
This article was reviewed by Neeru Gupta, MD, PhD, MBA

The first attempts at bleb repair after trabeculectomy and introduction of the use of mitomycin C (MMC) to improve surgical success rates resulted in blebs that were avascular and prone to leaks.

“This scenario is a time bomb because, left unchecked, it can lead to blebitis and possibly endophthalmitis, and myriad other problems, such as hypotony with associated anatomic disruptions such as vision-blurring corneal striae, shallow anterior chambers, buildup of excess fluid leading to dome-shaped choroidals, and hypotony maculopathy,” said Neeru Gupta, MD, PhD, MBA.



Bleb leaks treated with minimally invasive conjunctival surgery

Gupta is a professor of ophthalmology and chief of glaucoma at the University of Toronto, and president-elect of the World Glaucoma Association.

Techniques that have attempted to address the problem of leaky blebs include conservative treatment with antibiotics, aqueous suppressants, steroids, collagen shield, bandage contact lens, pressure patch, cyanoacrylate tissue glue, autologous blood, and argon laser or Nd:YAG laser. The microsurgical approaches include bleb resuturing, and bleb excision and conjunctival advancement with or without various grafting techniques.

Despite all this, no procedure stands out as effective.

“Despite the number of attempted procedures, we continue to struggle with managing bleb leaks,” Gupta said.



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Gupta developed the minimally invasive conjunctival surgery incision-free procedure to address late-onset bleb leaks close to the limbus.

For a patient with a history of high myopia, advanced pigmentary glaucoma, retinal detachment treated with pars plana vitrectomy and later with pneumatic retinopexy and cryotherapy, use of multiple glaucoma medications for advanced glaucoma, thin corneas, bilateral cataracts, and remaining central islands of vision of 20/60 to 20/70, Gupta performed bilateral trabeculectomies with MMC. Vision was stable with intraocular pressures (IOPs) of 8 to 10 mm Hg bilaterally. 

In 2012, however, the vision in the left eye decreased to 20/100 with an IOP of 2 mm Hg and an avascular leaking bleb. Three days later, the vision was 20/200 with an IOP of 0 mm Hg.



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In surgery, Gupta acted to address this situation without undoing the previous treatments. Instead of excising the bleb and covering the area with conjunctiva, she injected subconjunctival lidocaine above the bleb. She described the conjunctival epithelium as highly voluminous and able to move freely. 

With gentle tugging, and without disturbing Tenon capsule, she pulled a sizable area of the conjunctival tissue to the limbus over the leaking area and put in a series of stitches (typically 3 to 4) without using a great deal of pressure that resulted in a sealed wound.

“This was a short, incision-free procedure,” she said of this first such case.

The patient has done well during the ensuing 8 years. Gupta reported that she has performed this procedure in 14 cases and reported the results in the 

In all cases, the patients have remained stable and medication free from 2 weeks to 5 years later. She said that with time the transposed conjunctival tissue becomes translucent and seems to take on the characteristics of the early bleb that was leaking.

Gupta enumerated the surgical benefits of this procedure.



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“It is short and incision free with good success; the bleb is preserved; the procedure is relatively simple, inexpensive, efficient, and accessible; and the patients are comfortable postoperatively and can return to normal activities,” she said. “They leave after the surgery with an antibiotic and a steroid.

She advised that studies are needed to determine the long-term outcomes. 




Gupta has no financial interest in this subject matter.

1. Gupta N. Incision-free minimally invasive conjunctival surgery (MICS) for late-onset bleb leaks after trabeculectomy (an American Ophthalmological Society thesis). 

. 2019;207:333-342. doi:10.1016/j.ajo.2019.04.031

Articles

Minimally invasive conjunctival surgery option is an efficient procedure. 

Straightforward procedures for leaking blebs: No incision required

can benefit from perioperative use of artificial tears, particularly by starting the treatment preoperatively, according to the findings of a retrospective study conducted by Italian investigators.

The researchers analyzed data from the Standard Patient Evaluation of Eye Dryness (SPEED) questionnaire, tear breakup time (TBUT) measurements, and corneal fluorescein staining (CFS) in 3 groups of patients. 



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The groups comprised those who did not use any artificial tears perioperatively (n = 140); patients who began to instill artificial tears 1 week preoperatively and continued for 2 months postoperatively (n = 139); and a cohort that used artificial tears postoperatively for 2 months (n = 140). 

The DED-related evaluations were performed preoperatively and at follow-up visits occurring at 1, 4, and 8 weeks after surgery. 

The artificial tear product was a commercially available lubricant formulation containing hydroxypropyl guar and hyaluronic acid, and all patients were treated with the same perioperative regimen of antibiotic and anti-inflammatory medications.

 showed statistically significant benefits of treatment with the artificial tears for mitigating surgically induced signs and symptoms of DED. 

