Case Series Study - Volume 2 - Issue 3

Evaluation of plasma-assisted noninvasive surgery (PANIS) effect on punctal occlusion after multiple consecutive treatments; A clinical case series

Farhad Nejat* ; Khosrow Jadidi; Shima Eghtedari; Nazanin-sadat Nabavi

Vision health research center, Tehran, Iran.

Received Date : Apr 13, 2022
Accepted Date : May 26, 2022
Published Date: Jun 10, 2022
Copyright:© Farhad Nejat 2022

*Corresponding Author : Farhad Nejat, Vision health research center, Tehran, Iran. Tel: +989124014938.


Background: The current study aims to evaluate the plasma-assisted noninvasive surgery (PANIS) as a novel technique for punctal occlusion to attain a long-term stricture of the punctum.

Methods: This study involved 10 eyes from 10 female patients with grade 3 and 4 severity of dry eye disease (DED) based on the Delphi Panel scheme of dry eye. The punctal occlusion was conducted using the fusion mechanism of plasma spots using the white handpiece of plexr device. One single surgeon implemented the procedure three times at 2 weeks intervals. This office-based technique was assessed with acuity parameters, dry eye tests, and patient satisfaction evaluated by OSDI questionnaire before, and one month and six months after the procedure.

 Results: A remarkable improvement was observed in tear meniscus height (TMH) and tear break-up time (TBUT) in quite all patients. The visual parameters and intraocular pressure (IOP) had not considerably changed but CFS decreased due to more tear stability in the 6 months. The OSDI questionnaire scores of all patients had obviously reduced after the procedure. After all sessions, patients reached a quite long-term stricture in their puncta, whereas no complication or side-effects were reported after a 6-month follow-up.

Conclusions: Findings of this clinical case serial study led to a novel therapy method for DED that results in the punctum stricture for months, using the PANIS method as an effective, safe, office-based, easy, and inexpensive approach where recalcitrance to the medical therapy occurs.

Trial registration: This study registered in Semnan University of medical science, Semnan, Iran identified by IR.SEMUMS.REC.1398.319.

Keywords: Punctal occlusion; punctal stricture; dry eye disease (ded); plasma; panis method; ocular surface disorders.


Occluding tear drainage system is known as a mechanical blocking procedure of punctum to preserve natural tear for a longer time [1]. Punctal occlusion is an underutilized therapy for treating dry eye disease (DED) [2] that can be an option when the prescribed medications are no longer ameliorating the complaints and symptoms in patients [3]. Dry eye can occur due to immoderate tear evaporation or tear deficiency [4-6] and have a deleterious consequent on the visual function and life quality in DED patients [7]. DED-conflicted patients suffer from signs including, but not limited to, irritation, burning, redness, photophobia, visual disturbance, and foreign body sensation [8, 9]. The age-related prevalence is 5 to 35 percent in a many countries and 27.7% in Iran [10-13]. Risk factors include advanced age, smoking, low relative humidity, excessive screen-exposure, refractive surgery, and certain drugs [14-18]. Depending on the severity, warm compresses to the eyelids, omega-3 nutritional diet, medical therapy including artificial tear, topical cyclosporine, autologous serum drops, short term topical antibiotics, and some corticosteroids are prescribed to relieve the symptoms of DED [19-21]. Punctal occlusion is suggested as a good remedy for cases that the above-mentioned approaches were inadequate [16, 22]. In recent years, plasma (the fourth state of matter following solid, liquid, and gas) has appeared potential to be utilized in many fields of medicine. One novel approach for producing reactive components of oxygen and nitrogen, is non-thermal atmospheric pressure plasma, which is employed in sterilization, dentistry, oncology, pharmacology, wound healing, and cancer therapy [4, 5]. First time, Nejat et al. evaluated the safety of applying atmospheric low-temperature plasma (ALTP) on rabbits’ eyes and after a one-month and six-month follow-up, histopathological examinations revealed the safety of this novel technique on the conjunctiva [23, 24]. Thus, they initiate a case series studies, applying plasma with a plexr device for conjunctival cyst, pinguecula ablation, conjunctivochalasis treatment, and dry eye treatment by one-session punctal occlusion and their results approved the efficacy of the plasma-assisted noninvasive surgery (PANIS) [25-28].

In the same regard, the present study assesses an innovative method to strict punctum to increase tear stability in the ocular surface for the long term to treat DED.

Materials and Methods

Study design

The research protocol was approved by the medical ethics committee of the Semnan University of Medical Sciences, IR.SEMUMS.REC.1398.319. Written informed consent was obtained from all included subjects after delivering an oral explanation of the nature and possible consequences of the procedure. The research adhered to the tenets of the Declaration of Helsinki. The current study included 10 eyes of 10 female Participants (4 left eyes and 6 right eyes), the mean age was 39.9 years old and diagnosed with severe dry eye based on the Delphi Panel dry eye severity grading scheme (2021).

