|Year : 2014 | Volume
| Issue : 1 | Page : 37-40
Posterior lens capsule delineation during pars plana vitrectomy
Mohamad A. S. Eddin Abdelhakim
Department of Ophthalmology, Kasr Al Ainy, Faculty of Medicine, Cairo University, Cairo, Egypt
|Date of Submission||30-Aug-2013|
|Date of Acceptance||17-Sep-2013|
|Date of Web Publication||21-Jun-2014|
Mohamad A. S. Eddin Abdelhakim
MD, Cairo University, Cairo
Source of Support: None, Conflict of Interest: None
A known complication of cataract surgery, during combined phacoemulsification and vitrectomy, is rupture of the posterior capsule, which occurs at a rate of 0.82-2.1%.
The aim of the study was to optimize the visualization of the posterior lens capsule during pars plana vitrectomy to prevent its injury during the procedure.
This investigation was designed as a case-control study.
Patients visiting the Kasr Al-Aini Cairo University Hospitals Outpatient Clinic of Ophthalmology during the period from January 2012 to June 2013 were selected for the study.
Participants and methods
This study was conducted on two groups of patients. In group I (49 eyes), a few small air bubbles were allowed to pass through the infusion cannula and into the eye where they adhered to the posterior lens capsule, whereas in group II (control, 52 eyes) phacovitrectomy was carried out without air bubbles.
Primary outcome measure
The integrity of the posterior lens capsule during vitrectomy was considered the primary outcome measure.
In group I comprising 49 (100%) vitrectomized eyes, the posterior lens capsule was perfectly visualized and avoided during detachment of the anterior hyaloid face, during total vitrectomy and during vitreous base shaving. In group II, there was one eye with posterior capsule rupture and intraocular lens drop (1.9%).
Conclusion and relevance
Small air bubbles help perfect delineation of the posterior lens capsule during vitrectomy, avoiding its injury.
Keywords: Air bubbles, posterior lens capsule, vitrectomy
|How to cite this article:|
Eddin Abdelhakim MA. Posterior lens capsule delineation during pars plana vitrectomy. J Egypt Ophthalmol Soc 2014;107:37-40
| Introduction|| |
Cataract and vitreoretinal pathology are frequently addressed simultaneously by a single surgeon. A combined approach minimizes the surgical and economic burden of multiple surgeries, as well as the risks associated with anesthesia. In addition, combination surgery allows for faster patient recovery and earlier visual rehabilitation .
Removing the cataract before vitrectomy optimizes visualization of the posterior pole, which is important when peeling epiretinal membranes and the internal limiting membrane. Removal of the cataract additionally allows for better access to the vitreous base without the risk of touching the lens. More extensive removal of the anterior vitreous may be required in complex cases of diabetic tractional retinal detachment and in proliferative vitreoretinopathy (PVR) .
The optimal placement of the intraocular lens (IOL) is in the capsular bag. However, a known complication of cataract surgery, during combined phacoemulsification and vitrectomy, is rupture of the posterior capsule, which occurs at a rate of 0.82-2.1% . Thus, the aim of this study was to optimize the visualization of the posterior lens capsule during pars plana vitrectomy (PPV) to prevent its injury during the procedure.
| Patients and methods|| |
Approval for the study was obtained from the Ophthalmology Department's Ethical Committee. All patients received a thorough explanation of the surgical technique and aims and were provided with written informed consent.
This is a case-control study conducted on two groups of patients. In group I (49 eyes), a few small air bubbles were allowed to pass through the infusion cannula and into the eye where they adhered to the posterior lens capsule, whereas in group II (control, 52 eyes) phacovitrectomy was carried out without air bubbles.
The patients were selected from the outpatient ophthalmology clinic of Kasr Al-Aini Teaching Hospital Outpatient Ophthalmology Clinic, Cairo University, during the period from January 2012 to June 2013.
The inclusion criterion for the patients was the presence of phakic eyes with posterior segment pathology requiring vitrectomy, which was performed in combination with phacoemulsification and IOL implantation. Posterior segment pathologies addressed in this technique were rhegmatogenous retinal detachment (RRD) with different grades of PVR, and proliferative diabetic retinopathy (PDR) requiring surgery (vitreous hemorrhage, tractional retinal detachment affecting the macula, and combined tractional RRD). The exclusion criteria were the presence of aphakic eyes with no visible remnants of posterior capsule and eyes with visible opacified posterior capsule remnants (aphakic or pseudophakic).
Preoperatively all patients were evaluated for best-corrected visual acuity, slit-lamp examination results, intraocular pressure, and dilated fundus examination results.
Phacoemulsification was accomplished before fashioning the sclerotomies. In our approach, the IOL was inserted immediately after phacoemulsification, before vitrectomy. It improved surgical time and efficiency, particularly if a fluid-air exchange was performed or intraocular tamponade was used. We also found that, when a wide-angle viewing system was used, the IOL did not interfere with the surgeon's view during the subsequent vitrectomy.
The sclerotomies were fashioned using a 20-G Micro-vitreoretinal (MVR) blade. The infusion cannula was inserted and opened allowing saline into the vitreous cavity. A few air bubbles were allowed to perfuse into the eyes of patients of group I. If too many bubbles entered, hindering visibility, they were aspirated using a vitreous cutter to prevent obstruction of visibility. The air, having lower specific gravity than water, floated on the surface and adhered to the posterior lens capsule. In group II, vitrectomy was carried out without the use of air bubbles. If any were perfused into the eye, they were aspirated using the suction mode of the vitreous cutter.
