|Year : 2018 | Volume
| Issue : 1 | Page : 65-71
Visual and anatomical outcome of early Densiron-68 removal in primary retinal detachment
Basem M Ibrahim MD
Department of Ophthalmology, Faculty of Medicine, Zagazig University, Zagazig, Egypt
|Date of Submission||26-May-2017|
|Date of Acceptance||12-Oct-2017|
|Date of Web Publication||1-Feb-2018|
Basem M Ibrahim
Department of Ophthalmology, Faculty of Medicine, Zagazig University, Zagazig 44519
Source of Support: None, Conflict of Interest: None
The aim of this study was to evaluate the effect of early Densiron removal regarding the anatomical and visual outcome, as well as the occurrence of Densiron-related complications.
A prospective interventional noncomparative case series study was done at the Ophthalmology Unit, Zagazig University Hospital.
Patients and methods
Fifteen Densiron-filled eyes (15 patients) were included in this study. All patients had previous pars plana vitrectomy with Densiron oil injection for treatment of retinal detachment (RD) owing to inferior breaks with or without associated proliferative vitreoretinopathy. Densiron removal was done after 2–2.5 months from the time of the initial surgery. Active suction by the vitrectomy machine was used for Densiron removal under direct illumination and visualization by using long 18-G silicone cannula. Postoperative follow-up was done at first day; first, second, and third week; and first, second, third, and fourth month after Densiron oil removal. Retinal attachment, visual acuity (VA), and various complications were recorded.
Two eyes had RD before Densiron removal. Another eye developed RD after Densiron removal. Therefore, 12 of 13 eyes remained attached after Densiron removal (92%). The final mean best-corrected VA improved from 1.39±0.59 minimal angle of resolution (logMAR) before Densiron removal to 1.114±0.55 logMAR at the fourth month after Densiron removal; this improvement in VA was statistically significant (P=0.0046). The most frequent recorded complications were cataract which occurred in six of 13 (46%) phakic eyes and emulsification in three of 15 (20%) eyes.
Regarding anatomical and visual outcomes, it could be safe to remove Densiron-68 after 8–10 weeks from the initial surgery, which consequently decreases the chances of Densiron complications.
Keywords: anatomical outcome, Densiron-68, retinal detachment, visual outcome, vitrectomy
|How to cite this article:|
Ibrahim BM. Visual and anatomical outcome of early Densiron-68 removal in primary retinal detachment. Delta J Ophthalmol 2018;19:65-71
|How to cite this URL:|
Ibrahim BM. Visual and anatomical outcome of early Densiron-68 removal in primary retinal detachment. Delta J Ophthalmol [serial online] 2018 [cited 2018 Feb 24];19:65-71. Available from: http://www.djo.eg.net/text.asp?2018/19/1/65/224565
| Introduction|| |
The endotamponades that have lower specific gravity than water such as conventional silicone oil, perfluoropropane (C3F8), and sulfur hexafluoride (SF6) are the standard endotamponades used in retinal surgeries nowadays; these tamponades are less effective in supporting the lower retina, so cases with inferior retinal pathology such as inferior breaks or inferior proliferative vitreoretinopathy (PVR) represent a challenge to these endotamponades. This necessitates the development of heavier than water endotamponades which give a good support to the lower retina, seal the lower retinal breaks, and decrease the chance of PVR formation by taking the retinal pigment epithelial cells and inflammatory ingredients away from the lower part of the retina .
Early heavy tamponades had many limitations such as induction of inflammation owing to its rapid dispersion and the fact that many of these tamponades have intrinsic retinal toxicity ,. On the contrary, the new heavy tamponades had fewer complications and gave encouraging results. Densiron-68 is one of these recently used heavy tamponades, which is a mixture of 69.5% polydimethylsiloxane and 30.5% perflurohexyloctane (F6H8; Labtician Ophthalmics, Inc., Ontario, Canada). It has less tendency to disperse than early heavy tamponades. Densiron-68 has a viscosity of 1400 mPas and has a specific gravity of 1.06 g/cm3 .
