Corneal Endothelial Decompensation after Ocular Chemical Burn: Description of a New Finding.

BACKGROUND: Ocular chemical burn is an ophthalmological emergency. Therefore, chemical injuries should be promptly addressed in order to initiate the appropriate treatment as soon as possible and optimize the visual prognosis. We present a retrospective study of ten cases with ocular chemical burn including one with superglue and one with a liquid plaster material injury and describe their clinical course. HISTORY AND SIGNS: Ten adult patients (34 - 92 years, 8 males) presented with moderate to severe alkali or neutral chemical burns in our emergency clinics. They exhibited a variable degree of conjunctival injection, limbal ischemia, corneal erosion, and Descemet's folds. THERAPY AND OUTCOME: Patients were treated and complete corneal epithelial closure was achieved in all cases without significant signs of limbal stem cell insufficiency. Corneal endothelial insufficiency was observed in all cases. Nine patients had to be listed for corneal endothelial keratoplasty and one was treated with Descemet's stripping endothelial automated keratoplasty. CONCLUSIONS: Isolated corneal endothelial decompensation after chemical burns has not yet been described. The pathophysiological explanation of this observation remains, however, unknown. In view of this rare complication, it is important to follow patients after chemical ocular burn for possible development of endothelial decompensation.

INCREASED INTRAOCULAR PRESSURE IS A RISK FACTOR FOR UNEXPLAINED VISUAL LOSS DURING SILICONE OIL ENDOTAMPONADE.

PURPOSE: To identify the incidence rate and risk factors for unexplained visual loss associated with silicone oil endotamponade used during primary repair of macula-sparing rhegmatogenous retinal detachments. METHODS: This retrospective cohort study included patients undergoing pars plana vitrectomy for primary surgical repair of macula-sparing rhegmatogenous retinal detachments in whom silicone oil endotamponade was used. The primary outcome measure was the incidence rate of unexplained visual loss and identification of risk factors associated with vision loss. RESULTS: Of 1,218 eyes undergoing pars plana vitrectomy for primary retinal detachment repair, 44 eyes were included for analysis. In 9 eyes (20%), an unexplained vision loss occurred. Logistic regression identified increased intraocular pressure (IOP) (prospectively defined as IOP readings during silicone oil endotamponade ≥21 mmHg on two consecutive visits or ≥25 mmHg at any time during this period) as significant predictor (odds ratio = 4.9; P = 0.04) and a classification tree ranked IOP as the most important variable for vision loss. Incidence rate of vision loss in eyes experiencing IOP increase was 4.5 vision loss events per 1,000 days at risk compared with 1 event per 1,000 days in eyes without IOP increase, yielding an incidence rate ratio of 4.5 (95% confidence interval: 1.1-17.9; P = 0.02). CONCLUSION: Sufficient control of IOP during silicone oil endotamponade for primary retinal detachment repair is warranted to reduce the probability of vision loss.

Decrease of gray matter volume in the midbrain is associated with treatment response in medication-overuse headache: possible influence of orbitofrontal cortex.

Patients with chronic daily headache and overuse of analgesics, triptans, or other acute headache compounds, are considered to suffer from medication-overuse headache (MOH). This implies that medication overuse is the cause of headache chronification. It remains a key question why only two-thirds of patients with chronic migraine-like headache and overuse of pain medication improve after detoxification, whereas the remainder continue to have chronic headache. In the present longitudinal MRI study, we used voxel-based morphometry to investigate gray matter changes related to medication withdrawal in a group of humans with MOH. As a main result, we found that only patients with significant clinical improvement showed a significant decrease of previously increased gray matter in the midbrain including periaqueductal gray matter and nucleus cuneiformis, whereas patients without improvement did not. Patients without treatment response had less gray matter in the orbitofrontal cortex. Another striking result is the correlation of treatment response with the amount of orbitofrontal gray matter. Thus, we demonstrate adaptive gray matter changes within the pain modulatory system in patients with MOH who responded to detoxification, probably reflecting neuronal plasticity. Decreased gray matter in the orbitofrontal cortex at baseline may be predictive of poor response to treatment.

Grey matter changes associated with medication-overuse headache: correlations with disease related disability and anxiety.

OBJECTIVES: Medication-overuse headache (MOH) is associated with psychiatric comorbidities. Neurobiological similarities to substance dependence have been suggested. This study investigated grey matter changes, focussing on pain and reward systems. METHODS: Using voxel-based morphometry, structural MRIs were compared between 29 patients with both, MOH and migraine, according to International Headache Society criteria, and healthy controls. The Migraine Disability Assessment (MIDAS) score was used. Anxiety and depression were screened for with the Hospital Anxiety and Depression Scale (HADS) and confirmed by a psychiatrist, using the Mini International Neuropsychiatric Interview. RESULTS: Nineteen patients (66%) had a present or past psychiatric disorder, mainly affective (N = 11) and anxiety disorders (N = 8). In all patients a significant increase of grey matter volume (GMV) was found in the periaqueductal grey matter of the midbrain, which correlated positively with the MIDAS and the HADS-anxiety subscale. A GMV increase was found bilaterally in the thalamus, and the ventral striatum. A significant GMV decrease was detected in frontal regions including orbitofrontal cortex, anterior cingulate cortex, the left and right insula, and the precuneus. CONCLUSION: These findings are consistent with dysfunction of antinociceptive systems in MOH, which is influenced by anxiety. Dysfunction of the reward system may be a neurobiological basis for dependence in a subgroup of MOH patients.