NEW YORK (Reuters Health) – Patients who undergo successful vitrectomy for a common type of retinal detachment (RD) may have better visual acuity after gas tamponade (GT) than after silicone-oil tamponade (SOT), new research from Japan suggests.
“Propensity score analysis of eyes with rhegmatogenous RD showed that postoperative vision was worse in eyes treated once with silicone oil than with gas even after completely successful surgery,” Dr. Taiji Sakamoto of Kagoshima University Graduate School of Medicine and Dental Sciences and colleagues report in the British Journal of Ophthalmology.
“In cases of RD where the use of SOT is being considered, the use of SOT should be selected very cautiously,” they advise. “More specifically, careful consideration for the use of SOT should be made especially in eyes with possible damaged retina, such as glaucoma, diabetic retinopathy or optic neuropathy.”
The researchers conducted a nationwide retrospective study of patients with RD whose data were in the Japan Retinal Detachment Registry.
They examined all cases with RD treated with successful vitrectomy over one year and estimated the mean difference of postoperative best-corrected visual acuity (BCVA) at six months between eyes treated with SOT and those treated with GT. Their propensity-score-matching technique used preoperative findings as covariates to adjust the relevant confounders.
Of the 2,097 cases that met the inclusion criteria, 2,042 eyes had GT and 55 eyes had SOT. Primary success was considered to be a reattached retina with no tamponade at six months. Propensity-score-matching yielded 40 cases in each group.
Before surgery, BCVA was 0.966 logMAR units in the GT group and 1.270 logMAR units in the SOT group (P=0.177). Six months after surgery, the GT group’s BCVA was 0.309 logMAR units compared with the SOT group’s 0.671 logMAR units (P=0.002).
“This study adds to the growing body of evidence suggesting that silicone oil potentially has some negative effects on the retina and that it can, over time, affect long-term vision in some patients,” Dr. Nimesh Patel, a physician and surgeon at Massachusetts Eye and Ear in Boston, told Reuters Health by email.
Dr. Patel, who was not involved in the study, noted that the results can help doctors counsel patients, “particularly when silicone oil is used more as a convenience for patients who would like to fly by airplane postoperatively and avoid the use of gas.”
The retrospective nature of this study is important, he added. “The choice for silicone oil tamponade initially may be made intraoperatively based on poor prognostic findings. Although the authors attempted to match the preoperative characteristics between the two groups, this cannot be done without some selection bias.”
Dr. J. Fernando Arevalo, professor and chair of the department of ophthalmology at Johns Hopkins Bayview Medical Center in Baltimore, Maryland, commended the authors and laboratory “on their tremendous effort to use sound scientific analysis to elucidate important questions based on real-world data.”
Dr. Arevalo agreed that its retrospective design is a limitation and a potential source of bias. “A minority of cases had SOT, suggesting that SOT was used in cases that were more complex and in which BCVA was expected to be limited anyway,” he told Reuters Health by email.
Sometimes though, he explained in his email, the benefit may outweigh the risk. “As the authors point out, SOT is mainly used to treat severe retinal diseases, but it may also be used for relatively mild cases, including patients with only one eye, patients needing flight travel, and those who cannot maintain a specific posture.” He joined Dr. Patel in recommending prospective studies.
Dr. Sakamoto did not respond to requests for comment.
The study did not receive commercial support, nor did the authors indicate any conflicts of interest.
SOURCE: https://bit.ly/3zkeyjj British Journal of Ophthalmology, online August 9, 2021.
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