RISK OF RETINAL TEARS IN PATIENTS WITH VITREOUS FLOATERS
E D W I N E. B O L D R E Y , M.D. Palo Alto, California
A total of 589 patients (369 women and 220 men, 123 of whom were less than 40 years old and 52 of whom were more than 70 years old) with photopsia, vitreous floaters, or both participated in a prospective study designed to identify patients at particularly high risk for retinal tears. The patients were graded on a number of factors before undergoing peripheral retinal examinations. Computer analysis showed that the following factors had the strongest associations (P
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TABLE 1 SUMMARY OF CLINICAL DATA ABOUT THE PATIENTS
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I did not differentiate the cells by type (red blood cells, pigmented cells, and the like).
Next, I used a Hruby lens to look for a complete or partial glial ring in the vicinity of the optic nerve, indicating a posterior vitreous separation. A three-mirror contact lens is the best means of determining whether or not a partial or complete vitreous detachment is present, but, because one purpose of this study was to develop a triage system useful to general ophthalmologists who might not be experienced in vitreous examination, I used the easily determined end point of a glial ring in the vitreous near the optic nerve to define posterior vitreous separation. These rings are usually easy to find with a Hruby lens.
Finally, any grossly visible vitreous or preretinal blood was identified with the indirect ophthalmoscope before scierai depression. This category included linear accumulations of blood in the inferior periphery as well as small clots within the vitreous. I included microscopically apparent blood seen with the slit lamp but not with the indirect ophthalmoscope
under "vitreous cells" rather than under "grossly visible" (Table 3).
R E S U L T S
Of the 589 patients, 109 (18.5%) had retinal tears or operculated holes believed to be tractional. Sixteen patients (2.7%) had round holes without traction; these were not included in this analysis. In 585 cases, the patient's asymptomatic (or not recently symptomatic) fellow eye was also examined and 15 (2.6%) were found to have at least one tear and 21 (3.6%) had at least one round hole.
Correlations between light flashes and floaters and retinal breaks have been made previously.1'6 This study, however, included enough patients to permit a statistically significant selection of those at extremely high and extremely low risk for retinal detachment. I used computer analysis to identify a small number of factors that can be used to identify patients who have exceptionally high and low risks for retinal tears.
Of the factors which characterized the patients themselves, increasing age and male sex showed associations with tears,
RESULTS O F T H E CLINICAL EXAMINATIONS
Vitreous cells 0 Trace 1+ 2+ 3+ 4+
Vitreous syneresis Minimal Moderate Severe
Posterior vitreous separation Present Absent
Grossly visible blood Present Absent
No. of Patients
348 85 62 39 36 19
112 358 119
Patients With Retinal Tears No.
16 17 28 16
8 72 29
6.6 10.6 25.8 43.6 77.8 84.2
7.1 20.1 24.4
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but these associations were not strong enough to allow selection of patients at especially high risk (Table 1).
Factors relating to the patient's symptoms were more useful (Table 2). The most useful category was the patient's perception of the floaters as consisting primarily of diffuse dots with or without lines. Patients who described their floaters this way were approximately five times as likely to have a tear as those who did not have diffuse dots (62 of 120 patients or 51.7% vs 42 of 418 patients or 10%). A previous study that attempted to correlate the appearance of dots with the presence of retinal tears showed less of a correlation because in this study only the presence and not the diffuseness of the dots was considered.5 The location of the flashes or floaters was not particularly useful unless the floaters were not localized into any particular quadrant. However, computer analysis showed this latter group for the most part to consist of patients who were already included in the diffuse dots category.
Factors related to the slit-lamp examination were useful in screening for both high- and low-risk patients (Table 3). I found a high correlation between the presence of vitreous cells and retinal tears. When the correlation was simplified by considering those patients with cells graded 1+ or less as one group and those with cells graded 2+ or more as another group, the first group contained 48 patients (of 495, or 9.7%) with retinal tears and the second group contained 61 patients (of 94, 64.9%) with retinal tears. Computer analysis showed some overlap between these higher risk patients and the patients who saw diffuse dots, with 48 patients included in both categories. However, sufficient additional patients fell into the high-risk group to warrant considering these as being separate categories. An association between retinal tears and various types of cells (pigment-
ed cells, gray cells, and red blood cells) in the vitreous has been described previously.5'8"10 I grouped these categories together because cells of more than one kind are often present simultaneously, because pigmented and red blood cells tend to lose color with time, and because all of these subcategories can be associated with tears.
