Nocturnal normobaric hyperoxia treatment in a case of chronic diabetic macular edema.

PURPOSE: To study the long-term anatomic and physiologic effects of nocturnal normobaric hyperoxia (NNBH) in a patient with treatment-resistant diabetic macular edema (DME). METHODS: A 64-year-old diabetic man with bilateral DME requiring regular anti-VEGF treatments in both eyes was started on 5 LPM (40% FiO2) NNBH treatment 6-h per night. Visual acuity, OCT measurements of retinal thickness and volume, as well as the number of injections given in each eye were retrospectively examined one year prior and prospectively after initiation of NNBH, as well as before and after a planned 1-month discontinuation of NNBH. RESULTS: The patient received 12 anti-VEGF injections in the year prior to beginning NNBH treatment (4 OD; 8 OS) and did not require any injections after commencing NNBH treatment. Visual acuity improved and stabilized to 20/20 and macular edema rapidly resolved in both eyes following initiation of NNBH. After a planned 1-month NNBH vacation, DME recurred but quickly resolved once NNBH treatment was restarted. CONCLUSION: This model case demonstrates that a 6-h NNBH regimen can be successful in treating DME and improving vision, without the need for intravitreal injections. NNBH is a more acceptable treatment regimen compared to 24-h continuous oxygen delivery and may provide a less invasive alternate method for treating DME in patients with diabetes. Further study is warranted.

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.

POSTERIOR VITREOUS DETACHMENT STATUS AS A PREDICTIVE FACTOR FOR OUTCOMES OF VITRECTOMY FOR DIABETIC VITREOUS HEMORRHAGE.

PURPOSE: The purpose of this study was to evaluate the prognostic utility of the degree of vitreous attachment for predicting outcomes of vitrectomy for nonclearing vitreous hemorrhage associated with proliferative diabetic retinopathy. METHODS: Medical records of patients who underwent primary vitrectomy for dense nonclearing vitreous hemorrhage secondary to proliferative diabetic retinopathy were examined retrospectively. Eyes were divided into four groups based on the intraoperatively assessed stage of posterior vitreous detachment (PVD), ranging from Stage 0/1 (complete or near-complete vitreoretinal adhesion) to Stage 4 (complete PVD). RESULTS: Overall, 136 eyes (117 patients) were included. In comparison with eyes with a partial or complete PVD (Stages 2-4), eyes with no PVD (Stage 0/1) had a higher incidence of postoperative hypotony (8%, P = 0.03) and traction retinal detachment (27%, P = 0.002), an increased rate of repeat vitrectomy (49%, P = 0.04), and poorer best-corrected visual acuity at 6 months and 1 year postoperatively (P = 0.04 and P = 0.01, respectively). Presence of a complete PVD at baseline was independently associated with improved postoperative vision at 6 months (P = 0.04). CONCLUSION: More extensive vitreoretinal adhesion is associated with higher rates of reoperation and poorer visual outcomes after vitrectomy for dense nonclearing vitreous hemorrhage associated with proliferative diabetic retinopathy. Preoperative determination of PVD status using B-scan ultrasonography may be useful for predicting anatomical and functional outcomes after vitrectomy in these patients.

Intravitreal Methotrexate for Recalcitrant Epiretinal Membrane Reproliferation.

This article reports a case of a 65-year-old woman with recalcitrant recurrent epiretinal membrane (ERM) treated with revision vitrectomy and membrane peeling followed by 12 weekly intravitreal methotrexate injections. Visual acuity and central macular thickness significantly improved, and no ERM recurrence developed 7 months after surgery. This case represents the first documented use of methotrexate to treat surgically resistant ERM reproliferation and indicates a potential for its use in cases that do not respond to standard treatment. [Ophthalmic Surg Lasers Imaging Retina. 2022;53:49-51.].

Endoscope-Assisted Sutureless Intrascleral Haptic Fixation of a Posterior Chamber Intraocular Lens.

Purpose: In eyes with compromised capsule support, sutureless scleral fixation is a popular method of placing a posterior chamber intraocular lens (PCIOL). We describe an endoscope-assisted sutureless technique for intrascleral fixation of a 3-piece PCIOL. Methods: Eyes of patients who had endoscope-assisted scleral-fixated intraocular lens (SFIOL) implantation were examined retrospectively. The technique comprised direct capture of the IOL haptic with a forceps through a pars plana sclerotomy with subsequent haptic fixation into scleral tunnels created with a 26-gauge needle. The endoscope was used to visualize haptic positioning under the iris and ensure proper centration of the IOL. Results: Thirteen eyes of 13 patients were examined. The mean age of the patients was 68.2 years (range, 38-87 years), and the mean follow-up was 13.6 months (range, 5-23 months). The indications for surgery were a subluxated IOL (6 eyes), postoperative aphakia (5 eyes), and a subluxated cataract (2 eyes). The mean best-corrected visual acuity ± SD improved significantly from 1.2 ± 0.6 logMAR preoperatively to 0.6 ± 0.7 logMAR at last the follow-up (paired Welch t test; t10 = 2.69; P = .023). IOL stability and centration were maintained in all patients. Conclusions: Endoscopic visualization during sutureless SFIOL implantation helped improve haptic localization, minimize intraoperative complications, and achieve excellent IOL centration.

