sleep quality was significantly poorer in the TCL group (P = 0.004). The VA on the first postoperative day was similar for the two groups. CONCLUSIONS: The application of TCL in the first 24 h after pterygium surgery resulted in more discomfort and pain and decreased quality of sleep compared with tight bandage patching. Despite the limitation in monocular vision and the inconvenience of gauze bandages, they are preferred over TCL for alleviating pain following pterygium surgery.

Ocular Human Papillomavirus Infections.

CONTEXT: - Human papillomavirus (HPV) has a well-known role in the pathogenesis of squamous cell carcinoma and precursor lesions of the cervix, anogenital region, and head and neck, but its role in the development of squamous neoplasms of the eye, particularly the conjunctiva, remains unclear. OBJECTIVE: - To review recent evidence implicating HPV in the pathophysiology of ocular lesions. DATA SOURCES: - Published articles obtained from a PubMed search of the English literature were the primary sources for this review. CONCLUSIONS: - The low-risk HPV types 6 and 11 appear to play a role in the development of at least a subset of conjunctival squamous papillomas. The role of HPV in the pathogenesis of pterygium and ocular surface squamous neoplasia is less well defined. There is evidence to suggest that HPV may be a cofactor in the development of these lesions, acting in concert with ultraviolet radiation and/or human immunodeficiency virus infection in a subgroup of cases.

[Pterygium surgery by conjunctiva autograft with autologous blood fixation]. / Chirurgie du ptérygion avec greffe de conjonctive fixée par du sang autologue.

INTRODUCTION: Pterygium surgery is marked by the possibility of recurrences; one of the techniques which results in the least recurrences is conjunctival autograft. Fixation of the conjunctiva had traditionally been accomplished with sutures. In recent years, conjunctival grafting has also been performed with fibrin glue. Even more recently, with a view towards improving the quality of postoperative results, some surgeons recommend the use of autologous blood. This study aims to evaluate the stability of this latest method of graft fixation, while assessing its postoperative results. METHODOLOGY: After diagnosis of pterygium, the patients underwent pterygium surgery with a conjunctival graft fixated with autologous blood. They were then monitored for one year, at 24h postoperatively, then seven days, 15 days, one month 3months, and every 3months thereafter. RESULTS: In totl, 84.21 % of the patients demonstrated stable postoperative fixation; 5.26 % of patients experienced significant displacement of the graft. After one year of follow-up, 15.79 % of patients experienced recurrent pterygium. Recurrences were more frequent in younger patients and in patients with previous recurrence. CONCLUSION: Pterygium surgery by conjunctival graft fixated with autologous blood is a safe surgery, with results similar to other pterygium surgery techniques with conjunctival autograft. However, this technique has the advantage less irritation, no risk of transmitting infection and lower cost.

Caracterización clínica e histopatológica del pterigion primario / Clinical and histopathologic characterization of the primary pterigion

Fundamento: el pterigion es una lesión tumoral benigna de causa multifactorial, con proliferación de la conjuntiva y crecimiento fibrovascular hacia la córnea más común en climas cálidos. Puede ser primario o recidivante de acuerdo al nivel y de acuerdo al nivel de invasión corneal se describen IV grados. Es una masa de tejido subepitelial con degeneración elastótica, sobre un fondo de degeneración hialina, neovasos y cambios inflamatorios, el epitelio que lo cubre puede mostrar acantosis, disqueratosis y displasia; y con estas características se tipifica en: angiomatosos, fibrosos y mixtos. Objetivo: identificar las características clínicas e histopatológicas en pacientes operados de pterigion primario.Métodos: estudio descriptivo transversal, en el Hospital Militar Clínico Quirúrgico Docente Dr. Octavio de la Concepción y de la Pedraja desde septiembre hasta diciembre de 2016, el universo lo constituyeron 77 pacientes operados. Resultados: el mayor número de enfermos tenían entre 40 a 59 años del sexo femenino y europoides. Fue más frecuente el grado de invasión corneal III, seguido por el II y el IV. En las muestras examinadas se informó hiperplasia epitelial, degeneración hialina y elastótica, displasia ligera, estructuras vasculares asociadas o no a otros cambios fibrosos, células caliciformes en el epitelio, inflamación crónica y depósito de pigmentos y el pterigion de tipo fibroso predominó sobre el fibroso y al angiomatoso. Conclusiones: se tuvo en cuenta que el pterigion es una enfermedad que incide con gran frecuencia en la población cubana, el estudio de sus características clínicas e histopatológicas es vital para las buenas prácticas oftalmológicas. El resultado del estudio histopatológico fue similar a los descritos por otros autores, su histopatología se manifiesta como un tejido benigno de la conjuntiva(AU)

Blackground: pterygium is a tumoral lesion of benign behavior and multifactorial ethiology, where conjunctive proliferates with fibro vascular growing and it invades cornea in warmer climates. It can be primary or recidivant and according to the level that reaches the corneal invasion four grades are described. It is a mass of subepitelial tissue with elastotic degeneration, on a bottom of hyaline degeneration, new blood vessels and inflammatory changes, the epithelium that covers it can show acanthosis, dyskeratosis and dysplasia. Taking into account these characteristics, it is classified as angiomatous, fibrous and mixed.Objective: to identify clinical and histopathologic characteristics in operated patients of primary pterygium.Methods: a descriptive, transverse study was carried out in the Educational Surgical Hospital Dr. Octavio de la Concepción y de la Pedraja in Camagüey from September to December 2016. The universe was constituted by 77 operated patients.Results: the biggest number of sick persons was among 40 to 59 years of age, and those studied were white. According to the grade of corneal invasion the biggest frequencies were for grade III, followed by grade II and grade IV. In the examined samples epithelial hyperplasia was informed, hyaline and elastotic degeneration, slight dysplasia, vascular structures associated or not to other fibrous changes, chaliciforms cells in the epithelium, chronic inflammation and deposit of pigments. Pterygium of fibrous type prevailed over the fibrous one and on the angiomatous.Conclusions: keeping in mind that the pterigion is an illness that impacts with great frequency in the Cuban population, the study of its clinical and histopathologic characteristics is vital for good ophthalmologic practices The result of the histopathologic study was similar to those described by other authors. Its histopathology continues showing as a benign tissue of the conjunctiva(AU)

Detection of increase in corneal irregularity due to pterygium using Fourier series harmonic analyses with multiple diameters.

