Chapter 1: Review of Literature

As mentioned in the introduction it is evident from some of the literature and also from the investigation now presented that we have here an eye-anomaly with a series of characteristic findings. The individual findings consist most often of an inferiornasal crescent, dysversion of the optic disc with inverse vessel emergence, nasal fundus ectasia with thinning of the sclera, choroid and retina, myopia, astigmatism and relative temporal visual field defect. All of these symptoms are not necessarily present in every patient with the anomaly. Since one is dealing with commonly occurring individual symptoms with a gradual approach to the normal there is no sharp natural line to define the presence of the anomaly. The individual symptoms, definition, criteria and limits are discussed in the individual chapters. Some symptoms vary from one patient to the other, both within families wherein several have the anomaly and between the two eyes in the same patient, which entails using the total number of eyes rather than the total number of patients in the final analysis. The ectasia of the fundus and the consequent presence of the relative visual field defect have in my own work been decisive in my selection of patient material which is therefore not immediately comparable with several of the works to which I refer. Many of the works mentioned, even when they have taken another starting point, include so much important and relevant information about the anomaly herein described that I found it natural to attach much importance to them in reviewing the literature. The practical ophthalmological interest attaches chiefly to the fundus ectasia and the visual field defect this causes. On these grounds I have found that in the existing name jungle the term “the nasal fundus ectasia” was that which best covered the anomaly.