Clinical trial NCT03204084: Assessment of Low-temperature Plasma Surgery System in Pterygium With Fibrin Glue and Conjunctival Autografts
Official title: Assessment of Low-temperature Plasma Surgery System in Pterygium With Fibrin Glue and Conjunctival Autografts
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Pterygium
Keywords: pterygium,Low temperature plasma
Lead sponsor: Zhongshan Ophthalmic Center, Sun Yat-sen University
Sponsor class: OTHER
First posted: 2017-06-29
Enrollment: 56
Sex: ALL
Minimum age (years): 40
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_CONTROL
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Fifty-six patients participated in the study. The LTP group consisted of 28 patients (6men) with a mean age±SD of 58.79±1.65 years (range, 42-75 years). The control group consisted of 28 patients (9men) with a mean age±SD of 59.79±1.35 years (range, 41-80years). There were no significant differences in age, gender or eye.

Brief summary: Pterygium is a wing-shaped fibrovascular tissue that has proliferated onto the cornea. Ultraviolet radiation and hot, dusty, windy, dry, smoky environments are regarded as risk factors for pterygium . Surgical removal is the treatment of choice, and surgical wound intraoperative and inflammatory response postoperative have been considered two of the most significant factors that can increase the recurrence rate of pterygium. Low-Temperature Plasma Surgery System(LTP), avoids causing burn injuries to patients, has been introducing into minimally invasive surgery. The mechanism by which this equipment stop bleeding and abolish tissue is to directly occupy the injury with the formed blood clots, plasma flows close the vessel and plasma active particles cause physical and chemical reactions with tissue. The different levels of energy density of plasma can affect the bacteria, cells and cancer cells and even to death, therefore it is widely used in the disinfection of medical devices, dental root canal therapy, skin disease treatment and surgical wound disinfection. Whether it's possible to apply the advantages and benefits of plasma technology in ophthalmic surgery? Like pterygium surgery? However, there is no research to answer until now. In this study, the investigators retrospectively observed the efficacy, postoperative discomfort, inflammation, complications, and recurrence rates in a group of patients for whose LTP was used in pterygium excision and wound hemostasis. The investigators Observe the clinical benefits of LTP in pterygium surgery and find the facilitates and problems it need to be addressed reasonably.

Detailed description: About Plasma It's confirmed that there are 3 physical forms of material existence in human living environment. They are solids, liquids and gass. And any physical form can exist in different states due to the influence of environmental factors. Plasma is the fourth form of material existence. It's composed of ionized conductive gases, including six typical particles, which are electron, positive ion, negative ion, atom or molecule at excited state, atom or molecule at ground state, and photon. Plasma is composed of those positive and negative charged particles and neutral particles, and is a kind of quasi-neutrality gas with collective behavior. It's called plasma when the total negative electric charge equals to the total positive electric charge. 99% visible materials in universe may exist in plasma state, including fixed stars. Plasma can be natural or man-made. For example, the lighting during rainstorms is plasma phenomena, because the high voltage difference between cloud layer and ground makes the air ionized. And neon light and fluorescent lamp are from man-made plasma. The gases in light tube are ionized into plasma state.

About Plasma Low temperature plasma (LTP) Surgery System Low temperature plasma (LTP) Surgery System(made in Chengdu Mechan Electronic Technology Co.,Ltd), which avoids causing burn injuries to patients, has been introducing into minimally invasive surgery. The mechanism by which this equipment stops bleeding is to directly occupy the injury with the formed blood clots, and different from the mechanism of the common electrical hemostatic devices that cauterize the tissues around the bleeding to stem the blood flow. At the same the Plasma Low temperature plasma (LTP) Surgery System has a some biological effects, such as ablation of the organization, this ablation function is generally not penetrating, and only has effect on the contact surface,which can safely handle with the tissue wound and prevent the planting and recurrence.

Eligibility criteria: Inclusion Criteria:

* all cases are primary pterygium,a follow-up period of more than 3 months after surgery

Exclusion Criteria:

* no immunorelated disease, ocular surface disease, glaucoma, or eyelid disease. Patients with recurrent pterygium were excluded from the study.

Primary outcomes:
measure: The changes of Best-corrected visual acuity (BCVA),
timeFrame: Before surgery,1-day, 1-week, 1-month, 3-month
Secondary outcomes:
measure: The changes of Patient's subjective discomfort evaluated in terms of the ocular symptom scores(OSS)
timeFrame: Before surgery,1-day, 1-week, 1-month, 3-month
measure: conjunctival autograft inflammation
timeFrame: 1-day, 1-week
measure: The changes of the ocular surface inflammation assessed by the Oculus Keratograph○R5M (Oculus Optikgerate GmbH, Wetzlar, Germany), with temporal conjunctival hyperaemia index(TCHI)
timeFrame: Before surgery, 1-week, 1-month, 3-month
measure: The postoperative complications were examined, including dehiscence, dislocation, sclera wound healing defects, granuloma and high intraocular pressure
timeFrame: 1-week, 1-month, 3-month
measure: The recurrence
timeFrame: 3-month
measure: slit-lamp examination
timeFrame: Before surgery,1-week, 1-month
measure: determination of intraocular pressure
timeFrame: Before surgery, 3-month
measure: The changes of Patient's subjective discomfort evaluated in terms of the visual analogue scale(VAS) by a questionnaire method
timeFrame: Before surgery,1-day, 1-week, 1-month, 3-month
measure: The subconjunctival haemorrhage (SCH)
timeFrame: 1-day, 1-week
measure: graft stability according to scoring scale
timeFrame: 1-day, 1-week
Other outcomes:
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