CUTTING THE ENCIRCLING BAND:

Autofluorescence Imaging in the Long-Term Follow-Up of Scleral Buckling Surgery for Retinal Detachment

Purpose

To analyse fundus autofluorescence (AF) changes in retinal reattachment following primary scleral buckling (SB) surgery for rhegmatogenous retinal detachment (RRD).

Methods

Prospective noninterventional chart review study. AF images were reviewed for peripheral and central changes and compared to clinical and OCT findings.

Results

A total of 73 eyes from 69 patients were included, four presenting with bilateral RRD. Mean age was 55 ± 12 years, male/female ratio 40/29, fovea-on/-off RRD 43/30, and mean follow-up time 376 ± 270 days, with a mean of 5 ± 3 postoperative visits. Preoperatively, RRD was seen as a hypofluorescent area with a hyperfluorescent leading edge. Immediately postoperatively, three types of cryopexy could be differentiated, gradually transforming to scleral hyperfluorescence. Buckle tightening produced alternating hyper-/hypofluorescent streaks, and demarcation lines showed a persistent rugged hyperfluorescent signal. Choroidal detachment led to transient hypofluorescence, whereas vortex vein compression induced persistent hypofluorescence. Peripheral retinal folds were hyperfluorescent and the drainage site was hypofluorescent. AF was highly sensitive in detecting even small amounts of hyperfluorescent persistent subretinal fluid (SRF) that showed a slow resolution during follow-up. A granular “salt-and-pepper-” like pattern in the central macula was seen in 80% of eyes with fovea-off RRD and alternating streaks in 10%. Findings from OCT imaging correlated well with AF regarding SRF, macular oedema, retinal pigment epithelial detachment, and presence of a subretinal scar, but only moderately in epiretinal membrane formation and choroidal folds.

Conclusions

AF is a useful, noninvasive, adjuvant tool in the long-term follow-up after SB surgery.

Worldwide outcomes of nasal transposition of the split lateral rectus muscle for strabismus associated with 3rd-nerve palsy

BACKGROUND/AIMS

To determine success rate and complications associated with nasal transposition of the split lateral rectus muscle (NTSLR) for treating strabismus from 3rd-nerve palsy.

METHODS

An international, multicentre, registry of patients with unilateral 3rd-nerve palsy treated with NTSLR was created. Patients with concurrent surgery on the contralateral eye were excluded. Primary outcome was horizontal alignment within 15 prism dioptres (PD) of orthotropia. Incidence of technical difficulties and vision-threatening complications by 6 months post-procedure were reported.

RESULTS

Ninety-eight patients met inclusion criteria. Median age was 33.5 years (IQR 10.75-46). Aetiologies included congenital (31%), neoplastic (16%) and traumatic (15%). Twenty-five per cent of patients had prior ipsilateral strabismus surgery. Median exotropia decreased from 70PD preoperatively (IQR 50-90) to 1PD postoperatively (IQR 0-15.5), with a success rate of 69%. Performing concurrent superior oblique muscle tenotomy (SOT) was independently associated with success (p=0.001). Technical challenges occurred in 30% of cases, independently associated with a history of ipsilateral strabismus surgery (p=0.01). Eleven per cent of patients had vision-threatening complications, independently associated with more posterior placement of the split lateral rectus (LR) muscle (p<0.001), and most commonly transient serous choroidal effusion. Surgical placement of the split LR muscle within 4.25 mm of the medial rectus (MR) muscle insertion reduced this risk.

CONCLUSION

NTSLR significantly improved primary position alignment altered by 3rd-nerve palsy. Concurrent SOT and placement of the split LR muscle ≤4.25 mm posterior to the MR muscle insertion optimised outcomes. NTSLR proved technically challenging when prior ipsilateral strabismus surgery had been performed.

Scleral buckle removal: indications and outcomes

Primary scleral buckling has been an effective means to reattach the retina for over 50 years. After surgery, complications may arise that require scleral buckle (SB) removal. The most common indications for SB removal are extrusion, infection, and pain. I review the pertinent literature in an effort to develop guidelines for when to remove a SB.

Visual changes after encircling band removal

AIMS

Visual changes over 1 year in 40 eyes were studied in 40 patients after removing scleral encircling bands.

METHODS

Encircling bands in 20 eyes were cut and removed. The fellow eyes of the above patients and the eyes of another 20 patients with encircling bands that were not removed over the same period served as controls. Intraocular pressure, best-corrected visual acuity, axial length, microperimetry and corneal topography were evaluated preoperatively and at 1 week and 1, 3 and 6 months postoperatively.

RESULTS

Both best-corrected visual acuity and astigmatism were significantly improved at 6 months postoperatively (p < 0.05 for each). Microperimetry examination showed that 2° fixation stability increased by 52.6% (p < 0.01), 4° fixation stability increased by 17.65% (p < 0.01) and 10° mean sensitivity increased by 30% (p < 0.05). However, the pre- and postoperative axial length showed no significant difference.

CONCLUSION

These results suggest that removing scleral encircling bands within the desired time postoperatively may give better visual outcomes due to decreased corneal astigmatism and improved average macular retinal light sensitivity. Removal of the encircling band is a safe, simple and feasible operation.

The ocular pulse amplitude as a noninvasive parameter for carotid artery stenosis screening: a test accuracy study

PURPOSE

To investigate a potential correlation between the ocular pulse amplitude (OPA; i.e., the intraocular pressure difference between the systolic and diastolic phases of the heartbeat) and the severity of carotid artery stenosis (CAS) and to test its role as a screening parameter for CAS during routine ophthalmic examination.

