Optic nerve sheath fenestration for treatment of progressive ischemic optic neuropathy. Results in 26 patients

Optic nerve sheath decompression saves sight in severe papilloedema: results from 81 eyes in 56 patients with pseudotumor cerebri

PURPOSE

To report the outcome of optic nerve sheath decompression (ONSD) for papilloedema in a teaching hospital in western Turkey.

METHODS

The charts of 56 patients who had ONSD surgery between April 2007 and September 2019 were collated; and a total of 81 operated and 31 fellow eyes were included. Pre- and postoperative ophthalmologic examination including best-corrected visual acuity (BCVA), colour vision (CV), visual field (VF) analysis, fundoscopic examination and demographic and medical characteristics of the patients were noted and outcomes after surgery were investigated.

RESULTS

Of all study eyes, 49 (43.7%) eyes had BCVA 0.2 or less and 62 (55.3%) eyes had mean deviation (MD) below - 20.0 dB. 62 (55.3%) eyes had Frisen grade 4 or 5 papilloedema. Almost half of the eyes had severe vision loss. After ONSD, BCVA, CV and MD in both operated and fellow non-operated eyes improved significantly (p < 0.001, p = 0.009 and p < 0.001 for operated, p < 0.001, p = 0.007 and p < 0.001 for fellow eyes, respectively). Earlier surgery and higher cerebrospinal fluid opening pressure were related to better outcomes. None of the patients had major operative complications.

CONCLUSION

Optic nerve sheath decompression can safely improve vision not only of the operated but also of the non-operated eye, even in cases with severe vision loss from severe bilateral papilloedema. Regardless of initial VA and VF, patients may benefit from ONSD; the earlier it is done the more likely the better outcome.

Superonasal Transconjunctival Optic Nerve Sheath Decompression: A Simplified Technique for Safe and Efficient Decompression

BACKGROUND

Severe, permanent vision loss is a feared sequela of untreated or refractory idiopathic intracranial hypertension (IIH). For patients with progressive vision loss despite maximally tolerated medical treatment, optic nerve sheath decompression (ONSD) remains a viable and effective option to protect vision. Our objective is to introduce a modified transconjunctival technique for ONSD and determine its safety, efficacy, and efficiency in patients with IIH.

METHODS

We performed analyses for a retrospective case series of consecutive patients with IIH by modified dandy criteria who underwent isolated superonasal transconjunctival optic nerve sheath decompression (stOND) at single eye institute in a large academic center from January 2013 to February 2017. Sixty-six patients were identified who met these criteria with at least 6 weeks of follow-up data. Primary outcome measures were visual field mean deviation, grading of papilledema by the modified Frisen scale, and best-corrected visual acuity. Secondary outcome measures were presence of postoperative diplopia and operative time.

RESULTS

One hundred thirty-two eyes of 66 patients were identified; 58 were female (88%), and 8 were male (12%). The mean age was 30 years (range 13-55) with an average lumbar puncture opening pressure of 38 cm H2O. Participants mean body mass index was 36 (range 20-59) with Grade 3 papilledema on average by the modified Frisen scale. No patients experienced operative complications, postoperative diplopia, or worse visual acuity at 1 week after surgery. Average operative time was 50 minutes (range: 25-89). The median decrease in papilledema grading was 3 grades on the Frisen scale (95% confidence interval [CI], 2-3, P < 0.0001). Snellen visual acuity changes did not meet statistical significance. The average Humphrey Visual Field mean deviation change was +1.91 (95% CI, 0.58-3.24, P = 0.0052). Despite successful bilateral decompressions, 4 patients (6.1%) progressed in their visual loss.

CONCLUSIONS

The superonasal transconjunctival approach to ONSD is a safe, efficient and effective surgical treatment for patients with deteriorating visual function due to IIH. Although additional study is required to further clarify the best timing and indications for ONSD among other treatment options for refractory IIH, providers should be aware of the reduced complication rates and efficacy of the stOND technique.

Visual outcomes following optic nerve sheath fenestration via the medial transconjunctival approach

