Peculiar arcuate scotoma in pathologic myopia—optical coherence tomography to detect peripapillary neural tissue loss over the disc crescent

Background Optical coherence tomography (OCT) was used to detect peripapillary neural tissue loss (PPNTL) over the disc crescent in pathologic myopia. The retinal neural tissue loss located inside the disc crescent in pathologic myopia is a newly recognized fundus lesion.Methods Review of ten eyes of ten patients with peripapillary yellowish-white retinal lesions who underwent OCT for evaluation of the nature of PPNTL in pathologic myopia. OCT, fluorescein angiography, automated visual fields, axial length measurement with ultrasound A scan, and ultrasound B scan were performed.Results Ten eyes of ten patients were identified during a 14-year period to have findings characteristic of PPNTL. The mean age of the patients was 46 years. They were followed up for an average of 9 years. The mean spherical equivalent correction was –10.50 diopters (D) (range –6.0––16.0 D). The mean axial length was 28.6 mm (range 26.30–31.50 mm). In each case, OCT showed a complete retinal discontinuity in the PPNTL lesion. Automated visual field examination showed corresponding arcuate scotoma. During the follow-up period, the inner retina layer of the retinal defect margin was elevated by posterior hyaloid and partial retinal detachment developed in one eye.Conclusions PPNTL in pathologic myopia is a relatively asymptomatic, yellowish-white peripapillary retinal discontinuity. Recognition of this lesion is important because the visual field defect may mimic glaucomatous changes owing to the loss of nerve fiber layer. Progressive partial retinal detachment may ensue as one of the complications of the peripapillary lesion.     

Longterm findings in peripapillary crescent formation in eyes with mild or moderate myopia

Purpose: To describe early changes of optic disc deviation and peripapillary crescent formation in eyes with mild or moderate myopia. Methods: We carried out a retrospective review of medical records and fundus photographs. We evaluated serial fundus photographs taken in 10 patients with mild or moderate myopia. We observed longterm changes in optic disc areas by creating video files using these photographs and Photoshop ^® and Windows Movie Maker ^® software. The distance between the fovea and the temporal edge of the optic disc was measured in each photograph and any gradual changes in distance between these in the same patient were regarded as representative of optic disc deviation. Correlations between optic disc deviation (0–34.5% disc diameter) and either progression of myopia (? 0.75 D to 6.25 D) or length of follow‐up (21–98 months) were statistically examined. Results: On video files, the optic disc appeared to gradually deviate towards the nasal side and the myopic crescent developed gradually in the temporal side of the optic disc in most myopic patients. A significant correlation was found between optic disc deviation and progression of myopia (r² = 0.61, p < 0.0001), but no correlation was detected between disc deviation and follow‐up period (r² = 0.055, p = 0.33). As optic disc deviation progressed, the peripapillary crescent became larger. Conclusions: The optic disc appears to deviate mostly nasally as myopia progresses and the peripapillary crescent forms as a result of optic disc deviation in eyes with mild or moderate myopia.     

視盤周圍視網膜脈絡膜出血

目的探討視盤周圍視網膜脈胳膜出血(peripapillary retinal choroid hemorrhage,PPRCH)的發病原因及臨床特點、鑒别診斷和PPRCH患者視網膜新生血管的治療.方法對17例18眼PPRCH患者的臨床表現及眼底熒光血管造影(fundus luoresceinangiography,FFA)等臨床資料作回顧性分析.結果 17例均爲中度以下近視,平均年齡24歲,16例單眼發病.PPRCH分4種類型4例視盤表面出血.6例(7眼)視盤出血伴PPRCH.4例PPRCH,3例PPRCH伴玻璃體出血,其中出血及新生血管波及黄斑1例.FFA顯示PPRCH爲遮蔽熒光,患者2周至6個月出血全部吸收,其中1例視網膜新生血管行激光治療,半年后出血吸收.結論根據臨床及FFA表現,我們推測,PPRCH是視盤埋藏性玻璃疣的視網膜并發症.     