In the face of the advantages of Densiron, it still has some undesirable adverse effects such as cataract formation, intraocular inflammation, epiretinal membrane formation, dispersion and emulsification, and increased intraocular pressure (IOP) ,. In spite of the fact that it is difficult to know whether these complications are directly related to the heavy endotamponades or are associated with the underlying complicated retinal diseases, it was observed that the longer the time the Densiron is left inside the eye the greater the rate of its complications, especially dispersion and emulsification .
Densiron emulsification is one of the most common complications that can occur as early as few weeks . Emulsification is a predisposing factor for many other complications such as increased IOP, epiretinal membrane formation, ocular inflammation, cystoid macular edema, and cataract formation . Early removal of Densiron will avoid many of these complications. However, to escape retinal re-detachment following removal, a definite period of time is required to complete sealing of retinotomy and breaks edges. Regarding the time of conventional silicone oil removal, recommendations ranged from 3 to 6 months ,. Studies conducted on Densiron have not shown a specific date of its removal. Although the study done by Heimann et al.  recommended Densiron removal after a period between 108 and 120 days, other studies reported a very wide choice of Densiron removal timing that ranged from 3 weeks up to 10 months ,,,,,.
The purpose of this study was to demonstrate the safety of Densiron removal regarding the visual and anatomical outcome and related complications.
| Patients and methods|| |
This is a prospective interventional noncomparative case series study of 15 eyes of 15 patients. The work was carried out between 2013 and 2016. It was approved by the Ethical Committee of the Faculty of Medicine, Zagazig University.
All patients included had previous pars plana vitrectomy with Densiron (Labtician Ophthalmics, Inc., Ontario, Canada) oil injection for treatment of retinal detachment (RD) owing to inferior breaks with or without associated PVR.
Informed written consent was signed by all the patients included in the study and short details of the surgery and possible complications were explained to them.
Preoperative assessment included history taking, best-corrected visual acuity (VA) testing using Landolt’s broken ring chart, Goldmann applanation tonometery for IOP measurement, slit lamp examination for anterior segment evaluation, and indirect ophthalmoscopy to examine the fundus. The PVR grading was based on the updated classification of Machemer et al. .
Postoperative follow-up was done at the first day; first, second, and third week; and first, second, third, and fourth month after Densiron oil removal. In each visit, a brief history was taken, best-corrected VA and IOP were recorded, and anterior segment examination with the slit lamp and fundus examination using indirect ophthalmoscopy were performed.
Densiron removal was done within 2–2.5 months from the time of the initial surgery of vitrectomy and Densiron injection.
All surgeries were performed under general anesthesia using either standard 20-G three-port or 23-G three-port pars plana vitrectomy. Vitrectomy machines used were either DORC Associate 2500 (Dutch Ophthalmic Company, Zuidland, The Netherlands) or the OS3 3000 (Oertli Instruments AG, Berneck, Switzerland).
Active suction by the vitrectomy machine was used for Densiron removal. This was accomplished under direct illumination and visualization by using18-G silicone cannula which was aimed toward the posterior pole. For complete aspiration of Densiron, aspiration rate of 600 mmHg was needed. A second operation may be needed if after Densiron extraction detachment occurred. In the cases that presented with cataract at the time of Densiron removal, combined procedure of phacoemulsification and Densiron removal was performed.
Data were collected and submitted to statistical analysis using unpaired t-test and χ2-test. A P value less than 0.05 was considered statistically significant. All statistical calculations were performed using statistical package for the social sciences (SPSS), version 19 (IBM Company, New York, New York, USA).
| Results|| |
Fifteen eyes of 15 patients were included in the present study. The mean age of the patients was 46±14 years (range: 10–64 years). There were 11 males and four females. Mean VA just before Densiron removal was 1.39±0.59 minimal angle of resolution (logMAR). IOP ranged from 11 to 18 mmHg, with a mean of 14.47±2.53 mmHg. Thirteen eyes were phakic and two eyes were pseudophakic. The baseline characteristics of the patients are shown in [Table 1].
Densiron was removed within 2–2.5 months. It was removed by the end of the second month in eight eyes. The remaining seven eyes had Densiron removal 2 weeks later.
