SUSTAINED BIWEEKLY AFLIBERCEPT FOR REFRACTORY NEOVASCULAR AGE-RELATED MACULAR DEGENERATION: The Prospective TRISTAR Study.

PURPOSE: To assess the safety and efficacy of biweekly (every 2 weeks) intravitreal aflibercept injections (IAI) 2 mg in eyes with refractory neovascular age-related macular degeneration (NVAMD). METHODS: A prospective, single-arm, interventional study was conducted. Eyes with refractory NVAMD received six biweekly IAIs through week 12, followed by a 4-week treatment pause until week 16. Eyes with residual subretinal fluid (SRF) at week 16 were randomized 1:1 to either four additional biweekly IAIs or to 4-week (q4W) IAI dosing through week 24. All eyes were subsequently treated q4W through week 52. RESULTS: Enrolled eyes (n = 22) had persistent SRF despite a mean of 11.8 injections over the prior 12 months. One patient developed endophthalmitis at week 12. There were no additional drug/procedure-related adverse events. Best-corrected visual acuity (BCVA) improved significantly from baseline to week 14 (2.52 letters, P < 0.001). The mean central subfield thickness (CST) was also significantly improved at week 14 (-31.9 µ m, P < 0.001) with eight of 22 eyes achieving complete SRF resolution. Only two of eight eyes remained free of SRF at week 16, with a corresponding increase in mean CST of 26.7 µ m compared with week 14. By week 52, improvements in BCVA and CST were lost. CONCLUSION: In patients with refractory NVAMD-related SRF, sustained biweekly IAIs resulted in significant functional and anatomical improvements during biweekly dosing. These gains, however, were lost on return to monthly dosing. These findings suggest that efforts to reduce refractory SRF in NVAMD with biweekly dosing may provide added benefit compared with standard of care treatment if biweekly dosing is sustained.

BASELINE CHARACTERISTICS OF VITREOMACULAR TRACTION PROGRESSING TO FULL-THICKNESS MACULAR OR LAMELLAR HOLES IN THE PHASE III TRIALS OF ENZYMATIC VITREOLYSIS.

PURPOSE: To identify characteristics associated with progression from vitreomacular traction (VMT) to a full-thickness macular hole (FTMH) or lamellar hole (LH). METHODS: Post-hoc analysis of the Phase III clinical trial comparing ocriplasmin with placebo for treatment of vitreomacular adhesion (MIVI-TRUST). Exact logistic regression analyses were used to identify baseline characteristics significantly associated with progression from vitreomacular traction to FTMH or LH over the 6-month study period. RESULTS: Twenty eyes (4.5%) developed an FTMH and 38 (9.7%) developed an LH during the study period. The rate of progression to FTMH or LH did not differ significantly between ocriplasmin- and saline-treated eyes (P = 0.090 for FTMH, P = 0.369 for LH). On univariate analysis, the presence of subretinal fluid (adjusted odds ratio 5.64, 95% confidence interval 2.02-17.17, P < 0.001) and mean subretinal fluid thickness (adjusted odds ratio 1.10, 95% confidence interval 1.04-1.16, P = 0.003) were associated with FTMH development. Both remained significantly associated with FTMH development on multivariate testing. On univariate analysis, the presence of macular schisis (adjusted odds ratio 2.26, 95% confidence interval 1.30-3.82, P = 0.004) and mean retinal thickness (adjusted odds ratio 1.06, 95% confidence interval 1.01-1.10, P = 0.010) were associated with LH development. Schisis remained a significant predictor of LH formation on multivariate testing. CONCLUSION: Vitreomacular traction is more likely to progress to FTMH when associated with subretinal fluid, but when associated with intraretinal changes (such as schisis), vitreomacular traction appears more likely to progress to a LH after a single intravitreal injection of ocriplasmin or saline.

Optical coherence tomography angiography in the management of age-related macular degeneration.

