Abstract
This thesis, presented as a thesis incorporating publications, examines the effects of phacoemulsification, uveitis and high intensity focused ultrasound on the aqueous humour dynamics.The interplay between aqueous humour parameters are complex. The impacts of various pathologies and pharmacological changes in glaucoma and healthy subjects have been extensively investigated. However, the evidence on the modern cataract surgery and the aqueous humour dynamics has not been consistent. It has been shown in previous studies that phacoemulsification reduces intraocular pressure (IOP). But the mechanism through which IOP is reduced is not fully understood. I performed electronic Schiøtz tonography to measure outflow facility before and after phacoemulsification. I demonstrated that the tonographic outflow facility (TOF) enhancement as a result of cataract surgery in open angle glaucoma (OAG) cases is responsible for IOP reduction. On the other hand, uveitis can be a sight threating condition especially due to its sequlae such as glaucoma. The animal studies on the effects of uveitis on the aqueous humour dynamics are limited. They are mainly focused on the acute phase of the intraocular inflammation. However, only two human studies in assessing the aqueous humour dynamics are available to date. But neither has been comprehensive nor comparative with healthy subjects or quiescent eyes. In my study of the uveitis and aqueous humour dynamics changes, I have 3 illustrated that raised IOP is mainly due to compromised TOF, whilst the-aqueous flow rate and the uveoscleral outflow remained unchanged.
There is a plethora of new treatment modalities emerging in the field of glaucoma every day. One of these new additions is high intensity focused-ultrasound (HiFU). Although it reduces IOP to some extent the mechanism of action is unclear. There have been some speculations that it may affect the aqueous flow rate and the uveoscleral outflow. Also, there have been no studies on the effects of HiFU on the aqueous humour dynamics especially with glaucoma medication washout. In my study of the effect of HiFU on aqueous humour dynamics, I have shown that IOP at three months post procedure was reduced by 12% whilst aqueous flow rate was reduced by 10%. The calculated uveoscleral outflow and TOF was remained unchanged.
| Date of Award | 1 Oct 2020 |
|---|---|
| Original language | English |
| Awarding Institution |
|
| Supervisor | Kin Sheng Lim (Supervisor) & Chris Hammond (Supervisor) |