Time courses of changes in the intraocular pressure, and the optic nerve head and peripapillary parameters after an APAC attack in APAC eyes (<i>closed circles</i>) and contralateral eyes (<i>open circles</i>).

<p>The presented data are mean and 95% confidence intervals. <i>Asterisks</i> indicate significant changes relative to before follow-up, and <i>double asterisks</i> indicate significant intereye differences at each follow-up. Participants were followed up at 1 week (FU1), 1~2 months (FU2), 2~3 months (FU3), 5~6 months (FU4), and 11~12 months (FU5). <i>APAC = acute primary angle closure; IOP = intraocular pressure; RNFL = retinal nerve fiber layer; PLT = prelaminar tissue thickness; LCD = anterior lamina cribrosa surface depth; JCT = juxtapapillary choroidal thickness; BMO = Bruch’s membrane opening</i>.</p

Measurement of the optic nerve head and peripapillary parameters.

<p><b>(A)</b> Infrared fundus image of an eye with acute primary angle closure, indicating the locations where the measurements were made. <b>(B)</b> Enhanced depth-imaging spectral-domain optical coherence tomography image obtained at the location indicated by the <i>light-green line</i> in (A). The anterior lamina cribrosa surface depth (LCD) was determined by measuring the distance from the Bruch’s membrane (BM) opening reference plane (<i>horizontal white line</i> connecting the two BM termination points as indicated by <i>red glyphs</i>) to the level of the anterior lamina cribrosa (LC) surface at the three most depressed points (<i>blue glyphs</i>). The prelaminar tissue thickness was determined as the distance between the optic cup surface (<i>orange glyphs</i>) and the anterior LC border (<i>blue glyphs</i>), as measured at the three points that were used to measure the LCD. The juxtapapillary choroidal thickness was defined as the perpendicular distance between the BM and the choroidoscleral interface (<i>light-green dashed lines</i>), and measured at 250 μm both from the nasal and temporal BM termination points (<i>red lines</i>).</p

Factors Associated with the Retinal Nerve Fiber Layer Loss after Acute Primary Angle Closure: A Prospective EDI-OCT Study

<div><p>Purpose</p><p>To determine the factors associated with retinal nerve fiber layer (RNFL) loss in eyes with acute primary angle-closure (APAC), particularly focusing on the influence of the change in the anterior lamina cribrosa surface depth (LCD).</p><p>Methods</p><p>After the initial presentation, 30 eyes with unilateral APAC were followed up at the following specific time points over a 12-month period: 1 week, 1~2 months, 2~3 months, 5~6 months, and 11~12 months. These follow-ups involved intraocular pressure measurements, enhanced depth-imaging spectral-domain optical coherence tomography (SD-OCT) scanning of the optic disc, and measurements of the circumpapillary RNFL thickness. The prelaminar tissue thickness (PLT) and LCD were determined in the SD-OCT images obtained at each follow-up visit.</p><p>Results</p><p>Repeated measures analysis of variance revealed a significant pattern of decrease in the global RNFL thickness, PLT, and LCD (all <i>p</i><0.001). The global RNFL thickness decreased continuously throughout the follow-up period, while the PLT decreased until 5~6 months and did not change thereafter. The LCD reduced until 2~3 months and then also remained steady. Multivariable regression analysis revealed that symptoms with a longer duration before receiving laser peripheral iridotomy (LI) (<i>p</i> = 0.049) and a larger LCD reduction (<i>p</i> = 0.034) were significant factors associated with the conversion to an abnormal RNFL thickness defined using OCT normative data.</p><p>Conclusion</p><p>Early short-term decreases in the PLT and LCD and overall long-term decrease in the peripapillary RNFL were observed during a 12-month follow-up after an APAC episode. A longer duration of symptoms before receiving LI treatment and larger LCD reduction during follow-up were associated with the progressive RNFL loss. The LCD reduction may indicate a prior presence of significant pressure-induced stress that had been imposed on the optic nerve head at the time of APAC episode. Glaucomatous progression should be suspected in eyes showing LCD reduction after the APAC remission.</p></div

Factors associated with the progressive retinal nerve fiber layer loss after remission of acute primary angle closure (<i>n</i> = 30).

<p>Factors associated with the progressive retinal nerve fiber layer loss after remission of acute primary angle closure (<i>n</i> = 30).</p

Patients’ clinical characteristics.

<p>Patients’ clinical characteristics.</p

Representative case with acute primary angle closure where the progressive RNFL loss was accompanied by the reversal of the LC.

<p><b>(A)</b> Color disc photographs obtained at FU1. <b>(B)</b> Serial global and sectorial RNFL thickness measurements made using spectral-domain optical coherence tomography, showing progressive RNFL thinning. <b>(C)</b> Color disc photographs obtained at FU5. Note the increased cupping and pallor of the optic nerve head in both eyes. <b>(D)</b> Serial B-scan images obtained at the same locations at each follow-up. Superior and inferior <i>dashed lines</i> indicate the level of nasal Bruch’s membrane termination points and the level of anterior LC surface at FU1. Note that the anterior LC surface depth decreased gradually during the follow-up. Eyes were followed up at 1 week (FU1), 1~2 months (FU2), 2~3 months (FU3), 5~6 months (FU4), and 11~12 months (FU5). <i>RNFL = retinal nerve fiber layer; LC = lamina cribrosa</i>. <i>Sectors</i>: <i>nasal-superior (NS</i>, <i>90–135°)</i>, <i>nasal (N</i>, <i>135–225°)</i>, <i>nasal-inferior (NI</i>, <i>225–270°)</i>, <i>temporal-inferior (TI</i>, <i>270–315°)</i>, <i>temporal (T</i>, <i>315–45°)</i>, <i>and temporal-superior (TS</i>, <i>45–90°)</i>. <i>G</i>, <i>global</i>.</p