Retinal thinning in tree shrews with induced high myopia: optical coherence tomography and histological assessment

This study determined retinal thinning in a mammalian model of high myopia using optical coherence tomography (OCT) and histological sections from the same retinal tissue. High myopia was induced in three tree shrews (Tupaia belangeri) by deprivation of form vision via lid suture of one eye, with the other eye a control. Ocular biometry data was obtained by Ascan ultrasonography, keratometry and retinoscopy. The Zeiss StratusOCT was used to obtain Bscans in vivo across the retina. Subsequently, eyes were enucleated and retinas fixed, dehydrated, embedded and sectioned. Treated eyes developed a high degree of axial myopia (−15.9 ± 2.3 D; n = 3). The OCT analysis showed that in myopic eyes the nasal retina thinned more than the temporal retina relative to the disc (p = 0.005). Histology showed that the retinas in the myopic eyes comprise all layers but were thinner than the retinas in normal and control eyes. Detailed thickness measurements in corresponding locations of myopic and control eyes in superior nasal retina using longitudinal reflectivity profiles from OCT and semithin vertical histological sections showed the percentage of retinal thinning in the myopic eyes was similar between methods (OCT 15.34 ± 5.69%; histology 17.61 ± 3.02%; p = 0.10). Analysis of retinal layers revealed that the inner plexiform, inner nuclear and outer plexiform layers thin the most. Cell density measurements showed all neuronal cell types are involved in retinal thinning. The results indicate that in vivo OCT measurements can accurately detect retinal thinning in high myopia.     

视盘出血在正常眼压青光眼中的形态学分析

目的 对正常眼压性青光眼（NTG）患者，前瞻性评估视盘出血和视网膜神经纤维层缺损及盘周萎缩弧之间的形态学关系。 方法 患者行每月1次眼底照相，眼底立体照相和计算机图像分析系统定性及定量评估视盘出血与神经纤维层缺损及萎缩弧的关系。 结果 NTG出血组37位患者42只眼有50处眼底视盘出血，出血眼中有35只有神经纤维层缺损，发生率83.3%（35/42）。非出血组35位患者40只眼中神经纤维层局限缺损为21个，发生率52.5%（21/40），两组间神经纤维缺损发生率无统计学意义（χ2=1.403, P=0.236，P＞0.05）。出血组和非出血组两组间β区萎缩弧的发生率差异有统计学意义（χ2=7.008, P=0.008，P＜0.01)，出血组β区萎缩弧面积(2.05±0.88) mm2，非出血组β区面积(1.42±0.53) mm2，两组比较有统计学意义（t=-2.785, P=0.008）。β区萎缩弧范围在出血组：(164.00±49.87)°，非出血组(128.42±40.04)°，两组间比较有统计学意义（t=-2.618, P=0.012，P＜0.05)。随诊中出血组和非出血组盘沿丢失发生率组间比较有统计学意义（χ2=5.802, P=0.016，P＜0.01），但组间比较随诊视野损害的发生率则无统计学意义。 结论 NTG中视盘出血和神经纤维层缺损及萎缩弧之间有密切的关系。随诊中发现出血组较非出血组有更多的盘沿丢失和萎缩弧面积改变，提示NTG视盘出血是疾病进展的危险因素。 (中华眼底病杂志, 2006, 22: 232-235)     

Optic disc pit with peripapillary retinoschisis presenting as a localized retinal nerve fiber layer defect

A 59-year-old woman was referred to our clinic for a glaucoma evaluation. The visual acuity and intraocular pressure were normal in both eyes. However, red-free fundus photography in the left eye showed a superotemporal wedge-shaped retinal nerve fiber layer defect, and visual field testing showed a corresponding partial arcuate scotoma. In an optical coherence tomography examination, the macula was flat, but an arcuate-shaped peripapillary retinoschisis was found. Further, the retinoschisis seemed to be connected with a superotemporal optic pit shown in a disc photograph. After 3 months of a topical prostaglandin analogue medication, the intraocular pressure in the retinoschisis eye was lowered from 14 to 10 mmHg and the peripapillary retinoschisis was almost resolved. We report a rare case of an optic disc pit with peripapillary retinoschisis presenting as a localized retinal nerve fiber layer defect.     