PURPOSE OF REVIEW: Optical coherence tomography angiography (OCT-A) provides rapid, flow-based imaging of the retinal and choroidal vasculature in a noninvasive manner. This review contrasts this novel technique with conventional angiography and discusses its current uses and limitations in the management of age-related macular degeneration (AMD). RECENT FINDINGS: Initial work with OCT-A has focused on its ability to identify choriocapillaris flow alterations in dry AMD and to sensitively detect choroidal neovascular membranes (CNVs) in neovascular AMD. Reduced choriocapillaris flow beyond the borders of geographic atrophy seen on OCT-A suggests a primary vascular cause in geographic atrophy. Longitudinal OCT-A analysis of CNV morphology has demonstrated the transition from an immature to mature CNV phenotype following treatment. Current clinical applications of OCT-A include identification of asymptomatic CNV and monitoring for CNV development in the setting of an acquired vitelliform lesion. SUMMARY: OCT-A remains a promising diagnostic tool but one still very much in evolution. Larger studies will be needed to more accurately describe its sensitivity and specificity for CNV detection and to better characterize longitudinal CNV morphologic changes. Anticipated hardware and software updates including swept-source light sources, automated montaging, and manual adjustment of interscan timing should enhance the capabilities of OCT-A in the management of AMD.

Home Optical Coherence Tomography Monitoring for Neovascular Age-Related Macular Degeneration: Transformative Technology or Cool Toy?

The pending introduction of home-based optical coherence tomography (OCT) in managing neovascular age-related macular degeneration (nAMD) has sparked interesting debates. Advocates assert that home-based OCT will revolutionize care of patients with nAMD, while skeptics question its real-world viability and point out its potential drawbacks. This article delves into the dichotomy, presenting the "pro" argument highlighting the transformative potential of home OCT and the "con" perspective, which scrutinizes the limitations and challenges to adapting the technology to the real-world setting. By exploring both sides of the discourse, we aim to address the promises and complexities surrounding the role of home OCT in the management of nAMD.

Chronic retinal necrosis: cytomegalovirus necrotizing retinitis associated with panretinal vasculopathy in non-HIV patients.

PURPOSE: To characterize a unique cytomegalovirus (CMV)-associated retinopathy in patients with limited immune dysfunction. METHODS: Retrospective observational case series. CMV was confirmed as the pathogenic agent via polymerase chain reaction analysis of aqueous or vitreous humor samples or via immunohistochemical analysis of retinal biopsy specimens. RESULTS: Five non-HIV patients with granular necrotizing retinitis, vitritis, and severe occlusive vasculopathy were identified. Patient histories all suggested a basis for limited immune dysfunction including advanced age (n = 4), diabetes mellitus (n = 4), and noncytotoxic immunotherapy (n = 3). Diagnosis of CMV retinitis was delayed in all cases and patients received either no antiviral therapy (n = 2) or incorrect antiviral therapy (n = 3) for presumed herpes simplex/varicella zoster-related acute retinal necrosis. Retinitis subsequently regressed in all cases with introduction of systemic ganciclovir/valganciclovir (n = 5) and/or intravitreal foscarnet (n = 2). Four of five patients developed neovascularization because of extensive retinal ischemia. CONCLUSION: The clinical expression of CMV-associated retinopathy is strongly related to immune status. In patients with limited immune dysfunction, a mixed clinical picture of intraocular inflammation with panretinal occlusive vasculopathy, more characteristic of acute retinal necrosis, and peripheral slowly progressive granular retinitis, more characteristic of classic CMV retinitis, is observed. Recognition of this atypical clinical presentation, which the authors term chronic retinal necrosis, should prompt molecular testing for CMV to determine the appropriate antiviral therapy. Consideration should also be given to prophylactic panretinal photocoagulation in such eyes, given the high risk of neovascular complications.

A Comparison of Peel-Induced Maculopathy Following ILM Peeling Using a Microvacuum Pick Versus Forceps.

OBJECTIVE: To compare peel-induced maculopathy (PIM) using surgical forceps versus the microvacuum pick (MVP). METHODS: Consecutive eyes undergoing internal limiting membrane (ILM) peeling using either the MVP or forceps were assessed. En face optical coherence tomography (OCT) images at the level of the nerve fiber layer were generated for 6-month postoperative visit. The percentage of the imaged area showing PIM was termed the PIM index. PIM severity was additionally measured using a qualitative PIM severity scale. RESULTS: Seventy-four consecutive eyes underwent ILM peeling with either the MVP (36/74; 49%) or forceps (38/74; 51%). At month-6 postoperatively, the mean PIM index for forceps was 7.7% vs 4.7% for the MVP (P < 0.001, R2 = 0.15). At 6 months, 26/38 eyes (68.5%) in the forceps group had either moderate or severe PIM compared to 12/36 eyes (33.3%) in the MVP group (P = 0.001). CONCLUSIONS: ILM peeling with the MVP resulted in lower PIM severity compared to forceps. [Ophthalmic Surg Lasers Imaging Retina 2023;54:37-42.].

