Diabetic tractional retinal detachment (TRD) is one of the major causes of blindness in cases of diabetic retinopathy.1 When TRD involves fovea, pars plana vitrectomy (PPV) is the surgical procedure of choice. Based on the status of the proliferative retinopathy, adherence of the hyaloid, and extent of fibrovascular proliferation, additional manipulation with delamination, segmentation, and en bloc dissection may be necessary. In the current era, 23-, 25-, and 27-gauge vitrectomy instruments and accessories are available. With improved fluidics and high cut rates, efficient removal of posterior vitreous with minimal traction on retina is possible.
Proportional reflux hydrodissection (PRH) is a feature of the Constellation vitrectomy system (Alcon, Fort Worth, TX) that provides a controlled egress of fluid from the cutter tip with footswitch control. In this study, we have described the use of PRH in dissecting and removal of fibrovascular membranes in eyes with TRD. We aimed to analyze the functional and anatomical outcome of TRDs using the technique of PRH.
In this retrospective study, records of patients with diabetic TRD visiting the Retina Services between January 2015 to March 2017 were screened. Patients with fovea-involving diabetic TRD undergoing PPV were included. Patients with complete surgical operative notes and at least 3-month follow-up were included. In all cases, PRH was used. Preoperative evaluation included demographic features such as age and gender, surgical eye, previous ocular history, and best-corrected visual acuity (BCVA) of both eyes (Snellen's acuity was converted to logMAR for statistical analysis).
(A) Insertion of cutter under the fibrovascular tissue (FVP) and starting of infusion underneath the membrane. (B) Delineating the FVP from the retina to the full extent of proliferation. (C) Removing the dissected membrane with the help of the cutter. (D) Dissecting the residual FVP.
The technique for surgical management consisted of modified delamination technique using the Constellation system's proportional reflux feature. All surgeries were performed by one senior surgeon (VG). Three-port standard 25-gauge vitrectomy was done (Alcon 25 Ga+ vitrectomy system). Vitreous along the ports and core was removed, ensuring complete removal of anteroposterior traction. The technique of PRH was applied when the cutter probe was placed in the plane between the normal retinal tissue and the fibrous tissue. Using PRH, the surgeon infused just the right amount of fluid (using the footswitch control) for the right amount of time to create a small space between the fibrovascular (FVP) tissue and the retina (Supplemental Video 1). The separated FVP was removed using a 7,500 cpm vitreous cutter. The process was continued until all the FVP and traction was removed (two case examples shown in Supplemental Video 2). In order to identify the posterior hyaloid, staining of the vitreous was done with triamcinolone acetonide. Excess triamcinolone particles were displaced with PRH, and using active extrusion, they were aspirated. PRH was also used to displace hemorrhages layering over the retinal surface during the procedure.
All the iatrogenic breaks that occurred during surgery were marked with endocautery and lasered. Endolaser photocoagulation was done in all ischemic areas of the retina. Patients who developed intraoperative iatrogenic breaks were noted. The use of silicon oil or gas tamponade was recorded for all cases. The use of a second instrument during surgery, such as vertical scissors, mini-light source (MLS), or delaminators, was recorded. In addition, preoperative use of anti-vascular endothelial growth factor agents was recorded. Success was recorded both in terms of anatomical outcome indicated by reattachment of retina and functional in terms of improvement of BCVA.
Thirty-three eyes of 33 patients (17 males) were included in the study. Of these, 10 eyes had combined retinal detachments. Preoperative visual acuity was 1.80 units. Eight patients underwent preoperative pan-retinal photocoagulation. Fifteen patients received preoperative ranibizumab (Lucentis; Genentech, South San Francisco, CA) 0.5 mg / 0.1 mL within 72 hours of PPV. Four eyes (12.12%) required additional help with a second instrument, such as internal limiting membrane forceps or intraocular scissors. Eleven eyes developed intraoperative iatrogenic breaks (33.3%). Internal tamponade was used in 13 patients (silicon oil was used in four patients, and perflouropropane [C3F8] was used in six patients, sulphur hexafluoride [SF6] in three cases). One eye required vitreous lavage due to persistent loose blood in the postoperative period.
All patients had successful retinal attachment at 3 months' follow-up. Postoperative mean BCVA was 1.20. Twenty-six patients had improvement in BCVA, of whom, 17 patients had improvement of more than two lines. Ten patients had final visual acuity of 0.48 or less. No patient had recurrence of RD in follow-up period.
Microincision vitreous surgery is now the surgery of choice for a majority of cases including TRD. PRH is an easy dissection technique, as shown by Dugel et al., that can be employed in eyes undergoing PPV for TRDs.2 PRH helped in the dissection of FVP by identifying the appropriate surgical plane and creating a wider working space. Secondly, it decreased the need for a second instrument in surgery, reducing the manipulation at the port site, decreasing the surgical time, and reducing the risk of iatrogenic breaks with scissors. Lastly, the dissection becomes fairly easy, as the fluidics control is in the foot pedal of the surgeon. With PRH, there is a better surgical view as it avoids excessive globe tilt during the surgery. The rate of surgical reattachment in our study was 100%, which is comparable to studies done elsewhere ranging from 69% to 100%.3–5
In our study, there were iatrogenic retinal breaks in 33% eyes. This rate may be higher because 10 eyes had combined retinal detachment, which are at a higher risk of developing iatrogenic breaks. Other studies such as those by Kumar et al.6 have reported an incidence of 20% and 16% with 23- and 25-gauge PPVs, respectively. Few studies report similar or higher incidence of iatrogenic breaks such as Stelnfeld et al.,7 who mention a rate of 41.7%. The complexity of FVP may be an important predictor of development of retinal breaks.
In conclusion, our results suggest that PRH is a very useful technique in management of TRD and complex RD cases. Advantages of this technique are that it is simple, cost-effective, avoids the use of second instrument, surgeon-friendly and highly controlled.
- Machemer R. Pathogenesis of proliferative neovascular retinopathies and the role of vitrectomy: A hypothesis. Int Ophthalmol. 1978;1(1):1–3. doi:10.1007/BF00133271 [CrossRef]
- Dugel PU. Proportional reflux hydrodissection. Retina. 2012:32(3);629–630.
- Han PH, Murphy ML, Mieler WF. A modified en bloc excision during vitrectomy for diabetic traction retinal detachment. Ophthalmology. 1994;101(5):803–808. doi:10.1016/S0161-6420(94)31255-3 [CrossRef]
- Thompson JT, de Bustros S, Michels RG, Rice TA. Results and prognostic factors in vitrectomy for diabetic traction retinal detachment of the macula. Arch Ophthalmol. 1987;105(4):497–502. doi:10.1001/archopht.1987.01060040067035 [CrossRef]
- Williams DF, Williams GA, Hartz A. Results of vitrectomy for diabetic traction retinal detachments using the en bloc excision technique. Ophthalmology. 1989;96(6):752–758. doi:10.1016/S0161-6420(89)32813-2 [CrossRef]
- Kumar A, Duraipandi K, Gogia V, Sehra SV, Gupta S, Midha N. Comparative evaluation of 23- and 25-gauge microincision vitrectomy surgery in management of diabetic macular traction retinal detachment. Eur J Ophthalmol. 2014;24(1):107–113. doi:10.5301/ejo.5000305 [CrossRef]
- Stenfeld A, Siegel RA, Kalish HS, Weinberger D, Ehrlich R. Advantages of diabetic tractional retinal detachment repair. Clin Ophthalmol. 2015;9:1989–1944. doi:10.2147/OPTH.S90577 [CrossRef]