Towards transforming community eye care: an observational study and time-series analysis of optometrists' prescribing for eye disorders.

OBJECTIVES: This study aimed to provide evidence on the therapeutic prescribing activity by community optometrists in Scotland and to determine its impact on workload in general practice and ophthalmology clinics. STUDY DESIGN: Scottish administrative healthcare data for a 53-month period (November 2013-April 2018) were used to analyse non-medical prescribing practice by optometrists. METHODS: Using interrupted time-series regression (Autoregressive Integrated Moving Average), we assessed the impact of optometrist prescribing on ophthalmology outpatient attendances and general practice prescribing for eye disorders. RESULTS: A total of 54,246 items were prescribed by 205 optometrists over the study period. Since the commencement of data recording, optometrist prescribing activity increased steadily from a baseline of zero to 1.2% of all ophthalmic items prescribed. Neither the monthly number of items prescribed nor the size of optometric workforce were associated with a reduction in ophthalmology outpatient appointments over time. CONCLUSIONS: Optometrists increasingly contribute to community ophthalmic prescribing in Scotland, releasing capacity and lessening general practice, but not secondary care workload. There appears to be an underutilisation of optometrists related to the management of dry eye, which represents an opportunity to release further capacity.

Assessment of a variable frame (polygonal) method to estimate corneal endothelial cell counts after corneal transplantation.

PURPOSE: To assess the agreement of the 'polygonal' variable frame cell count option on a confocal microscope after keratoplasty, with planimetry as the reference method. METHODS: One hundred clear corneal grafts of 83 patients attending the cornea clinic at Gartnavel General Hospital in Glasgow underwent slit-scanning in vivoconfocal microscopy. Endothelial cell images were assessed with the Nidek Advanced Vision Information System (NAVIS), using the polygonal variable frame and the manual fixed-frame methods. Planimetry was used as the reference. The agreement between methods was assessed by Bland-Altman analysis. RESULTS: Planimetry provided a mean (± SD) endothelial cell density (ECD) of 1348 ± 726 cells/mm(2), a value that was very similar to that found by the polygonal method (1404 ± 784 cells/mm(2)). The fixed-frame method provided lower cell counts with a mean ECD of 1026 ± 610 cells/mm(2) (P<0.001). When compared with the reference ECD, the polygonal method overestimated the ECD only very slightly with a mean difference of 58 cells/mm(2) (limits of agreement, LoA, of -222 and 339 cells/mm(2)). Manual counting underestimated the ECD with a mean difference of -320 cells/mm(2) (LoA -814 and 173 cell/mm(2)). CONCLUSION: Following keratoplasty, endothelial cell counts with the NAVIS polygonal method are in good agreement with planimetry. The 'polygonal' option is proposed as the method of choice for clinical applications with this confocal microscope and a good compromise between reliability and ease of use.

In vivo confocal microscopy of the corneal endothelium: comparison of three morphometry methods after corneal transplantation.

PURPOSE: The purpose of this study was to assess the endothelium of corneal grafts by in vivo confocal microscopy (IVCM), and to evaluate an automated endothelial software system in comparison with a manual cell count and planimetry. PATIENTS AND METHODS: Overall, 40 corneal grafts (20 deep anterior lamellar keratoplasties (DALKs) and 20 penetrating keratoplasties (PKs)) were assessed by scanning-slit IVCM. The endothelial cell density (ECD) was estimated with the automated and the manual cell count method of the instrument's Nidek Advanced Vision Information System (NAVIS) software. The results were compared with planimetry as the reference method, and the agreement was assessed. RESULTS: The mean (±SD) automated ECD was 2278±524 cells/mm(2) (range 1167-3192 cells/mm(2)), whereas the manual cell count method gave significantly lower ECDs with a mean of 1213±677 cells/mm(2) (range 218-2440 cells/mm(2); P<0.001). The manual cell counts were also significantly lower than those by planimetry, with a mean ECD of 1617±813 cells/mm(2) (range 336-2941, P<0.001). Bland-Altman analyses indicated that the limits of agreement (LoA) between the automated and the planimetry method were -671 and +1992 cells/mm(2), whereas they were -1000 and +202 cells/mm(2) when comparing the manual cell counts with planimetry. CONCLUSION: Following keratoplasty, the NAVIS automated method is likely to overestimate endothelial cell counts due to oversegmenting of the cell domains. Automated ECDs are substantially higher than those by the manual counting method or planimetry. The differences are considerably larger post-keratoplasty than for normal corneas, and the methods should not be used interchangeably.