The Journal of International Medical Research 2011; 39: 662 666 The Effect of Posterior Scleral Reinforcement for High Myopia Macular Splitting XUEYING JI 1, *, JINGUO WANG 2, *, JINSONG ZHANG 1, HONGLIANG SUN 1, XIYU JIA 1 AND WEIHONG ZHANG 2 1 Department of Ophthalmology, The First Affiliated Hospital, and 2 The Nursing College, Zhengzhou University, Zhengzhou, China This study investigated the effect of posterior scleral reinforcement for high myopia macular splitting in 15 patients with high myopia and macular splitting (20 eyes), including three eyes with shallow retinal detachment. Main outcome measures included best-corrected visual acuity, refractive error, axial length, optical coherence tomography (OCT) findings and post-surgical complications. Best-corrected visual acuity, myopial dioptres and axial length reduced significantly post-surgery. The OCT findings showed different degrees of reduction in the split-cavity between inner and outer retinal layers, and that retinal thickness declined significantly post-operatively. No serious complications were observed. Posterior scleral reinforcement was effective, with a good safety profile, for patients with high myopia macular splitting with or without retinal detachment. KEY WORDS: HIGH MYOPIA; MACULAR SPLITTING; POSTERIOR SCLERAL REINFORCEMENT; OPTICAL COHERENCE TOMOGRAPHY (OCT) Introduction As a common oculopathy, high myopia severely influences visual acuity. Many pathological symptoms are observed in highly myopic eyes, with conditions such as fundus tigre, conus, Fuchs spots and posterior scleral staphyloma being common. 1 With the application and development of optical coherence tomography (OCT), posterior scleral staphyloma and macular splitting are being identified more frequently, including some cases where shallow retinal detachment is *Xueying Ji and Jinguo Wang contributed equally to this work and are joint first authors. also observed. 2 4 If the duration of macular splitting and shallow retinal detachment is long, the photoreceptor will be damaged and this may result in hypopsia. The present study investigated the effect of posterior scleral reinforcement for high myopia macular splitting. 5 Patients and methods PATIENTS The present study was a retrospective analysis of patients with highly myopic eyes who were treated with posterior scleral reinforcement at the Department of Ophthalmology, The First Affiliated Hospital, 662
Zhengzhou University, Zhengzhou, China, between November 2006 and March 2009. Inclusion criteria were: no severe opacity of refractive media observed on ophthalmic examination; OCT showing macular splitting in at least one eye, with no macular holes in highly myopic eyes; no history of intraocular surgery; no external retinal operation; no history of fundus laser surgery; and no ocular history of trauma. The study was conducted with the approval of the Institutional Review Board of the First Affiliated Hospital of Zhengzhou University. Verbal informed consent was obtained from all patients. ASSESSMENTS A phoropter (Topcon DK3100; Topcon Corp., Tokyo, Japan) was used for measurement of visual acuity and refractive dioptre, pre- and post-operatively, in all patients. Visual acuity was also assessed, using the international standard visual acuity chart, and dioptre measurement was represented by the spherical equivalent refraction. Axial length was measured by A-scan ultra - sonography (Axis II PR Biometer/ Pachymeter; Quantel Medical SA, Clermont- Ferrand, France). To identify macular splitting, images of the macular region were obtained using OCT (Stratus OCT ; Carl Zeiss Meditec, Oberkochen, Germany). Identification of retinal detachment and calculation of the mean retinal thickness (i.e. the distance from the pigment epithelial layer to the nerve-fibre layer) were also carried out from the OCT findings. The mean post-operative follow-up period was 10 months (range 8 12 months). SURGICAL PROCEDURES Single-band posterior scleral reinforcement was performed on all patients by the same operator (J.Z.), under