Surgical approaches for low-to-moderate complexity RDs have been well studied [1,4,5]. The most common cause of surgical failure in RRD is PVR. However, less is known about surgical outcomes in patients at high risk for PVR. This study presented a new technique involving combined local dry vitrectomy and segmental scleral buckling in RRD patients with local vitreous traction and a high risk for PVR.
Scleral buckling is an ophthalmic surgical technique that has been successfully used to repair RRDs for over 60 years. Scleral buckling has an important role in the repair of certain categories of RRDs. These include detachments in young phakic patients, detachments associated with dialysis, and also in conjunction with vitrectomy in patients who sustain trauma or have developed PVR [6]. However, in patients of RRD with vitreous traction, who are also at high risk for PVR, performing segmental scleral buckling alone poses a significant surgical challenge because persistent vitreous traction may lead to failure of the surgery. For patients at high risk for PVR, PPV-scleral buckling has been associated with significantly higher rates of anatomical success compared with PPV alone [1].
Combining local dry vitrectomy and segmental scleral buckling were performed in these eyes. Regular vitrectomy was not chosen because all cases in the present study were partial RD, including five macula-on cases. The patients were young, and four were younger than 18 years old. Two teenage patients’ fellow eye had poor visual acuity (FC/40cm [case 3] and FC/10cm [case 7]) with a history of RD. The minimal interference of the vitreous cavity may lead to better prognosis, especially in young patients.
It has been established that vitrectomy is a risk factor for complicated cataract surgery and IOL dislocation. The main cause for nuclear cataracts after vitrectomy most probably is oxidative stress. Oxygen in the avascular lens is provided by diffusion, meaning that the surrounding oxygen content is crucial for the oxygen content within the lens. The partial oxygen pressure is highly elevated in the vitreous cavity after vitrectomy and posterior to the lens since the vitreous is lacking as a diffusion barrier for the oxygen. The partial oxygen pressure might be additionally elevated by ventilation with oxygen and a high oxygen pressure in the infusion fluid during surgery. This elevated partial oxygen pressure may lead to increased oxygen stress and thus to lens opacification by oxidation of structural proteins [7]. The key for the prevention of cataract formation therefore seems to be avoidance of oxidative stress. Local dry vitrectomy only removes the vitreous limited to the vitreous traction around retinal hole, tear or retinal dialysis without fluid infusion, which may reduce the oxidative stress of the lens and lead to less postoperative cataract formation.
Our case series demonstrates that this technique was highly effective for addressing these cases. The indications for this combined surgery were partial rhegmatogenous retinal detachment with local vitreous traction around the retinal hole or tear with preoperative PVR B plus. The following situations would be considered but not mandatory when making the decision, such as young age, macula-on status and good preoperative visual acuity. All seven eyes of seven patients in our case series (100%) achieved anatomical success with a single surgical intervention. Postoperative visual acuity was improved in all patients, and five preoperative macula-on cases have maintained a better visual acuity of 20/25. It is also a good method of finding hidden retinal holes with a light probe under microscopy. In case 1, a small retinal hole was found under microscopy, which was hidden beneath the vitreous traction.
The technique was also very safe. None of the cases experienced significant surgical complications intraoperatively or postoperatively. The entire procedure involves minimal surgical injury. The benefits of minimally invasive scleral buckling were well addressed in a previously published study [3]. Local limited dry vitrectomy can relieve vitreous traction with minimal disturbance of the vitreous cavity and carries less risk for PVR. Local dry vitrectomy can avoid the potential negative effect of intraocular infusion solutions on the retina [8]. None of our patients has experienced a complicated postoperative cataract, which has a high incidence in patients after regular vitrectomy [2]. This is especially important in young patients.
However, two patients exhibited mildly increased IOP one to two weeks postoperatively (cases 3 and 4), which returned to normal two to three weeks after the operation. When performing dry vitrectomy, viscoelastic solution was injected to maintain IOP instead of the regular infusion to avoid overly disturbing the vitreous. The reason for the temporarily increased IOP may be due to the migration of the viscoelastic solution from the vitreous cavity into the anterior chamber via the fragile zonule. The IOP may return to normal after the absorbance of viscoelastic solution.
Limitations of this study include a relatively small sample size and its retrospective design. Moreover, this was only a single surgeon’s experience and, therefore, the results may not be universally applicable. A larger prospective cohort study involving multiple surgeons would be needed to assess the true success and complication rates of this technique.
In summary, combined local dry vitrectomy and segmental scleral buckling was a highly successful method of managing RRD with local vitreous traction in patients at high risk for PVR, especially in young patients. Careful preoperative and intraoperative planning should be undertaken to achieve minimal invasiveness and the best postoperative visual results.