Assessment of changes in optic disc parameters and peripapillary retinal nerve fiber layer thickness in myopic patients and its correlation with axial length and degree of myopia

Purpose:The present study aimed to assess the changes in optic disc and peripapillary retinal nerve fiber layer (RNFL) parameters in myopic patients and its correlation with axial length (AL) and spherical equivalent (SE) using optical coherence tomography (OCT).Methods:This was a cross-sectional study carried out from August 2019 to September 2021 in the ophthalmology department of a tertiary care hospital in eastern India. Myopic patients in the age group of 20–40 years and SE between − 0.5 to − 10 Diopters (D) were included in the study. Patients were divided into two groups on the basis of degree of myopia and AL. Appropriate statistical analysis was done at the end of the study period.Results:The study included 307 eyes of 307 myopic patients. There were 181 females (58.96%) and 126 males (41.04%). The mean age of the patients enrolled for the study was 28.78 ± 5.76 years. Statistically significant difference (P < 0.001) was found between SE and AL in between the subgroups of A and B. With every 1 D increase in SE, the average peripapillary RNFL thickness decreased by 0.61 µ while with every 1 mm increase in AL, the average peripapillary RNFL thickness was found to reduce by 1.03 µ.Conclusion:Analysis of optic nerve head parameters and RNFL thickness by OCT for the diagnosis should be compared with a normative control group that has been matched for refractive error and AL instead of comparison with a normative database that has only been age matched.     

Macular retinal detachment associated with peripapillary detachment in pathologic myopia

Purpose A peripapillary detachment in pathologic myopia (PDPM) appears as a yellowish-orange lesion around the optic disc in highly myopic eyes. We report a case in which a macular retinal detachment (RD) accompanied a PDPM. Method A case report was used in this study. Results The right eye in a 48-year-old man showed a macular RD and a PDPM. Fluorescein fundus angiography showed no dye leakage, suggestive of an optic pit within the optic disc. Optical coherence tomography (OCT) examination revealed that there was a full-thickness tissue defect in the retina overlying PDPM, the vitreous cavity was connected to PDPM through this defect, and the PDPM was continuous with the RD through the subretinal path at the conus area. Conclusions These findings suggest that this eye had a macular RD associated with a PDPM, and eyes with a PDPM might be at risk of developing macular RD.     

Fundus Characteristics of High Myopia in Children

Purpose To evaluate the fundus characteristics of highly myopic eyes in children.Methods We reviewed the medical records of 46 children (1 to 8 years old; mean age, 6.8 years) (80 eyes) with high myopia (4 D or more for children younger than 5 years, 6 D or more for children aged 6–8 years) seen consecutively during a 10-year period at the high-myopia clinic in our hospital. Children of up to 8 years of age at the initial visit were included in the study.Results Fundus examination revealed posterior staphyloma in only one eye (1.3%) and mild chorioretinal atrophy around the optic disc in 13 eyes (16.3%). There were no patients with choroidal neovascularization or geographic atrophy in the posterior fundus. Myopic peripapillary crescent was observed in 26 eyes (33.8%), but the area of the crescent was relatively small (mean, 0.5 disc area).Conclusions The results of the present study showed that myopic fundus changes are uncommon and mild in children. They suggest that aging, in addition to mechanical stretching of the eyeball, might be important for the development of myopic fundus changes. Jpn J Ophthalmol 2005;49:306–311© Japanese Ophthalmological Society 2005     

Quantification of reduced macular pigment optical density in the central retina in macular telangiectasia type 2

Recently, a unique distribution, namely a reduction of macular pigment optical density (MPOD) within the central retina with a surrounding ring-like structure of preserved MPOD at about 6 degrees eccentricity was suggested to be a common finding in macular telangiectasia (MacTel) type 2. In order to quantify this reduced MPOD, 28 eyes of 14 patients with MacTel type 2 were investigated by fundus reflectometry and two wavelengths fundus autofluorescence (FAF; at 488 nm and 514 nm). Fundus reflectometry showed a reduced MPOD within the central 4 degrees eccentricity that was most absent temporal to the foveola. At 6 degrees, MP density was not different from normative values. Two wavelengths FAF was in accordance with these findings. Fundus reflectometry also allowed separate determination of lutein and zeaxanthin. The patients with MacTel type 2 showed a disproportionally high zeaxanthin reduction. The study suggests that in MacTel type 2, there might be an inability to accumulate MP in the central retina. This disease might serve as a model to further study abnormalities of MP distribution in retinal disorders and to elucidate the mechanisms of MP deposition in the retina.     