local anaesthesia (2 ml of 2% lidocaine retrobulbar anaesthesia). The eye was then prepared, disinfected and draped according to standard procedures (0.45% 0.57% effective iodine for skin degerming, aseptic hole tower). A standard speculum was placed between the eyelids. The conjunctiva was opened with a 360 dissection near the corneal limbus using corneal scissors and an actinomorphic incision was made into the superonasal and infratemporal areas. The four rectus muscles were isolated and traction sutures of 4-0 braided silk were then passed around the isolated muscles and were used to rotate the eye during placement. The proximal end of a scleral band (approximately 10 mm wide) was passed nasally and just posteriorly to the superior rectus under the muscle belly; the distal end of the band was then passed under the lateral rectus, inferior oblique and inferior rectus muscles, and the band was positioned nasally to the inferior rectus muscle. Two 6-0 chromic collagen sutures, on spatulated needles, were used to attach the band nasally and just posteriorly to the superior rectus insertions. Smooth forceps were used to push the band posteriorly and bridle sutures were used to position the lateral rectus muscle so as to allow the band to be slowly and gently pushed temporally. In its final position, the band was barely visible on extreme adduction of the eye. A scleral slice (8 8 mm) was made between the scleral band and the posterior scleral staphyloma at the macular region. Next, the band was pulled up snugly, but not tightly, so that it apposed the globe at the level of the posterior pole, temporal to the optic nerve, without collapsing or cinching the eye wall. Any excessive band length was trimmed from the distal part, and two additional chromic sutures were used to attach the band nasally and posteriorly to 663
the inferior rectus muscle. After the traction sutures were removed, the conjunctiva was closed with interrupted 6-0 plain gut sutures. Dexamethasone 3 mg was administered by subconjunctival injection; eye ointment comprising 0.3% tobramycin and 0.1% dexamethasone, and also 1% atropine ointment, were applied to the conjunctival sac. Finally, both eyes were bandaged for 3 days and all patients remained in the prone position. STATISTICAL ANALYSES The mean ± SD of the data were calculated and statistical analyses were carried out using the SPSS statistical package, version 13.0 (SPSS Inc., Chicago, IL, USA) for Windows. Patients vision data were analysed by the Wilcoxon signed-rank test. The paired-sample t-test was used for assessments of the measurements of dioptre, axial length and retinal thickness of the macular region. A P-value < 0.05 was considered to be statistically significant. Results A total of 20 highly myopic eyes (15 patients; eight men [10 eyes treated], seven women [10 eyes treated]) with macular splitting identified by OCT met the study inclusion criteria and were treated with posterior scleral reinforcement. The mean ± SD age of the patients was 31.8 ± 10.6 years (range 13 50 years). Prior to operation, best-corrected visual acuity was 0.3 dioptres for five of the 20 eyes (25%) and 0.1 dioptres for 11 of the 20 eyes (55%). The range of best-corrected visual acuity prior to operation was 0.04 0.4 dioptres and the range of refractive error was 15.0 to 32.0 dioptres. Post-operative bestcorrected visual acuity was 0.3 dioptres for 13 of the 20 eyes (65%) and 0.1 dioptres for 17 of the 20 eyes (85%). Improvement in bestcorrected visual acuity, as indicated by improvement over two lines in the international standard visual acuity chart, was 75% (i.e. in 15 of the 20 eyes); postsurgical best-corrected visual acuity was statistically significantly improved compared with the pre-operative measurements (Wilcoxon signed-rank test, P < 0.05). Following surgery, mean spherical equivalent refraction decreased significantly compared with pre-operative measurements (Table 1; P < 0.01). Differences between preand post-operative axial length were also statistically significant (Table 1; P = 0.041). In all 20 highly myopic eyes, OCT revealed an extensive hyporeflective space that split the neuroretina into an outer and an inner layer, connected by vertical or inclined bridging or a columnar light band. In addition, the anterior membrane of the TABLE 1: Comparison of pre- and post-operative measurements of spherical equivalent refraction, axial length and macular retinal thickness in 15 patients (20 eyes) with high myopia macular splitting who underwent posterior scleral reinforcement Spherical equivalent Axial length Macular retinal refraction (dioptres) (mm) thickness (µm) Pre-operative 19.11 ± 3.32 29.78 ± 2.19 464.63 ± 72.82 Post-operative 18.39 ± 3.24 29.42 ± 2.41 244.13 ± 55.95 Statistical significance a P < 0.01 P = 0.041 P < 0.01 Data presented as mean ± SD. a Paired-sample t-test. 664
pigment epithelial layer appeared to indicate a moderate degree of reflection. Macular splitting with localized shallow retinal detachment was found in three cases. Post-operative follow-up at 8 12 months revealed that the space in the previously split neuroretina had deflated: the space disappeared in five cases and retinal reattachment to the pigment epithelial layer occurred in the three cases where detachment had been observed preoperatively. When the mean pre- and postoperative macular retinal thicknesses were compared, the difference was statistically significant (Table 1; P < 0.01). Diplopia occurred in one patient 3 days following surgery, but disappeared 1 month later. No evidence of optic nerve compression, abnormal recirculation of vorticose veins, subretinal haemorrhage, macular holes and manifest rejections were observed. Discussion Retinal splitting is one of the common complications identified in people with high myopia: splitting and detachment of the retinal neuroepithelium can usually be observed in highly myopic eyes with posterior scleral staphyloma. 2,6,7 Although myopic foveoschisis may remain stable for many years without affecting visual acuity, when combined with the presence of a premacular structure, the risk of a decrease in visual acuity increases. 8 In the past, this type of retinopathy was hard to identify using ophthalmoscopy, and could be misdiagnosed as flat retinal detachment and macular oedema. Use of OCT can, however, reveal the transverse section of the retina, correctly visualize changes in retinal structure and reveal vitreous retina traction. 4,9 11 Until recently, the cause of myopic foveoschisis was unknown and no effective treatment was available. Ikuno 12 however, postulated that myopic foveoschisis may be caused by interactions in vitreous retinal traction, posterior scleral staphyloma and posterior retinal degeneration. Other research indicated that axial length, macular chorioretinal atrophy and vitreoretinal interface factors are independently associated with this pathological condition. 13 Pars plana vitrectomy, with or without internal limiting membrane peeling, is a method to which attention is increasingly being paid. Although this method can increase the rate of retinal reattachment, it is associated with a high rate of complications, including macular holes and endophthalmia. In addition, patients may need to maintain a prone position for several weeks postsurgery. 14 18 Retinal thickness may be reduced significantly by scleral buckling with a macular plombe in eyes with myopic macular retinoschisis and retinal detachment without macular holes. 19 In the present study, we considered using modified posterior scleral reinforcement as a treatment for retinopathy. A wide band and a scleral slice were inserted directly into the macular region so that the volume of the eyeball was reduced and the axial length was shortened. This decreased myopia dioptre, enabled reattachment of shallow detached retinas and improved visual function. The operation was easily undertaken and no severe complications were observed. As a treatment for myopic foveoschisis with or without retinal detachment, the present small-scale study indicated that satisfactory results can be obtained with posterior scleral reinforcement, enabling retinal reattachment and improvements in retinal function. Posterior scleral reinforcement avoids the lesions that are 665
