Peculiar Findings in a Case of Bilateral Uveal Pigmented Lesions

Purpose: To describe a probable case of bilateral diffuse uveal melanocytic proliferation (BDUMP) with unusual manifestations and prognosis.

Design: Case report.

Methods: Clinical follow-up of the patient lasting 50 months with recurrent fundus examination using color photographs, angiography, ultrasound, and optical coherence tomography. Serological and radiological investigations were performed to assess possible extraocular alterations.

Results: In both eyes patch-shaped pigmented alterations of the fundus were revealed. Fluorescein and indocyanine angiography evidenced corresponding areas of hyperfluorescent pinpoints and subtle serous detachment of the neurosensory retina, respectively. Ten months after the initial evaluation, flat pigmentary lesions appeared in the superior scleral surface of the right eye and underwent histological examination. After an initial decrease in visual acuity, the patient experienced a spontaneous recovery. He did not develop cataracts or any systemic malignancies.

Conclusions: Although not all the criteria for the diagnosis were fulfilled, clinical findings were compatible with BDUMP. The presence of scleral pigmented lesions and the good visual prognosis may widen the spectrum of this rare disease.     

Keratoglobus: An experience at a tertiary eye care center in India

Context:

This study was carried out as a part of an internal audit and is the largest series of patients having keratoglobus, published in the literature. Poor visual acuity of the patients indicates the blinding nature of the disease.

Aims:

We report our experience with patients having keratoglobus at a tertiary eye care center in India.

Settings and Design:

Retrospective study.

Materials and Methods:

We analyzed adults and pediatric patients (<16 years) with keratoglobus, seen during 2008–2012. The age, gender, consanguinity, presenting ocular signs, ocular and systemic associations, visual acuity, corneal topography, and surgeries were documented.

Results:

Forty-eight patients (mean age 22 ± 15 years, 31 males) having keratoglobus were analyzed. 21 patients (42 eyes) were <16 years. Twelve eyes (16 events) had positive history of trauma. The presenting clinical signs were corneal scars/scars of tear repair (15 eyes), hydrops, healed and acute (14 eyes) and corneal or globe rupture (9 eyes). Best-corrected visual acuity was >20/40 in 6/42 (14.3%) pediatric eyes and 15/53 (28.30%) adults. Visual acuity ranging from counting of fingers to no light perception was noted in 20/53 (37.74%) adults and 21/42 (50%) pediatric patients; 13/20 (65%) with blue sclera and 8/22 eyes (36.37%) without blue sclera. Vernal keratoconjunctivitis was present in one pediatric patient. Choroidal osteoma, retinitis pigmentosa, and retinal detachment were present in adults. Surgeries performed were corneal tear repair (5 eyes), tissue adhesive application (2 eyes), descematopexy (4 eyes) and penetrating keratoplasty (PK - 8 eyes: Three had post-PK glaucoma, graft failure-one eye, 4 patients wore scleral lens - prosthetic replacement of the ocular surface ecosystem).

Conclusions:

About 50% of pediatric eyes (65% having blue sclera) had no functional vision. Trivial trauma was responsible for corneal rupture indicating need for protective glasses. About 50% patients had post-PK glaucoma though grafts were clear.     

后巩膜加固术的组织学观察

目的：为进一步了解巩膜加固术后的组织学改变。方法：选用白色家兔为实验对象，采用人体巩膜施行巩膜加固术，于术后不同时期分批处死动物，并对手术区巩膜进行组织学检查结果：术后1－2周，为炎症浸润期：术后1－2个月为肉芽肿及新生血管增殖期，植片与巩膜粘连；术后3－6月，纤维母细胞形成，植片与巩膜完全愈合，形成“新巩膜”。实验结果为后巩膜加固术提供了理论根据。     

后巩膜加固术治疗进行性近视的临床研究

目的：研究后巩膜加固术(PSRD)治疗进行性近视的疗效及机理。方法：对20例(36眼)进行性近视行改良的Snyder—Thompson式PSRO，手术前后观察裸眼视力、矫正视力、眼底、屈光度、眼轴、闪光视网膜电图(F—ERG)，振荡电位(Ops)。术后随访1年者36眼，5年以上13眼。结果：(1)术后90％以上的高度近视患者视力稳定，部分患者视力有不同程度的提高。(2)术后眼轴及屈光度稳定(P＞0．05)。(3)F—ERG的a波b波波幅术后较术前有提高(P＜0．05)，Ops振幅有非常显著性提高(P＜0．002)，且均随时间的延长，提高更加明显。结论：后巩膜加固术治疗进行性近视，的确起到稳定眼轴及屈光度，改善黄斑病变及视网膜血液循环，从而提高视功能的作用。     

