While the use of digital ocular massage after trabeculectomy has been well described, information about this technique following glaucoma drainage device surgery is limited. Smith et al. (468) conducted a nonrandomized prospective study evaluating ocular massage during the hypertensive phase after Ahmed implant surgery. Eighteen consecutive patients who were found to have postoperative intraocular pressure (IOP) above target after Ahmed implantation underwent digital massage. Nine patients with IOP reduction > 20% at one hour after massage were considered responders and instructed on how to perform ocular massage at home. One patient was excluded from analysis because of an inability to perform home digital ocular massage. IOP measurements pre- and one-hour post-massage and use of glaucoma medical therapy were assessed at two weeks, six weeks, and six months after enrollment.
The study provides valuable information about the short-term effect and safety of digital ocular massage in patients who have undergone placement of an Ahmed glaucoma valve . A 37.6% decrease in mean IOP was observed immediately after digital massage with 93.8% of patients achieving > 20% drop in IOP. However, the IOP response was short lived in many patients with only 50% of patients maintaining a 20% IOP drop one hour after massage. The immediate IOP reduction is simply a result of aqueous humor being forced from the eye through the tube and into the bleb. The more sustained IOP response may be related to flushing inflammatory material through the device or expansion of the bleb with increased aqueous filtration across the bleb capsule from raised hydrostatic pressure in the bleb cavity. No massage-associated complications were observed in the study.
Conclusions on the long-term effect of ocular massage after glaucoma drainage device surgery are limited by the study design. The study defined a hypertensive phase as IOP above a preset target level, although no criteria were established for setting the target IOP. Over the course of the study, a significant reduction in IOP was observed after starting digital massage in the small number of patients who were classified as responders. However, it is well known that many patients experience resolution of a hypertensive phase after glaucoma drainage device surgery without intervention. Moreover, glaucoma medical therapy was added in half the patients during the course of follow-up. It is impossible to discern how much of the IOP improvement among study patients was related to ocular massage, commencement of glaucoma medical therapy, or spontaneous resolution of the hypertensive phase. Randomizing patients to massage or no massage would have allowed a better determination of the effects of digital ocular massage. It is also noteworthy that only patients who underwent Ahmed implantation were enrolled in this study, and the results may not be generalizable to other implant types. Smith et al. are to be congratulated on an excellent prospective study. However, additional studies are needed to validate the authors' conclusion that 'digital ocular massage has a useful role to play in the management of the hypertensive phase after Ahmed glaucoma drainage device surgery.'
Conclusions on the long-term effect of ocular massage after glaucoma drainage device surgery are limited by the study design.