The mean follow-up duration after surgery was 15±2 weeks (range: 14–17 weeks).
The anatomical outcome is summarized in [Table 2]. Anatomical success can be defined as complete retinal attachment after Densiron extraction.
Regarding retinal assessment before Densiron removal, 13 of 15 (86.6%) eyes had attached retina and two (13.4%) eyes had RD. The first eye (patient no. 4) developed superior giant retinal break with superior macula off detachment and the other eye (patient no. 11) had localized lower detachment with macular pucker.
At the time of Densiron removal, another eye developed RD (patient no. 13) which developed a superior RD caused by a new break. Vitrectomy was done for patients 4 and 13, and conventional silicone oil was used as an endotamponade. However, patient number 11 developed extensive macular membrane with lower RD and refused further intervention. By the end of the fourth month after Densiron removal, 14 (93%) eyes had attached retina.
Regarding the anatomical success after early Densiron removal, the retina was attached in 13 of 15 eyes before Densiron removal. After Densiron removal, only one eye developed RD. Therefore, 12 of 13 eyes had attached retina after early Densiron removal up to the end of the fourth month of follow-up, which means that the anatomical success of early Densiron removal is 92%.
Preoperative and postoperative VAs are shown in [Figure 1]. Best-corrected VA at the end of the follow-up showed improvement in eight cases, no change in five cases, and worsening in two cases. The final mean best-corrected VA improved from 1.39±0.59 logMAR before Densiron removal to 1.114±0.55 logMAR at the fourth month after Densiron removal. Mean differences in VA is 0.283333 with SD of 0.326161. This improvement in VA was statistically significant (P=0.0046). The 95% confidence interval of the differences in VA is from 0.102711 to 0.463955.
|Figure 1: Chart showing visual acuity in logMAR before Densiron removal and at final follow-up.|
Click here to view
Details of anatomical and visual outcomes are demonstrated in [Table 3].
Eleven of 15 cases of the study had pre-Densiron removal complications which motivated early removal of Densiron. The most common was cataract formation which occurred in six of 13 (46%) phakic eyes (patients no. 2, 6, 8, 11, 12, 13). Phacoemulsification at the time of Densiron removal was done successfully in all eyes. Other complications were emulsification in three (20%) eyes (patients no. 3, 6, 10), recurrent RD in two (13%) eyes (patients no. 4 and 11), inflammatory fibrinous reaction in the anterior chamber in two (13%) eyes (patients no. 14 and 15), and secondary glaucoma in two (13%) eyes (patients no. 14 and 15). Glaucoma was inflammatory owing to inflammatory fibrinous reaction in the anterior chamber, and both inflammation and glaucoma were controlled medically.
Epiretinal membranes were found in two (13%) eyes; patient no. 11 who refused further surgery and patient no. 13, who was complicated also by recurrent RD 3 weeks after removal of Densiron, and this case was treated by vitrectomy, peeling of epiretinal membrane, and silicone oil injection.
Hypotony was recorded in only one (6.6%) eye (patient no. 11). Hypotony was because of recurrent RD and persisted as the patient refused further operation after Densiron removal.
On the contrary, no complications were noted after Densiron removal in all cases except for one patient (patient no. 13) where RD occurred 3 weeks after removal of Densiron because of occurrence of a new superior break. [Table 4] illustrates the details of the complications.
| Discussion|| |
Many authors confirmed the efficacy of Densiron as a heavy endotamponade to support the lower retina in cases with RD associated with lower or posterior breaks ,,,. The difference between Densiron and other previous heavy tamponades is that Densiron has some advantageous physical properties that allow it to be left in the vitreous cavity for a longer duration. However, Densiron has some adverse complications such as cataract, dispersion, emulsification, intraocular inflammatory response, and ocular hypertension. These complications may occur early and may progress with time and necessitate Densiron extraction ,.
Densiron emulsification is a frequent complication that indicates tamponade removal. Emulsification occurs owing to numerous factors such as changes in temperature and pressure and strong eye movement . The incidence of emulsification increases with increase of time of tamponade left in the eye. There are other complications related to emulsification such as cataract formation and elevated IOP . Moreover, F6H8 which results from emulsification of Densiron is toxic to the retina when left for long time and induces cystoid macular edema and epiretinal membrane formation ,.
