Shortened Pattern Electroretinogram Latency and Impaired Autoregulatory Dynamics to Steady-State Stimuli in Patients With Multiple Sclerosis.

BACKGROUND: The steady-state pattern electroretinogram (PERG) is a sensitive measure of retinal ganglion cell (RGC) function that includes within-test progressive changes-adaptation-reflecting RGC autoregulatory dynamics. Comprehensive PERG assessment in patients with multiple sclerosis (MS) (with or without optic neuritis [ON]) may provide unique information about RGC dysfunction and its progression, as well as a comparison between functional loss and structural loss as measured by optical coherence tomography (OCT). The goal of this project was to measure steady-state PERG components and their associations with intraretinal layer thicknesses in MS. METHODS: One hundred forty eyes of 70 patients with relapsing-remitting MS and 126 eyes of 63 age- and sex-matched healthy control subjects (HC) were investigated using a new-generation PERG method and ultrahigh-resolution OCT. Of MS eyes, there were 30 eyes with ON (MSON), 22 non-ON fellow eyes (MSFE), and 88 non-ON MS eyes (MSNON). PERG amplitude, phase (latency), and adaptation of amplitude and phase were measured and correlated with OCT-determined thicknesses of intraretinal layers. RESULTS: The average PERG amplitude in MSON eyes was significantly lower than MSFE (P = 0.007), MSNON (P = 0.002), and HC (P < 0.001). The PERG amplitude in MSFE eyes was also significantly lower than HC (P = 0.039). The PERG latency in MSON eyes was significantly shorter than in MSFE (P = 0.001), MSNON (P = 0.002), and HC (P < 0.001). The PERG latency in MSFE (P = 0.007) and MSNON (P = 0.002) was significantly shorter than in HC. However, no significant differences were found between MSFE and MSNON (P > 0.05). PERG adaptation of amplitude in MSON was significantly lower than that in MSNON (P = 0.039) and HC (P = 0.037). Both the amplitude and latency in the MS eyes were significantly correlated with the thicknesses of the macular retinal nerve fiber layer (mRNFL) and ganglion cell-inner plexiform layer (GCIPL). CONCLUSIONS: Shortened PERG latency and impaired autoregulatory dynamics occurred in MS, suggesting preferential dysfunction of small, slower RGC axons and decreased ability of RGC to autoregulate their gain in response to PERG stimulus. The established relations of PERG measurements with intraretinal thickness measurements suggested that PERG losses were primarily associated with GCIPL and mRNFL thinning.

Long-term PERG monitoring of untreated and treated glaucoma suspects.

PURPOSE: To investigate long-term structural and functional progression of untreated and treated glaucoma suspects (UGS and TGS). METHODS: Retrospective analysis of serial steady-state pattern electroretinogram (PERG), mean retinal nerve fiber layer thickness (RNFLT), and standard automated perimetry mean deviation (SAP-MD) in UGS (N = 20) and TGS (N = 18). Outcome measures were the rates of change (linear regression slopes) of PERG amplitude, PERG phase, mean RNFLT, and SAP-MD over 9.8 ± 1.3 years (15.6 ± 4.2 visits). RESULTS: The number of patients with significant (P < 0.05) progression slopes for PERG amplitude, PERG phase, RNFLT, and SAP-MD was, respectively, UGS: 5, 0, 4, 2; TGS: 8, 2, 6, 5. In UGS, outcome measures were not correlated with each other. In TGS, both PERG amplitude and RNFLT were significantly (P < 0.05) correlated with SAP-MD (R ≥ 0.58), while PERG amplitude and RNFLT were not correlated with each other (R = 0.43, P = 0.064). The rate of change of SAP-MD was predicted (P < 0.05) by a linear combination of RNFLT slope and PERG amplitude slope. CONCLUSIONS: Results substantiate and extend previous results showing that steady-state PERG amplitude progressively decreased over time in a proportion of glaucoma suspects, with relatively steeper slope in TGS compared to UGS. RNFLT progression also had a steeper slope in TGS compared to UGS; however, progressions of PERG amplitude and RNFLT were not significantly correlated. Both PERG progression and RNFLT progression independently contribute to prediction of visual field progression.

Cataract progression after primary pars plana vitrectomy for uncomplicated rhegmatogenous retinal detachments in young adults.