Ophthalmoscopic appearance of the normal optic nerve head in rhesus monkeys

PURPOSE: To evaluate the ophthalmoscopic appearance of the normal optic disc, parapapillary region, and retinal nerve fiber layer in rhesus monkeys. METHODS: Color stereo fundus photographs of 17 normal eyes of 17 rhesus monkeys aged between 13 and 23 years were morphometrically evaluated. RESULTS: The neuroretinal rim was significantly (P: < 0.008) broadest in the inferior disc region followed by the superior disc region, the nasal region, and the temporal region. Retinal nerve fiber layer visibility was significantly highest in the inferior temporal fundus region followed by the superior temporal fundus region, the superior nasal fundus region, and the inferior nasal fundus region. It decreased significantly (P: < 0.001) with increasing age. The retinal arterioles were significantly (P: < 0.01) wider in the inferior temporal and superior temporal fundus regions than in the superior nasal and inferior nasal fundus regions. The alpha zone of parapapillary atrophy (14/17 or 82.4%) occurred significantly (P: < 0.001) more often than the beta zone (2/17 or 11.8%). In 15 eyes (88. 2%), the foveola was located inferior to a horizontal line drawn through the center of the optic disc. Neuroretinal rim shape and area and size of alpha and beta zones of parapapillary atrophy were independent of age. CONCLUSIONS: As in humans, in normal rhesus monkeys the neuroretinal rim has a typical physiologic configuration that spatially correlates with the retinal arteriole diameter, retinal nerve fiber layer visibility, and position of the foveola inferior to the center of the optic disc. Neuroretinal rim shape is independent of age. Retinal nerve fiber layer visibility decreases significantly with increasing age. These findings may be useful for the early detection and differentiation of experimental optic nerve damage in rhesus monkeys.     

Grado de concordancia y diferencias entre los valores de capa de fibras nerviosas de la retina peripapilar en niños mediante dos tipos de tomografía de coherencia óptica espectral

ObjectiveTo assess absolute agreement and differences in peripapillary retinal nerve fiber layer (pRNFL) values according to sex, age, laterality, origin and optical coherence tomography (OCT) type in normal pediatric patients undergoing OCT scans using both Cirrus and Spectralis.Material and methodsProspective, cross-sectional, and comparative study. We used Spectralis OCT and Cirrus OCT to measure optic disc values of both eyes in one hundred pediatric patients (age 5 to 15 years), with no previous ocular pathology or systemic disease that could affect the eye. Due to the similarity between eyes, only right eyes were considered (n = 100).ResultsThe average peripapillary retinal nerve fiber layer (pRNFL) values were 99.6 μm with Cirrus and 106.7 μm with the Spectralis system. The four quadrants followed the ISNT rule (inferior-superior-nasal-temporal). The average pRNFL measures correlated negatively with the AL (P < .01) in both OCTs, and the degree of agreement between OCTs for pRNFL and inferior RNFL was moderate (CCI: 0.67 and 0.61, respectively), and low in the rest of the sectors. The average pRNFL values of both OCTs were higher in women than in men (P > .05) and there were also no statistical differences in the pRNFL according to age or laterality (P > .05). All RNFL values were significantly different between both types of OCTs (P < .05) and average pRNFL values were significantly thicker (P < .05) in Latin American than in European children in both eyes.ConclusionsWe suggest that the respective peripapillary RNFL values obtained using these two OCTs should not be considered interchangeable in pediatric patients.     

视盘周围视网膜下出血

目的 探讨视盘周围视网膜下出血（peripapillay subretinal hemorrhage,PPSRH）的临床特征和发病相关因素。 方法 回顾性地分析23例（23只眼）PPSRH患者的荧光素眼底血管造影（fundus fluorescein angiography, FFA）等临床资料。 结果 23例（23只眼）均为中、轻度近视眼患者，矫正远视力大于或等于1.0；单纯PPSRH9例（9只眼），PPSRH伴视盘表面出血13例（13只眼），PPSRH伴视盘表面出血和玻璃体积血1例（1只眼），PPSRH均位于视盘鼻侧；FFA显示PPSRH为遮蔽荧光，晚期视盘呈结节状强荧光，对侧眼各期未见异常荧光。 结论 推测PPSRH的发病与埋藏性视盘玻璃疣有关。 (中华眼底病杂志, 2002, 18: 96-97)     

