Tear Proteomics in Infants at Risk of Retinopathy of Prematurity: A Feasibility Study.

Purpose: This feasibility study investigated the practicability of collecting and analyzing tear proteins from preterm infants at risk of retinopathy of prematurity (ROP). We sought to identify any tear proteins which might be implicated in the pathophysiology of ROP as well as prognostic markers. Methods: Schirmer's test was used to obtain tear samples from premature babies, scheduled for ROP screening, after parental informed consent. Mass spectrometry was used for proteomic analysis. Results: Samples were collected from 12 infants, which were all adequate for protein analysis. Gestational age ranged from 25 + 6 to 31 + 1 weeks. Postnatal age at sampling ranged from 19 to 66 days. One infant developed self-limiting ROP. Seven hundred one proteins were identified; 261 proteins identified in the majority of tear samples, including several common tear proteins, were used for analyses. Increased risk of ROP as determined by the postnatal growth ROP (G-ROP) criteria was associated with an increase in lactate dehydrogenase B chain in tears. Older infants demonstrated increased concentration of immunoglobulin complexes within their tear samples and two sets of twins in the cohort showed exceptionally similar proteomes, supporting validity of the analysis. Conclusions: Tear sampling by Schirmer test strips and subsequent proteomic analysis by mass spectrometry in preterm infants is feasible. A larger study is required to investigate the potential use of tear proteomics in identification of ROP. Translational Relevance: Tear sampling and subsequent mass spectrometry in preterm infants is feasible. Investigation of the premature tear proteome may increase our understanding of retinal development and provide noninvasive biomarkers for identification of treatment-warranted ROP.

Potential cost of assumptions within a visual assessment.

We report a man in his 80s who described sudden unilateral loss of vision, resulting in extensive urgent investigations by the accident and emergency department team. Subsequent evaluation of visual acuity with pinhole demonstrated significant improvement, triggering further questioning. It transpired that he was mistakenly wearing his wife's glasses, which accounted for his visual symptoms. This case illustrates the importance of a stepwise approach to visual assessment, and avoiding assumptions, as using the simple pinhole test could have avoided extensive investigations and their subsequent costs.

An Unusual Case of Unilateral Maculopathy.

A 44-year-old male presented with unilateral sudden onset reduced visual acuity. The optical coherence tomography (OCT) scan demonstrated submacular fluid with thickening and hyper-reflectivity of the outer retinal layers, together with subfoveal retinal pigment epithelial hyper-reflectivity corresponding to a small area of foveal interdigitation zone/ellipsoid zone (IZ/EZ) loss in the detached retina. An OCT 4 months later showed resolution of the submacular fluid, but the IZ/EZ loss persisted with thinning of the outer nuclear layer, resulting in a poor visual outcome. The clinical findings most likely represent a case of unilateral acute idiopathic maculopathy; however, the OCT features and poor visual outcome are not typical. Differential diagnoses include acute solar maculopathy, central serous chorioretinopathy, poppers maculopathy, whiplash maculopathy, and acute retinal pigment epitheliitis.

Anterior segment optical coherence tomographic characterisation of keratic precipitates.

BACKGROUND/OBJECTIVES: Anterior segment optical coherence tomography (AS-OCT) can be used to visualise keratic precipitates (KPs) on the corneal endothelium. However, there has been no correlation between characteristic clinical appearances of KPs and AS-OCT morphology. We wished to assess the potential diagnostic role of AS-OCT in patients presenting with inflammatory eye disease and KPs. SUBJECTS/METHODS: Six patients with inflammatory KPs were compared to one patient with infective interface keratitis following Descemet Membrane Endothelial Keratoplasty (DMEK) and one patient with endothelial pigment. AS-OCT was performed in each case and morphological features of the KPs were compared. Reflectivity of KPs was also compared numerically by measuring their relative lightness. RESULTS: AS-OCT images in acute and active inflammation generally demonstrated hyperreflective KP variants in comparison to conditions with moderate or longstanding inflammation. In the patient with infective interface keratitis, KPs were evident on the endothelial surface but no changes could be identified at the graft-host interface. There were no significant differences between infective and inflammatory KPs to help distinguish between the two. Endothelial pigment deposits were clearly differentiated from keratic precipitates with smaller, poorly defined deposits on the endothelium surface which were isoreflective to the cornea. CONCLUSION: Hyperreflective KPs could be suggestive of newly deposited KPs and active inflammation; they may also be increased in KPs of herpetic origin. AS-OCT should not be used to differentiate infective infiltrate from inflammatory KPs if a patient were to present with post-operative inflammation and interface infection should still be suspected even if only endothelial deposits are identified on AS-OCT. AS-OCT may be used as a diagnostic and monitoring tool to assess response to treatment in cases where anterior segment inflammation of uncertain aetiology is present.