Dysfunctional lens syndrome: a prospective review / Síndrome do cristalino disfuncional: uma revisão prospectiva

ABSTRACT The term dysfunctional lens syndrome has gained acceptance in the field and encompasses natural changes due to aging of crystalline lens. The evolution of diagnostic devices has been a key factor in better staging, understanding and characterizing of these degenerative changes. Even with these technological advances and the use of subjective classifications, such as the classic Lens Opacities Classification System, an objective staging of early dysfunctional lens syndrome has yet to be established. Ocular wavefront aberrometry and objective scatter index, associated with Scheimpflug backscatter densitometry, have proven instrumental in detecting early dysfunctional lens syndrome. Staging of early dysfunctional lens syndrome has been proposed in the literature, but no classification has been recognized worldwide. The purpose of this literature review is to assess the current state of dysfunctional lens syndrome from a technological perspective and propose a new staging system to assist surgeons in making surgical decisions.

RESUMO O termo "síndrome disfuncional do cristalino" tem sido mais aceito na área e engloba mudanças naturais devido ao envelhecimento do cristalino. A evolução dos dispositivos diagnósticos tem sido fator fundamental para melhor estadiamento, compreensão e caracterização dessas alterações. Mesmo com esses avanços tecnológicos e o uso de classificações subjetivas, como o Lens Opacities Classification System , um estadiamento objetivo da síndrome disfuncional do cristalino precoce ainda não foi estabelecido. A aberrometria ocular total e o índice de superfície ocular, associado à densitometria de Scheimpflug, mostraram-se instrumentais na detecção da síndrome disfuncional do cristalino precoce. Embora estadiamentos precoces de síndrome disfuncional do cristalino tenham sido propostos na literatura, nenhum foi reconhecido mundialmente até o momento. O objetivo desta revisão de literatura é avaliar o estado atual da síndrome disfuncional do cristalino a partir de uma perspectiva tecnológica, e propor um novo sistema de estadiamento para auxiliar os cirurgiões na tomada de decisões cirúrgicas.

Optic shrinkage and retraction in opacified hydrophilic acrylic intraocular lens: an anterior segment optical CT-based observation.

Intraocular lens (IOL) opacification is a rare phenomenon noted with hydrophilic acrylic IOLs. We report a case of advanced IOL opacification appreciated on anterior segment optical CT (ASOCT)as a shrunken biconcave optic retracted away from the posterior capsule (PC), unlike the other eye which had a clear biconvex IOL of similar material abutting the PC. After IOL exchange, the affected eye was noted to have more folds and Elschnig's pearls on the PC when compared with the other eye. Our case points towards rare IOL changes seen in advanced cases of opacification, their association with posterior capsular changes and the aid of ASOCT as a non-invasive tool in diagnosing them correctly.

Lenticono posterior en imágenes Scheimpflug / Posterior lenticonus in Scheimpflug images

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A case of late-onset capsular block syndrome and its surgical treatment / Um caso de síndrome de bloqueio capsular tardio e uma abordagem cirúrgica

ABSTRACT - Capsular block syndrome is a rare complication of phacoemulsification surgery with continuous curvilinear capsulorhexis and intraocular lens implantation. Here, we report a case of very late-onset capsular block syndrome that developed 13 years after cataract extraction and present the surgical approach used for its successful treatment.

RESUMO - Síndrome do bloqueio capsular é uma complicação incomum da cirurgia de facoemulsificação com capsulorrexis curvilínea contínua e implante de lente intraocular. Nós relatamos um caso de síndrome de bloqueio capsular de início tardio que se desenvolveu após 13 anos da extração da catarata e apresenta a abordagem cirúrgica utilizada para o sucesso do tratamento.

A case of late-onset capsular block syndrome and its surgical treatment.

Capsular block syndrome is a rare complication of phacoemulsification surgery with continuous curvilinear capsulorhexis and intraocular lens implantation. Here, we report a case of very late-onset capsular block syndrome that developed 13 years after cataract extraction and present the surgical approach used for its successful treatment.

Long-term follow-up of persistent low vault after implantable collamer lens exchange.

The implantable collamer lens (ICL) is a widely used posterior chamber phakic intraocular lens that achieves excellent refractive results. Nonetheless, serious postoperative complications related to inadequate vault have been previously reported. Therefore, lens exchange is advised when the vault is out of the recommended ranges. This article presents a case with persistent low vault after lens exchange in which no clinical evidence of crystalline lens opacity or decrease in uncorrected distance visual acuity has been identified during the 6-year clinical follow-up performed to date. Therefore, this suggests that clinical follow-up could be an appropriate approach for patients presenting with low vault, especially those who are older than 40 years and have a history of lens exchange.

Treatment of late-onset capsular distension syndrome with a neodymium:YAG laser peripheral iridotomy and anterior capsulotomy.