异种巩膜作为HA眼台包裹材料的实验研究

目的：观察猪巩膜作为羟基磷灰石（hydroxy apatite,HA)眼台包裹材料，应用于兔眼的临床表现及病理组织学改变。方法：对纯种新西兰大白兔行眼球摘除术后于肌锥内植入直径10mm HA眼台，并在其上覆盖边长10mm以上的正方形猪巩膜1块。4周后全麻下观察外眼，有无感染及有无上台暴露，取出上台并猪巩膜后，光镜下观察包裹材料与眼台的炎症反应情况及血管化情况。结果：10只兔中无一只眼台暴露或排出。经组织学观察可见猪巩膜的弹力纤维仍然排列紧密，部分有轻度肿胀，HA眼台中心有新生小血管长入，结论：异种（猪）巩膜作为HA眼台的包裹材料，应用于兔眼在临床表现上类似于同种异体巩膜，有望成为HA眼台包裹材料的新来源。     

Ultrastructural changes in scleral proteoglycans precede destruction of the collagen fibril matrix in necrotizing scleritis

Proteoglycans were localized using cuprolinic blue and visualized by electron microscopy in sclera from the eye of a 58-year-old woman with necrotizing scleritis. Samples of sclera taken from clinically normal anterior and posterior sclera and from sites involved in anterior necrotizing scleritis with ulceration and posterior scleritis showed markedly different patterns of proteoglycan distribution. Proteoglycans appeared as stain-positive filaments associated regularly with the 'd/e' bands of the collagen fibrils in normal anterior sclera, but were absent from intact collagen fibrils in the zone of anterior ulcerative scleritis. In posterior sclera including a site of posterior scleritis, proteoglycans were reduced in number with more heterogeneous associations with collagen fibrils. Depletion of scleral proteoglycans therefore precedes the degradation of scleral collagen in necrotizing scleritis, which may also involve the synthesis of atypical proteoglycan types in pathological sclera.     

A rabbit model for assessing the ocular barriers to the transscleral delivery of triamcinolone acetonide

Transscleral delivery of triamcinolone acetonide into the vitreous using sub-Tenon's injections may be a safer alternative to reduce the sight-threatening complications of direct intravitreal injections. However, sub-Tenon's injections have demonstrated low and poorly sustained vitreous drug levels in animal studies. To improve our understanding of the clearance mechanisms of corticosteroids, we evaluated vitreous drug levels following sub-Tenon's injection of triamcinolone acetonide in rabbits with selective elimination of conjunctival lymphatic/blood vessels and the choroid. Pigmented rabbits were given a sub-Tenon's injection of a preservative-free triamcinolone acetonide formulation of either a 10- or 20-mg dose in the superotemporal quadrant. The effect eliminating both conjunctival and choroidal clearance was evaluated by injecting the drug, followed by immediate euthanasia, effectively terminating both lymph and blood flow in the conjunctiva and choroid. To inhibit only the clearance from conjunctival lymphatics/blood vessels of a sub-Tenon's injection of triamcinolone acetonide, a group of rabbits had a 'conjunctival window' created by incising an 7 mmx7 mmx7 mm square through the conjunctiva to bare sclera in the superotemporal quadrant. To eliminate only the clearance of drug from the choroidal circulation, cryotherapy was performed in another group of rabbits creating a chorioretinal scar in the superotemporal quadrant. Following the sub-Tenon's drug injection, the eyes were enucleated in all groups after 3 hr and vitreous drug levels were measured with HPLC. In normal animals, a 10-mg sub-Tenon's injection showed no detectable vitreous drug levels; however, a 20-mg injection showed positive vitreous drug levels. This suggested that collectively, the transscleral clearance mechanisms inhibiting delivery into the vitreous may be saturated with a drug depot that has a higher release rate. A 10-mg sub-Tenon's drug depot was able to deliver drug into the vitreous when both the conjunctival and choroidal drug clearance was eliminated by euthanizing the animal immediately following the drug injection. In rabbits that had only a 'conjunctival window', selectively eliminating conjunctival drug clearance, vitreous drug levels were detected. However, in rabbits that had only cryotherapy, selectively eliminating choroidal drug clearance, vitreous drug levels were not detected suggesting that the conjunctival lymphatics/blood vessels may be an important barrier to the transscleral delivery of triamcinolone acetonide. Variability in the vitreous drug levels between rabbits in each group precluded statistical testing. In summary, the rabbit appeared to demonstrate saturable ocular barriers to transscleral delivery of triamcinolone acetonide into the vitreous following a sub-Tenon's injection. The results suggested that the conjunctival lymphatics/blood vessels may be an important barrier to the delivery of triamcinolone acetonide to the vitreous in this rabbit model. The barrier location and clearance abilities of the ocular tissues are important to consider when developing a successful transscleral drug delivery system. Animal models, retaining the dynamics of blood and lymph flow, may improve the basic understanding of the ocular barriers involved with transscleral drug transport and warrants further investigation.     