Statistically significant differences favoring the group that started using the artificial tears preoperatively compared with the group using the ocular lubricant only after surgery were seen in analyses of SPEED scores and TBUT.



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Based on the findings, the investigators concluded that the artificial tears were effective in protecting the ocular surface, particularly if initiated in the preoperative period. 

Noting that DED can lead to biometric errors and adversely affect patient comfort and vision after surgery, they stated that the findings highlight the importance of improving the homeostasis of the ocular surface not only in patients with established DED but also in those without frank disease or evident DED risk factors.



The study identified patients who had undergone unilateral cataract surgery across 17 centers in Italy. 

A total of 419 patients met the inclusion criteria that required eligible patients to be aged at least 50 years and have undergone an uncomplicated procedure with a clear corneal incision, IOL implantation in the capsular bag, and postoperative treatment with dexamethasone and tobramycin 4 times a day for 10 days and nepafenac 0.1% 3 times a day for 1 month.



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In addition, patients needed to have data from DED diagnostic tests conducted between 30 and 7 days before surgery and at 1, 4, and 8 weeks postoperatively. 

Patients were excluded if they had preexisting DED, which was diagnosed based on a Schirmer test without anesthesia less than 7 mm/5 min, TBUT less than 10 seconds, SPEED score greater than 4, and CFS score greater than 1, or if they had any other findings that could confound the results.

Preoperatively, the 3 study groups were well matched with respect to mean age ( ~ 72 years), mean Schirmer test score ( ~ 13 mm/5 min), mean TBUT ( ~ 12 sec), and percentage of eyes with a CFS score equal to 0 (65% to 76%). 

The postoperative data from all groups were consistent with previous reports showing that cataract surgery can induce signs and symptoms of DED.

Mean SPEED questionnaire scores did not change significantly in groups that were using artificial tears but increased significantly (worsened) at week 4 in the untreated patients. 

The differences in mean SPEED scores were statistically significant favoring both groups using the artificial tears versus the untreated group at all follow-up visits. 

The investigators noted that 25% of the patients in the untreated group had SPEED scores corresponding to mild-moderate dry eye symptoms at 8 weeks after surgery.


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In addition, a statistically significant difference favoring the group starting artificial tear use preoperatively compared with the group treated only postoperatively was noted at postoperative weeks 1 and 4.

The TBUT was significantly higher in both groups using the artificial tears compared with the controls at all follow-up visits, and mean TBUT fell to below 10 seconds postoperatively only in the control group. 

In addition, TBUT recovered faster in the group using artificial tears preoperatively compared with the group that was treated only after surgery. At the week 4 postoperative visit, the TBUT was higher in the group that started artificial tear use preoperatively compared with the group treated only postoperatively.

The investigators noted the difference was statistically significant, but it was not clinically significant.

The results for CFS showed that patients using artificial tears had less corneal damage after surgery than their untreated counterparts. 

Among patients who used the artificial tears preoperatively and postoperatively, a small minority had CFS scores of 2 (7.2%) or 3 (0.7%) at the week 1 postoperative visit. 

In this same group by week 4, more patients had a CFS score of 0 compared with baseline, and the percentage was increased further at week 8.

A similar pattern of early worsening in CFS scores and subsequent progressive improvement was noted in the group that used artificial tears postoperatively only and in the untreated group.

However, among patients who used the artificial tears after surgery, approximately 6% of patients had a CFS score greater than 1 at week 4, whereas in the untreated group a CFS score greater than 1 was found in 20% of eyes at week 1, 13% at week 4, and 6.4% at week 8. 


1. Favuzza E, Cennamo M, Vicchio L, Giansanti F, Mencucci R. Protecting the ocular surface in cataract surgery: the efficacy of the perioperative use of a hydroxypropyl guar and hyaluronic acid ophthalmic solution.

2020;14:1769-1775. doi:10.2147/OPTH.S259704

Study supports preoperative ocular surface optimization with artificial tears.

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This article was reviewed by Gustavo B. Melo, MD, PhD

The ideal syringe for administering intravitreal injections does not exist. With improved awareness of the drawbacks of existing devices and the characteristics desired for intravitreal use, however, syringe manufacturers are stepping up to design products that will help maximize the safety and efficiency of intravitreal injection, said Gustavo B. Melo, MD, PhD.

“Retina specialists are well aware that intravitreal injection can lead to the presence of silicone droplets in the vitreous. The droplets come from the syringes used for injection because most are manufactured with silicone oil to allow for better glide of the plunger. In addition, almost all needles are dipped in a silicone oil bath to coat the outer surface to enable tissue penetration,” said Melo, an associate researcher at the Federal University of São Paulo and the head of the ophthalmology residency at Sergipe Eye Hospital, Brazil.

