Uncorrected myopia is considered one of the leading causes of blindness worldwide [1], and its prevalence has grown significantly in recent decades [2]. Specifically, in myopic individuals with increased axial length (AXL), structural changes may occur in the posterior pole that characterizes pathological myopia, including posterior staphyloma, myopic macular degeneration, optic neuropathy associated with myopia, and myopic tractional maculopathy (MTM) [3, 4]. The incidence of pathological myopia increases with age but can also occur in younger patients [5]. The impact of myopic maculopathy lies in its frequent occurrence in both eyes, its irreversibility, and its potential to affect individuals of working age [6].
MTM is a specific condition of pathological myopia secondary to tangential and anteroposterior tractional alterations at the vitreoretinal interface, where the retina is unable to adapt to the progressive increase in AXL and ends up undergoing structural changes. Characteristically, it involves a progressive combination of macular retinoschisis, lamellar or full-thickness macular holes, and, ultimately, retinal detachment (RD) [1]. Hence, while antiangiogenic therapy is used to treat neovascular membranes and there is no treatment for atrophic changes, MTM, and its complications require precise surgical interventions, and Macular buckle (MB) surgery, with or without vitrectomy, is one of the surgical techniques options.
In this study, we present the historical aspects of MB, discussing preoperative evaluation and criteria for surgical indication. Hereby we also discuss our experience with MB surgery cases, describing the assembly of a customizable MB using accessible materials.
Historical context and evolution of the macular buckle
The surgical treatment of RD has undergone revolutionary advancements following the theory developed by Jules Gonin in 1921, which involved surgically blocking tears and breaks in the retina [2]. However, it was soon understood that cases of surgical failure were related to the traction exerted by the vitreous on areas of retinal discontinuity, perpetuating the infiltration of subretinal fluid [3, 4]. In an attempt to alleviate this traction by approximating the underlying choroid to the detached retina, several authors proposed techniques such as subchoroidal injection of plasma, transient indentation with gauze, or even a piece of plastic sutured to the sclera near the treated area [5, 6]. In 1957, Schepens conceived the technique now known as scleral buckling, revolutionizing retinal surgery, and also proposing some adaptations for the treatment of the macular region in cases of retinal detachment associated with macular holes by positioning the buckle beneath the macular region [6].
Over time, other MB techniques were developed by different authors [7,8,9,10,11,12]. In 1980, Ando [13] created the first solid silicone MB, facilitating its implantation without the need for muscle disinsertion or suturing of the implant to the thinned posterior sclera. However, it presented limitations such as the adjustment of force and interference in imaging exams due to the presence of embedded metal [14]. In 2012, Stirpe et al. developed a new MB that did not contain metal wires and had adjustable sutures [15], while Mateo et al. proposed the coupling of an illuminated probe to facilitate the precise positioning of Ando’s MB beneath the macula [16].
Unfortunately, Ando’s device presents limitations regarding shape, tension adjustment, and posterior suture thus hindering its reproducibility. Hence, certain authors explored alternative methods to tailor their implants, such as utilizing silicone sponges internally coated with stainless steel [17] or employing a titanium stent [18, 19], as described by Parolini et al. (2013). In their report, Parolini et al. detailed three cases where they utilized MB exclusively for macular detachment unrelated to macular holes. Additionally, they introduced a novel L-shaped design of MB devoid of posterior sutures, enhancing its feasibility for surgical implementation [18].
In Brazil, there are no commercially available MBs, so we chose to manufacture one following the descriptions provided by Parolini et al. [18], as we will describe throughout this article.
Preoperative evaluation, imaging exams in myopic tractional maculopathy, and their role in the surgical indication of macular buckle
Macular buckle surgery requires a comprehensive preoperative ophthalmological assessment and complementary imaging exams to assist in the classification of MTM and surgical planning. Here, we highlight and discuss ocular ultrasonography (USG) and optical coherence tomography (OCT).
