To determine the effect of pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling and primary silicone oil tamponade without any postoperative position restrictions for retinal detachment (RD) caused by macular hole in high myopia.
Retrospective, interventional case series.
Twenty-four eyes of 24 patients with RD caused by macular hole in high myopia (axial length more than 27.0 mm) were treated by PPV with ILM peeling and primary silicone oil tamponade. No position restrictions were issued to patients postoperatively.
The retina reattached in 22 eyes (92%) following the initial surgery. The final retinal reattachment rate was 100% after a second surgery of macular buckling for the 2 eyes with initial failure. For eyes with initial successful reattachment, the mean best-corrected visual acuity (BCVA) was significantly improved from 1.8 ± 0.5 logMAR units before surgery to 1.2 ± 0.4 ( P < .001, paired t test). No clinical factors were significantly associated with improvement of BCVA or macular hole closure using multivariate analysis.
For the treatment of RD caused by macular hole, PPV with ILM peeling and primary silicone oil tamponade showed a high retinal reattachment rate without any postoperative position restrictions. It also improved postoperative BCVA significantly. This may be a preferable method for the treatment of RD caused by macular hole in high myopia.
Retinal detachment (RD) caused by macular hole occurs mainly in highly myopic eyes. This condition is commonly seen in Asia and is often seen in female patients. Various surgical procedures exist for the repair of RD caused by macular hole, including macular buckling, intraocular gas tamponade with or without pars plana vitrectomy (PPV), and silicone oil tamponade.
PPV, fluid-gas exchange, and face-down positioning, with internal limiting membrane (ILM) peeling, have become popular procedures used for the treatment of RD caused by macular hole. Initial retinal reattachment rate with these procedures is reported to range from 69% to 93.8%. However, these procedures usually require a face-down positioning for 1 to 2 weeks postoperatively and this imposes a great physical strain on the patients. In this study, we used silicone oil in the initial surgery without face-down positioning because we hypothesized that silicone oil tamponade provides a long-enough duration to remain effective without position restrictions. This idea follows the rationale of providing a long-term tamponade with allowance for sufficient glial closure of the hole and complete absorption of the subretinal fluid.
The purpose of this study was to determine the effect of PPV with ILM peeling assisted with indocyanine green (ICG) staining and primary silicone oil tamponade without any postoperative position restrictions for the treatment of RD caused by macular hole in highly myopic eyes.
Patients and Methods
The medical records of patients with RD caused by macular hole in highly myopic eyes and treated by PPV with ILM peeling and primary silicone oil tamponade between March 1, 2005 and December 31, 2007 were retrospectively reviewed. The inclusion criteria were as follows: 1) clinical presentation of RD caused by macular hole; 2) an axial length of more than 27.0 mm in an eye with RD caused by macular hole; 3) treatment with conventional 20- or 23-gauge 3-port PPV with primary silicone oil tamponade; and 4) a follow-up duration of 29 months from the first surgery (range, 29-61 months). Eyes were excluded from the study if they had pre-existing ocular diseases or a history of ocular surgery, except for cataract surgery. Other exclusion criteria included grade C proliferative vitreoretinopathy.
The following examinations were performed preoperatively and at every postoperative visit: measurement of best-corrected visual acuity (BCVA) using the Landolt C acuity chart, noncontact tonometry, and slit-lamp examination of the anterior and posterior segment. Preoperatively and at every postoperative visit, the retinal situation was documented using fundus photography. All axial lengths were measured preoperatively by A- and B-scan ultrasonography. Optical coherence tomography (OCT) examination was performed postoperatively in all eyes using commercially available time-domain OCT (OCT 3000; Carl Zeiss, Dublin, California, USA) or spectral-domain OCT (3D OCT-1000; Topcon, Tokyo, Japan) to confirm whether the macular hole was closed after retinal reattachment. Macular hole closure was defined as the absence of a neurosensory defect over the fovea. After installation in our institution (March 2008), spectral-domain OCT was used to reconfirm macular hole closure in patients for whom this had been confirmed previously using time-domain OCT.