Pars plana vitrectomy without adjuvant procedures for repair of primary rhegmatogenous retinal detachment.

PURPOSE: To evaluate the anatomical and functional outcomes of pars plana vitrectomy without adjuvant scleral buckling, prophylactic 360° endolaser photocoagulation, or perfluorocarbon liquid use for the treatment of primary uncomplicated rhegmatogenous retinal detachment. METHODS: Retrospective interventional case series of consecutive patients undergoing vitrectomy for noncomplex rhegmatogenous retinal detachment over a 10-year period. Main outcome measures included primary anatomical success rate, defined as retinal reattachment at final follow-up after a single operation, proportion of eyes achieving a final best-corrected visual acuity ≤ logarithm of the minimum angle of resolution 0.3 (≥ Snellen 20/40), and postoperative complications. RESULTS: With a mean follow-up of 31 months, primary anatomical success was achieved in 95.7% (89 of 93) of eyes. Final anatomical success, defined as retinal attachment at final follow-up without regard to additional procedures, was achieved in 98.9% (92 of 93). Final best-corrected visual acuity of ≤ logarithm of the minimum angle of resolution 0.3 (≥ Snellen 20/40) was achieved in 77.4% of eyes in the cohort. Postoperative proliferative vitreoretinopathy developed in 3.2% of eyes. No new retinal breaks developed postoperatively in the absence of clinically evident proliferative vitreoretinopathy. CONCLUSION: Thorough pars plana vitrectomy alone, without adjuvant scleral buckling, 360° endolaser photocoagulation, or routine perfluorocarbon liquid use, yields high anatomical and functional success rates and low complication rates in the treatment of primary uncomplicated rhegmatogenous retinal detachment. In the absence of observable proliferative vitreoretinopathy, postoperative vitreous base contraction does not appear to be a clinically relevant phenomenon.

Intravitreal daptomycin: a safety and efficacy study.

PURPOSE: To determine the ocular toxicity of intravitreally injected daptomycin, a novel antibiotic for treatment of vancomycin-resistant organisms, and its efficacy in treating intraocular infection with coagulase-negative Staphylococcus epidermidis. METHODS: Four doses of intravitreal daptomycin were injected (75, 188, 375, and 750 µg) into 1 eye of Dutch belted rabbits (n = 3 per dose). Clinical examination, electroretinography, and histologic analysis were performed preinjection and 2 weeks after injection and compared with the fellow eye that received only intravitreal balanced salt solution. Experimental S epidermidis endophthalmitis was induced in Dutch belted rabbits (n = 24), and the ability of 200 µg of intravitreal daptomycin to result in culture-negative vitreous samples was measured at 24 hours and 48 hours. RESULTS: Seventy-five micrograms and 188 µg of daptomycin demonstrated acceptable safety profiles when injected intravitreally in Dutch belted rabbits. There was a dose-dependent increase in cataract formation, electroretinogram suppression, and photoreceptor damage with higher doses. Two hundred micrograms of intravitreal daptomycin resulted in near-complete vitreous sterilization 24 hours after treatment. Vitreous sterilization was complete by 48 hours. CONCLUSION: A dose of 200 µg of intravitreal daptomycin appears to be safe and efficacious in a rabbit model of bacterial endophthalmitis. Future investigations should focus on daptomycin as a therapeutic option for treating intraocular infection caused by vancomycin-resistant organisms.

Brolucizumab-associated intraocular inflammation in eyes without retinal vasculitis.

PURPOSE: To analyze a series of eyes with brolucizumab-associated intraocular inflammation (IOI) without retinal vasculitis reported to the American Society of Retina Specialists (ASRS). METHODS: The ASRS Research and Safety in Therapeutics (ReST) Committee analyzed clinical characteristics from submitted reports of IOI after brolucizumab. Eyes with retinal vasculitis or that received intraocular antibiotics were excluded. RESULTS: Forty-nine eyes of 45 patients were collected. Mean visual acuity (VA) at baseline was 20/49 (range 20/20 - 5/200). Patients presented with IOI a mean of 24 (range 3-63) days after most recent brolucizumab injection; 61% presented for an unscheduled visit while 39% presented at routine follow-up. Mean VA at IOI presentation was 20/67 (range 20/20 - 3/200). Most common symptoms were floaters (78%) and blurry vision (76%). Pain (20%) and redness (16%) were less common; 3 (6%) eyes were asymptomatic. IOI was anterior only in 18%, posterior only in 31%, and both anterior and posterior in 51% of eyes. Treatment included topical steroids alone in 67% eyes, while 10% eyes received no treatment. Mean VA at last follow-up was 20/56 (range 20/20 - 1/200). Three (6%) eyes lost 3 or more lines and 1 (2%) eye lost 6 or more lines. CONCLUSIONS: Brolucizumab-associated IOI without retinal vasculitis typically presented with a delayed onset of a few weeks. Often, visual acuity decline was relatively mild. Most symptoms resolved and nearly all had a return to baseline VA, but a small percentage of patients had a significant decrease in VA at last follow-up.

