ABSTRACT
Patients with both cataract and keratoconus present unique challenges for the surgeon. Accurate keratometry (K) and axial length (AL) readings may be impossible, and uncertainty is introduced when estimating the corneal power for intraocular lens (IOL) selection. Different options on how to choose an IOL and how to manage irregular astigmatism of a keratoconic patient with cataract have been proposed and are reviewed. The stage of keratoconus and the history of the patient are both critical in determining the strategy used in treatment of cataracts.
Subject(s)
Cataract/complications , Intraoperative Complications/prevention & control , Keratoconus/complications , Lenses, Intraocular , Optics and Photonics , Postoperative Complications/prevention & control , Astigmatism/therapy , Axial Length, Eye/pathology , Biometry , Cataract/physiopathology , Humans , Keratoconus/physiopathology , Lens Implantation, Intraocular , PhacoemulsificationABSTRACT
Age-related hearing loss - presbycusis - is the most common communication problem and third most prevalent chronic medical disorder of the aged. The CBA and C57BL/6 mouse strains are useful for studying features of presbycusis. The CBA loses its hearing slowly, like most humans. Because the C57 develops a rapid, high frequency hearing loss by middle age, it has an "old" ear but a relatively young brain, a model that helps separate peripheral (cochlear) from central (brain) etiologies. This field of sensory neuroscience lacks a good mouse model for the 5-10% of aged humans with normal cochlear sensitivity, but who have trouble perceiving speech in background noise. We hypothesized that F1 (CBA×C57) hybrids would have better hearing than either parental strain. Measurements of peripheral auditory sensitivity supported this hypothesis, however, a rapid decline in the auditory efferent feedback system, did not. Therefore, F1s might be an optimal model for studying cases where the peripheral hearing is quite good in old age; thereby allowing isolation of central auditory changes due to brain neurodegeneration.
Subject(s)
Aging/physiology , Breeding/methods , Chimera/physiology , Hearing Loss, Central/genetics , Hybrid Vigor/physiology , Animals , Auditory Pathways/physiopathology , Disease Models, Animal , Efferent Pathways/physiopathology , Female , Male , Mice , Mice, Inbred C57BL , Mice, Inbred CBA , Species SpecificityABSTRACT
Juvenile neuronal ceroid lipofuscinoses, or Batten disease, is the most common type of NCL in the United States and Europe. This devastating disorder presents with vision failure and progresses to include seizures, motor dysfunction, and dementia. Death usually occurs in the third decade, but some patients die before age twenty. Though the mechanism of visual failure remains poorly understood, recent advances in molecular genetics have improved diagnostic testing and suggested possible therapeutic strategies. The ophthalmologist plays a crucial role in both early diagnosis and documentation of progression of juvenile neuronal ceroid lipofuscinoses. We update Batten disease research, particularly as it relates to the eye, and present various theories on the pathophysiology of retinal degeneration.