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“Available data show these droplets matter,” he said. “In the 2018 American Society of Retina Specialists PAT [Preferences and Trends] survey, 5% of US retina specialists said they had done vitrectomy for symptomatic droplets and 2% have patients seeking legal action for their floaters. In addition, silicone droplets are linked to inflammatory reactions after aflibercept injection.”



According to Melo, the ideal syringe for intravitreal injections would be silicone oil free; have negligible dead space to minimize expensive medication waste; use an attachable needle, giving physicians the option to choose their needle; and feature a Luer lock tip that allows for an attachable needle and prevents liquid leakage along with accidental needle removal.

“Preferably, it would also be designed for ophthalmic use,” Melo said.


Melo and Geoffrey G. Emerson, MD, PhD, an ophthalmologist in private practice at The Retina Center in Minnesota, reviewed the advantages and disadvantages of syringes used for intravitreal injections, including those most commonly used in the Americas and Europe, along with emerging products. 



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They based their information on the silicone oil released by each syringe on scientific publications and personal research. Clinical and scientific experiences were the foundation for comments on additional features.

“Our review included the syringes that we are aware are being used for intravitreal injection. Other syringes, both good and bad, may be available,” Melo said.


The OcuJect syringe (SJJ Solutions), which is expected to receive CE and FDA certification in mid 2021, seems to meet all the ideal criteria outlined by Melo. It is silicone oil free, has a low volume of dead space and a Luer lock tip, and is designed for ophthalmic use.

The StaClear syringe (TriboFilm Research) recently received FDA clearance for marketing for use in intravitreal injections. It has low dead space and low particulates, complying with USP Chapter 789 testing for ophthalmic solutions. 

The syringe is manufactured with a silicone lubricant, but the lubricant is fixed to the syringe’s lumen.

The Zero Residual Luer Lock syringe (SJJ Solutions) is another syringe that has a lot of positive characteristics. It has a low volume of dead space and a Luer lock tip, can be prefilled air free, and is designed for ophthalmic use. It is not silicone oil free, as it is lubricated with a small amount of oil.



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The Daikyo Crystal Zenith (West Pharmaceutical Services) and Plajex (Terumo) syringes have the advantages of being silicone oil free and having a Luer lock tip. In addition, the Daikyo Crystal Zenith complies with USP Chapter 789. However, both syringes have significant dead space and are not available to be filled at point of care.

The Injekt-F (B. Braun Medical Inc) and Norm-Ject (Henke-Sass Wolf) syringes have the advantage of being silicone free. However, they both have moderate dead space and a Luer slip tip.

“The protruding tip of the Injekt-F syringe helps to minimize dead space. However, the design of this syringe can lead to some confusion regarding the injected volume,” Melo noted.



The BD Luer-Lok syringe (Becton, Dickinson and Company), which is distributed with aflibercept in some markets, has a Luer lock tip. On the downside, it is siliconized, albeit with a small amount of silicone oil. In addition, this syringe has a large dead space that wastes expensive drugs, and it is heavy.

Similarly, the company’s BD Plastipak syringe, which is available worldwide, and BD Tuberculin syringe, which is more commonly used in the US, are also siliconized and have significant dead space. Another disadvantage is that they have a Luer slip tip.



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Available in many markets, the BD Ultra-Fine syringe is an insulin syringe that has negligible dead space. However, it is siliconized with a large amount of oil.

“This syringe is notorious for its association with silicone oil droplets in the vitreous,” Melo pointed out. “It has a fixed needle that cannot be substituted.”


Distributed with ranibizumab (Lucentis, Genentech/Roche) in some markets, the Omnifix-F syringe (B. Braun Medical Inc) is siliconized but with just a small amount of silicone oil. However, it has significant dead space and a Luer slip tip.

The Comfort Point insulin syringe (Exel) is available in the US. It has negligible dead space but a fixed needle, and although it is also siliconized, it releases less oil than the BD Ultra-Fine syringe, according to Melo.

Available in many markets, the insulin syringe manufactured by Terumo Medical also has a low volume of dead space. However, it has a fixed needle and releases a large amount of silicone oil.

This article is based on Melo’s video presentation at the European Society of Retina Specialists 2020 Virtual meeting. Melo and Emerson have no financial interests to declare.

All syringes used for intravitreal injections have pros and cons. Some recently marketed and forthcoming products are coming closer to meeting “ideal” criteria.

Ophthalmology Times: January 2021

Straightforward procedures for leaking blebs: No incision required

Zeroing in on dry eye treatment for patients with cataracts

Pearls for selecting a syringe for intravitreal injection