浅视杯小视盘与前部缺血性视神经病变发病的关系

目的 观察非动脉炎性前部缺血性视神经病变(NAION)患者视盘视杯形态特征与发病的关系.方法 符合NAION诊断标准,病史≥3个月,水肿消退期的96例NAION患者的96只患眼、96只对侧眼和80只正常对照眼纳入研究.应用德国Carl Zeiss公司Humphrey2000型光相干断层扫描(OCT)检查系统进行"十字交叉"和"环形"扫描,分别测量视盘、视杯水平垂直直径、视杯深度及视盘周围(盘周)视网膜神经纤维层(RNFL)厚度,依OCT视杯深浅形态图像分为4级:Ⅰ级,视杯底部高于盘周神经上皮层前表面水平;Ⅱ级,视杯底部高于盘周神经上皮层面水平;Ⅲ级,视杯底部位于盘周神经上皮层面与脉络膜色素上皮水平之间;Ⅳ级,视杯底部位于脉络膜色素上皮水平连线之下,对视杯分级情况和各组测量数值进行统计分析.随访观察6个月～3年,平均随访观察15个月.结果 患眼、对侧眼、正常对照眼视盘水平扫描直径分别为(1.29±0.19)、(1.32±0.17)、(1.40±0.15)mm,垂直扫描直径分别为(1.52 4±0.14)、(1.49±0.17)、(1.60±0.22)mm.患眼、对侧眼视盘水平扫描直径平均值与正常对照眼视盘水平扫描直径平均值比较,差异有统计学意义(t=4.291,3.315;P<0.05);视盘垂直扫描直径平均值与正常对照眼垂直扫描直径平均值比较,差异有统计学意义(t=2.812,3.654;P<0.05);患眼视盘水平、垂直扫描直径平均值与对侧眼视盘水平、垂直扫描直径平均值比较,差异无统计学意义(t=1.153,1.335;P>0.05).患眼中Ⅰ级视杯者36只眼,占37.50%,Ⅱ～Ⅲ级视杯者52只眼,占54.17%,Ⅳ级视杯者8只眼,占8.33%,Ⅰ～Ⅲ级视杯者共88只眼,占91.67%;对侧眼中Ⅰ级视杯者18只眼,占18.75%,Ⅱ～Ⅲ级视杯者69只眼,占71.88%,Ⅳ级视杯者9只眼,占9.34%,Ⅰ～Ⅲ级视杯者87只眼,占90.66%.依颞侧、上、鼻、下各象限顺序患眼RNFL测量平均值与对侧眼、正常对照眼比较,差异有统计学意义(t=12.862,10.147,15.046,8.180,12.859,9.562,12.174,8.632;P<0.001);对侧眼与正常对照眼各象限RNFL厚度平均值比较,差异无统计学意义(t=1.040,1.576,1.062,1.192;P>0.05).在观察期内,患眼8只眼复发,其视杯为Ⅰ、Ⅱ级形态;对侧眼44只眼发病,占45.8%,相关性分析显示发病率和视杯深度呈负相关(t=-0.757,P=0.000).结论 NAION患跟及对侧眼视杯及视盘明显小于正常人,浅视杯和小视盘的解剖学特点是NAION发病的基础之一.     

高度近视眼弧形斑形态与眼底病变关系的研究

目的研究高度近视眼近视弧形态与近视性眼底病变发生的关系,为临床上早期发现近视性眼底病变提供形态学上的参考。方法回顾性分析高度近视眼25例46眼患者黄斑光学相干断层扫描图像(optical coherence tomography,OCT)、吲哚青绿血管造影(indocyanine green angiography,ICGA)、视力等资料,将单纯漆纹样裂纹改变眼设为A组(5例10眼);出现近视性眼底病变眼为B组(17例30眼;包括A组);无近视性眼底病变眼为C组(8例16眼);分析3组近视弧类型、近视弧面积、白色脉络膜萎缩弧面积、白色脉络膜萎缩弧与近视弧面积比、黄斑部视网膜厚度、黄斑部视网膜体积等形态学变化。结果 A组、B组、C组矫正远视力分别为0.45±0.29、0.34±0.25、0.82±0.22,A、B组与C组比较,差异均有统计学意义(均为P<0.05)。A、B2组近视弧形态各方面比较差异均无统计学意义。B、C组比较:近视弧面积比较差异有统计学意义(P=0.030),95%可信区间分别是5.85～8.45mm2、2.67～6.79mm2;白色脉络膜萎缩弧面积比较差异有统计学意义(P=0.010),95%可信区间分别是2.03～4.04mm2、0.08～2.07mm2;白色脉络膜萎缩弧与近视弧面积比比较差异也有显著统计学意义(P=0.000),95%可信区间分别为0.28～0.47、0.00～0.25。75%(24/32)环形弧眼、82.7%白色脉络膜萎缩弧眼出现近视性眼底病变。A、B、C3组黄斑区视网膜厚度、黄斑部视网膜体积差异均无统计学意义(均为P>0.05)。结论近视性眼底病变明显影响视力;近视弧面积超过5.85mm2,白色脉络膜萎缩弧面积达到2.00mm2且与近视弧面积比超过0.28以上,白色脉络膜萎缩弧、环形弧的出现,均应警惕近视性眼底病变的发生。     

