|Year : 1990 | Volume
| Issue : 1 | Page : 24-26
Functional integrity of lacrimal drainage apparatus by radionuclide dacryocystography
Vivek Kadambi, B Victor Williams
Bombay Hospital & Medical Research Centre, Mumbai, India
Tarapati Institute of Ophthalmology, Bombay Hospital & Medical Research Centre, Mumbai
Source of Support: None, Conflict of Interest: None
30 patients with epiphora and related complaints were investigated by Radionuclide Dacrocystography. It was possible to do this procedure easily in all age groups. The site of block in the lacrimal system could be accurately determined by this non-invasive technique.
|How to cite this article:|
Kadambi V, Williams B V. Functional integrity of lacrimal drainage apparatus by radionuclide dacryocystography. Indian J Ophthalmol 1990;38:24-6
|How to cite this URL:|
Kadambi V, Williams B V. Functional integrity of lacrimal drainage apparatus by radionuclide dacryocystography. Indian J Ophthalmol [serial online] 1990 [cited 2020 May 28];38:24-6. Available from: http://www.ijo.in/text.asp?1990/38/1/24/24558
| Introduction|| |
The anatomy and drainage of the lacrimal system was evaluated noninvasively using 99m technetium pertechnetate and nuclear medicine instrumentation. 30 patients were investigated by this method. Sequential and static images of the lacrimal system were obtained at the end of fixed time-intervals and the site of obstruction or the functional intergrity of the lacrimal drainage apparatus was determined. Dynamic pictures were acquired at I sec intervals for a total of 2 minutes and static pictures were recorded at the end of 2, 5, 10 and 30 minutes. Accurate estimation of the function of the lacrimal drainage system was thus possible.
| Material and methods|| |
The Siemens Scintiview Pho/gamma ZLC/37 with 37 photomultiplier tubes and a crystal of half inch thickness was used along with Scintiview 118080 microprocessor. Video and A scope type of display was employed. Initial acquisition and storage of data was done by using the histoacquisition programme supplied by Siemens, a formatted floppy disc was used to store the acquired data. The radionuclide used was 99 technetium pertechnetate in saline at a pH of 7. This physical state is near to the physiological state of the tears and there is no irritation to the eye. A 21 gauge hypodermic needle was used to instill two to three drops of the radionuclide from a 2 ml syringe that was loaded to the 1.5 ml mark in order to facilitate easy administration of uniform drops on to the centre of the cornea which is a reference point for drainage into the lacrimal ducts. Thus 100 to 200 microcuries (3.70 to 7.40 MBq) of the radionuclide was administered into each eye. The subjects were studied mostly in the "sitting upright" posture facing the vertically positioned crystal surface of the gamma camera. In children and infants we found the supine posture to be better for imaging as it was easier to restrain them. It was also useful in adults who were obese or restless. The subjects were advised to remain still and blinking was allowed to meet with the physiological requirements for tear drainage. After the subject was briefed and positioned, tears were wiped with cotton wool in those who had epiphora. The palperbrae were manually held apart by an attendant and about two drops of the radionuclide were quickly instilled into both eyes. Excess and overflowing drops were meticuluously wiped away and the subject was quickly brought close to the crystal surface of the gamma camera. Sequential images were quickly acquired for two minutes at one second intervals. At the end of two minutes a static scan was performed till 5K counts were obtained. The subject was then free to move. Similar static images were acquired at the end of 5, 10 and 30 minutes taking extreme care to avoid tear overflow while imaging. The images were reviewed on the video screen and subsequently exposed on the rnentgenographic plates of 8" X 10" size. Such studiess were conducted before and after surgery on the nasolacrimal system whenever possible.