Occlusive Retinal Vasculitis Following Intravitreal Brolucizumab.

PURPOSE: To analyze a case series of retinal vasculitis reported to the American Society of Retina Specialists (ASRS) following Food and Drug Administration approval of brolucizumab for treatment of neovascular age-related macular degeneration. METHODS: The ASRS Research and Safety in Therapeutics Committee analyzed clinical and imaging characteristics from submitted reports of retinal vasculitis after brolucizumab. RESULTS: Retinal vasculitis was reported in 26 eyes of 25 patients (22 [88%] female) after treatment with brolucizumab. Imaging studies were available for 24 of 26 eyes. Most cases (92%) were associated with intraocular inflammation, which presented at a mean of 25 days (range, 3-63 days) after the most recent brolucizumab injection. Mean visual acuity (VA) was 20/52 (range, 20/25-4/200) before the adverse event, 20/151 (range, 20/25-hand motion) at presentation of the adverse event, and 20/243 (range, 20/30-light perception) at last follow-up. Twelve eyes (46%) had a greater than 3-line decrease in VA at final follow-up, and 12 eyes (46%) had a final VA of 20/200 or worse. Analysis of retinal imaging identified vasculopathy that involved retinal arteries (91%), retinal veins (79%), and choroidal vessels (48%). Occlusive disease was apparent on imaging in 83% of eyes. Treatment approaches were varied. CONCLUSIONS: Retinal vasculitis has been identified in a series of eyes following brolucizumab. Although a few eyes in this series were asymptomatic or minimally symptomatic, some eyes had significant vision loss. A careful examination for signs of active inflammation prior to brolucizumab injection is recommended. Once vasculopathy is suspected, angiographic imaging may help define the spectrum of involvement. Optimal treatment strategies remain unknown.

Reported Complications Following Laser Vitreolysis.

Importance: Use of laser vitreolysis for symptomatic floaters has increased in recent years, but prospective studies are not available and the complication profile is poorly understood. Objective: To analyze cases of complications following laser vitreolysis as voluntarily reported to the American Society of Retina Specialists Research and Safety in Therapeutics (ASRS ReST) Committee, an independent task force formed to monitor device-related and drug-related safety events. Design, Setting, and Participants: A retrospective assessment was performed of all cases of complications following laser vitreolysis that were voluntarily reported by practitioners throughout the United States to the ASRS ReST Committee from the first report on September 19, 2016, through March 16, 2017, the date of data analysis and manuscript writing. Main Outcomes and Measures: Complications reported to the ASRS ReST Committee following laser vitreolysis were analyzed by type to gain an understanding of the spectrum of potential complications. Results: A total of 16 complications following laser vitreolysis were reported in 15 patients by 7 US vitreoretinal specialists during the study period. Complications included elevated intraocular pressure leading to glaucoma; cataracts, including posterior capsule defects requiring cataract surgery; retinal tear; retinal detachment; retinal hemorrhages; scotomas; and an increased number of floaters. Conclusions and Relevance: This report presents a spectrum of complications reported to the ASRS ReST Committee across 6 months. The rate of complications cannot be determined because the denominator of total cases is unknown. Also, these findings cannot determine whether there is a causal association between these complications and laser vitreolysis. Prospective studies are warranted to better understand the efficacy of this procedure and the frequency of attendant complications. Until then, practitioners should be aware of the profile of potential complications to properly inform patients during the consent process. The ASRS ReST Committee will continue to monitor device-related and drug-related adverse events and encourages active surveillance and reporting by all physicians.

A Comparative Study of Rebound Tonometry With Tonopen and Goldmann Applanation Tonometry Following Vitreoretinal Surgery.

