Optical Coherence Tomography of Ocular Structures in Epiphora and Dry Eye Syndrome (OCT)
试验速览
- 阶段
- 不适用
- 发起方
- 入组人数
- 60
- 主要终点
- Qualitative difference in OCT appearance of lacrimal and buccal glands measured at a single time-point, between dry eye patients and asymptomatic patients
研究概览
简要总结
The primary aim of the study is to investigate whether optical coherence tomography (OCT) may be a useful tool for investigating the in-vivo histology of ocular structures in patients with tear film pathology. In epiphora the investigators will image the proximal lacrimal system. In dry eye syndrome the investigators will image the lacrimal gland and also the buccal mucosa.
The secondary aim of the study is to investigate the appearance of the normal cornea and conjunctiva under OCT imaging.
详细描述
Optical Coherence Tomography (OCT) is a safe and non-invasive method of high resolution cross-sectional imaging of tissue microstructures using infra-red radiation. It was first described by Huang et al in 1991.
The principle of OCT imaging is similar to ultrasound; infra-red light is shone at a tissue of interest and the reflectivity of each layer within the tissue gives rise to a signal that enables a cross-sectional picture of the tissue to be constructed. In contrast to ultrasound however, it is not possible to use the timing of reflected pulses of light to infer the distance of the reflecting surface. This is because of the extremely high velocity of light (3x10^8 ms^-1), which would require the detector to have a temporal resolution of a few tens of femtoseconds in order to provide a spatial resolution of 10 microns within the tissue under observation. therefore, interferometry is applied to the infra-red light source in order to determine the distance that reflected light has travelled.
OCT currently has a wide range of applications including imaging the retina, the anterior chamber of the eye and the endothelium of the coronary arteries (when used intravascularly). It has also been used in preclinical cancer research to image tumours. IT has a resolution of 1-20µm and can penetrate approximately 1-2mm into tissue.
Dry Eye Syndrome:
Sjögren's is a common cause of dry eye syndrome. Currently a biopsy of the lacrimal gland is required to establish the diagnosis. In this study the investigators explore whether it is possible to distinguish the lacrimal gland in Sjögren's patients from the normal lacrimal gland using OCT imaging. The investigators will also image the buccal mucosa of suspected Sjögren's patients and compare the results to previously published images of the normal mucosa.
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Cross Sectional
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Patients with watery eyes who are listed for punctoplasty surgery
- •Patients with dry eyes secondary to Sjögren's (i.e. presence of anti-Ro/SSA or La/SSB autoantibodies, reduced Schirmer's test less than 5mm over 5 minutes without local anaesthesia or typical clinical presentation).
- •Members of staff at our eye clinic with no history of previous ocular surgery or watering/dryness.
排除标准
- •Previous eyelid or lacrimal surgery
- •Patients without capacity to consent
- •Patients unwilling to participate
- •Age under 18
结局指标
主要结局
Qualitative difference in OCT appearance of lacrimal and buccal glands measured at a single time-point, between dry eye patients and asymptomatic patients
时间窗: Baseline, at the time of listing for surgery
OCT images of the lacrimal gland and buccal mucosa will be taken from dry eye patients and asymptomatic patients. These images will be compared qualitatively, to determine if there are any differences in the appearance of the lacrimal and buccal glands under OCT, in patients with dry eye disease compared to healthy subjects.
Comparison of punctual diameter, canalicular diameter and canalicular depth between asymptomatic patients and patients with epiphora pre-operatively and post-operatively, and correlation with Lac-Q questionnaire score
时间窗: 26 weeks
All patients with epiphora who are due to undergo punctoplasty (for punctual stenosis) or conjunctivoplasty (for conjunctivochalasis) will have pre- and post-operative imaging of their left and right lower punctum / conjunctiva respectively. Patients will also have their epiphora symptoms graded according to the Lac Q questionnaire before and after surgery. Asymptomatic patients will have OCT imaging taken of the cornea and conjunctiva.
次要结局
未报告次要终点