Modificación de la técnica de flap invertido en la cirugía del agujero macular completoestudio anatómico y funcional

Abstract

Introduction: Full-thickness macular hole is an anatomical discontinuity at the foveal level, affecting all retinal layers, from the internal limiting membrane to the retinal pigment epithelium, causing loss of visual acuity. It is a rare pathology, with a prevalence of 0.2-3.3 per 1000 population. The macular hole is caused by a vitreomacular traction syndrome and can present with different stages, defined according to the International Vitreomacular Traction Study Group. This classification is based on the size of the macular hole measured at its minimum opening zone. It divides them into small (<250 microns), medium (250-400 microns) and large (>400 microns). The diagnosis is clinical and is confirmed with imaging tests, mainly structural optical coherence tomography. The main differential diagnosis is with epiretinal membrane and lamellar macular hole. The classification of macular hole according to optical coherence tomography differentiates stages 0, 1, 2, 3 and 4. Stage 0 is a preclinical stage; stage 1 is vitreous traction with alteration of the foveal profile; stage 2 presents rupture of the hole roof with vitreous adhesion; stage 3 is a hole with a free operculum; and stage 4 is also associated with posterior vitreous detachment. Without treatment, most macular holes progress with worsening visual acuity in weeks or months. Exceptionally, small holes may close spontaneously. Treatment of macular holes is surgical. The technique, called posterior vitrectomy, consists of removing the vitreous by means of an aspiration and cutting system, maintaining the eye pressure with an infusion system. After removing the vitreous and posterior hyaloid, we access the macular hole for treatment. The classic technique consists of peeling the macular inner limiting membrane. Since 2010, flap techniques have been proposed that manipulate the internal limiting membrane to cover the macular hole. Of these, the most popular is the single-layer temporary inverted flap technique. Among the complications associated with surgical treatment of the macular hole, dissociation of nerve fiber layers, secondary to peeling of the internal limiting membrane, has been described. Other complications include macular hole reopening, primary closure failure and visual field defects. Objectives: The primary objective of the study is to determine whether or not the technique with a monolayer superior inverted flap of the internal limiting membrane, associated with maculorrhexis, improves the classic maculorrhexis technique of the internal limiting membrane, assessing the anatomical and functional results. Secondary objectives: to determine if the superior inverted flap technique is applicable to macular holes of all sizes, to study the functional results of visual acuity, the anatomical results of surgical success, the type of closure and the recovery of the outer retinal layers. Also, to determine which variables are directly associated with the visual prognosis of patients. Study design: Retrospective, consecutive, non-randomized, comparative study. Material and methods: The surgeries of 80 eyes of 80 patients with symptomatic macular hole in stages 2, 3 and 4 according to the classification of "International Vitreomacular Traction Study" were included. The study was approved by the ethical committee of the Infanta Leonor University Hospital of Madrid, and was performed according to the principles of the Declaration of Helsinki. All patients signed the informed consent before treatment. Cases comprised between 2011 and 2015 were operated using the classic maculorrhexis technique with internal limiting membrane peeling; whereas in cases operated from 2016 onwards, the maculorrhexis technique with superior inverted flap superior was used. In all cases, a minimum postoperative follow-up of 6 months was performed, with data collection at 3 and 6 months. Inclusion criteria were: patients over age and presence of symptomatic macular hole without exclusion by size of the hole or axial length of the eye. Traumatic macular holes, patients with glaucoma and other neuropathies, and other retinal pathologies were excluded. Preoperative evaluation included best corrected visual acuity, measured on Snellen scale and converted to LogMar scale, anterior pole slit lamp examination, intraocular pressure measurement, dilated fundus, and optical coherence tomography. Preoperative variables included age, gender, eye, lens status, macular hole and base size measured with spectral domain optical coherence tomography, axial eye length and macular hole stage. Patients in group with flap were 44 eyes operated by vitrectomy with circular maculorhexis of the internal limiting membrane and superior inverted flap of the internal limiting membrane. Group without flap was 36 eyes operated with vitrectomy plus classic internal limiting membrane peeling (maculorrhexis). Postoperative data collection included: macular hole closure or not, visual acuity at 3 and 6 months, type of closure, presence of DONFL, and condition of the outer retinal layers: ellipsoid line and external limiting membrane. Results: Both groups presented a homogeneous distribution in terms of gender, age, axial length and size of the macular hole and its base. Macular foramen closure occurred in 100% of the eyes operated with inverted flap, and in 91.67% of those operated with classic maculorrhexis. Both groups presented improvement in visual acuity at 3 and 6 months. At 3 months the visual acuity results of the group operated with flap were significantly better and these tend to equalize at 6 months between the two groups. There was recovery of the ellipsoid line at 6 months in group with flap in 36 cases (81.82%); and 19 cases (52.78%) in group without flap. Recovery of the external limiting membrane measured at 6 months was achieved in 81.82% of the cases in group with flap and in 69.44% in group without flap. A statistically significant association was found between the type of macular hole closure and the flap technique (p=0.017). Among patients operated with flap, U closure occurred in 90.91% and V closure in 9.09% of cases. In patients operated with maculorexis without flap, U-closure occurred in 58.33% and V-closure in 33.33% of cases. Discussion: The inverted flap technique has a faster functional recovery by improving visual acuity at 3 months and equalizing at 6 months. It also has a higher percentage of U-shaped closures with greater recovery of the outer retinal layers. The inverted flap technique achieves closure in all cases. The better postoperative visual acuity results at 3 and 6 months, of the pooled sample, are associated with better preoperative visual acuities, younger patients, U-shaped closures and holes less than 400 microns. Conclusions: Maculorrhexis with superior inverted flap is a technique with functional results that are not inferior to the classic maculorrhexis technique. It achieves these results more quickly. Our flap technique improves macular anatomic restoration with a higher percentage of U-shaped closures, and closure occurs in all cases. This technique can be considered effective for the treatment of macular holes of all sizes.