Hypothesis 1. MfERG is useful in the assessment of retinal dysfunction in patients following photodynamic therapy with verteporfin. / Hypothesis 2. MfERG is useful in the evaluation of retinal dysfunction in patients following safety-enhanced photodynamic therapy using half-dose verteporfin. / Hypothesis 3. MfERG is useful in the assessment of retinal dysfunction in patients receiving hydroxychloroquine therapy. / Hypothesis 4. MfERG findings correlate to certain extent with the visual field findings in patients receiving hydroxychloroquine therapy and mfERG might be more sensitive compared with 10-2 visual field testing in assessing retinal dysfunction associated with hydroxychloroquine therapy. / Hypothesis 5. MfERG is useful In the assessment of retinal dysfunction associated with intraoperative application of indocyaniue green for internal limiting membrane staining in epiretinal membrane surgery. / Multifocal electroretinography (mfERG) is an investigation which can provide objective assessment of retinal function, In contrast with full-field electroretinography which measures the mass electrical activity of the entire retina, mfERG allows simultaneous measurements of multiple retinal responses from the macula. / Several studies have demonstrated that mfERG might be useful in assessing retinal dysfunction caused by pharmacological agents and following laser therapy. This thesis aims to demonstrate the application of mfERG in the evaluation of retinal dysfunction associated with various ocular or systemic pharmacological agents. Three treatment modalities including photodynamic therapy with verteporfin, systemic use of hydroxychloroquine, and intraoperative application of indocyanine green dye were chosen for evaluation. These pharmacological agents were selected as they are associated with potential retinal dysfunction and are commonly encountered in the ophthalmic clinical practice. The thesis examines the following hypotheses: / Summary of studies arising from the thesis. Based on the findings from the above studies, it was demonstrated that mfERG can objectively evaluate the retinal dysfunction caused by a variety of ocular or systemic pharmacological agents. These included PDT with verteporfin, systemic therapy with hydroxychloroquine, as well as intraoperative application of ICG dye for ILM staining. The use of mfERG has enhanced the understanding of the underlying pathophysiology of drug-associated retinal toxicity. As mfERG becomes more widely available, its application will provide a valuable option for clinicians to assess toxic retinopathy objectively and enable safer administration of treatment to minimize potential retinal toxicity. (Abstract shortened by UMI.) / by Lai Yuk Yau, Timothy. / Source: Dissertation Abstracts International, Volume: 69-02, Section: B, page: 0951. / Thesis (M.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 161-183). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / School code: 1307.