View clinical trials related to Pterygium.
Filter by:Corneal disease is a leading cause of blindness in the world. A shortage of corneal donor tissue has prevented many patients from regaining vision. Additionally, refractive error such as myopia is a major cause of impaired visual function worldwide. Although refractive error is correctable by procedures that modify the refractive power of the cornea, these procedures often weaken corneal integrity and have risk of complications. This study aims to evaluate the safety and efficacy of corneal surface epithelium repair and regeneration in the treatment of corneal surface diseases and refractive error using autologous limbal stem cell transplantation.
The purpose of this randomized multi-center clinical trial is to compare the efficacy and safety of intraoperative mitomycin C(MMC),amniotic membrane transplantation(AMT) and Conjunctival Autograft(CAG) for primary pterygium surgery. The investigators will also evaluate particular risk factors related to pterygium recurrence.
Currently, due to the advantage of noninvasive, localized, rapid, painless and easily repeatable of impression specimens, the technique is an ideal method of investigating ocular surface disorders when the diagnosis is not clinically obvious or detecting the post-operative change without tissue damage. Using impression cytology for primary diagnosis and follow-up of ocular surface squamous neoplasia, including after therapy with topical mitomycin C has been well-studied. [29]. In addition to the applications described above, pterygium is another disease of interest. Pterygium, a common disease of ocular surface, has high recurrence rate after surgical excision. [30-33] However, the exact etiology and mechanism for recurrence is unknown. A transformation of the phenotypic characteristics of the conjunctival fibroblasts may play an important role. Due to the concern of improvement in treatment, it is important to explore the change of cytomorphology after pterygium operation, to identify the risk factors of developing recurrence, and, furthermore, to clarify the etiology and mechanism. Some ophthalmologists may think this procedure too time-consuming to be a routine examination in outpatient clinics. [34] However, National Taiwan University Hospital (NTUH), as one of the largest tertiary medical centers in Taiwan, is now in charge of a big part of difficult cases of ocular surface. With the need of further precise diagnosis and delicate clinical skills, the investigators are competent for this meaningful program.
The purpose of this study is to evaluate that intralesional injection of bevacizumab on primary pterygium can reduce the corneal pterygium area, inflammation, redness and other symptoms.
The purpose of this study is to determine if there is any difference in the surgical time when the surgery is performed with a graft taken from under the upper lid versus lower lid. The investigators will also be recording the level of pain felt by patients after surgery, any difficulties during or after surgery, and if the pterygium grows back.
The purpose of this study is to determine if patching the eye or a bandage contact lens along with Tylenol #3 is more effective for pain control following pterygium surgery.
Ranibizumab, an effective antineovascular drug, will be studied for safety and efficacy in pterygium, a neovascular disorder of the ocular surface.
Purpose of this study is to evaluate efficiency and safety of Alcohol 20% for peeling pterygium and to compare 3 different methods of operative wound closure: Bare sclera, Sliding flap, Amniotic membrane + biological glue
Pterygium is known to induce with-the-rule astigmatism. The corneal curvature along the long axis of the pterygium body is flattened. The excision of pterygium will result in steepening of the cornea and reduction of astigmatism. Therefore, the effect of pterygium excision on intraocular lens (IOL) power calculation has been examined in our previous study. The study confirmed that pterygium can cause alteration of IOL power. The determination of IOL power for cataract surgery is usually calculated from IOL formula called SRK II formula. IOL power = A - (2.5 x AL)-(0.9 x K). Variable A denotes the A-constant of the intraocular lens which is dependent on the IOL material and refractive index. Other variables for input include axial length (AL) and keratometry (K). A larger K reading will result in a lower estimated IOL power and vice versa. Previous studies have documented simultaneous cataract and pterygium operation resulted in reasonable visual outcome without adjustment of IOL power. With the presence of a pterygium, the cornea is flattened and lead to a reduction of K value and over-estimation of calculated IOL power. This randomized controlled trial is designed to compare the refractive outcomes of sequential and simultaneous pterygium and cataract operation. Pterygium excision should be done with various adjuvant therapies to minimize recurrence. Our previous studies reliably demonstrated limbal conjunctival graft and mitomycin C were effective methods to achieve low pterygium recurrence. We use limbal conjunctival autograft as the adjuvant therapy in the current study because this method is safer to be performed either alone or in combination with phacoemulsification. We avoid using mitomycin C as the adjuvant therapy in order to minimize the possibility of intraocular toxicity due to seepage.
The purpose of this study is to determine whether the ologen (OculusGen) Collagen Matrix are effective and safe to implant as an aid of glaucoma surgery and pterygium excision surgery.