T H E I N C I D E N C E O F MACULAR PUCKER AFTER RETINAL D E T A C H M E N T SURGERY L o u i s A.

LOBES, JR.,

M.D.,

AND T H O M A S C. B U R T O N ,

M.D.

Iowa City, Iowa

Spontaneous, idiopathic, and congeni­ tal occurrences of preretinal membrane formation in the macula have been de­ scribed by Wise 1,2 and Bellhorn and coworkers. 3 Such formation is associated with retinal vein obstructions, diabetes, posterior uveitis, retinal detachment, and ocular trauma. 1 The histopathology con­ sists of fibrous astrocytes, Muller's cells, and other glial cell types in the spontane­ ous avascular membranes. 3 Tannenbaum and associates 4 described the clinical characteristics of the vitreous and retina in 105 patients with macular pucker complicating retinal detachment surgery. Patients with loss of. formed vit­ reous, multiple operations, macular de­ tachments, and multiple attempts at subretinal fluid drainage were at greatest risk. The authors thought vitreous degenera­ tion affecting the vitreoretinal interface was the most important determinant in the development of the preretinal mem­ brane. Hagler 5 observed that macular pucker occurred most often in patients between 50 and 60 years old. Patients with vitre­ ous hemorrhage, vitreous membranes, or diathermy treatment had the highest inci­ dence. Machemer and L a q u a 6 - 8 have dem­ onstrated periretinal membranes that formed starfolds, rolled edge tears, and equatorial ridges throughout the retina in experimental detachments in the owl From the Department of Ophthalmology, Univer­ sity of Iowa, Iowa City, Iowa. Reprint requests to Louis A. Lobes, Jr., M.D., Department of Ophthalmology, University of Pitts­ burgh, School of Medicine, Eye and Ear Hospital, 230 Lothrop St., Pittsburgh, PA 15213. 72

monkey. These changes were clinically indistinguishable from similar changes in human retinal detachments. The mem­ branes developed from retinal pigment epithelial cell and glial cell metaplasia and hyperplasia. Clinical studies to date 4 , 5 , 9 - 1 1 stress the role of the vitreous collagen, hyalocytes, and vitreoretinal interface in the forma­ tion of macular pucker after detachment surgery. We initiated this study to identify risk factors predisposing patients to macular pucker after retinal detachment surgery and, indirectly, to test the hypothesis that preretinal membrane formation in the macula is related not to vitreous altera­ tions, but rather to retinal glial cell or pigment epithelial cell proliferation. S U B J E C T S AND M E T H O D S

We obtained clinical information from 1,049 consecutive cases of retinal reattachment performed at the hospitals and clin­ ics here. There were 863 primary proce­ dures and 186 reoperations. Patients with retinal breaks surrounded by less than 1 disk diameter of subretinal fluid (205 cases) were excluded. By requiring a minimal follow-up period of six months, we eliminated 192 patients, thus reduc­ ing the final study population to 857. Seventy-four (8.6%) patients overall de­ veloped macular pucker, 63 (7.5%) pa­ tients developed a macular pucker as the only late postoperative complication after successful reattachment of the retina. An additional 11 patients developed macular pucker in association with other signifi­ cant complications. We excluded them to acquire a more homogeneous population,

AMERICAN JOURNAL OF OPHTHALMOLOGY 85:72-77, 1978

thus minimizing multiple interrelating factors and keeping our risk factors more specific for macular pucker. We prepared computer punch cards from a six-page data collection sheet de­ veloped with the assistance of the Depart­ ment of Biostatistics and Preventive Med­ icine. Fifteen major categories of indepen­ dent variables contained a total of 129 linear and categorial variables. Each vari­ able was cross-tabulated with the pres­ ence or absence of postoperative macular pucker. Statistical analysis included the chisquare method for determining difference among proportions, the two by two chisquare test, Fisher's exact test, and parti­ tioning of the overall chi-square test to determine trends in the proportions. 1 2 RESULTS

The age-specific incidences of macular pucker were demonstrated (Fig. 1). The overall chi-square test for the entire popu­ lation was not significant for age. Similar­ ly, there was no significant difference in the group of patients aged 50 years and older as compared to the group younger than 50 years. Graphically, however, a linear trend after age 30 years was evi­ dent. Partitioning of the overall chi-

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MACULAR PUCKER

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square according to Maxwell's 1 2 method described the trend after age 30 years as a statistically significant linear trend with an increase in risk with advancing age (P.05). There was no statistically significant correlation between ocular trauma and macular pucker (Table 1). The rates of macular pucker were similar for emmetropic and aphakic patients (Table 2). However, patients with greater than 4 diopters of myopia had a significantly lower rate of macular pucker (P10 >™-"v

TABLE 3

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incidence among the control group. The presence of lattice degeneration or a di­ alysis on preoperative examination did not increase the risk of macular pucker (P>.05). There was no statistically significant difference in the incidence of macular pucker between procedures involving episcleral exoplants (7.5%) and those in­ volving scleral dissection and implants (9.6%). Cryopexy was used in all but six cases, so comparison between diathermy and cryopexy was impossible. The immediate intraoperative and post­ operative complications of vitreous loss, choroidal detachment, vitreous hemor­ rhage, and uveitis did not produce an increase in the risk of macular pucker (P>.05 in all cases). However, three of 11 patients with choroidal hemorrhage de-

PREOPERATIVE COMPLICATIONS RELATED TO MACULAR PUCKER

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