Lacrimal duct obstructive disease is a common disease in ophthalmology clinic. Data show that the average annual incidence rate of primary acquired nasolacrimal duct obstruction is 30.47/100000, which is more common in middle-aged and elderly women. The etiology has not yet been determined. Some studies show that changes in systemic or local hormone levels and their impact on downstream products may have a very close relationship with the incidence of primary acquired nasolacrimal duct obstruction. Patients usually experience lacrimal overflow after the age of 40, followed by symptoms and signs of chronic or acute dacryocystitis, often due to narrowing or obstruction of the nasolacrimal duct causing a large accumulation of tears in the lacrimal sac.
Research has shown that obstructive diseases of the lacrimal duct may be related to factors such as anatomical parameters of the nasolacrimal duct, variations in the anatomical structure of the sinonasal complex, nasolacrimal duct injury, anti glaucoma drugs, gender, hormones, ocular surface, and chronic inflammation of the nose. Patients may experience long-term tear overflow, accompanied by an increase in yellow purulent secretions and conjunctival congestion. In severe cases, it can lead to diseases that damage vision such as corneal ulcers, seriously affecting the patient's quality of life. Therefore, its treatment requires the artificial establishment of a new channel to ensure smooth drainage of tears. At present, surgery is the main treatment for this disease in clinical practice, and dacryocystorhinostomy is one of the main treatment methods for lacrimal duct obstructive diseases. Due to individual differences in tear duct anatomy caused by congenital development or acquired eye nose related lesions, identifying the size, shape, direction, and location of tear duct obstruction are important factors for successful surgery. Digital X-ray photography dacryocystography (DR-DCG) can provide strong imaging evidence for clinical practice.
1、 The purpose of DR-DCG in lacrimal duct obstructive diseases
Due to the different indications and contraindications of existing treatment methods, it is necessary to understand the detailed information of the lacrimal drainage system before surgery for lacrimal duct obstructive diseases, and DR-DCG can provide strong imaging evidence for clinical practice. To obtain well developed DR imaging data, first, the secretions in the lacrimal duct are basically cleaned with physiological saline, and then iodized oil is injected into the lacrimal duct. Due to the different density of iodized oil and surrounding tissues, a sharp contrast in DR imaging data of the lacrimal drainage system is obtained. 2、 The clinical application value of DR-DCG in lacrimal duct obstruction diseases
1. Clarify the location of lacrimal duct obstruction/degree of lacrimal duct stenosis;
2. Clarify the size and dilation of the lacrimal sac;
3. Clarify whether the maxilla and nasal bones are fractured, etc. In addition, in order to avoid the impact of nasal diseases such as deviated nasal septum and nasal polyps on intraoperative operations, it is generally necessary to undergo nasal endoscopy at the otolaryngology clinic before surgery. In addition, if there are patients who have not been visualized, a comprehensive analysis should be conducted while reviewing the images, taking into account the tear passage flushing situation and the patient's condition. By observing whether the tissue around the lacrimal sac is raised and whether the resistance is too high when injecting contrast agent, it can be determined whether the contrast agent is injected into the false passage, or not injected into the tear passage, or if there is functional tear overflow.
3、 Limitations of DR-DCG in lacrimal duct obstructive diseases
DR-DCG can clearly display the condition of the lacrimal duct and has the advantages of simplicity, economy, and intuitiveness. However, it cannot display the relationship between the lacrimal drainage system and surrounding bone structures or soft tissues. Therefore, other examination methods are needed to eliminate the symptoms of overflow and pus caused by soft tissue changes or bone abnormalities around the lacrimal drainage system.
DR-DCG enables surgeons to have a clear understanding of the characteristics of the lacrimal duct, providing strong clinical evidence for the diagnosis and treatment of lacrimal system diseases, enabling personalized surgical selection for patients, and having clinical significance for intraoperative surgical operations and prognosis evaluation. In addition, this technology has a shorter examination time and lower examination costs, and can accurately determine the location of lacrimal duct obstruction, lacrimal duct stenosis, and lacrimal sac dilation. It can be widely applied in clinical practice for patients with lacrimal duct obstruction diseases.