Graded vertical rectus tenotomy for small-angle cyclovertical strabismus in sagging eye syndrome

Abstract

Background/Aims Graded vertical rectus tenotomy (GVRT) is postulated as effective for small angle vertical heterotropia. We aimed to determine dosing recommendations for GVRT in sagging eye syndrome (SES). Methods This was a retrospective, observational study of surgical outcomes for GVRT from 2009–2014 in a single surgeon’s academic practice. There were 37 (20 women) patients of average age 68±10 (standard deviation, SD) years with comitant or incomitant hypertropia ≤10Δ caused by SES. The main outcome measure was the dose-effect of GVRT required to correct intra-operative hypertropia. Results Pre-operative average central gaze hypertropia measured 4.7±2.2Δ. Three patients underwent repeat GVRT for residual or consecutive hypertropia, 1 undergoing it twice. All surgeries were analyzed, increasing the total operations to 41. The inferior rectus (IR) tendon in the hypotropic eye was operated in 32 eyes and the superior rectus (SR) tendon in the hypertropic eye in 9 eyes. Mean tenotomy was 68±19% of tendon width. Hypertropia was always eliminated intraoperatively by progressive GVRT. Mean hypertropia was 1.1±1.6Δ at average 93 days post-operatively. Linear regression demonstrated that 3–6Δ hypertropia correction requires 30–90% graded tenotomy (R2=0.32, P<0.0001), but with substantial individual variability. Undercorrection necessitated reoperation in 10% of cases. Conclusions GVRT precisely corrects hypertropia of up to 10Δ, but because of variable effect, should be performed with intraoperative monitoring under topical anesthesia.

Long-term Surgical Outcomes in the Sagging Eye Syndrome

“…It is interesting to note that nomograms were developed for surgeries on patients with SES with intra-operative adjustment and topical anesthesia. 1,3,5 This approach has proven useful in providing precise alignment ameliorating diplopia in the immediate post-operative period while avoiding risks of general anesthesia in elderly patients.…”

“…The operated cohort comprised 40 males and 53 females of average 68 ± 12 years (mean, SD). Surgeries performed were MR recession (28 cases) 3 ; LR resection (8 cases) 3 ; LR plication (1 case) 10 ; imbrication and superior transposition and myopexy of the LR to the SR (6 cases); GVRT (41 cases) 5 ; and vertical rectus muscle recession (9 cases). 5 The average distance esotropia was 4.2 ± 7.5Δ (the near horizontal deviation being close to 0), while mean hypertropia with the higher eye fixing was 4.7 ± 5.9Δ.…”

“…An anesthesiologist monitored surgery, and upon surgeon request administered minimal doses of propofol or alfentanil so that patients remained alert and cooperative during intra-operative adjustment. 11–13 Recession of the MR and GVRT were performed under 1% lidocaine topical anesthesia, with intra-operative adjustment, as published, 3,5 immediately correcting diplopia because alternate cover testing was performed in diagnostic positions in the operating room with the patient seated upright wearing the required refractive correction. If diplopia persisted following initial surgical dose, further 5–10% increments of GVRT up to a maximum of 90% and further MR recession were performed with interval intraoperative alignment monitoring by cover testing.…”

“…Surgeries comprised equatorial myopexy of LR muscles to their correct positions, 10 mm behind its insertion with imbrication of the LR muscle to the superior rectus (SR) muscle, bilateral LR resection or plication, bilateral medial rectus (MR) recession, vertical EOM recessions, and graded vertical rectus partial tenotomy (GVRT). 1,3,5,6…”

Magnetic Resonance Imaging in Strabismus

“…14,15 Symmetrical bilateral sag of the LR muscle resulted in divergence paralysis / insufficiency esotropia (DPE) due to the conversion of the sagging LR to an infraductor bilaterally ( Figure 4) while asymmetrical sag results in the genesis of small angle cyclovertical deviations (CVD). [16][17][18][19] Mathematical analysis of the displacement of pulley positions in young and elderly normal established this entity as a distinct clinical syndrome for which a high degree of suspicion should be entertained, especially in elderly patients with sudden onset diplopia and small angle horizontal and vertical strabismus and clinical features of aponeurotic ptosis, limited supraduction and superior sulcus deformity. 16,20 This often prevents extensive neurological evaluation of such elderly patients for unexplained diplopia, which in any case cannot be corrected if the etiology is not established, often putting both, the patients and the health care providing system to unnecessary expenditure.…”