Anterior vitrectomy was performed first, trying to separate the anterior hyaloid face from the posterior lens capsule. The capsule was well visualized with the aid of the air bubbles on the back of the posterior capsule. The aim of the anterior vitrectomy also was to free the internal sclerotomies from vitreous.
After completion of anterior vitrectomy, the core vitreous was addressed. All through the procedure, a few air bubbles were left to aid in delineating the posterior capsule to avoid its injury. This was followed by core vitrectomy and peeling of the posterior hyaloid face.
In eyes with tractional retinal detachment, conformal cutter delamination using a side approach was used. Segmentation was primarily used as access to expose the dissection plane (potential space) for delamination. A bimanual delamination technique was used for eyes with combined tractional RRD.
Perfluorocarbon liquid (PFCL) was injected. Vitrectomy for the vitreous base was performed for 360°, with scleral indentation accomplished by the assistant for all eyes. Endolaser panretinal photocoagulation and endolaser application to retinal breaks were done. PFCL/silicone oil exchange was performed through the infusion cannula. Finally, the sclerotomies were closed using a 7-0 Vicryl suture.
Postoperatively, all patients were examined on the first day, after 1 week, and then monthly for 3 months. The examination included best-corrected visual acuity, anterior segment examination, intraocular pressure, and dilated fundus examination. Silicone oil was removed 3 months postoperatively.
| Results|| |
In group I, the patients' ages ranged from 23 to 76 years with a mean of 48.06 ± 11.81 years. The female to male ratio was 3 : 4. The patients were candidates for vitrectomy for PDR for different reasons and for RRD with different grades of PVR [Table 1].
The preoperative visual acuity of the patients ranged from 2.20 to 1.20 in logMAR, with a mean of 1.79 ± 0.27.
PPV was performed for the 49 eyes, together with phacoemulsification and IOL implantation. The posterior capsule was well delineated in the 49 eyes because of the adherence of air bubbles to it. All 49 (100%) eyes had an intact posterior capsule throughout the procedure [Figure 1].
The results of vitrectomy are shown in [Table 2]. The postoperative visual acuity ranged from 1.90 to 0.20 in logMAR, with a mean of 0.91 ± 0.52.
In group II, the patients' ages ranged from 13 to 75 years, with a mean of 48.67 ± 14.49 years. The female to male ratio was 7.9 : 10. The patients were candidates for vitrectomy for PDR and for RRD [Table 3].
The preoperative visual acuity of the patients ranged from 2.20 to 1.30 in logMAR, with a mean of 1.82 ± 0.23.
PPV was performed for the 52 eyes, together with phacoemulsification and IOL implantation. Fifty-one of the 52 (98.1%) eyes had an intact posterior capsule throughout the procedure, whereas only one (1.9%) eyes suffered a rent in the posterior capsule intraoperatively. This rent occurred during shaving of the vitreous base and was followed by drop of the IOL in the vitreous cavity, which was already half-filled withPFCL. The IOL was grasped with retinal forceps from its optic and it was repositioned and placed on the capsulorhexis in the ciliary sulcus, and the procedure was resumed [Figure 2].
The results of vitrectomy are shown in [Table 4]. The postoperative visual acuity ranged from 2.20 to 0.20 in logMAR, with a mean of 1.08 ± 0.56.
| Discussion|| |
In our study we added a new step to PPV to protect the posterior lens capsule during the procedure. We allowed a few air bubbles to perfuse into the vitreous cavity, and as the air has lower specific gravity than water it floated on the surface of saline and adhered to the back of the posterior capsule .
Only one (1.9%) of the 52 eyes in group II experienced posterior capsular rupture during the procedure, whereas in group I none of the eyes had posterior capsular rupture. This was attributed to the air bubbles being adherent to the posterior capsule. To the best of my knowledge this technique has not been adopted before and no other special technique to delineate the posterior capsule has been adopted before.
One of the steps that also helped to protect the posterior capsule was implantation of the IOL in the capsular bag and before the beginning of vitrectomy, as the posterior lens capsule adhered to the back of the IOL. This was achieved after washing the viscoelastic from behind the IOL.
In the study by Armaly , conducted on 117 eyes from 114 patients who had undergone PPV combined with phacoemulsification and IOL implantation, intraoperative complications consisted of retinal tears in 14 (12.0%) eyes and posterior capsular rupture in two (1.7%) eyes.
Hence, in conclusion, making use of air bubbles through a simple step at the beginning of PPV helped proper delineation of the posterior lens capsule throughout the procedure, consequently avoiding its rupture.
| Acknowledgements|| |
Conflicts of interest
There are no conflicts of interest.
| References|| |
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|2.|| Thompson JT, Smiddy WE, Glaser BM, Sjaarda RN, Flynn HW Jr. Intraocular tamponade duration and success of macular hole surgery. Retina 1996; 16 :373-382. |
|3.|| Wensheng L, Wu R, Wang X, Xu M, Sun G, Sun C. Clinical complications of combined phacoemulsification and vitrectomy for eyes with coexisting cataract and vitreoretinal diseases. Eur J Ophthalmol 2009; 19 :37-45. |
|4.|| Armaly MF. Ocular tolerance to silicones. Arch Ophthalmol 1962; 68 : 390-395. |
[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3], [Table 4]