Comparison of and correlation between anterior and posterior corneal elevation maps in normal eyes and keratoconus-suspect eyes

PURPOSE: To compare the anterior and posterior corneal elevation maps between keratoconus-suspect eyes and normal eyes. SETTING: Rothschild Foundation, AP-HP, University Paris VII, H?pital Bichat Claude Bernard, Paris, France. METHODS: The anterior and posterior corneal surface elevations were analyzed and compared in 60 normal myopic patients and 48 keratoconus-suspect patients. The anterior and posterior best-fit sphere radii, central and thinnest corneal pachymetries, anterior and posterior aconic shape parameters (aconic radius, aconic asphericity, aconic toricity), and anterior and posterior elevation in the 1.0 mm radius zone were analyzed. The correlations between elevation and aconic shape parameters between the anterior and posterior surfaces were compared. RESULTS: The mean central and thinnest pachymetry values were significantly lower in keratoconus-suspect eyes (P<.0001). Compared with normal eyes, keratoconus-suspect eyes had significantly increased anterior toricity (P = .0002) and posterior toricity (P<.0001), more negative asphericity (P = .042), and higher posterior elevation (P<.0001). The correlation between aconic toricity and the anterior and posterior corneal surfaces was better in keratoconus-suspect eyes than in normal eyes. Aconic asphericity and apical curvature were less correlated in keratoconus-suspect eyes than in normal eyes. CONCLUSIONS: The posterior corneal elevation and the corneal thickness values were different in keratoconus-suspect eyes. The correlation between the anterior and posterior corneal aconic shapes was between keratoconus-suspect eyes and normal eyes.     

Ongoing and prolonged response in adult low-grade gliomas treated with radiotherapy

The aim of the present study was to evaluate the impact of first-line radiotherapy on low-grade gliomas (LGGs) growth kinetics. The mean tumor diameter (MTD) of 39 LGGs was retrospectively measured on serial magnetic resonance images before (n = 16) and after radiotherapy onset (n = 39). After radiotherapy, a decrease of the MTD was observed in 37 patients. Median duration of the MTD decrease was 1.9 years (range 0–8.1 years). According to RANO criteria, the rates of partial and minor responses were 15 and 28 % at the first evaluation after radiotherapy and 36 and 34 % at the time of maximal MTD decrease. The presence of a 1p19q codeletion and the absence of p53 expression were associated with longer durations of MTD decrease (5.3 vs 1 years, p = 0.02 and 2.4 vs 1.8 years, p = 0.05, respectively) while no association was observed between IDH1-R132H expression and duration of MTD decrease. In most patients, MTD decrease after radiotherapy occurred in two phases: an initial phase of rapid MTD decrease followed by a second phase of slower MTD decrease. Patients with a high rate of MTD decrease during the initial phase (>7 mm/year) had both a shorter duration of response (1.9 vs 5.3 years, p = 0.003) and a shorter overall survival (5.5 vs 11.6 years, p = 0.0004). LGGs commonly display a prolonged and ongoing volume decrease after radiotherapy. However, patients who respond rapidly should be carefully monitored because they are at a higher risk of rapid progression.     

Three-dimensional representation and qualitative comparisons of the amount of tissue ablation to treat mixed and compound astigmatism

PURPOSE: To compare the shape and volume of the lenticules of corneal tissue ablated for the correction of spherical, cylindrical, and spherocylindrical refractive errors using Boolean operations of theoretical 3-dimensional (3-D) surfaces. SETTING: Department of Ophthalmology, Rothschild Foundation, Paris, France. METHODS: Digital modeling software was used to perform graphic representations of ablated lenticules on 3-D virtual surfaces. Various Boolean operations were performed between different preoperative and postoperative surfaces, and the additional and subtractive properties of ablated theoretical lenticules were analyzed to determine profiles of ablated lenticules for mixed and compound myopic and hyperopic astigmatism. RESULTS: Negative-cylindrical treatment, used to treat simple myopic astigmatism, was equivalent to the combination of a positive-cylindrical and a negative-spherical treatment of the same magnitude. Combining a pure negative-cylindrical and a positive-spherical treatment in a sequential strategy when treating compound astigmatism resulted in redundant ablation (plano lenticule), leading to an unnecessary increase in the amount of tissue ablation. CONCLUSIONS: Negative-cylindrical treatments result in greater tissue ablation than corresponding positive-cylindrical treatments. For any given compound astigmatic error, the strategy using the greater magnitude of positive cylinder incurs the minimal amount of tissue ablation.     

Principes de traitement des lymphomes primitifs du système nerveux central chez l’immunocompétent

Interest in primary CNS lymphoma (PCNSL) is growing because of its increasing incidence in both the immunocompetent and immunodeficient populations. The addition of high-dose methotrexate (MTX) based chemotherapy (CT) before whole brain radiotherapy (WBRT) has significantly improved the prognosis for PCNSL with a median survival rate of 3–4 years and about 30% of the patients having the possibility of lengthy survival and cure. In the elderly (age > 60 years) CT alone (without RT) as initial treatment is recommended. This approach seems a good way of avoiding RT and thereby reducing the risk of delayed neurotoxicity. Intensive CT followed by hematopoietic stem cell rescue (ICH) seems a promising approach for recurrent tumours and a potential alternative option to RT as consolidation treatment in newly diagnosed patients.     

Long-term visual outcome of childhood blepharokeratoconjunctivitis

PURPOSE: To assess the visual outcome of childhood blepharokeratoconjunctivitis. DESIGN: Retrospective noncomparative case series. METHODS: We reviewed visual acuity and corneal examination results for 23 patients (mean age 19 +/- 4 years, range, 11 to 26 years) who had healed more than three years previously (up to 15 years). RESULTS: The disease involved 29 eyes and was unilateral in 17 children. Corneal sequelae (neovascularization or scars) involved 18 eyes (62%) of 15 children (65%). Mean best-corrected visual acuity was 20/25 (range, 20/100 to 20/20). Best-corrected visual acuity was no more than 20/30 in seven eyes (24%) of seven children (30%). Fifteen eyes (52%) of 13 children (45%) had astigmatisms of at least 0.75 diopters attributable to corneal scars. CONCLUSIONS: Corneal and visual sequelae are frequent in childhood blepharokeratoconjunctivitis. Early diagnosis and specific treatment are mandatory.     

Brain lymphoma: usefulness of the magnetic resonance spectroscopy

The diagnosis of primary central nervous system lymphoma (PCNSL) should always be considered as an emergency because of the therapeutic consequences it implies. In immunocompetent patients, it relies on stereotactic biopsy. Unfortunately, clinical and radiological features may be misleading and delay the diagnostic procedure. The case we report here illustrates the contribution of magnetic resonance spectroscopy in the diagnostic approach of a very atypical PCNSL.