BACKGROUND: Scleral buckling is typically implemented to repair rhegmatogenous retinal detachments (RRD) in young patients. Therefore, there is limited data on post-pars plana vitrectomy (PPV) cataract formation in this cohort. We report the rates and risk factors of cataract progression after PPV for RRD repair in young eyes. METHODS: Retrospective single-center cohort study. Medical records of patients between the ages of 15 to 45 undergoing PPV for uncomplicated RRD between 2014 and 2020 were reviewed. RESULTS: Twenty-eight eyes from 26 patients met inclusion criteria. Cataracts developed in 20/28 (71%) eyes after PPV. After PPV, nuclear sclerotic cataract (NSC) rates were higher in patients above 35 (65%) compared to below 35 years (18%) (p = 0.024). Cataracts developed more frequently after macula-off RRDs (88%) compared to macula-on RRDs (50%) (p = 0.044) with NSC more common in macula-off detachments (p = 0.020). At postoperative month 2, all eyes with C3F8 gas developed cataracts compared to 59% of eyes with no gas (p = 0.040). CONCLUSIONS: Cataract formation was common and frequent after PPV. After PPV, young eyes and macula-on detachments developed cataracts less frequently than older eyes and macula-off detachments. If appropriate, a shorter acting gas tamponade should be considered in young eyes to minimize cataract formation.

Lens and Peripheral Retinal Relationships During Vitrectomy: Comparison of 23-, 25-, and 27-Gauge Vitrectomy and Curved Endolaser Probes.

Purpose: This work aims to compare spatial relationships between the crystalline lens and vitrectomy instruments of different gauges. Methods: Eight phakic eyes recovered from deceased donors were used after fixation. Valved trocars (27-gauge, 25-gauge, and 23-gauge) were sequentially placed in the superotemporal quadrant 4 mm posterior to the limbus in each eye. Intraocular relationships of vitrectomy and curved endolaser probes were measured for each gauge. Results: There were no significant differences in maneuverability between instruments of different gauges. The mean distance from instrument to lens at the geometric center of the globe was 5.5 mm. Vitrectomy probes of all gauges could access the peripheral retina on both sides of the sclerotomy in the 3 to 4 o'clock position adjacent to the sclerotomy without touching the lens. The instruments could be advanced without lens touch to contact the retina within at least 2 mm of the ora serrata 180° away from the insertion site. Conclusions: Vitrectomy and curved endolaser probes achieved similar maneuverability relative to the lens regardless of gauge. This study confirms that small-gauge vitrectomy instruments have a considerable range of safe access to the peripheral retina in phakic eyes from a single sclerotomy.

Clinical Features, Antibiotic Susceptibility Profiles, and Outcomes of Infectious Keratitis Caused by Achromobacter xylosoxidans.

PURPOSE: Reports on Achromobacter xylosoxidans ocular infections are increasing, drawing attention to its emerging role in infectious keratitis. The purpose of this study is to report the clinical features, antibiotic sensitivities, and visual outcomes of infectious keratitis secondary to Achromobacter xylosoxidans. METHODS: A microbiology database and clinical chart review was performed in all patients diagnosed with A. xylosoxidans keratitis at the Bascom Palmer Eye Institute between the years 1987 and 2014. Initial presentation, antimicrobial susceptibilities, minimum inhibitory concentrations (MICs), treatment course, and outcomes were recorded. RESULTS: Twenty-eight patients were identified. The main risk factors were corneal graft (n = 8, 28.6%) and contact lens wear (n = 8, 28.6%). On presentation, visual acuity was 20/100 or worse in 20 (71.2%) patients. Hypopyon was present in 7 (25.0%) patients. In most cases, topical fluoroquinolones or tobramycin were the initial treatment, often accompanied by vancomycin. High susceptibility rates were found for piperacillin [100%, minimum inhibitory concentration for 90% of isolates (MIC90) = 8] and ticarcillin (100%, MIC90 = 16). Low susceptibility rates were documented for ciprofloxacin (46.7%, MIC90 = 8), tobramycin (26.7%, MIC90 = 16), and gentamicin (20%, MIC90 = 16). One (3.6%) patient suffered endophthalmitis. Six (21.4%) patients underwent therapeutic penetrating keratoplasty, and 2 (7.1%) patients had conjunctival flap surgery. Visual acuity at final follow-up was 20/100 or worse in 16 (57.1%) patients. CONCLUSIONS: Infectious keratitis caused by A. xylosoxidans is associated with poor visual outcomes. Fluoroquinolones and aminoglycosides are not appropriate treatments for these ocular infections. Further studies are needed to define the clinical application of compound piperacillin and ticarcillin eye drops.