Because patients were all elderly and expected to have cataract after the surgery because of initial vitrectomy, silicone oil placement and silicone oil removal, phacoemulsification and aspiration, and intraocular lens (IOL) implantation on all phakic eyes were performed prior to PPV. Conventional 20- or 23-gauge 3-port PPV with separation of the vitreoretinal adhesion between the posterior vitreous membrane and the retina was performed. Triamcinolone acetonide was used intraoperatively to facilitate visualization of the vitreous and posterior hyaloid. The ILM around the macular hole within the major temporal vascular arcades were peeled off with vitreous forceps after the ICG staining procedure. The ICG solution was prepared by dissolving 25 mg/vial of dry ICG dye in 1 mL of distilled water, and was then mixed with 19 mL of intraocular irrigation solution (BSS plus; Alcon Laboratories, Inc., Fort Worth, Texas, USA) to obtain a final ICG concentration of 1.25 mg/mL (0.125%). Fluid-air exchange with drainage of subretinal fluid through the macular hole was then performed, and the air was replaced with silicone oil. In all eyes, silicone oil with a viscosity of 1000 centistokes was used. No attempt was made to dry the central subretinal space completely. No intraoperative or postoperative laser coagulation was applied to the hole margin or to the central retina. No instructions concerning position restrictions were issued to patients after surgery.
Silicone oil was removed at the patient’s convenience at least 6 months after the initial surgery, or earlier if intraocular pressure (IOP) was not controlled under 20 mm Hg even with the use of antiglaucomatous drops.
In this study, statistical analyses were performed using SPSS version 17.0 (SPSS Inc, Chicago, Illinois, USA). A value of P < .05 was considered statistically significant. Visual acuity was converted into a logarithm of the minimal angle of resolution (logMAR) for statistical analysis. Visual acuity of counting fingers and hand motions was arbitrarily assigned an equivalent of 2.3 and 2.6 logMAR units, respectively. A change greater than 0.3 logMAR units between preoperative and postoperative visual acuity was classified as improvement or worsening of BCVA and within 0.3 logMAR units as stable BCVA.
We evaluated initial retinal reattachment rate. For eyes with initial successful reattachment, differences between preoperative and postoperative BCVA were evaluated by a paired t test. Logistic regression analysis was also used to examine the contribution of clinical factors to the improvement of BCVA (>0.3 logMAR units) and macular hole closure after reattachment, respectively. The clinical factors assessed were as follows: age, preoperative logMAR visual acuity, area of retinal detachment (within vs beyond staphyloma), axial length, combined phacoemulsification with IOL implantation, duration of silicone oil tamponade, and follow-up period from the initial surgery. Individual clinical factors were subjected to univariate logistic regression analysis and were subsequently entered in the multivariate analysis in a backward stepwise manner if the P value was <.2. If a clinical factor occurred infrequently (n < 5), the factor was excluded from the univariate analysis. The criterion for retention in the multivariate model was P value < .05. For these eyes, the correlation between macular hole closure after reattachment and improvement of BCVA (>0.3 logMAR units) was assessed using the Spearman correlation coefficient. The correlation between macular hole closure after reattachment and postoperative logMAR visual acuity was also assessed using the Spearman correlation coefficient.
In this study, 24 eyes of 24 patients were enrolled. There were 3 male and 21 female patients whose ages ranged from 49 to 78 years (66.7 ± 8.4 years, mean ± SD) and whose axial eye lengths ranged from 27.0 to 34.0 mm (29.6 ± 1.8 mm). Baseline clinical factors are shown in Table 1 .
|Factor||All Cases (n = 24)|
|Mean age ± SD, years||66.7 ± 8.4|
|Range||49 to 78|
|Best-corrected visual acuity a|
|Hand motion||5 (21%)|
|Counting fingers||2 (8%)|
|Mean axial length ± SD, mm||29.6 ± 1.8|
|Area of retinal detachment|
|Within staphyloma||11 (46%)|
|Beyond staphyloma||13 (54%)|
|Intraocular lens||8 (33%)|
|Mean follow-up ± SD, months||44.5 ± 9.6|
|Range||29 to 61|