PURPOSE: To investigate agreement in intraocular pressure (IOP) measurements among Icare rebound tonometry, Tonopen tonometry, and Goldmann applanation tonometry following vitreoretinal surgery. DESIGN: Reliability analysis of tonometers. METHODS: Fifty-eyes of 50 adults undergoing vitreoretinal surgery were enrolled. IOP was measured on first postoperative day using Icare (Tiolat, Helsinki, Finland), followed by Tonopen (Reichert, Depew, New York, USA) and Goldmann (Haag-Streit USA, Mason, Ohio, USA) in randomized order. Intraclass correlation coefficients (ICC) and Bland-Altman plots were calculated for all subcategories. RESULTS: Icare successfully measured IOP in all eyes, while Goldmann was unmeasurable in 6 eyes (12%) and Tonopen in 1 eye (2%). Mean IOP by Icare, Tonopen, and Goldmann was 15.9 ± 8.9, 16.9 ± 6.2, and 16.0 ± 7.3 mm Hg, respectively (P = .76). Type of intraocular tamponade, status of lens, status of cornea, gauge of instrumentation, and history of prior vitrectomy did not result in significant differences among the 3 tonometers. ICC was excellent (>0.75) in all subgroups, except at IOP <10 and ≥ 23 mm Hg (based on Icare). In eyes with IOP <10 mm Hg, Icare underestimated IOP (mm Hg; P = .01) compared to Goldmann (2.0 ± 2.1) and Tonopen (3.5 ± 2.4), whereas at IOP ≥ 23 mm Hg Icare was overestimated (P = .01) compared to Goldmann (3.77 ± 3.49) and Tonopen (4.97 ± 3.33). Overall, differences in IOP were ≤ 3 mm Hg in 58% of eyes for Icare-Tonopen, 72% for Tonopen-Goldmann, and 62% for Icare-Goldmann. CONCLUSION: IOP measurements using Icare rebound tonometry, Tonopen, and Goldmann tonometry are in excellent agreement following vitreoretinal surgery. However, Icare overestimates at IOP ≥ 23 and underestimates at IOP <10 mm Hg.

Retained Intraocular Perfluoro-n-octane After Valved Cannula Pars Plana Vitrectomy for Retinal Detachment.

BACKGROUND AND OBJECTIVE: To investigate cases of retained intraocular perfluoro-n-octane (PFO) after pars plana vitrectomy (PPV) for retinal detachment (RD). PATIENTS AND METHODS: Retrospective, noncomparative case series of six eyes with retained intraocular PFO after RD repair. Clinical data were supplemented with an experimental silicone eye model. RESULTS: A cluster of six cases of retained intraocular PFO after PPV for RD repair were noted shortly after transitioning to valved cannulas. PFO was noted in the anterior chamber (AC) and/or vitreous and removed with AC paracentesis, AC wash-out, and/or PPV. A silicone eye model demonstrated that PFO levels are maintained anterior to cannula insertion with valved cannulas only. CONCLUSION: The authors hypothesize that anterior PFO fill using valved cannulas can lead to sequestration within the AC, zonules, ciliary sulcus, ciliary teeth, and/or capsular bag. They suggest vigilance in not overfilling PFO, particularly when transitioning to use of valved cannulas, to minimize the risk of intraocular retention.

Effect of optical coherence tomography scan pattern and density on the detection of full-thickness macular holes.

PURPOSE: To evaluate the impact of different scan patterns and scan densities on small full-thickness macular hole (MH) detection. DESIGN: Retrospective cross-sectional analysis. METHODS: Analysis was performed on 25 eyes from 24 patients with full-thickness MHs imaged with the Heidelberg Spectralis HRA+OCT. Included eyes underwent concurrent imaging with a standard (61-line) raster volume and a 24-line radial pattern. A 6-line radial scan pattern was extrapolated from the higher-density radial pattern. Comparisons of the missed hole rate as well as the proportion of individual B-scans demonstrating a full-thickness defect (termed "full-thickness detection index") were carried out for the 3 scan patterns. Additionally, qualitative and quantitative hole parameters were evaluated to identify factors associated with "missed" holes. RESULTS: Full-thickness defects were missed at substantially higher rates using both standard raster volume (20.0%, 90% confidence interval [CI] 8.2%-37.5%) and 6-line radial scanning (12.0%, 90% CI 3.7%-30.4%) when compared to 24-line radial scanning (0% for both comparisons). Full-thickness detection indices were significantly higher for both radial scan patterns when compared to raster scanning (P < .001 for both comparisons). Missed holes were smaller and commonly associated with prehole flaps. CONCLUSION: High-density radial scanning demonstrated superior detection rates of small full-thickness MHs compared to standard raster volume scanning. This finding may be attributable to the greater foveolar scan density attained with radial scan patterns. Failure to utilize radial scanning in the setting of suspected macular holes may lead to a delay in surgical treatment, with attendant worse anatomic and visual outcomes.