There has been a wide debate on the proper timing of Densiron removal. Heimann et al.  specified that Densiron should be left in the eye for a period between 108 and 120 days. Other studies conducted to evaluate the efficacy and the complications of Densiron showed a wide range of variation concerning the time of Densiron removal as shown in [Table 5]. Levasseur et al.  suggested that Densiron should only be used as a short-term tamponade to avoid its complications.
In the current study, early tamponade removal was defined as removal before 10 weeks (2.5 months). All 15 eyes had Densiron extraction before 2.5 months. Two eyes developed RD with Densiron in situ; one eye developed superior giant break possibly owing to incomplete Densiron filling during vitrectomy and the other developed lower RD associated with epimacular membrane. Only one eye had RD after Densiron extraction. Therefore, if we excluded these two eyes which developed RD with Densiron in situ, the anatomical success after early Densiron removal would be 92% (12 of 13 eyes).
Auriol et al.  reported a 90% success rate after early Densiron extraction (before 10 weeks), where only one of 10 eyes developed RD after early Densiron removal as a result of a new break which occurred 4 months after extraction. Levasseur et al.  removed Densiron before 10 weeks in 35 of 39 eyes with lower RD included in their study. The retina was attached in ∼86% of them after extraction of Densiron (30 of 35 eyes) . On the contrary, Sander et al.  reported that only 66% (four out of six eyes) remained attached after early Densiron removal (before 10 weeks).
VA improved in the present study from a mean preoperative VA of 1.39±0.59 logMAR to 1.114±0.55 logMAR after 4 months of follow-up. Many factors contribute to this improvement in VA after Densiron removal such as removal of emulsified Densiron, cataract extraction, and epiretinal membrane removal at the time of oil removal. Other studies showed also VA improvement as with Auriol et al.  from 1.55±0.21 to 1.34±0.39 and Macias-Murelaga et al.  from 1.45±0.5 to 1.16±0.4.
Regarding complications, in the current study, emulsification developed in three (20%) eyes. Factors that predispose for early emulsification include low viscosity of Densiron and contamination of the endotamponade from intrinsic and extrinsic materials during the operation ,. However, early emulsification in the present study could be attributed to high environmental temperature that could affect Densiron storage, as well as vigorous ocular motility as most of the study cases were farmers or workers. These reasons were advocated by Duane et al.  who referred to the role of environmental factors in emulsification. Cataract formation was noticed in only six (46%) eyes in the present study which is a low incidence compared with other studies. Several studies have shown cataract progression in 80–100% of patients at 2 years of follow-up. Nuclear sclerosis is the most common type of cataract following vitrectomy ,. Early removal of Densiron, in the present study, may contribute to reducing the incidence of cataract and may represent an advantage of early removal. Cataract formation could be related to the tamponade itself, which affects the normal metabolism of the crystalline lens. Another reason is the effect of the emulsified droplets that can adhere to the hyaloid membrane just behind the crystalline lens resulting in its opacification .
Early emulsification and ocular inflammatory response could be possible reasons for other complications such as elevated IOP which was noticed in two (13%) eyes and epiretinal membrane formation that was seen in two (13%) eyes in the present study.
In Auriol et al.  study, some complications were reported after early Densiron removal in 10 eyes of their study, such as fibrin reaction (one eye), corneal dystrophy and ocular hypotony (two eyes). These two eyes which developed corneal dystrophy were aphakic, and Densiron was present in the anterior chamber . Sander et al.  reported certain complications related to Densiron in the six eyes that had early Densiron removal. These included inflammatory reaction in four eyes, elevated IOP in one eye, and cataract formation in one eye .
Other studies that used Densiron as an endotamponade did not mention details about the complications related to each patient individually. Therefore, we could not correlate the occurrence of complications to the time of Densiron removal.
| Conclusion|| |
It could be safe to remove Densiron early between 8 and 10 weeks. However, a further larger randomized comparative series comparing the safety of early oil removal versus late removal should be conducted to determine the best time of Densiron removal.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]