Ocular ultrasonography
The importance of USG in the surgical planning of MB procedures lies in its ability to assess vitreous and retinal conditions, such as the presence of anteroposterior vitreoretinal tractions (VMT) and/or tears, and to locate and estimate the extent of RD. OCT can also be useful for identifying VTM, but standard OCT does not have sufficient width and depth to capture the entire retinal detachment. Sometimes, in eyes with very high myopia, it is challenging to acquire images of the macular holes and, in these cases, examining with the patient using contact lenses can provide better image acquisition. As wide-field OCT is not available in Brazil, USG is very useful in these situations.
USG also aids in selecting the appropriate surgical technique and determining the indication for MB [18, 19]. Moreover, it facilitates the measurement of AXL in cases where optical biometry is unreliable, allows for the accurate calculation of intraocular lens power using the immersion technique to avoid corneal compression [21], assists in identifying structures in cases of media opacity, and ensures accurate intraoperative positioning and postoperative follow-up of the MB. Regarding the anesthetic procedure, USG is essential in evaluating the size of the staphyloma, helping to select the most suitable anesthetic method for highly myopic eyes (retrobulbar block or subtenon anesthesia) to avoid complications such as ocular perforation or intraocular injection of anesthetic in significantly large eyes [22,23,24].
Optical coherence tomography
The diagnosis and monitoring of MTM can be challenging due to the atrophic changes associated with pathological myopia. In this context, OCT has emerged as a fundamental diagnostic method for the non-invasive and detailed evaluation of the vitreoretinal interface, retinal layers, the retinal pigment epithelium, and the choroid, allowing for a better understanding and classification of these structures, as described below [25,26,27,28].
Classification and criteria for surgical indication in MTM based on OCT findings
The evaluation of OCT and the correct interpretation of findings are essential steps in surgical indication in MTM. In 2021, Parolini et al. [27,28,29,30] introduced a new OCT classification for MTM, which has strong reproducibility between examiners, intending to streamline information sharing and improve understanding of disease progression. [29]. The MTM staging system (MSS) categorizes findings into two types of evolution: perpendicular and tangential. Perpendicular evolution describes the anatomical sequence of predominantly internal or inner retinoschisis (stage 1), predominantly external retinoschisis (stage 2), retinoschisis with macular detachment (stage 3), and complete macular detachment without schisis (stage 4). Tangential evolution, in turn, describes the anatomical sequence of preserved foveal contour (a), internal lamellar macular hole (b), and full-thickness macular hole (c). This classification allows for the combination of evolution types, facilitating disease categorization. The occurrence of external lamellar macular holes is described in the classification as “O”, which can happen at any stage, while the presence of epiretinal abnormalities is indicated as “Plus” [28].
Based on the MSS, a surgical management approach for MTM was proposed. The idea is that comparing MB vitrectomy and pars plana vitrectomy (PPV) alone does not make sense, as each approach has its value in treatment. Early-stage cases warrant observation (stages 1a and 2a), while intervention is reserved for those who experience a progressive decline in visual acuity (stages 1b and 2b). When tangential forces predominate, PPV alone presents good results in stages 1a, with significant epiretinal membrane, and 1b and 1c.
In cases where perpendicular evolution predominates, MB alone has proven effective in stages 2b, 3a, 3b, 4a, and 4b. If epiretinal abnormalities are identified as clinically significant for visual improvement following the MB procedure, rapprochement with PPV remains a viable option. Finally, in cases where perpendicular and tangential forces are present, leading to macular involvement and/or macular or retinal detachment, MB + PPV is indicated (stages 2c, 3c, and 4c). The presence of “plus” alterations may require surgical intervention to improve complaints of metamorphopsia. Table 1 summarizes OCT findings and their implications in surgical indication [30].
Based on the criteria outlined by Parolini et al. [28,29,30], we sought to share our experience in this small case series, where all patients underwent MB surgery, with or without PPV, and have been followed up for over a year. Additionally, we will outline the methodology employed for the MB procedure and offer a concise analysis of the results, correlating them with the current literature.
Add Comment