Wittich, Walter (2006) Visual function in patients with macular hole. Masters thesis, Concordia University.
|PDF - Accepted Version|
Individuals with Macular Hole (MH) experience visual distortions and a drop in visual acuity. Surgical intervention can restore the retina structurally, but restoration of function remains to be investigated in more detail. The present study examined the rate of acuity recovery over time, using growth-curve analyses with Hierarchical Linear Modeling (HLM), as well as perceptual distortions before and after MH surgery. Pre-operative MH diameter, visual acuity (Snellen, ETDRS and Landolt-C) and perception of a vertical line were recorded in 25 eyes of 24 patients. Participants' perceptual reports of distortions were measured by classification of the line as solid, bent right/left, thinned at the center, or broken. Pre-operative MH diameter predicted pre-operative acuity but not rate of recovery; the latter depended on the patients' lens status instead. Participants with natural lenses and consequent cataract formation had slower recovery when compared to patients with already implanted infra-ocular lenses. The majority of patients (81%) reported symmetrical distortions of the line pre-operatively. After surgery, participants with larger MHs were more likely to retain residual distortions. The use of HLM provides insight into the functional recovery process after MH surgery. The perceptual reports indicate that the majority of MH patients fixate along the vertical axis, resulting in symmetrical perception of the line. Of particular interest is the group reporting thinning of the line preoperatively, as the center should be perceptually missing. Patients seem to fill in the information cortically, resulting in perception of a thinner line at the center.
|Divisions:||Concordia University > Faculty of Arts and Science > Psychology|
|Item Type:||Thesis (Masters)|
|Pagination:||vii, 93 leaves : ill. ; 29 cm.|
|Thesis Supervisor(s):||Overbury, Olga|
|Deposited By:||Concordia University Libraries|
|Deposited On:||18 Aug 2011 14:33|
|Last Modified:||18 Aug 2011 15:14|
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