In our series, the rate of anatomical success in patients who underwent PPV, gas tamponade, and SB for inferior break RD was 90.9%. Although about half of the RRD patients can be treated with only SB successfully, PPV with gas tamponade has been popular in the primary RRD treatment in recent years [8]. The classical SB is effective in most of the cases, except for complicated cases. In such cases, SB should be combined with PPV, and also cataract surgery if needed. The requirement of PPV is mandatory in patients with bullous detachments, vitreous opacity that prevents the visualization of the retina, and multiple, posterior retinal breaks [5]. However intraocular gas tamponades may support the temporal, nasal, and also superior quadrant retinal breaks with appropriate position, the inferior retinal breaks require alternative solutions [9], so the combined SB or the novel heavy SO tamponade could be preferred [10].
The placement of a SB may be challenging technically, prolongs operation time, and have possible complications such as refractive changes [11], diplopia or strabismus [12], explant intrusion or extrusion [13], infection [14], choroidal hemorrhage [15], and anterior segment ischemia [16]. However, these risks are negligible if superior results are achieved. Heimann et. al. found a significant recurrence rate in patients who underwent alone PPV for inferior break RD and concluded that the short-acting internal tamponades are not sufficient to provide the flatness of inferior breaks in the absence of additional buckling. They also commented that the diagnosis of inferior breaks is delayed due to asymptomatic and less likely spontaneous absorption of subretinal fluid due to gravity [17]. The longer existence of retinal breaks may lead to intravitreal fibro cellular proliferations and redetachments, but this data is not proven [18]. Related to the possible complications of SB, the authors suggested that the vitrectomy alone provides acceptable success rates in RRD. Sharma et al compared the outcomes of PPV in inferior and superior retinal breaks retrospectively and resulted no significant difference between groups [19]. In only inferior break RD, Wickham et al. reached the conclusion that there was no significant difference in the outcomes of PPV alone and combined PPV/SB [20]. The disadvantage of these studies is the retrospective design because it is not always possible to reach the data about PVR. In our series, all the patients had PVR that is equal to or more than stage C, so we have combined our surgeries with SB to prevent the vitreoretinal tractions due to PVR. Finally, the success of our result exceeded the previous reports.
This can be related to the additional cataract surgery. The dense opacities in the lens or dense cataracts may prevent the evaluation of the posterior segment. In such cases, combined cataract and retinal surgery could be performed. There are several advantages of combined phacovitrectomy such as better visualization of the peripheric retina for requirement the complete peripheric vitrectomy and endolaser photocoagulation, visualization of retinal breaks, and reduced rate of second surgery which can be challenging in the absence of vitreous support. In ‘lens sparing’ PPV surgeries, the complete vitreous cleaning may not always be achieved due to inadequate visualization of the peripheric retina. Even the lens removal and complete vitreous cleaning were performed, the rate of success was 90.5% with primer surgery in our series. We comment that all of the eyes had advanced stage PVR, and the success rate increased to 100% after repairing redetachment in a PVR stage D patient. Whether the removal of the lens may vary depending on the surgeon's preference and the condition of the lens, but in selected cases, the lens extraction is mandatory if there is a traumatic large detachment, requirement of extensive vitreous cleaning, the need for medium to long-term viscous tamponade, the lens is already not clear [21]. On the other hand, there are a few disadvantages of lens removal such as postoperative refractive error due to misalignment of intraocular lens calculation, removal of accommodation function in no or mild cataract cases.
The most frequent complication after SB and PPV was reported as cataract [4]. In previous literature, the duration between PPV (no matter etiology) and cataract extraction varies between 16–24 months [22]. In fact, the formation of cataracts is even much earlier. The underlying mechanism of cataract formation is not well-understood [23]. The protective role of the vitreous has been defined by preventing the direct interaction between the lens and molecular oxygen in retinal vasculature [24]. The secondary surgery may be challenging in a vitrectomized and scleral-buckled eye due to hypotony, so the combined procedure including both retinal surgery and lens extraction seems reasonable. In previous studies, the final visual acuity after ‘lens-sparing’ PPV was found similar to the extracted lens at the end of follow-up [25], but the possible formation of the cataract after surgery should be discussed with the patient before surgery.
In our series, the rate of anatomical success after combined surgery was 90.9% with primary surgery and 100% at the final. There is no data about the combined surgery in inferior quadrant RDs, so we can compare our results with combined vitrectomy and phacoemulsification. Mora et. al found the anatomical success rate after combined PPV and phacoemulsification as 96.7% [21], while Haugstad et al. achieved anatomical success with the rate of 98.1% with only PPV, and 100% with combined PPV and SB [26]. Similar to our results, Ling et al. reported the anatomical success rate as 90.5% in primary RRD [27]. Tan et al. reported the primary anatomical success rate as 84.3% in the combined group (PPV + Fako), and 89.2% in the only PPV group [28]. Guber et. al detected retinal re-detachment in 10.1% of the patients [29]. In total, we recorded one case of recurrence, and resurgery was performed in this patient with SO tamponade. The failure after the first surgery was related to advanced PVR (stage D).
The difference between the efficacy of internal tamponades for complicated RDs was investigated in Silicone Oil Study and resulted that the effectiveness of SF6 is less than SO and C3F8 while there was no difference between SO and C3F8 [30]. In this study, C3F8 and SO were used as internal tamponade in primary surgery, and SO was used in patient who had recurrence RD. The main advantage of the usage of C3F8 is no requirement of secondary surgery for reuptake and the absence of SO-related complications.
The limitation of the study was the relatively small sample size and the absence of a control group. The results can not be generalized to the general population due to the sample size. Although the study helded in a tertiary hospital that the retinal surgery is performed frequently, only the patients with inferior break RD and equal or above PVR-stage C were selected, and the number of the included cases were small.
In conclusion, the combined phacovitrectomy and SB is an effective and reliable surgical method in patients with inferior quadrant RD.