Although vitreous syneresis and posterior vitreous detachment showed a correlation with retinal tears, this correlation appeared to be age-related, and was not useful for triage.
Grossly visible vitreous or preretinal blood on indirect ophthalmoscopy was highly significant because 51 of 56 patients (91.1%) with this finding also had retinal tears. This percentage was higher than the approximately 70% to 80% incidence of tears in patients with grossly and microscopically apparent blood found in previous studies,1,5,6 probably because I included only grossly visible hemorrhage in this category.
Because all the patients came from a retinal referral practice and were, therefore, selected, the percentage of tears found in each category was probably higher than would have been found in a general ophthalmic practice.
A simple means of identifying eyes at high risk for retinal tears can be devised by using the three highest risk factors: symptom of diffuse dots, the presence of vitreous cells graded 2+ or more, and the presence of grossly visible vitreous or preretinal blood. Of the 176 eyes with at least one of these three factors, 52.8% (93 eyes) had retinal tears compared with 3.9% (16 of 413) of the remainder. Thus, an eye with any one of the three highest risk factors was more than 13 times as likely to have a retinal tear as an eye that did not have one of these factors. Conversely, eyes with none of the highest
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risk factors had an incidence of retinal tears only slightly higher than the 2.6% found in the asymptomatic fellow eyes.
Part of this triage system can be used by any receptionist, who can screen patients with floaters by asking one question ("Do you see tiny dots everywhere?"). This separates out a high-risk group with tiny dots (51.7% with tears) and a lower risk group without tiny dots (10% with tears).
Another low-risk group can also be identified by using four factors associated with a lower incidence of retinal tears: an age of less than 40 years, the symptom of a single floater, minimal vitreous liquefaction, and no or only trace vitreous cells. Of the 118 eyes with at least three of these factors, only one (0.9%) had a retinal tear.
Because this triage system does not absolutely exclude retinal tears in any group, all patients with flashes or floaters should undergo prompt careful peripheral retinal examination. However, a group at especially high risk can be selected for extra attention.
REFERENCES 1. Jaffe, N. S.: Complications of acute posterior
vitreous detachment. Arch. Ophthalmol. 79:568, 1968.
2. Morse, P. H.: Symptomatic floaters as a clue to vitreoretinal disease. Ann. Ophthalmol. 7:865, 1975.
3. Medardo, T., Karp, L. A., and Benson, W. E.: Posterior vitreous detachment. Ann. Ophthalmol. 12:59, 1980.
4. Kanski, J. ]. : Complications of acute posterior vitreous detachment. Am. J. Ophthalmol. 80:44, 1975.
5. Linder, B.: Acute posterior vitreous detachment and its retinal complications. Acta Ophthalmol. 87(suppl.):l, 1966.
6. Tasman, W. S.: Posterior vitreous detachment and peripheral retinal breaks. Trans. Am. Acad. Ophthalmol. Otolaryngol. 72:217, 1968.
7. Davis, M. D.: Natural history of retinal breaks without detachment. Arch. Ophthalmol. 92:183, 1974.
8. Shafer, D. M., and Stratford, D. P., in discussion, Pomerantzeff, O., and Schepens, C. L.: Binocular indirect ophthalmoscopy. In Schepens, C. A., and Regan, C. D. J. (eds.): Controversial Aspects of the Management of Retinal Detachment. Boston, Little, Brown & Co., 1965, p. 51.
9. Hamilton, A. M., and Taylor, W. : Significance of pigment granules in the vitreous. Br. J. Ophthalmol. 56:700, 1972.
10. Tolentino, R. I., Schepens, C. L., and Freeman, H. M.: In Vitreoretinal Disorders. Diagnosis and Management. Philadelphia, W. B. Saunders, 1976, pp. 379 and 416.