Sublimation of Benign Conjunctival Nevi Using Plasma-Assisted Noninvasive Surgery: A Clinical Case Series.

Background: Conjunctival nevi (CN) are common benign ocular tumors. Given their low risk of malignancy, surgical removal of nevi is primarily requested by patients. Herein, we introduce Atmospheric Low-temperature Plasma (ALTP) as a novel noninvasive method for the removal of CN. Methods: A clinical case series was conducted from 2020 to 2021 at the Vision Health Ophthalmic Center in Tehran, Iran. CN in one of the eyes of seven patients was treated. In all patients, the benignity of CN was confirmed by ocular oncologists. The white handpiece of the Plexr device, which generates plasma with the lowest output, was used to apply plasma spots on the nevi. In addition, the Ocular Surface Disease Index (OSDI) questionnaire was completed by all patients before and six months after the treatment. Results: In all patients, the nevi outside the limbus area completely disappeared. The mean size of pre- and post-operative nevi was 3.89×11.7 and 0.54×1.69 mm, respectively. Results of the OSDI questionnaire showed significantly lower scores after the surgery in all patients. Conclusion: The ALTP method is a simple, cost-effective, and office-based surgery to remove CN safely and effectively.

The assessment of the concentration of candidate cytokines in response to conjunctival-exposure of atmospheric low-temperature plasma in an animal model.

BACKGROUND: Atmospheric Low-Temperature Plasma (ALTP) can be used as an effective tool in conjunctival cyst ablation, but little is known about how conjunctival ALTP-exposure affects the concentration of inflammatory mediators and also the duration of inflammatory responses. METHODS: We used 8 female adult Lewis rats that were followed up in 4 groups. The right eye of each rat was selected for the test, whereas the left eye was considered as a control. The ALTP was generated and used to target 3 spots of the conjunctiva. The digital camera examinations were performed to follow-up the clinical outcomes after ALTP exposure. Tear and serum samples were isolated-at 2 days, 1 week, 1 month, and 6 months after treatment-from each rat and the concentration of candidate pro-inflammatory (i.e. IL-1α, IL-2, IL-6, IFN-γ, and TNF-α) and anti-inflammatory cytokines (i.e. IL-4 and IL-10) were measured using flow cytometry. RESULTS: The external and digital camera examinations showed no ocular surface complications in all ALTP-exposed rats after 1 week. The analyses revealed that the ALTP transiently increases the concentration of pro-inflammatory cytokines-IL-1α and IL-2 in tear samples in 1 week and 2 days after exposure, respectively; no differences were observed regarding other pro- and anti-inflammatory cytokines in the tear or serum samples. CONCLUSIONS: ALTP can probably be used as a minimally-invasive therapeutic method that triggers no permanent or continual inflammatory responses. The results of this study might help the patients to shorten the consumption of immunosuppressive drugs, e.g. corticosteroids, that are prescribed to mitigate the inflammation after ALTP-surgery.

Safety evaluation of the atmospheric low-temperature plasma (ALTP) on the conjunctiva: an animal study and histopathological findings; 6-month follow-up.

BACKGROUND: Plasma medicine is an innovative research field focused on the application of atmospheric-pressure low-temperature plasmas (ALTP) for therapeutic purposes. Considering the potentials of plasma in ophthalmology, in this study, we evaluated the safety of plasma on the conjunctival tissue in animal models for 6 months. METHODS: Twelve adult male New Zealand albino rabbits were divided into four groups. The right eye of each rabbit was chosen for the test and the left eye was considered as the control. Experiments were performed using the Plexr device (GMV, Rocca Priora, RM, Italy). Four plasma spots were applied on the superior part of the conjunctiva (from 10 to 2 o'clock positions) using the continuous mode and a low power level (white handpiece) of the Plexr. For evaluation of the plasma safety, the histopathological changes were assessed 1 week (A), 1 month (B), 3 months (C), and 6 months (D) after the intervention. RESULTS: According to the histopathological findings, a mild decrease in blood vessels and severe stromal edema, as well as a superficial epithelium loss, were observed in group A. No chronic inflammation, scar tissue, deposition, and hemorrhage were found in group B. Epithelialization was confirmed by the histological examinations after 1 month. There was no evidence of atypia or dysplasia after 3 and 6 months. CONCLUSION: In conclusion, there were no persistent histopathological changes on conjunctival tissue after plasma exposure. Then, plasma can be considered as a minimally invasive alternative method for treating some ocular surface disorders.

A Novel Approach to Treatment of Conjunctival Cyst Ablation Using Atmospheric Low-Temperature Plasma.

PURPOSE: Introducing a new technique to remove the conjunctival cyst using atmospheric low-temperature plasma (ALTP) and assessing its effectiveness. PATIENTS AND METHODS: Five eyes with conjunctival cysts were included in this study. The procedure was started by applying a plasma spot on the highest point of the cyst, and then other spots were spirally applied to the base of the cyst to debulk it. The conjunctival cysts were removed using the white handpiece of the plasma generator device (Plexr, GMV s.r.l Grottaferrata, Italy). Refraction, visual acuity, intraocular pressure (IOP), contrast sensitivity (CS), aberrometry, dry eye tests, and ocular surface disease index (OSDI) questionnaire were measured before, one and six months after treatment. RESULTS: The mean size of the cysts was 3.6 mm (range 2.1 to 4.8 mm). No intraoperative and postoperative complications were observed. Postoperative examinations showed that the patients' cysts were completely healed and recurrence did not occur. Significant changes in visual parameters, IOP, CS, aberrometry and dry eye tests were not observed in the follow-up periods after treatment compared to before. OSDI score decreased after cyst removal. CONCLUSION: Our recommended technique using ALTP can be used as a new approach to treating conjunctival cysts. This technique is a simple, office-based, minimally invasive, effective and inexpensive way to remove a cyst.