Factors affecting the results of argon laser trabeculoplasty in open-angle glaucoma

Argon laser trabeculoplasty (ALT) was performed in 232 eyes of 180 patients affected by uncontrolled primary open-angle glaucoma (POAG), exfoliation syndrome glaucoma (ESG) or pigment dispersion syndrome glaucoma (PDSG). Mean follow-up was 9 months (3-22). Mean IOP change was -21.6% (+/- 19) from the initial value. The effect of IOP was larger in patients with ESG, PDSG, and in POAG cases with more pigmented trabecular meshwork. No relationship was found between IOP changes and age or refraction of patients; the association with iridoplasty did not influence final results. An Octopus computerized perimeter was used for pre and post-treatment visual field tests. In 113 eyes Octopus exams met the requirements for quantitative analysis. In this group 17% of visual field improved, 64% remained stable and 19% worsened. A good functional response was more frequent among the eyes with less advanced disease.     

The effect of repeating full-circumference argon laser trabeculoplasty

Seventeen eyes of 16 patients who were classified as treatment failures following 360 degrees of argon laser trabeculoplasty underwent repeat treatment of the meshwork with the argon laser. Average intraocular pressure was significantly reduced from 22.5 +/- 6.8 to 19.3 +/- 6.1 mm Hg (P less than 0.05). Fifty-three percent of cases had a reduction and 12% had an increase in intraocular pressure of greater than or equal to 3 mm Hg at an average follow-up of 12 weeks. Visual function was not stabilized in 41% of the cases with 29% requiring further glaucoma surgery.     

Mitochondrial disorders caused by mutations in respiratory chain assembly factors

Mitochondrial diseases involve the dysfunction of the oxidative phosphorylation (OXPHOS) system. This group of diseases presents with heterogeneous clinical symptoms affecting mainly organs with high energy demands. Defects in the multimeric complexes comprising the OXPHOS system have a dual genetic origin, mitochondrial or nuclear DNA. Although many nuclear DNA mutations involve genes coding for subunits of the respiratory complexes, the majority of mutations found to date affect factors that do not form part of the final complexes. These assembly factors or chaperones have multiple functions ranging from cofactor insertion to proper assembly/stability of the complexes. Although significant progress has been made in the last few years in the discovery of new assembly factors, the function of many remains elusive. Here, we describe assembly factors or chaperones that are required for respiratory chain complex assembly and their clinical relevance.     

Perinatal cerebral insults alter auditory event-related potentials

Background

Auditory event-related potentials (AERPs) can be used as indices of neural information processing. Altered AERPs have been reported in children and young adults with frontal lobe infarction.

Aim

To test the hypothesis that perinatal brain injury affects cortical auditory processing.

Methods

We assessed AERPs at term, 6 and 12 months of age in preterm infants [n = 9, median gestational age (GA) 27.9, range 23.9-30.0 wk], term infants with perinatal intracerebral hemorrhage (ICH) [n = 5, GA 40.3, range 37.4-42.3 wk], and term infants with perinatal asphyxia [n = 4, GA 39.4, range 37.9-40.3 wk]. Healthy preterm (n = 16) and term infants (n = 22) served as controls. A harmonic tone of 500-Hz frequency was used as standard and of 750-Hz as deviant stimulus. Mean AERP amplitudes were calculated over 100 ms periods from 50 to 350 ms. The developmental outcome was followed until 2 years of age.

Results

The term ICH (p = 0.012) and asphyxia (p = 0.0016) group had smaller or more negative responses to the deviant, resulting in smaller or more negative MMR amplitudes than those of the controls. The preterm ICH group did not differ significantly from their preterm born controls. MMR varied in all patient groups and was not associated with adverse outcome.

Conclusion

AERP alterations suggest that perinatal cerebral insults affect cortical auditory processing.     

Screening of <Emphasis Type="Italic">BCS1L</Emphasis> mutations in severe neonatal disorders suspicious for mitochondrial cause

The BCS1L gene encodes a chaperone responsible for assembly of respiratory chain complex III (CIII). A homozygous point mutation (232A-->G) has been found as the genetic etiology for fetal growth retardation, amino aciduria, cholestasis, iron overload, lactic acidosis, and early death (GRACILE) syndrome (MIM 603358). Variable phenotypes have been found with other mutations. Our aim was to assess whether 232A-->G or other BCS1L mutations were present in infants (n = 21) of Finnish origin with severe, lethal disease compatible with mitochondrial disorder. A further aim was to confirm the GRACILE genotype-phenotype constancy (n = 8). Three new cases with homozygous 232A-->G mutation were identified; all had the primary GRACILE characteristics. No other mutations were found in the gene in other cases. All infants with GRACILE syndrome had the typical mutation. In conclusion, the rather homogenous population of Finns seems to have a specific BCS1L mutation that, as homozygous state, causes GRACILE syndrome, whereas other mutations are rare or not occurring. Thus, the novel clinical implication of this study is to screen for BCS1L mutations only if CIII is dysfunctioning or lacking Rieske protein, and to assess 232A-->G mutation in cases with GRACILE syndrome.