This article determines the safety of optic nerve sheath fenestration (ONSF) for the treatment of patients with intracranial hypertension in the immediate 6-month post-operative period and its efficacy in reducing optic disk edema. Retrospective, non-comparative interventional case series. 207 eyes in 104 patients undergoing ONSF between the years 2005 and 2014. Papilledema grade based on modified Frisen scale and mean deviation of Humphrey visual field. 207 eyes of 104 patients (102 IIH, 2 IH due to dural sinus thrombosis) were included in the study. The patients were 96.1% female (N = 100) and 3.9% male (N = 4). The average patient age was 28.8 years (SD ± 9.5 years) and had a mean opening pressure of 39.85 cmH2O (SD ± 8.4 cmH2O). Mean follow-up period was 6.0 months (SD ± 5.9 months). Papilledema resolved in 76.1% of eyes at 1 week (N = 102 eyes), 75% of eyes at 1 month (N = 90 eyes), and 71% of eyes at 6 months (N = 94 eyes). Visual field comparison had a mean of the paired differences in MD at 1 week, 1 month, and 6 months of 1.59dB (P = 0.006), 2.53dB (P < 0.001), and 1.30dB (P = 0.016), respectively. ONSF is effective in reducing optic disk edema and does not cause vision loss in the 6-month post-operative period regardless of severity of IIH (as judged by elevation of opening pressure measured at pre-operative assessment).

Hyperbaric oxygen therapy for nonarteritic anterior ischemic optic neuropathy

PURPOSE

To evaluate the effectiveness of hyperbaric oxygen therapy in reducing optic nerve damage in acute nonarteritic anterior ischemic optic neuropathy.

METHODS

Twenty-two eyes in 20 patients with acute nonarteritic anterior ischemic optic neuropathy were treated with hyperbaric oxygen (100% oxygen, 2.0 absolute atmospheres of pressure) in two 90-minute inhalation sessions per day for ten days. Changes in mean visual acuity and mean sensitivity loss were compared with those of 27 untreated control patients with acute nonarteritic anterior ischemic optic neuropathy, and proportions of patients with a change in acuity or mean sensitivity loss were compared with controls. Similar analysis was performed on subgroups based on time delay from symptom onset to therapy.

RESULTS

Mean values for visual acuity were increased at final examination in both groups; although the increase was greater in controls, the difference was not statistically significant. Mean visual field sensitivity loss was minimally increased; although the increase was smaller in controls, the difference between groups was not significant. There was no significant difference between groups in proportions of patients with change in acuity score or mean sensitivity loss. Stratification by time delay to therapy did not suggest that treatment within nine days produced better visual results than that for either controls or those treated later.

CONCLUSIONS

Hyperbaric oxygen therapy using 100% oxygen and 2.0 absolute atmospheres of pressure did not produce a significant improvement in visual acuity or visual field for patients with acute nonarteritic anterior ischemic optic neuropathy.

Anterior ischemic optic neuropathy

AION is the most common acute optic neuropathy in patients over 50 and, although the diagnosis is often straightforward, our methods for managing the associated visual loss are inadequate. Analysis of the wealth of information gained from recent clinical studies may move us closer to an effective therapy.

Use of pattern electroretinography to differentiate acute optic neuritis from acute anterior ischemic optic neuropathy

The transient pattern electroretinogram (PERG) was recorded from 16 patients with acute optic neuritis and from 13 patients with acute non-arteritic anterior ischemic optic neuropathy (AION). All patients were tested within 35 days from the the onset of visual symptoms and all had significant central visual field abnormalities in their affected eyes as quantified by automated perimetry. Analysis of the PERGs showed that the amplitude of the N95 peak was abnormally reduced for each eye affected with AION while it remained normal in optic neuritis. No significant alteration in P50 amplitude was observed in either condition. The loss of N95 amplitude in AION was highly correlated with the average depth of visual field loss (in decibels) within a radius of 10 degrees of fixation. These results suggest that PERG could be used early in the course of optic neuropathy to distinguish optic neuritis from AION in those cases for which the diagnosis is still uncertain after the clinical examination.

Choroidal infarction after optic nerve sheath fenestration

PURPOSE

To describe a visual complication of optic nerve sheath fenestration.

METHODS

Case review of two patients who underwent seemingly uncomplicated optic nerve sheath fenestration.

FINDINGS

Both patients had a surgical complication that resulted in significant depression of their temporal visual field and development of a wedge-shaped region of subretinal pigmentation in the nasal fundus.

CONCLUSIONS

Both patients had choroidal infarctions as a complication of optic nerve sheath fenestration. Choroidal infarction should be considered in cases of unexpected loss of visual field after this type of surgery, although the funduscopic signs that assist in making the diagnosis may not be evident for several weeks after surgery.

A diagnostic quartet in leptomeningeal infiltration of the optic nerve sheath

A rare case of optic leptomeningeal carcinomatosis secondary to a rectal adenocarcinoma is recorded. The presentation of rectal disease with blindness is unique. A diagnostic quartet of symptoms and signs of leptomeningeal infiltration of the optic nerve sheath is proposed and its value emphasized by the inability of further investigation to confirm the clinical diagnosis. The investigation and treatment of leptomeningeal carcinomatosis is reviewed.