Retinal Disease
Conditions
Keywords
Vitrectomy, Bandage Soft Contact Lens, Corneal Protection, Noncontact Wide-Angle Viewing System
Brief summary
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.
Detailed description
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.
Interventions
DEVICEModified Soft Contact Lens
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 was applied intermittently to the corneal surface as required during pars plana vitrectomy to maintain corneal hydration and surgical-field clarity.
Sponsors
Northwest University First Hospital (Xi'an No.1 Hospital)
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Healthy volunteers
No
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Intraoperative Clarity of the Surgical Field | 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
| Measure | Time frame | Description |
|---|---|---|
| Ocular Surface Disease Index Score | 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. |
| Frequency of Corneal Irrigation | During pars plana vitrectomy | Number of balanced salt solution applications used to maintain corneal hydration and clarity during surgery. |
| Total Operative Time | During surgery | Time in minutes from the start to the end of the surgical procedure. |
| Vitrectomy Duration | During surgery | Time in minutes from insertion of the first trocar to removal of the last trocar. |
| Corneal Edema Grade | 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). |
| Corneal Epithelial Fluorescein Staining Score | 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. |
| Central Corneal Thickness | Preoperatively and at 1 day, 1 week, and 1 month after surgery | Central corneal thickness measured in micrometers using anterior-segment optical coherence tomography. |
| Tear Film Breakup Time | 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. |
Countries
China
Outcome results
None listed