 Surgical technique

The procedure was conducted under local anesthesia. For this purpose, 3 drops of tetracaine 0.5% eye drop (Sina Daro, Tehran, Iran) was instilled in each eye at 5 minute intervals for 15 minutes. While patients were placed behind the slit-lamp, punctal occlusion was performed using the white handpiece (Table 1) of the plasma generator device (Plexr, GMV s.r.l Grottaferrata, Italy). Applying one or two plasma spots on the punctum causes occluding for 2 to 5 days and this procedure was repeated for 3 consecutive times with a two-week interval (see the supplementary video). One surgeon (Dr. Farhad Nejat) performed the procedure on all subjects. The patients reported no intraoperative and postoperative complications. The patients continued their previous lubricating medications after surgery.

Table 1: Characteristics of Plexr device.

Ocular examinations

To scrutinize the efficacy of PANIS method, 9 parameters were measured before the procedure, and 1 month and 6 months after 3 times punctal occlusion. The examinations concluded refraction, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), ocular surface disease index (OSDI) (final scores ranges from 0 to 100), intraocular pressure (IOP), and dry eye tests including tear breakup time (TBUT), tear meniscus height (TMH), corneal fluorescein staining (CFS) using the National Eye Institute/Industry (NEI) grading scale, and Schirmer test. IOP was performed using a rebound tonometer (iCare Finland Oy, Vantaa, Finland). TBUT, TMH, and CFS were measured by a handheld ocular surface analyzer (OSA-VET, SBM Sistemi, Torino, Italy).


Comparing the values of preoperative and 6-month postoperative parameters shows significant improvement in tear meniscus height (TMH) and tear break-up time (TBUT) in all cases. As was expected, uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) had no remarkable changes. Five patients exhibited 1 grade diminution, four patients exhibited 2 grades diminution, and one patient exhibited 3 grades diminution in corneal fluorescein staining (CFS). The Schirmer test in all participants increased considerably. In the preoperative examinations, the mean OSDI score of all patients was 64.93 which was down trended to 6.33 in the postoperative examinations (Table 2). These results revealed that the stricture could help remaining the natural tear on the ocular surface, and also that the amelioration process could be reducing the volume of tears coming out of the eyes (Figure 1).

Figure 1: a) Before plasma procedure, b) 6 months after plasma procedure.

Table 2: Patient's ophthalmic characteristics.


Punctal occlusion is an appropriate therapeutic method to relieve symptoms in patients with moderate to severe aqueous tear deficiency dry eye who have rejected artificial tears or any other medical prescriptions [29-32]. Since tear can provide many indices such as vitamin A that are necessary for cornea, occluding or stricture will be a good survival for ocular surface dryness [33, 34]. Doughty et al. showed that in 13,517 DED patients, mild complaints about dry eye symptoms are 1 in 4 and severe complaints is 1 in 225 which can raise the adverse effects on their life quality [35, 36]. Patients with severe criteria could be treated with temporary [37] or permanent punctal occlusion [38]. Liu and Sadhan reported a good result for permanent punctal occlusion showing long-term tear stability. They removed the punctum's epithelium and the vertical portion of the canaliculus, then bared punctum occluded by 6-0 chromic suture [39]. In another study by Knapp et al., the final analyses on 90 puncta proved that deep cauterization is more effective than superficial blocking [40]. Furthermore, the research conducted by Vrabec et al. on 73 puncta disclosed that thermal cautery for occluding punctum has a longer effect over argon laser [41, 42, 43]. Another study with 10 eyes claimed that succinylated collagen punctal plugs (SCPP) preserve aqueous on the ocular surface for 14 days [44]. Temporary collagen punctal plugs have been introduced as a pre-permanent punctal closure to prevent epiphora or any possible complication after total occluding [2, 45, 46]. Plasma medicine application is increasingly developing in many fields day by day. Plasma is the fourth state of matter after solid, liquid, and gas, contains reactive species, and in some plasma generators present as ionizing the air [47].

Moreover, Sotiris et al. evaluated plasma in the dermatologic field by applying plasma on 80 patients' eyelids with a plexr device and showed that atmospheric low-temperature plasma (ALTP) can play an important role in altered nonsurgical blepharoplasty [48-50]. Thereafter, Nejat et al. brought plasma technology in the ophthalmic field and assessed the safety of applying plasma on rabbit's eye. After 1 month and 6 months follow-up, their results indicated that plasma exposure to the ocular surface has no complications [23, 24]. Evaluating plasma efficacy continued in the treatment of conjunctivochalasis, pinguecula, conjunctival cyst, and DED treatment with temporary punctal occlusion and it is noteworthy that in their case series, after 6 months follow-up, plasma-assisted noninvasive surgery (PANIS) proved to be a fast, office-based, easy, safe, and effective method in treating several ocular surface disorders. In the current study, Nejat et al. presented a novel technique for long-term punctal stricture that causes more tears on the ocular surface besides avoiding epiphora which is the most frequent occluding complication. To ensure the result, a study with a high sample size and longer follow-up is suggested.


In conclusion, plasma-assisted noninvasive surgery (PANIS) can be a fast, easy, safe, office-based, effective, and inexpensive method for long-term punctal stricture which is a novel approach for severe DED treatment and also prevention of possible epiphora simultaneously. This therapy might cure some patients with severe DED who are not demanding any permanent or invasive treatment.

Acknowledgment: None declared.

Conflict of interests: None declared.

Funding Source: None declared.


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