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Completed

NCT Number: NCT07807436

Modified Soft Contact Lens During Vitrectomy

This study compared a modified soft contact lens with balanced salt solution irrigation during pars plana vitrectomy performed with a noncontact wide-angle viewing system. Participants requiring vitrectomy were randomly assigned to have the modified lens placed on the cornea throughout surgery or to receive intermittent balanced salt solution irrigation. The study evaluated whether the modified lens could maintain a clear surgical view and protect the corneal surface. Participants were followed for one month after surgery.

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Key information

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Xi'an First Hospital

Xi'an, Shaanxi, 710002, China

About this study

This prospective, randomized, parallel-group study enrolled patients with retinal diseases requiring pars plana vitrectomy at Xi'an First Hospital. All operations were performed by the same experienced vitreoretinal surgeon using a standard three-port procedure and the RESIGHT noncontact wide-angle viewing system. In the modified soft contact lens group, a silicone hydrogel corneal bandage lens modified to a diameter of 10.5 mm was placed after surgical draping and maintained throughout the operation. In the comparator group, balanced salt solution was applied intermittently to maintain corneal hydration and clarity.

Intraoperative assessments included total operative time, vitrectomy duration, frequency of corneal irrigation, and graded clarity of the surgical field. Corneal epithelial edema, fluorescein staining, tear film breakup time, and central corneal thickness were assessed before surgery and at 1 day, 1 week, and 1 month after surgery. Ocular surface symptoms were assessed using the Ocular Surface Disease Index before surgery and at 1 month.

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • Diagnosis of a retinal disease requiring pars plana vitrectomy.
  • Corneal endothelial cell density of at least 2,000 cells/mm².
  • No ocular surface disease or significant anterior-segment abnormality.
  • No ocular surgery or trauma within the previous month, except intravitreal anti-VEGF injection.
  • Considered suitable for ophthalmic surgery under routine clinical conditions.

Exclusion criteria

  • Refusal to participate or withdrawal from the study.
  • Syncope or inability to tolerate study examinations or surgery.
  • Incomplete study data.
  • Any condition judged by the investigator to interfere with corneal assessment, including corneal edema secondary to persistently elevated intraocular pressure.

Treatment and study plan

Modified Soft Contact Lens

Device

A 10.5-mm silicone hydrogel corneal bandage soft contact lens was placed on the corneal surface immediately after surgical draping and maintained throughout pars plana vitrectomy.

Balanced Salt Solution Irrigation

Other

Balanced salt solution was applied intermittently to the corneal surface as required during pars plana vitrectomy to maintain corneal hydration and surgical-field clarity.

Primary outcomes

  1. Intraoperative Clarity of the Surgical Field

    Time frame: During pars plana vitrectomy

    Surgical-field clarity was graded on a 4-point ordinal scale: 1, poor visibility requiring corneal epithelial scraping; 2, slightly unclear but permitting basic identification of retinal vessels and the optic disc; 3, clear enough for epiretinal membrane peeling; and 4, excellent visibility permitting delicate macular procedures.

Secondary outcomes

  1. Frequency of Corneal Irrigation

    Time frame: During pars plana vitrectomy

    Number of balanced salt solution applications used to maintain corneal hydration and clarity during surgery.

  2. Total Operative Time

    Time frame: During surgery

    Time in minutes from the start to the end of the surgical procedure.

  3. Vitrectomy Duration

    Time frame: During surgery

    Time in minutes from insertion of the first trocar to removal of the last trocar.

  4. Corneal Edema Grade

    Time frame: Preoperatively and at 1 day, 1 week, and 1 month after surgery

    Corneal edema assessed by slit-lamp microscopy on a 5-point ordinal scale from grade 0 (transparent cornea without edema) to grade 4 (milky edema with obscured intraocular structures).

  5. Corneal Epithelial Fluorescein Staining Score

    Time frame: Preoperatively and at 1 day, 1 week, and 1 month after surgery

    Each corneal quadrant was scored from 0 to 3 after fluorescein staining; quadrant scores were summed to give a total score from 0 to 12, with higher scores indicating greater epithelial injury.

  6. Tear Film Breakup Time

    Time frame: Preoperatively and at 1 day, 1 week, and 1 month after surgery

    Fluorescein tear film breakup time measured in seconds from the last blink to appearance of the first dark spot on the corneal surface.

  7. Central Corneal Thickness

    Time frame: Preoperatively and at 1 day, 1 week, and 1 month after surgery

    Central corneal thickness measured in micrometers using anterior-segment optical coherence tomography.

  8. Ocular Surface Disease Index Score

    Time frame: Preoperatively and at 1 month after surgery

    The 12-item Ocular Surface Disease Index was calculated on a 0-to-100 scale, with higher scores indicating more severe ocular surface symptoms.

Sponsors and collaborators

Lead sponsor

Northwest University First Hospital (Xi'an No.1 Hospital)

Other

Registry information

Official study title

Effect of a Modified Soft Contact Lens Combined With a Noncontact Wide-Angle Viewing System During Vitrectomy

Important dates

Study start
2022
Primary completion
2022
Study completion
2023
First posted
Sep 8, 2026
Registry last updated
Sep 8, 2026

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

View the official ClinicalTrials.gov record (opens in a new tab)

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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