The present study prospectively analysed cataract progression, using the LOCS III grading system, in a cohort of eyes treated with PPV for RRD. The potential influence of various demographic, clinical and surgical characteristics was also evaluated. Factors related to cataract progression after vitrectomy have been extensively discussed in the literature. To date, most studies have been retrospective, including large samples but with low homogeneity in terms of the study populations, timing of follow-up visits, surgeons and investigators. [7, 8] The present study was unique in calculating the time to CES indication following PPV. The novelty is chiefly methodological, consisting in the “ex ante” definition of the level of lens opacification and/or refractive variation required to indicate CES. This way to collect data on the parameters possibly influencing cataract development ensures minimal biases of correlation. The median time between PPV and CES (14.5 months) was similar to that in a prospective series,  but longer than the means reported in other studies examining similar characteristics, such as small-gauge PPV or RRD treated with gas tamponade. [7, 10, 11] Regarding the type of cataract, the N form progressed significantly according to the LOCS III starting from 6 months after PPV, as did the PSC type. In contrast, the C type showed no significant progression during the whole follow-up period, in line with previous observations. [10, 11, 12, 13] Progression of the N and PSC forms supported the concept that noxa mainly affected the posterior surface of the lens. These forms may result from increased exposure to oxygen via the retinal vasculature due to an absence of vitreous gel, prolonged liquid flow from the pars plana and the use of steroids as vitreal stainer during vitrectomy. [14, 15] Unlike the N and SCP forms, C cataracts are associated with extensive disruption of cell structure beginning near the equator of the lens. 
Three parameters in this study were significantly correlated with cataract progression: patient age, the use of PDMS tamponade and macula-on RRD.
In older patients (at the time of PPV), the CES indication was earlier, with the hazard ratio approximately doubling for every 5-year increase in age. This supports the preference for lens-sparing PPV to treat RRD in younger patients, considering also the increased technical difficulty of phacoemulsification in vitrectomized eyes. Certainly, the lens-sparing technique implies some differences as compared to the PPV combined with cataract extraction (i.e. phacovitrectomy, PCV). These essentially concern the enhanced retinal visualization during posterior segment surgery; the better access to the vitreous base allowing for a more extensive vitrectomy and endolaser treatment (thereby ensuring more extensive gas filling and better tamponade of retinal breaks) when the lens removal occurs before the PPV. However, a recent prospective trial reported that the preservation of the crystalline lens at the time of PPV ensured similar outcomes to those obtained with PCV, in terms of the retinal reattachment rate and safety during postoperative management.
The correlation between cataract development and presence of PDMS identified in the present study was in line with the literature. [7, 11] The statistically significant results obtained in the small number of eyes with PDMS in this study confirms the appropriateness of the design.
The apparently more rapid progression of cataract when the macula is not detached is an original finding whose mechanism remains quite difficult to assess. We think this issue in particular needs a confirmation through the enlargement of the sample size, which represents the major limitation of this study. However, the study benefitted from a highly homogeneous cohort in terms of: pre-surgery disease, the technical approach and post-PPV follow-up duration. Through prospective observation, visual and refractive conditions that indicate CES were clearly identified and located in time.