Choroideremia Carriers: Dark-Adapted Perimetry and Retinal Structures

PurposeIn choroideremia (CHM) carriers, scotopic sensitivity was assessed by dark adapted chromatic perimetry (DACP) and outer retinal structure was evaluated by multimodal imaging.MethodsNine carriers (18 eyes) and 13 healthy controls (13 eyes) underwent DACP testing with cyan and red stimuli. Analysis addressed peripapillary (4 test locations closest to the optic disc), macular (52 locations), and peripheral (60 locations outside the macula) regions. Responses were considered to be rod-mediated when cyan relative to red sensitivity was >5 dB. Fundus imaging included spectral domain optical coherence tomography (SD-OCT), short-wavelength (SW-AF), near-infrared (NIR-AF), ultrawide-field (200 degrees) pseudocolor fundus imaging, and quantitative (qAF) fundus autofluorescence.ResultsDetection of the cyan stimulus was rod mediated in essentially all test locations (99.7%). In the macular and peripheral areas, DACP sensitivity values were not significantly different from healthy eyes. In the peripapillary area, sensitivities were significantly decreased (P < 0.05). SD-OCT imaging ranged from hyper-reflective lesions and discontinuities of the outer retinal bands to hypertransmission of signal. SW-AF and NIR-AF images presented with peripapillary atrophy in seven patients (14 eyes). Mosaicism was detectable in SW-AF images in seven patients and in NIR-AF images in five patients. Frank hypo-autofluorescence was visible in eight patients with distinct chorioretinopathy in seven patients. The qAF values were below the 95% confidence interval (CI) of healthy age-matched individuals in 12 eyes.ConclusionsRod mediated scotopic sensitivity was comparable to that in control eyes in macular and peripheral areas but was decreased in the peripapillary area where changes in retinal structure were also most severe.     

Peripapillary circle of Zinn-Haller revealed by fundus fluorescein angiography

AIMS—To observe the vascular pattern of the peripapillary circle of Zinn-Haller in humans by fundus fluorescein angiography.
METHODS—307 cases (from 212 patients) of fundus fluorescein angiograms performed in patients with myopic degeneration were evaluated to find the circle of Zinn-Haller and to observe its fundus fluorescein angiographic features.
RESULTS—15 cases (from 13 patients) with the circle of Zinn-Haller were found. It appeared as concentric or zigzag-shaped vascular fillings within the temporal crescent region. All cases were observed in pathological myopia with peripapillary atrophy and a tilted disc. Each arterial circle showed variations in location and shape.
CONCLUSIONS—The temporal part of the circle of Zinn-Haller can be revealed by fundus fluorescein angiography particularly in pathological eyes with prominent peripapillary atrophy and a tilted disc. The morphological variation of this arterial circle should be considered.