necessary with intraocular surgery for retinal function. Further research, involving larger numbers of patients and longer follow-up periods, is required. Acknowledgement We acknowledge the help of the ophthalmologists at the First Affiliated Hospital of Zhengzhou University who were involved in the collection of the original data. Conflicts of interest The authors had no conflicts of interest to declare in relation to this article. Received for publication 2 December 2010 Accepted subject to revision 17 December 2010 Revised accepted 24 February 2011 Copyright 2011 Field House Publishing LLP References 1 Zejmo M, Formińska-Kapuścik M, Pieczara E, et al: Etiopathogenesis and management of highdegree myopia. Part I. Med Sci Monit 2009; 15: RA199 RA202. 2 Takano M, Kishi S: Foveal retinoschisis and retinal detachment in severely myopic eyes with posterior staphyloma. Am J Ophthalmol 1999; 128: 472 476. 3 Benhamou N, Massin P, Haouchine B, et al: Macular retinoschisis in highly myopic eyes. Am J Ophthalmol 2002; 133: 794 800. 4 Jiang C, Wang W, Xu G, et al: Retinoschisis at macular area in highly myopic eye by optic coherence tomography. Yan Ke Xue Bao 2006; 22: 190 194. 5 Jinsong Z, Xi J, Cheng Z: Posterior scleral reinforcement in the treatment of retinal detachment with macular hole in high myopic patients. Chin J Ocular Fundus Dis 1996; 12: 214 216 [in Chinese]. 6 Baba T, Ohno-Matsui K, Futagami S, et al: Prevalence and characteristics of foveal retinal detachment without macular hole in high myopic eyes. Am J Ophthalmol 2003; 135: 338 342. 7 Fujimoto M, Hangai M, Suda K, et al: Features associated with foveal retinal detachment in myopic macular retinoschisis. Am J Ophthalmol 2010; 150: 863 870. 8 Gaucher D, Haouchine B, Tadayoni R, et al: Long-term follow-up of high myopic foveoschisis: natural course and surgical outcome. Am J Ophthalmol 2007; 143: 455 462. 9 Bing D, Xunqing G, Baohua Y: Macular retinoschisis in high myopia with optical coherence tomography. Shenzhen Sci Technol 2006; 26: 237 237 [in Chinese]. 10 Sayanagi K, Ikuno Y, Soga K, et al: Photoreceptor inner and outer segment defects in myopic foveoschisis. Am J Ophthalmol 2008; 145: 902 908. 11 Muscat S, Parks S, Kemp E, et al: Repeatability and reproducibility of macular thickness measurements with the Humphrey OCT system. Invest Ophthalmol Vis Sci 2002; 43: 490 495. 12 Ikuno Y: Pathogenesis and treatment of myopic foveoschisis. Nippon Ganka Gakkai Zasshi 2006; 110: 855 863. 13 Wu PC, Chen YJ, Chen YH, et al: Factors associated with foveoschisis and foveal detachment without macular hole in high myopia. Eye (Lond) 2009; 23: 356 361. 14 Kobayashi H, Kishi S: Vitreous surgery for highly myopic eyes with foveal detachment and retinoschisis. Ophthalmology 2003; 110: 1702 1707. 15 Kanda S, Uemura A, Sakamoto Y, et al: Vitrectomy with internal limiting membrane peeling for macular retinoschisis and retinal detachment without macular hole in highly myopic eyes. Am J Ophthalmol 2003; 136: 177 180. 16 Ikuno Y, Sayanagi K, Ohji M, et al: Vitrectomy and internal limiting membrane peeling for myopic foveoschisis. Am J Ophthalmol 2004; 137: 719 724. 17 Kwok AK, Lai TY, Yip WW: Vitrectomy and gas tamponade without internal limiting membrane peeling for myopic foveoschisis. Br J Ophthalmol 2005; 89: 1180 1183. 18 Hirakata A, Hida T: Vitrectomy for myopic posterior retinoschisis or foveal detachment. Jpn J Ophthalmol 2006; 50: 53 61. 19 Baba T, Tanaka S, Maesawa A, et al: Scleral buckling with macular plombe for eyes with myopic macular retinoschisis and retinal detachment without macular hole. Am J Ophthalmol 2006; 142: 483 487. Author s address for correspondence Professor Jinsong Zhang Department of Ophthalmology, The First Affiliated Hospital, Zhengzhou University, 3 Jianshe Road, Zhengzhou 450052, China. E-mail: ophzjs@yahoo.com.cn 666