|
|
ARTICLES |
|
Year : 1983 | Volume
: 31
| Issue : 3 | Page : 153-157 |
|
Fluorescein angiographic study of myopic macula
BS Goel, Bijendra Lal
Institute of Ophthalmology, Aligarh Muslim University, Aligarh, India
Correspondence Address: B S Goel Institute of Ophthalmology, Aligarh Muslim University, Aligarh India
Source of Support: None, Conflict of Interest: None | Check |
PMID: 6676204
How to cite this article: Goel B S, Lal B. Fluorescein angiographic study of myopic macula. Indian J Ophthalmol 1983;31:153-7 |
The reports regarding the fluorescein fundus angiography in high myopia are few and more so pertaining to study of macular region in this disease. The present study, therefore, deals with the fiuorescein angiography in myopic macula.
Material and Methods | | |
The present investigation was undertaken in 57 eyes of 38 individuals at the Institute of Ophthalmology, Aligarh Muslim University, Aligarh. The eyes were divided into three groups depending upon the history and clinical examination of the fundus.
Group I-Normal eyes (9 eyes)
All of these eyes were normal and had no abnormality in either the anterior or the posterior segment.
Group II-Simple Myopia (25 eyes)
These eyes were considered to be simple myopic because there was either complete absence or minimal degenerative changes in the central fundus. Their refractive error ranged from-5.5 D. spherical to-12.0 D. spherical.
Group III-Pathological myopia (23 eyes).
These eyes had a widespread central and peripheral degenerative changes in the fundus. The prominent degenerative changes included a large myopic crescent, peripapillary choroidal atrophy, central macular degenerative changes and Foster Fuch's flecks.
Fluorescein fundus angiography was undertaken in all the eyes with the help of the latest Carl Zeiss fluorescein angiographic equipment having an automated pentax camera with a dalaphot system and a high speed flash generator. 5 ml of 10% sodium fluorescein dye was injected in the antecubital vein and the fundus photographs were taken after swinging in the excitor filter knob. A series of photographs were taken at a preset interval of 1 second upto 20 seconds and later at approximately 1, 3, 5, 10 and 15 minutes intervals. ORWO, 400 ASA, 35 MM. film was used in the present investigation. The fluorangiograms were studied with the help of a projector and the interpretation of macular fluorescence was done.
Observations | | |
The ophthalmoscopic and fluorangiographic observations of the macular area in all the three groups are described as follows.
Group I (Normal eyes)
No ophthalmoscopic and fluorangiographic abnormality was observed in all the 9 eyes. The macular area appeared darker and the fine retinal parafoveal capillaries forming a dense arcade were clearly observed [Figure - 1].
Group II (Simple myopia)
In all the 25 eyes, no clinical and fluorangiographic abnormality were observed [Figure - 2].
Group III (Pathological myopia)
However, a number of findings were observed in the macula in this group.
(a) Ophthalmoscopic appearance
A dull foveal reflex and pigment mottling of varied density was observed in 5 (21.74%) eyes and an irregular dark patch (Forster Fuch's flecks) was observed in the macular area (2 eyes-8.7%) and in the paramacular area (1 eye4.35%). However, in 1 eye out of above eyes, the dark patch was situated in the centre with two pigmentary epithelium defects on either side of it. One eye revealed a macular coloboma with little pigment.
(b) Fluorescein angiographic appearance
Fluorangiographically, a number of findings were observed in 14 (60.8%) out of 23 eyes as follows:
(1) Localized hyperfluorescence
Localized or patchy hyperfluorescence was observed in the paramacular area of 3(13.04%) eyes in the late venous phase of the dye transit [Figure - 3][Figure - 4]. The patches represent chorio-retinal atrophy in these areas.
(2) Diffused hyperfluorescence
A diffuse type of hyperfluorescence was observed in 1(4.35%) eye in the paramacular area [Figure - 5]. The area represents some pigment epithelium disturbance.
(3) Hyperfluorescence in the region of Forster Fuch's fleck
In 2(8.7%) eyes an area of hyperfluorescence with a nonfluorescent rim was noticed. In 1 (4.35%) eye, the associated pigment epithelium defect on either side of Fuch's spot also contributed in hyperfluorescence in this area and was seen to be larger and matted together in the centre [Figure - 6]. In 1 (4.35%) eye, a diffused, but less defined paramacular hyperfluoresence was Observed in the region of Forster Fuch's spot [Figure - 7]. In the third eye, the area of hyper fluorescence was markedly seen in the late phase of dye transit [Figure - 8].
(4) Choroidal sclerosis
In ](4.35%) out of 23 eyes, macular area revealed sclerosed choroidal vessels and they contained no fluorescein in their lunen [Figure - 9].
(5) Macular coloboma
The early fluorangiogram of 1(4.35%) eye, revealed an area of hypofluorescence, and a few isolated choroidal vessels in the region of coloboma [Figure - 10] and in the late phase, a diffused hyperfluorescence with clear cut margins was observed [Figure - 11].
(6) Macular degeneration
5 eyes having a dull foveal reflex & pigment mottling on ophthalmoscopic examination, did not reveal any abnormality on fluorescein fundus angiography.
Discussion | | |
The macular area in myopic eyes has aroused the maximum interest of many ophthalmologists because of a number of degenerative changes seen in this region which in turn are responsible for poor visual acuity in the majority of the eyes. In normal eyes and in eyes with simple myopia, the dark macula represents a fairly normal pigment epithelium in this region rich in pigments. On the other hand, in eyes with pathological myopia, where the retinal pigment epithelium is comparatively unhealthy, various fluorangiographic findings suggest that the area has got a choroidal ischaemia of various degrees. Patchy hyperfluorescence in the paramacular area, represents that the choroidal atrophy leading to pigment epithelium defects is the main factor involved in the late scleral staining in these parts. Presence of apparent sclerosed choroidal vessels seen in this area further suggest that choroidal ischaemia is a mojor factor in causing various chorioretinal degenerative conditions in these areas.
A number of workers have reported the occurence of subretinal neovascular membrane (SRNM) in the macular area underlying Fuch's spot. However, in the present study such a feature was not observed, although a localized hyperfluorescence as seen in these eyes should be due to leakage from the under lying choriocapillaris. A nonfluorescent rim, surrounding the hyperfluorescence could be due to some pathology in the RPE representing density of the pigments.
Summary | | |
A comparison of the macula ophthalmoscopically and fluorangiographically has been made in normal, simple myopic and pathological myopic eyes. Generally, it was observed that there was no abnormality seen in normal and simple myopic group of cases, whereas disturbances in the pigment epithelium and choroidal vessel filling was observed in pathological myopic eyes. Clinical and fluorangiographic picture of Forster Fuch's flecks, myopic degeneration of the macula and coloboma of the macular is also described. Commonest findings on fluorescein angiography observed were, localized or diffuse hyperfluorescence of the macular and paramacular area and sclerosis and atrophy of the choroidal vessels.
[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4], [Figure - 5], [Figure - 6], [Figure - 7], [Figure - 8], [Figure - 9], [Figure - 10], [Figure - 11]
|