Foveal Cone Structure in Patients With Blue Cone Monochromacy.

Purpose: Blue cone monochromacy (BCM) is a rare inherited cone disorder in which both long- (L-) and middle- (M-) wavelength sensitive cone classes are either impaired or nonfunctional. Assessing genotype-phenotype relationships in BCM can improve our understanding of retinal development in the absence of functional L- and M-cones. Here we examined foveal cone structure in patients with genetically-confirmed BCM, using adaptive optics scanning light ophthalmoscopy (AOSLO). Methods: Twenty-three male patients (aged 6-75 years) with genetically-confirmed BCM were recruited for high-resolution imaging. Eight patients had a deletion of the locus control region (LCR), and 15 had a missense mutation-Cys203Arg-affecting the first two genes in the opsin gene array. Foveal cone structure was assessed using confocal and non-confocal split-detection AOSLO across a 300 × 300 µm area, centered on the location of peak cell density. Results: Only one of eight patients with LCR deletions and 10 of 15 patients with Cys203Arg mutations had analyzable images. Mean total cone density for Cys203Arg patients was 16,664 ± 11,513 cones/mm2 (n = 10), which is, on average, around 40% of normal. Waveguiding cone density was 2073 ± 963 cones/mm2 (n = 9), which was consistent with published histological estimates of S-cone density in the normal eye. The one patient with an LCR deletion had a total cone density of 10,246 cones/mm2 and waveguiding density of 1535 cones/mm2. Conclusions: Our results show that BCM patients with LCR deletions and Cys203Arg mutations have a population of non-waveguiding photoreceptors, although the spectral identity and level of function remain unknown.

Military Health System Opioid, Tramadol, and Gabapentinoid Prescription Volumes Before and After a Defense Health Agency Policy Release.

BACKGROUND: Clinical practice guidelines (CPGs) and health system policies to mitigate inappropriate opioid prescribing practices may have an extended impact on low-dose opioid (e.g., tramadol) and non-opioid (e.g., gabapentinoid) pain medication prescribing practices. OBJECTIVE: To evaluate changes in opioid, tramadol, and gabapentinoid prescribing rates from January 2016 to February 2020 within the Military Health System, including the degree to which prescribing rates changed after release of a US Defense Health Agency Procedural Instruction. METHODS: In this observational health services research study, opioid, tramadol, and gabapentin prescription dispense events of US Military Health System beneficiaries enrolled in care at military treatment facilities prior to US Defense Health Agency Procedural Instruction release (January 2016-May 2018) were used to forecast values from the post-intervention period (June 2018-February 2020). RESULTS: The median opioid and tramadol prescribing rates decreased from January 2016 to February 2020, aside from tramadol prescribing in Surgery Clinics, which increased. Gabapentinoid prescribing rate changes were mixed. In Bayesian time series models, the forecasted proportion of patients receiving each of the three medications, regardless of age group or clinic type, did not significantly vary from the actual prescribing rates in the post-intervention period. CONCLUSION: Overall, CPGs and policies targeting opioid prescribing practices may have provided the maximal impetus for providers to re-evaluate their prescribing practices, as the policy did not appear to change the slope in prescribing rates. However, it is unclear whether the policies mitigated the likelihood of plateaus in prescribing rates. Further work is needed to assess the degree to which providers simultaneously altered other non-opioid pain medication prescribing practices, self-management recommendations, and non-pharmacological therapy referrals.