Reduced fluorescein angiography and fundus photography use in the management of neovascular macular degeneration and macular edema during the past decade.

PURPOSE: We assessed recent trends in the use of diagnostic testing for neovascular age-related macular degeneration (NVAMD) and macular edema (ME). METHODS: Claims data from a managed-care network were analyzed on patients with NVAMD (n = 22,954) or ME (n = 31,810) to assess the use of fluorescein angiography (FA), fundus photography (FP), and optical coherence tomography (OCT) from 2001 to 2009. Repeated-measures logistic regression was performed to compare patients' odds of undergoing these procedures in 2001, 2005, and 2009. In addition, the proportions of patients with an incident NVAMD or ME diagnosis in 2003 or 2008 who underwent FA, FP, and OCT were compared. RESULTS: From 2001 to 2009, among patients with NVAMD, the odds of undergoing OCT increased 23-fold, whereas the odds of receiving FA and FP decreased by 68% and 79%, respectively. Similar trends were observed for ME. From 2003 to 2008, the proportion of patients undergoing OCT within 1 year of initial diagnosis increased by 315% for NVAMD and by 143% for ME; the proportion undergoing OCT without FA within 1 year increased by 463% for NVAMD and by 216% for ME. CONCLUSIONS: Use of OCT increased dramatically during the past decade, whereas use of FA and FP declined considerably, suggesting that OCT may be replacing more traditional diagnostic testing in patients with NVAMD or ME. Future studies should evaluate whether this increased reliance on OCT instead of FA and FP affects patient outcomes.

Emerging nonsurgical methods for the treatment of vitreomacular adhesion: a review.

With the dissemination of optical coherence tomography over the past two decades, the role of persistent vitreomacular adhesion (VMA) in the development of numerous macular pathologies - including idiopathic macular hole, vitreomacular traction syndrome, cystoid and diabetic macular edema, neovascularization in diabetic retinopathy and retinal vein occlusion, exudative age-related macular degeneration, and myopic traction maculopathy - has been established. While invasive vitreoretinal procedures have long been utilized to address complications related to these disorders, such an approach is hampered by incomplete vitreoretinal separation and vitreous removal, surgical complications, and high costs. In light of such limitations, investigators have increasingly looked to nonsurgical means for the treatment of persistent pathologic VMA. Chief among these alternative measures is the intravitreal application of pharmacologic agents for the induction of vitreous liquefaction and/or vitreoretinal separation, an approach termed pharmacologic vitreolysis. This article aims to review the available evidence regarding the use of pharmacologic agents in the treatment of VMA-related pathology. In addition, a discussion of vitreous molecular organization and principles of physiologic posterior vitreous detachment is provided to allow for a consideration of vitreolytic agent mode of action and molecular targets.

Lubricant degradation and related wear of a steel pin in lubricated sliding against a steel disc.

In lubricated sliding contacts, components wear out and the lubricating oil ages with time. The present work explores the interactive influence between lubricant aging and component wear. The flat face of a steel pin is slid against a rotating steel disk under near isothermal conditions while the contact is immersed in a reservoir of lubricant (hexadecane). The chemical changes in the oil with time are measured by vibrational spectroscopy and gas chromatography. The corresponding chemistry of the pin surface is recorded using X-ray photoelectron spectroscopy while the morphology of the worn pins; surface and subsurface, are observed using a combination of focused ion beam milling and scanning electron microscopy. When compared to thermal auto-oxidation of the lubricant alone, steel on steel friction and wear are found to accentuate the decomposition of oil and to reduce the beneficial impact of antioxidants. The catalytic action of nascent iron, an outcome of pin wear and disk wear, is shown to contribute to this detrimental effect. Over long periods of sliding, the decomposition products of lubricant aging on their own, as well as in conjunction with their products of reaction with iron, generate a thick tribofilm that is highly protective in terms of friction and wear.