Monitoring of visual field over 6 months after active ocular toxoplasmosis.

PURPOSE: To prospectively report the perimetric defects during a 6-month follow-up (FU) in patients with initially active ocular toxoplasmosis (OT). METHODS: Twenty-four patients were studied, including 11 eyes with chorioretinal toxoplasmosis proven with a positive aqueous humor sample and 13 eyes with a biologically unproven, chorioretinal lesion. Automated 24-2 SITA-Standard visual fields were performed at baseline, at the first, and sixth months of FU. A composite clinical severity score was calculated from visual acuity (VA), severity of vitreitis, chorioretinal lesion size, location of the lesion in zone 1, the presence of an initial macular or papillary edema, and long-term scarring. This provided a relative cutoff level of severity. Nine eyes out of the 24 eyes were considered severe (3 unproven and 6 proven OT). RESULTS: Initial and final visual field parameters (mean deviation [MD] and pattern standard deviation [PSD]) were significantly correlated (r = 0.873; p < 0.001, and r = 0.890; p < 0.001, respectively). During FU, only foveal threshold [FT] was correlated with VA at baseline (r = 0.48; p = 0.01) and at the 6-month FU visit (r = 0.547; p = 0.004). The MD initial predictive value of clinical severity was 0.739 according to the ROC curve. At baseline, severe and nonsevere OT exhibited no significant difference in term of MD (p = 0.06) and PSD (p = 0.1). During the FU, taking into account all the data, MD, PSD, visual function index [VFI], and FT were associated with the severity of toxoplasmosis (p = 0.018, 0.05, 0.016, and 0.02, respectively): the unproven group had a faster recovery of MD during FU (p = 0.05). CONCLUSION: Visual field parameters better reflected the chorioretinal destruction related to the toxoplasmosis lesion and the functional repercussions than VA alone. Interestingly, MD at presentation could be a discriminating factor of severity in active OT, and each visual field parameter follow-up could be a support to manage patients with active OT, especially in the severe group.

[How to ensure that glaucoma is stable? Intraocular pressure]. / Comment s'assurer de la stabilité d'un glaucome? La pression intraoculaire.

In patients with open-angle glaucoma, intraocular pressure (IOP) obtained through treatment should guard against the progression of glaucoma damage. This depends on the initial state of intraocular pressure, but also on the stage of glaucoma, how fast the alterations are progressing, the patient's age and life expectancy, as well as the presence of other risk factors. To determine the ideal level of treated IOP, the term "target pressure" is often used. This term is very much open to criticism, however, because it calls on a static figure for what is highly variable biological information belonging to the body's biological rhythms. A large number of formulas are used to calculate this target pressure number, but all of them come up against the disadvantage of not taking into account the variations in IOP during the day/night cycle. Yet it is these very variations that can characterize the severity of the disease in terms of IOP. In a glaucoma patient, the IOP curve plotted over 24 h has higher IOP values during the day than at night, contrary to a healthy subject. Fluctuations of more than 10 mmHg are not rare during the day/night cycle, most often with many peaks, which are deleterious for retinal nerve fibers. These dynamic pressure parameters are essential both in determining the therapeutic strategy and in evaluating the effectiveness of treatment. In practice, with any case of open-angle glaucoma and before any treatment is given, a diurnal curve should be established. Six to eight measurements between 8 AM and 6 or 8 PM should be enough. They should be carefully combined with concomitant measures of systemic blood pressure. Once treatment has started, we suggest that a new diurnal curve be established 1 month and then 4 months after the beginning of treatment. The treatment will be modified if needed, based on IOP criteria established at 1 month, and on IOP, perimetric, and anatomic criteria determined again at 4 months. If the disease continues to worsen despite a satisfactory diurnal IOP, IOP should be measured over 24 h, associated with Holter monitoring, looking for an escape of pressure at night.