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NCT Number: NCT03204084

Assessment of Low-temperature Plasma Surgery System in Pterygium With Fibrin Glue and Conjunctival Autografts

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.

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Key information

Conditions

Pterygium Conjunctival Diseases Eye Diseases

Age range

40 year–80 year

Sex eligibility

All sexes

Study type

Observational

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

Low-temperature Plasma Surgery System

Device

In pterygium surgery with fibrin glue(FG) and conjunctival autograft we use Low-temperature Plasma Surgery System(LTP)do the ablation of tissue and hemostasis.

Primary outcomes

  1. The changes of Best-corrected visual acuity (BCVA),

    Time frame: Before surgery,1-day, 1-week, 1-month, 3-month

    Non-contact ocular pressure measuring instrument

Secondary outcomes

  1. The changes of Patient's subjective discomfort evaluated in terms of the ocular symptom scores(OSS)

    Time frame: Before surgery,1-day, 1-week, 1-month, 3-month

    OSS including five kinds of subjective sensory scale of foreign body sensation, burning sensation, visual fatigue, dryness and eye pain.

  2. conjunctival autograft inflammation

    Time frame: 1-day, 1-week

    Inflammation Grade 0: No dilated corkscrew vessel in the graft Grade 1: 1 bright red, dilated corkscrew vessel crossing the graft-bed margin Grade 2: 2 bright red, dilated corkscrew vessels crossing the graft-bed margin Grade 3: three bright red, dilated corkscrew vessels crossing the graft-bed margin

  3. The changes of the ocular surface inflammation assessed by the Oculus Keratograph○R5M (Oculus Optikgerate GmbH, Wetzlar, Germany), with temporal conjunctival hyperaemia index(TCHI)

    Time frame: Before surgery, 1-week, 1-month, 3-month

    the ocular surface inflammation assessed by the Oculus Keratograph○R5M (Oculus Optikgerate GmbH, Wetzlar, Germany)

  4. The postoperative complications were examined, including dehiscence, dislocation, sclera wound healing defects, granuloma and high intraocular pressure

    Time frame: 1-week, 1-month, 3-month

    Digital slit-lamp photography was performed during each postoperative visit

  5. The recurrence

    Time frame: 3-month

    Digital slit-lamp photography was performed at 3-month

  6. slit-lamp examination

    Time frame: Before surgery,1-week, 1-month

    Corneal epithelium healing

  7. determination of intraocular pressure

    Time frame: Before surgery, 3-month

    Non-contact tonometer

  8. The changes of Patient's subjective discomfort evaluated in terms of the visual analogue scale(VAS) by a questionnaire method

    Time frame: Before surgery,1-day, 1-week, 1-month, 3-month

    Visual Simulation Scoring (VAS): The method is more sensitive and comparable. The specific approach is: on the paper to draw a 10 cm horizontal line, one end of the horizontal line is 0, that painless; the other end is 10, that pain; the middle part of the different degrees of pain. Let the patient according to self-feeling in the horizontal line on a mark, that the degree of pain

  9. The subconjunctival haemorrhage (SCH)

    Time frame: 1-day, 1-week

    Subconjunctival haemorrhage

  10. graft stability according to scoring scale

    Time frame: 1-day, 1-week

    Grade 0: None Grade 1: 25% of the size of the graft Grade 2: 50% of the size of the graft Grade 3: 75% of the size of the graft Grade 4: Haemorrhage involving the entire graft (no subconjunctival vessels visible

    Grade 4: >3 bright red, dilated corkscrew vessels crossing the graft-bed margin Graft stability Grade 0: All four sides of the graft margin are well apposed Grade 1: Gaping/displacement of one side of the graft-bed junction Grade 2: Gaping/displacement of two sides of the graft-bed junction Grade 3: Gaping/displacement of three sides of the graft-bed junction Grade 4: Graft completely displaced from the bed

Sponsors and collaborators

Lead sponsor

Zhongshan Ophthalmic Center, Sun Yat-sen University

Other

Registry information

Important dates

Study start
2016
Primary completion
2017
Study completion
2017
First posted
Jun 29, 2017
Registry last updated
Jun 29, 2017

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

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This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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