PURPOSE: To determine steep increase of corneal irregularity induced by advancement of pterygium. METHODS: A total of 456 eyes from 456 consecutive patients with primary pterygia were examined for corneal topography and advancement of pterygium with respect to the corneal diameter. Corneal irregularity induced by the pterygium advancement was evaluated by Fourier harmonic analyses of the topographic data that were modified for a series of analysis diameters from 1 mm to 6 mm. Incidences of steep increases in the asymmetry or higher-order irregularity components (inflection points) were determined by using segmented regression analysis for each analysis diameter. RESULTS: The pterygium advancement ranged from 2% to 57%, with a mean of 22.0%. Both components showed steep increases from the inflection points. The inflection points in the higher-order irregularity component altered with the analysis diameter (14.0%-30.6%), while there was no alternation in the asymmetry components (35.5%-36.8%). For the former component, the values at the inflection points were obtained in a range of 0.16 to 0.25 D. CONCLUSION: The Fourier harmonic analyses for a series of analysis diameters revealed that the higher-order irregularity component increased with the pterygium advancement. The analysis results confirmed the precedence of corneal irregularity due to pterygium advancement.

Corneal tomography and biomechanics in primary pterygium.

PURPOSE: To study the Scheimpflug's imaging and corneal biomechanics in primary pterygium. METHODS: A prospective observational study of 55 patients with unilateral primary nasal pterygium was done. The normal fellow eyes of patients with pterygium were taken as controls. Clinical parameters noted included visual acuity, values of corneal curvature by doing Scheimpflug imaging, wavefront aberrations in terms of higher and lower-order aberrations and corneal hysteresis (CH) as well as corneal resistance factor (CRF) values by using ocular response analyzer. RESULTS: Of the total 55 patients, mean age was 43.0 + 11.4 years (range: 20-72 years). Mean LogMar uncorrected visual acuity in pterygium eyes and control eyes was 0.21 + 0.20 and 0.12 + 0.15, respectively (p = 0.016). On Scheimpflug imaging the mean anterior corneal curvature values (Ka1/Ka2 D) were 41.09 + 3.38/44.33 + 2.29 in pterygium eyes, 43.13 + 1.79/43.98 + 2.17 in control eyes (p < 0.0005) and mean posterior corneal curvature (Kp1/Kp2 D) values were 6.14 + 0.39/6.53 + 0.43 in pterygium eyes and 6.13 + 0.28/6.46 + 0.47 in control eyes (p > 0.05). Analysis of corneal aberrations showed significantly higher corneal wavefront aberrations in pterygium eyes. Highest correlation of corneal astigmatism was noted with corneal area encroached by pterygium (ρ = 0.540 for LOA and 0.553 for HOA) and distance from pupillary center (ρ = 0.531 for LOA and 0.564 for HOA). Corneal biomechanical parameters including CH and CRF were found to be lower in the pterygium eyes, though not statistically significant (p value 0.60 and 0.59, respectively). CONCLUSION: Pterygium leads to deterioration of visual performance not only by causing refractive and topographic changes but also by causing a significant increase in corneal wavefront aberrations.

Comparison of Different Measurement Tools and Dimensional Parameters of Pterygium to Investigate its Impact on Refractive Indices and Ocular Aberrations.

OBJECTIVES: The aim of this study was to compare different measurement tools and parameters, including a new computer-assisted image processing technique for the quantitative analysis of the percentage of pterygium on the corneal surface, horizontal/vertical lengths obtained using slitlamp beam and surgical compass. METHODS: A total of 21 pterygia of 17 patients were included in the study. The pterygia were measured by three different methods: a slitlamp beam, a surgical compass, and a new computer-assisted image processing method. Refractive indices and higher-order aberrations were analyzed in all cases. RESULTS: The new computer-assisted image processing technique revealed excellent intraclass correlation coefficients for intraobserver and interobserver reliability (0.999 and 0.995, respectively). However, horizontal and vertical lengths revealed more deviation between the measurements obtained with slitlamp beam and surgical compass. Although uncorrected visual acuity did not show any significant correlation between horizontal and vertical lengths of pterygia measured by either slitlamp beam or surgical compass, it was correlated with the digital pterygium ratio (rho, 0.462; P=0.035). All ocular aberration (total, higher-order, coma, trefoil, quatrefoil, spherical, and higher-order astigmatism) Root-mean-square values more strongly correlated with higher percentage values of pterygium that covers the cornea, measured by the new computer-assisted image processing technique. CONCLUSION: The percentage of pterygium covering the corneal surface seems to be more associated with the pterygium-related visual disturbances than with horizontal and vertical lengths measured by conventional techniques. Moreover, the new computer-assisted image processing technique can accurately and reliably measure the percentage extension of pterygium on cornea.