DESIGN

Test accuracy study.

PARTICIPANTS

Patients referred for color duplex ultrasound examination of the extra- and intracranial cerebral arteries were enrolled consecutively.

METHODS

We measured OPA on both eyes by dynamic contour tonometry. Multivariate analyses were performed with risk factors for CAS (age, total cholesterol, low-density lipoprotein, and triglycerides) to compare the diagnostic value of OPA measurements with other non- or minimally invasive screening parameters.

MAIN OUTCOME MEASURES

The difference between OPA measurements in patients with no (<50%) and patients with severe CAS (>70%) as well as the value of OPA measurements to predict the severity of CAS taking further risk factors of CAS into consideration.

RESULTS

One hundred thirty-four eyes of 67 patients (25 women, 42 men) with a mean age of 67±13 years (range, 25-87) were included. The means of the OPA values of those patients showing no CAS (<50%) differed significantly (P = 0.036) from those with a stenosis of ≥70%. The multivariate model produced a statistically significant odds ratio (0.46; P = 0.007) for CAS of ≥70%.

CONCLUSIONS

The results of the present study provide proof of principle that the OPA is reduced in patients with CAS and may be used as a noninvasive, inexpensive, readily available, and unconfounded screening parameter to detect CAS and possibly to reduce the incidence of stroke.

FINANCIAL DISCLOSURE(S)

The authors have no proprietary or commercial interest in any of the materials discussed in this article.

[Effects of encircling scleral buckling on the morphology and biomechanical properties of the cornea]

OBJECTIVE

To investigate the effects of encircling scleral buckle (SB) on corneal biomechanical properties of the cornea and its morphological parameters.

METHODS

We prospectively examined twelve eyes diagnosed with vitreous haemorrhage undergoing pars plana vitrectomy (PPV), and fifteen eyes undergoing combined PPV and scleral buckle (PPV/SB) for repair of rhegmatogenous retinal detachment (RRD). Corneal biomechanical properties, including corneal hysteresis (CH) and corneal resistance factor (CRF), were measured with an Ocular Response Analyser (ORA) before and 1-month postoperatively. The ORA also determined the values of intraocular pressure (IOPg) and corneal compensated IOP (IOPcc). Finally, four morphological parameters of the cornea were measured with the Orbscan II topographer (Orbtek, Inc.): mean corneal power, thinnest corneal point (μm), and anterior chamber depth (ACD).

RESULTS

CH decreased significantly from 10.2+/-1.7mmHg to 7.6+/-1.1mmHg after PPV/SB (p=0.003), but not after PPV alone (9.8+/-3.2mmHg vs 11.6+/-2.7mmHg, P=.465). CRF did not change significantly after surgery in both groups. IOPg and IOPcc increased significantly in the PPV/SB group (P=.019 and P=.010, respectively) but not in PPV group (P=.715 and P=.273, respectively). Unlike the PPV group, values were significantly higher than IOPg values before (P=.001) and after surgery (P=.003) in the PPV/SB group IOPcc. Neither the PPV/SB group nor the PPV group showed any significant changes in the corneal morphological parameters after surgery (P>.05).

CONCLUSIONS

SB surgery leads to a change in the corneal biomechanical properties without altering corneal morphological parameters. It may cause an underestimation error in IOP measurement. PPV may be a less invasive surgical approach for the repair of noncomplex RRD than PPV/SB.

Anterior chamber depth is significantly decreased after scleral buckling surgery

OBJECTIVE

Myopic patients have an increased risk for the development of a rhegmatogenous retinal detachment (RRD). Currently, myopic patients have the choice to undergo correction of their refractive error by the implantation of a phakic intraocular lens (pIOL). After pIOL implantation, progressive endothelial cell loss may result if the anterior chamber is too shallow. Because scleral buckling (SB) surgery for treatment of an RRD may in itself result in a decreased anterior chamber depth (ACD), this may become an important issue not only for the retinal surgeon who is faced with a patient who has both an RRD and a pIOL, but also for the refractive surgeon who should consider the potential problems of the implantation of pIOL in an eye that has previously undergone SB surgery. The goal of this study was to evaluate how long changes in ACD persist after SB procedures in patients with RRD.

DESIGN

Prospective case series.

PARTICIPANTS

Thirty-eight eyes with a primary RRD treated by SB using an encircling element and a radial or segmental buckle; 31 fellow eyes served as controls.

METHODS

Anterior chamber depth (in the horizontal meridian) and axial length were measured preoperatively and at 1 week and 1, 3, 6, 9, and 12 months postoperatively with an anterior optical coherence tomography method and an IOLMaster (Carl Zeiss Meditec, Jena, Germany), respectively.

MAIN OUTCOME MEASURES

In all 38 eyes, ACD was significantly reduced compared with preoperative levels up to 9 months after SB surgery.

RESULTS

Anterior chamber depth returned to normal at 1 year after surgery. Axial length was significantly enlarged during the whole follow-up period. No significant differences were found between the use of radial or segmental buckles.

CONCLUSIONS

Anterior chamber depth may remain decreased after SB for a longer time period than previously reported.

FINANCIAL DISCLOSURE(S)

The authors have no proprietary or commercial interest in any materials discussed in this article.