| Discussion|| |
The results were obtained in 30 subjects who were investigated for epiphora and related complaints, by radionuclide dacryocystography. These included studies done on 16 males and 12 females, there were 2 infants. Their ages were in the range of 3 months to 72 years. The concept of using radiopharmaceuticals was introduced by Rossomondo et al to study the anatomy and drainage of the lacrimal system. They had however used a 1 mm pinhole collimator on a gamma camera, scans were obtained every minute for the first 5 minutes and then every 5 minutes upto 20 or 30 minutes. Denffer and Dressler modified this procedure so that both the right and the left lacrimal systems could be studied simulaneously by means of a large field of view (LEFOV) gamma camera with multiple parallel holes. There is no standardised method to perform a nuclear dacryostogram, dual pinhole collimator or computer manipulation can be used to study tearflow ,.A better method suggested was to compare one side with the other assuming that one lacrimal drainage system was normal. But bilateral obstruction could occur in many subjects as we had noticed in our study. Chavis  et al studied asymptomatic patients and found that tear flow from the conjunctiva to the lacrimal sac was less than 12 seconds in 98 percent subjects. We had similar results with a range of 8 to 11 seconds in adults. We found that flow from the lacrimal sac to the nose was too inconsistent to quantitate. Factors that can affect tear flow are blinking, gravity, resistance from nasolacrimal duct, previous intervention from syringing or surgey. We found that gravity did not have profound affect for the same patient in different postures used for imaging, the sitting and supine scans showed almost no difference, in the time required for drainage. The site of obstruction in subjects with epiphora was accurately determined. In a case of bilateral epiphora distal lacrimal drainage obstruction was detected at the nasal mucosa level due to recurrent bouts of allergic rhinitis. [Figure - 1]. In this case however sac syringing revealed normal patency of the lacrimal drainage system, relatively higher force was used for this purpose. We had a case of epiphora which was unilateral, lid laxity was found to be causative in this elderly subject, the lacrimal drainage system was found to be normal on syringing. While standardising this procedure we evaluated subjects who had their upper or lower canaliculum cauterized. Presuming the noncauterized canaliculum was normal, we found that tear drainage was within normal time limits. This technique was particularly found to be useful to evaluate the success of dacryocystorhinostomy and further help to plan surgery in cases that needed another surgery on the lacrimal drainage system.
Nuclear dacryocystography is superior to the contrast radiographic dacryocystogram both in anatomic and functional aspects. This was earlier suggested by Chaudhary et a1 . The contrast dyacryocystogram is an invasive procedure needing intubation of the lacrimal drainage system and syringing. Even if intubation is required nuclear techniques are preferable as better anatomic images and functional information is obtained . We did not perform scans after intubation of the lacrimal drainage system. Often other non-invasive tests liked the fluorescein dye test or the saccharin test are frequently inconclusive ,. The radiation dose absorbed to the germinal epithelium of the lens from 99 technetium pertechnetate is approximately 0.14 rads/m Ci (0.04 MGy/KBq) in complete blockage of the lacrimal system. We found it suitable to flush the conjunctival sac with sterile normal saline solution to further minimise the radiation absorbed dose from the conjunctival surface.
| Conclusion|| |
Standard imaging techniques using a gamma camera and a computer can be performed using radiopharmaceuticals and a low energy all purpose (LEAP) parallel hole collimator. Real and erect images can be obtained as compared to the inverted images obtained by using a pinhole collimator. Frequent change of collimator is thus avoided thereby saving time in a busy imaging department. 99 Technetium pertechnetate is an ideal pharmaceutical to perform dacryocystography, there was no contraindication to other radiopharmaceuticals like 99 Technetium phytate which we had used in one patient. The site of block in the lacrimal system can be assessed conclusively and more offer non-invasively in those subjects referred for the investigation of epiphora and related symptoms. It was found to be useful in infants and children and particularly in those subjects who needed frequent assessment of the lacrimal drainage system.
| Acknowledgement|| |
Thanks are due to Dr.R.C.Patel and Dr.B.N.,Sharmafor their valuable guidance. Special thanks to Mr.Atul Gada, Mr.Salvi, Mr.Parmar and other technical staff members of the department of Nuclear Medicine of this institute for their services.
| References|| |
Ressomoddo, R.M., Carlton, W.H., Trueblood, J.H. and Thomas, R.P., A new method of evaluating lacrimal drainage. Arch. Ophthalmol., 88 : 523,1972.
Denffer. H.V., and Dressler, J. Radionuklid-dacryocystographie in der diagnostik von stenosen dertran enableitenden wege. Albrecht Von Graetes Arch. Klin. Exp. Ophthalmol, 191,321, 1974.
Chavis, R.M., Welham, R.A.N., and Maisey, M.N.:Quantitative Lacrimal scintillography. Arch. Ophthalmol.. 96, 2066, 1978.
Chaudhan, T.K., Saparoff, G.R. Delan, K.D. Comparitive study of dacryocystogram and nuclear dacryocystogram. J.Nucl. Med., 16 : 605,1975.
Hurwitz, J.J., Welham, R.A.N., and Maisey, M.N.: Intubation macrodacryocystography and quantitative scintillography. The complete lacrimal assessment. Trans. Am.Acad. Ophthalmol. Otolaryngol., 81 : 575,1976.
Jones, L.T., Anatomy of the tear system. Int.Ophthalmol. Clin., 13 : 3, 1973.
Hornblass, A. : A simple taste test for lacrimal obstruction. Arch. Ophthalmol, 90: 435, 1973.
[Figure - 1], [Figure - 2], [Figure - 3]
[Table - 1], [Table - 2], [Table - 3]