Inhibiting the transient choroidal thickening response using the nitric oxide synthase inhibitor l-NAME prevents the ameliorative effects of visual experience on ocular growth in two different visual paradigms

It is generally accepted that the increase in choroidal thickness in response to myopic defocus in chicks acts to move the retina towards the image plane. It may also constitute part of the signal cascade in the visual regulation of eye growth. To test this, we used the nitric oxide synthase inhibitor l-NAME to inhibit the defocus induced choroidal thickening under two different visual conditions, and looked at the effects on ocular growth rate. Exp. 1: Deprivation/Vision: chicks were monocularly deprived of form vision with translucent diffusers from day 6 to day 9. In the middle of each day the diffusers were removed for 2 h. One group received an intravitreal injection of 30 microl l-NAME (16 micromole; n=12) prior to the vision, a second group received injections of physiological saline (n=11). Exp. 2: Recovery/Vision: chicks were made myopic by form deprivation from day 6 to day 10. On days 11 to 14 the diffusers were removed for 2 h per day for 4 days to allow eyes to "recover" from the myopia. One group received an injection of l-NAME prior to vision (n=8), the other saline (n=6). Refractive errors were measured with a refractometer at the start (days 6 and 11) and end (days 10 and 15, respectively) of both experiments. Ocular dimensions were measured with high frequency A-scan ultrasonography at the start and end, and on the third experimental day immediately before and after the period of vision. Choroidal retinoic acid synthesis was measured by HPLC. Finally, NO production and scleral proteoglycan synthesis were measured in eyes wearing positive lenses 6 and 24h after an injection of l-NAME. l-NAME prevented the transient vision-induced choroidal thickening in both experiments. Furthermore, l-NAME inhibited the protective effect of brief daily vision: eyes became significantly more myopic than saline controls (exp. 1: -9 D vs -2.7D; exp. 2: -0.9 D vs +4.3 D; p<0.005 for both) and grew faster (change in lens-sclera: exp. 1: 295 vs 158 microm; exp. 2: 147 vs 39 microm; p<0.05 for both). Notably, l-NAME inhibited the growth of the anterior chamber (exp. 1: 88 vs 185 microm; exp. 2: 147 vs 254 microm; p<0.01 for both). Injections of l-NAME after the periods of vision had no effect on growth at the back of the eye, but still had an inhibitory effect on the anterior chamber. Retinoic acid levels in the drug-injected choroids were significantly decreased compared to controls. In eyes responding to positive lenses, l-NAME inhibited NO synthesis and disinhibited scleral glycosaminoglycan synthesis 6h after the injection. In summary, preventing the transient vision-induced increases in choroidal thickness altered ocular growth rate in a consistent manner under two different visual conditions, in both preventing the vision-induced reduction in growth rate. This supports the hypothesis that visually-induced changes in choroidal thickness play a role in the visual regulation of ocular growth.     

后巩膜瓣旋转覆盖义眼座巩膜腔内植入术临床分析

目的:为了达到最佳的运动和仿真效果及长期的稳定,设计后巩膜瓣旋转覆盖巩膜腔内Medpor义眼座植入术,并评价此术式的手术适应证和疗效。方法:2008-01/2011-07在深圳市眼科医院接受眼内容剜除后巩膜瓣旋转覆盖巩膜腔内Medpor义眼座植入术120例患者:眼内容摘除后制作后巩膜瓣,将义眼座植入后方开放的巩膜腔内,旋转后巩膜瓣覆盖在义眼座表面,缝线固定义眼座。随访1～3a,记录最后一次就诊时的义眼座活动度,义眼片活动度,结膜囊剩余面积,结膜囊深度,并发症发生情况。结果:义眼座活动度:115例为优,5例为良;义眼片活动度89例为优,26例为良,5例为差;平均结膜囊剩余面积为178.1±7.5mm2;平均结膜囊深度为2.7±1.1mm;2例出现义眼座暴露感染,3例出现结膜下植入性囊肿,2例出现义眼座固定缝线外露,未出现义眼座内陷、上眶区凹陷、结膜囊狭窄、下睑外翻、眼眶蜂窝织炎。结论:后巩膜瓣旋转覆盖Medpor义眼座巩膜腔内植入术对于轻中度眼球萎缩、角巩膜葡萄肿、绝对期青光眼患者具有良好的治疗效果。