Deformation of Aflibercept and Ranibizumab Syringes Causes Variation in Intravitreal Injection Volume and Risks Retinal Tear Formation.

Purpose: The intravitreal injection volume is known to vary with plunger alignment and the speed of injection. We investigated the role that syringe stopper deformation plays in allowing excess volumes to be injected into the eye and the potential for the vitreous humor to become incarcerated when excess force is released within the eye. Design: Experimental study. Methods: Aflibercept prefilled syringes (PFSs), ranibizumab PFSs, and 1-ml tuberculin (TB) syringes were subjected to increasing injection force to assess the extent to which each design allowed for excess volumes to be expelled after the stopper reached the bottom of the syringe barrel (i.e., after the 50-µl dose was expelled). Main Outcome Measures: Additional volume expelled with stopper deformation. Results: Syringe stoppers are capable of deformation into the dead space when additional force is applied. This allows for progressively greater medication doses to be administered. At an additional force of 3.92 N after the syringe stopper came in contact with the bottom of the syringe barrel, the aflibercept PFSs, ranibizumab PFSs, and 1-ml TB syringes dispensed an additional 17.2%, 11.4%, and 0.8% higher volume than the intended volume of 50 µl, respectively. Upon release of this force, a proportional volume was observed to be drawn back into the needle. Conclusions: The intravitreal injection volume varies with the force applied to fully depressed syringes because of syringe stopper deformation. We advise that performing forceful intravitreal injections be avoided to prevent excessive dosing of medication. We also caution that pressure applied to the plunger during intravitreal injections not be released while the needle is in the vitreous cavity to guard against vitreous incarceration, which could lead to retinal tear formation or detachment.

Outcomes of Rhegmatogenous Retinal Detachment Repair When Comparing Surgeon Continuity in a Team-Based Practice.

BACKGROUND AND OBJECTIVE: To facilitate timely surgery and efficient use of operating room time, our practice uses a team-based approach so patients may undergo primary rhegmatogenous retinal detachment (RRD) surgery with a different surgeon instead of the diagnosing surgeon. PATIENTS AND METHODS: This was a retrospective cohort study of 331 eyes that underwent RRD surgery. Patients were divided into two groups: RRD surgery performed by the diagnosing surgon, and RRD surgery performed by a different surgeon. RESULTS: Of 331 eyes, 200 eyes (60.4%) were repaired by the diagnosing surgeon and 131 eyes (39.6%) were repaired by a different surgeon. Primary anatomic success (PAS) rates at 3 months postoperatively were equivalent between the two groups (87.0% and 87.8% in the diagnosing surgeon and different surgeon groups, respectively [P = .83]). There was no significant difference in preoperative (P = .08) or final (P = .28) visual acuity between the groups. Time between diagnosis and RRD repair was shorter in the different surgeon group (median of 1.5 days [IQR: 1.0-3.6] in the surgeon group versus 2.2 days [IQR: 0.8-5.7] in the diagnosing surgeon group) (P = .03). Logistic regression analysis gave no evidence to suggest that PAS rates depended on day of week, time of day surgery was performed, group, or the interaction between those factors (P = .93). CONCLUSIONS: Visual and anatomic success in RRD repair are equivalent when surgery is performed by either the diagnosing surgeon or a surgical colleague because time to surgery is reduced. Neither time of day nor day of the week had any influence on the outcomes. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:560-566.].

MOSAICISM AS A PROPOSED MECHANISM FOR ASYMMETRIC RETINAL TESSELLATIONS.

BACKGROUND/PURPOSE: Report a case of markedly asymmetric retinal tessellations and propose mosaicism as a mechanism. METHODS AND RESULTS: A 59-year-old pseudophakic woman presented with uncorrected 20/20 vision and was found to have markedly different retinal tessellation appearances in both eyes. The axial lengths were 25.66 mm and 25.88 mm in the right and left eyes, respectively, and no significant asymmetrical choroidal thinning was seen on optical coherence tomography or optical coherence tomography angiography. Fluorescein angiogram showed significant hyperfluorescence, representing the underlying choroid, which correlated with the tessellation patterns in the left eye. She had no other ocular or systemic findings such as stripes or whorled skin. CONCLUSION: This is the first reported case of markedly asymmetric retinal tessellation patterns that are not due to asymmetric axial myopia or choroidal thinning. We propose that mosaicism is a possible mechanism causing this finding.

Eyelid retraction discomfort with cotton-tipped applicator, unimanual and speculum intravitreal injection techniques: Eyelid retraction technique randomized comparison trial (Eyelid RETRACT).

Purpose: The aim of this study was to test the discomfort experienced during intravitreal injections with eyelid retraction between an eyelid speculum, cotton-tipped applicator (CTA), and unimanual eyelid retraction techniques. Methods: In total, 99 patients receiving intravitreal bevacizumab were enrolled into this prospective study. Participants were randomized to one of the three methods, given subconjunctival 2% lidocaine and then injected in the superior temporal quadrant. Immediately after the procedure, each patient was given a visual analog scale (VAS) to rate their discomfort. Results: The mean pain scores for eyelid retraction with unimanual, CTA, and speculum groups were 0.788 (standard deviation [SD] 0.70, 95% confidence interval [CI] 0.448-1.128), 0.945 (SD 1.28, 95% CI 0.600-1.291), and 1.561 (SD 1.28, 95% CI 1.210-1.912), respectively. A one-way analysis of variance (ANOVA) test revealed a significant difference between the groups (P = 0.006). Post hoc analysis also revealed a difference in mean pain scores between the speculum and both the CTA and the unimanual methods. Conclusion: Our study shows that the unimanual and CTA methods for eyelid retraction are significantly less painful for patients compared to the speculum method. Patient comfort is of the utmost importance as intravitreal injections are performed millions of times a year with most patients requiring multiple injections.

Retinal Toxicity in a Patient on Pentosan Polysulfate Sodium.

Pentosan Polysulfate Sodium (PPS) is commonly used in the treatment of interstitial cystitis/bladder pain syndrome. Recently there have been reported cases of retinal toxicity associated with long-term PPS use. We present a case of a 42-year-old female taking PPS for the last 10 years who was found to have signs of retinal toxicity, but was completely asymptomatic. PPS was discontinued after these retinal findings were discovered.

Intravenous Drug Use-Associated Scopulariopsis Endophthalmitis Treated with Systemic and Intravitreal Voriconazole.

PURPOSE: To report a case of intravenous (i.v.) heroin use-associated endogenous endophthalmitis caused by Scopulariopsis fungal species, and its response to intravitreal and oral voriconazole treatments. PATIENT: A 21-year-old-female with chronic hepatitis C and i.v. heroin use presented with subacute decreased vision to hand motion in her left eye. RESULTS: Endogenous fungal endophthalmitis caused by Scopulariopsis was confirmed by vitreous biopsy. The patient improved clinically after vitrectomy with intravitreal voriconazole and 3 weeks of oral voriconazole. The final vision was 20/60 after 6 months. CONCLUSIONS: Scopulariopsis is a rare cause of endophthalmitis, and is often difficult to treat due to its resistance to commonly used antifungals. This case is the first report of Scopulariopsis endophthalmitis secondary to i.v. drug use.