Relative Retinal Blood Flow: A Novel and Informative Measure of Unilateral Retinal Vein Occlusion Severity.

Purpose: This study quantifies retinal vascular blood flow affected by unilateral central or branch retinal vein occlusion (CRVO or BRVO). We created a new, unitless metric for the severity of these diseases-relative blood flow (RBF)-and contextualized it with subject demographics, ocular presentation, and systemic conditions. Finally, we explored its efficacy as a predictor of future outcomes. Methods: Data were collected from 20 control subjects and 32 clinically diagnosed CRVO (n = 15) or BRVO (n = 17) patients. We used laser speckle flowgraphy to quantify blood flow as mean blur rate and present RBF as the ratio between the blood flow in a subject's diseased and undiseased eyes. Because of our demonstration that blood flow has high intrapatient (between eyes and over time) but low interpatient correlation in eyes of healthy subjects, any differences between eyes can be attributed to the disease. These data were correlated with subject demographics and disease characteristics. Results: In CRVO and BRVO eyes, average blood flow decreased by 26% and 7%, respectively. In CRVO, occlusion duration, central macular thickness, intraocular pressure, diabetes, previous laser and injection treatments, and injection within three months after measurement were significantly associated with RBF. In BRVO, no significant associations with RBF were found. Conclusions: Blood flow in CRVO and BRVO was reduced compared to the unaffected fellow eye in most patients. RBF was useful in determining the severity of RVOs and predicting future treatment needs. Translational Relevance: RBF is a promising new and informative metric for quantifying the severity of unilateral RVOs.

Anterior versus posterior endoscopic cyclophotocoagulation: comparison of indications, populations, and outcomes.

PURPOSE: To examine how indications, patient characteristics, and outcomes differ between anterior and posterior approaches of endoscopic cyclophotocoagulation (ECP) in the treatment of glaucoma. METHODS: This is a retrospective chart review of 9 anterior and 20 posterior ECP cases (n = 29). RESULTS: Posterior ECP cases were typically associated with a dramatic increase in intraocular pressure (IOP), whereas the anterior ECP was associated with chronically elevated pressures. The initial IOPs in mm Hg of posterior ECP cases (26.8 non-NVG; 35.2 NVG) were much greater than anterior ECP cases (17.8), and a greater overall reduction in IOP was observed in the posterior versus anterior ECP cases (10.3 posterior non-NVG; 21.3 posterior NVG; 3.6 anterior, P < .001). With procedural success defined as 6-month post-operative IOP falling within normal ranges and a decrease in either IOP or number of prescribed glaucoma medications, the success rate of ECP was 92% for posterior NVG, 89% for anterior and 75% for posterior non-NVG cases (P = .34), similar to the previous literature. Of the four unsuccessful cases, two resulted in a normal IOP but lacked a drop in pressure or reduction in medication burden, one resulted in a 6-point drop in IOP but remained at 23 mm Hg, and one resulted in phthisis bulbi (3%) from an initial pressure above 40 mm Hg. CONCLUSION: Endoscopic cyclophotocoagulation is an effective and safe procedure for severe glaucoma cases from both an anterior and posterior approach. Ophthalmologists should consider this procedure as part of their glaucoma treatment arsenal.

Rapid reduction of macular edema due to retinal vein occlusion with low-dose normobaric hyperoxia.

PURPOSE: We investigated the effects of a relatively inexpensive, non-invasive, short-term treatment with low-dose normobaric hyperoxia (NBH) on macular edema in patients with retinal vein occlusion (RVO). METHODS: Participants with macular edema associated with RVO were treated with 5 LPM of NBH via facemask (40% fraction of inspired oxygen, FIO2) for 3 h. Patients with non-fovea involving edema who elected to be observed returned for a second treatment 1 month later to test reproducibility. RESULTS: A 3-h session of NBH (n = 45) resulted in decreased maximum macular thickness (MMT) (mean 7.10%, t34=9.63 P<.001) and central macular thickness (CMT) (mean 4.64%, t34=6.90, P<.001) when compared to untreated eyes with RVO measured over the same period of time (n = 12) or their healthy fellow eye (n = 34; MMT:t34=-9.60, P<.001;CMT: t34=-6.72, P<.001). Patients who had a second NBH treatment 1 month later experienced a recurrence of their edema, but demonstrated a similar significant reduction in MMT and CMT after the second NBH treatment. CONCLUSIONS: Three-hour treatment with 40% FIO2 NBH results in a significant reduction in MMT and CMT. This study supports an ischemic mechanism for macular edema associated with retinal vein occlusion. TRANSLATIONAL RELEVANCE: Short-term low-dose normobaric hyperoxia is a simple, inexpensive, and ubiquitous treatment that may provide an alternate or adjunctive approach to treating macular edema in patients who are resistant to or cannot afford anti-VEGF medications.