Syringing or ROPLAS before intraocular surgery: An ophthalmologist’s dilemma

Dear Editor, Nasolacrimal duct obstruction (NLDO) is associated with conjunctival colonization by pathologic bacteria as well as an increase in the number of conjunctival commensals. It remains an important risk factor for postsurgical endophthalmitis.[1] Lacrimal sac syringing and regurgitation on pressure over the lacrimal sac (ROPLAS) are the most commonly employed methods to rule out NLDO. Syringing has been regarded as the gold standard to determine the patency of lacrimal passage; however, it is an invasive and relatively time-consuming procedure. However, ROPLAS is a noninvasive and short procedure and has been a preferred method by majority (59.6%) of the oculoplasty surgeons in India.[2] But whether to rely on ROPLAS or to perform syringing in all patients undergoing intraocular surgery still remains a matter of debate. Earlier study by Thomas et al.[3] (n = 621) reported high sensitivity of ROPLAS (93.7%), while a recent study by Kim et al.[4] (n = 8369) reported low sensitivity of ROPLAS (54.5%). The cohort of patients evaluated by Thomas et al.[3] had higher number of patients (n = 135, 21.8%) who had symptoms related to NLDO and less number of asymptomatic patients undergoing routine cataract surgery (n = 318, 51.2%). However, Kim et al.[4] had included patients undergoing routine cataract surgery. Thomas et al.[3] reported the prevalence of chronic dacryocystitis to be 6.6%, while Kim et al.[4] reported it to be 1.4%. Thus, higher sensitivity of ROPLAS in the study by Thomas et al.[3] as opposed to that by Kim et al.[4] seems to be related to the study design, wherein Thomas et al.[3] had an inherent inclusion bias of including more number of patients with existing symptoms related to NLDO. Thomas et al.[3] also reported that the sensitivity of ROPLAS in asymptomatic patients reduced to 85% from 100% in symptomatic patients. In our setting, we performed ROPLAS for all patients undergoing intraocular surgery (cataract, n = 21,718), while syringing was performed in high-risk patients (those with symptoms of epiphora in either of the eyes or who had ROPLAS positive in the other eye). When performed in symptomatic ROPLAS-negative patients (n = 2194), syringing identified 413 (18.8%) patients with NLDO. When performed in asymptomatic ROPLAS-negative contralateral eye of the ROPLAS-positive patients (n = 62), syringing identified 23 (37.1%) patients with NLDO, possibly providing an answer to one of the questions raised by Nair et al.[2] [Fig. 1].Figure 1: Incidence of NLDO determined by syringing in ROPLAS-negative symptomatic eyes and contralateral eye of the ROPLAS-positive patients.However, does this mean that syringing must be performed in all eyes planned for intraocular surgery? The answer is probably no, as the main aim of this entire exercise of ROPLAS or syringing is to minimize the risk of postoperative endophthalmitis and in a large cohort of patients, the incidence of post-cataract surgery endophthalmitis in patients screened either by ROPLAS or syringing did not differ.[5] Based on the current data and the available scientific evidence, there is a fair possibility that, if syringing is performed in all ROPLAS-negative eyes, it will detect more patients with NLDO; however, probably, not all such patients will develop postoperative endophthalmitis if they undergo an intraocular surgery. An ideal and scientific way to test this hypothesis would be to perform a prospective pilot study, reporting the incidence of postoperative endophthalmitis in such ROPLAS-negative but syringing-proven NLDO patients, without performing a prior sac surgery. However, owing to an overall low incidence of postoperative endophthalmitis and ethical constraints, conducting such research may not be feasible at present. In the absence of such direct evidence, we can screen all patients undergoing intraocular surgery by ROPLAS and perform syringing in selected “high-risk” patients. Financial support and sponsorship: Nil. Conflicts of interest: There are no conflicts of interest.