     

Longer Axial Length Potentiates Relationship of Intraocular Pressure and Peripapillary Vessel Density in Glaucoma Patients

PurposeThe purpose of this study was to investigate how axial length (AL) changes the relationship of intraocular pressure (IOP) with peripapillary vessel density (pVD) in glaucoma versus non-glaucomatous eyes.MethodsA population-based, cross-sectional study of 2127 African Americans aged 40 years and older in Inglewood, California, were imaged with 6 × 6-mm optic disc optical coherence tomography angiography scans. There were 1028 healthy subjects (1539 eyes) and 65 subjects with glaucoma (86 eyes) who met inclusion criteria. A multivariable linear mixed effects regression model investigated the relationship of IOP on pVD after controlling for signal strength, retinal nerve fiber layer thickness, and age. These results were stratified by AL groups.ResultsHigher IOP was a significant predictor of lower pVD among subjects with glaucoma (P = 0.009), but not among healthy subjects (P = 0.26). After stratifying by the sample median AL (23.46 mm), higher IOP was associated with lower pVD among subjects with glaucoma with longer AL (≥ 23.46 mm, P = 0.005), but not among those in the shorter AL (< 23.46 mm, P = 0.45). IOP was not significantly associated with pVD among healthy subjects in either AL stratum.ConclusionsAmong subjects with glaucoma with longer AL, IOP was significantly associated with pVD. This relationship was not seen among subjects with glaucoma with shorter AL or non-glaucomatous subjects in either AL group. These findings support the hypothesis that disturbed retinal autoregulation may be present in subjects with glaucoma with longer AL. Longitudinal studies are needed to further investigate whether axial elongation increases glaucoma risk by compromising retinal autoregulation.     

Evaluation of the peripapillary circulation in healthy and glaucoma eyes with scanning laser Doppler flowmetry

In order to study peripapillary perfusion, one randomly selected eye of 34 healthy volunteers and 40 glaucoma patients (27 suffering from primary open-angle glaucoma (POAG) 10 from normal pressure glaucoma (NPG) and three from other types of glaucoma) was studied with a Heidelberg Retina Flowmeter. Temporal flow adjacent to the disc edge was significantly higher than the nasal flow (p < 0.01). It was reduced significantly in myopia both in controls (p < 0.05) and in glaucoma patients (p < 0.001). However, there was no difference between either controls and glaucoma patients or between POAG and NPG patients. It was independent of treatment type in glaucoma. Within the temporal peripapillary area extremely high flow values (values higher than the mean + 2 SD of the corresponding individual retinal flow) seemed to represent deep peripapillary vascular rings. They were significantly more frequent in glaucoma (72%) than in healthy volunteers (44%, p < 0.05). Their frequency was 83% in myopic and 23% in non-myopic eyes in the control group (p < 0.001). However, in glaucoma patients they were common both in myopic eyes (71%) and in non-myopic ones (75%). The results suggest that capillary perfusion adjacent to the temporal edge of the disc is significantly reduced in myopia. Deep peripapillary vascular structures can be measured on images focused on the surface of the retina, especially if the retina is thinner than normal (healthy myopic eyes and glaucomatous eyes independently of the refraction). This may mask a deficient function of the retinal capillary bed.The authors have no financial interest in the Heidelberg Retina Flowmeter.     

Influencia de la longitud axial ocular en el grosor de la capa de fibras nerviosas peripapilar medido con tomografía de coherencia óptica

BackgroundOptical coherence tomography (OCT) allows the measurement of the peripapillary optic nerve fiber layer (RNFL) thickness. The effect of ocular axial length (AL) on RNFL thickness measurement may be relevant in the interpretation of OCT results in diagnosing optic nerve diseases.PurposesTo assess the influence of ocular AL on RNFL thickness and on optic disc topographic parameters (optic disc area, rim area and cup volume) measured by OCT, in healthy individuals.MethodA sample of 109 healthy eyes classified into three groups according to AL (A: AL <22 mm; B: AL 22–24.5 mm; C: AL >24.5 mm) was studied. RNFL thickness and optic disc topographic parameters were measured using Swept-Source OCT Triton (Topcon Corporation, Tokyo, Japan) and were compared between groups using a variance analysis. Correlation between the AL and the study variables was performed using a Pearson's correlation coefficient test.ResultsThe RNFL thickness was lower in eyes with higher AL in the superior (r = −0.41; p < 0.001), inferior (r = 0.58; p < 0.001) and nasal (r = −0.43; p < 0.001) quadrants, in the mean value of the RNFL (r = −0.49; p < 0.001), optic disc area (r = −0.40; p < 0.001) and rim area (r = −0.25; p = 0.01).ConclusionAL is negatively correlated with RNFL thickness and optic disc topographic parameters measured by Swept-Source OCT Triton (Topcon).