We describe a new approach to treat late-onset capsular distension syndrome in which the fluid in the capsular bag is cloudy and prevents a posterior neodymium:YAG (Nd:YAG) laser capsulotomy. A peripheral laser iridotomy is created through which the anterior lens capsule peripheral to the IOL optic is accessed. This opening in the iris provides an access point through which an anterior Nd:YAG laser capsulotomy can be performed. Following disruption of the anterior lens capsule, the capsular fluid is released into the anterior chamber and absorbed through the inherent drainage system of the eye. This approach avoids the need for a more invasive surgical intervention.

[The methods for studying the lens].

The paper reviews the currently available methods for studying the lens. It describes the anatomic and functional features of the lens and the principles of its examination based on biomicroscopy, photorecording, etc. It also depicts quantitative methods for assessing the properties of the lens: the use of multifunctional devices in which the Scheimpflug principle is realized; methods based on the application of ultrasound energy (A-scanning, B-scanning, biomicroscopy).

Ultrasound biomicroscopy of zonular anatomy in clinically unilateral exfoliation syndrome.

PURPOSE: To evaluate the ability of ultrasound biomicroscopy (UBM) to detect abnormalities in the zonular apparatus in unaffected eyes of patients with clinically unilateral exfoliation syndrome (XFS) using a standardized grading system. METHODS: The affected and unaffected eyes of 17 patients with clinically unilateral XFS and 17 eyes of 17 control subjects underwent UBM. Radial sections detailing the lens and zonules at 12:00, 1:30, 3:00, 4:30, 6:00, 7:30, 9:00 and 10:30 clock hours were obtained. The images were graded by a masked, experienced UBM observer using a standardized scoring system based on the zonular appearance (0, none; 1 and 2, uneven or disrupted zonules with or without patchy deposits; 3, diffuse granulation, thick zonules or both; 4, total zonular disruption). Affected meridians were compared by the Friedman test, while distributions of unaffected and affected eyes were compared using the Student t-test. RESULTS: In the control group, 15/17 eyes showed normal zonules; the remaining two eyes showed grade 1 changes in some meridians. The mean grade score was 0.33 [standard deviation (SD) 0.84]. Eyes with XFS had a higher score than control eyes, with a mean score of 14.35 (SD 7.14, P < 0.001, Student t-test). In clinically unaffected fellow eyes, the mean score was 10.53 (SD 7.44), and was less than that of XFS eyes (P = 0.008, Student t-test). Twelve XFS eyes (71%) and six unaffected fellow eyes (35%) had grade 3 or 4 in at least one meridian (P = 0.07, Friedman test). CONCLUSION: Bilateral zonular involvement is present in subjects with clinically unilateral XFS. These zonular changes may be extensive in fellow eyes without clinically evident exfoliation material. UBM assessment of zonular status in fellow eyes prior to cataract extraction may aid in surgical planning.

Ultrasound biomicroscopic assessment of zonular appearance in exfoliation syndrome.

PURPOSE: To assess zonular appearance using biomicroscopy (UBM) in exfoliation syndrome (XFS). METHODS: Normal eyes and eyes with XFS were enrolled in this prospective, consecutive, comparative cohort study. Following pupillary dilation, XFS patients were classified into three clinical stages (early, moderate or severe) by a single examiner (R.R.). Cross-sectional zonular UBM images were obtained circumferentially at eight evenly spaced locations. Five experienced observers evaluated the images using a standardized scoring system based on the zonular appearance (0, none; 1, early; 2, moderate; 3, severe). The extent of zonular involvement on UBM based on UBM score of all observers was correlated with the clinical stage of XFS using a five-stage classification. RESULTS: We enrolled 44 eyes (44 patients), 11 normal and 33 with XFS (10 early, 10 moderate and 13 severe) [mean age 69.4 +/- 9.9 (SD) years; range 50-87 years]. UBM scores of all observers were significantly different between the normal/early and moderate/severe groups (P < 0.001, t-test). With discriminant analysis, the predicted XFS stage showed good agreement with the clinical staging [all kappa > 0.61, area under receiver operating characteristic (ROC) curve > 0.86]. CONCLUSION: UBM can detect zonular involvement in XFS and may be useful in preoperative planning. This may be important in eyes with posterior synechiae in which a diagnosis and the severity of XFS cannot be determined on slit-lamp examination.

Late postoperative capsular block syndrome: entrapment of liquefied after-cataract by capsular bend.

We report a case of capsular bend-related entrapment of liquefied after-cataract that resulted in late postoperative capsular block syndrome in a 56-year-old man. Slitlamp examination showed a capsular bend formation at the square edge of the optic. Superiorly, leakage in the capsular bend resulted in fluid extending into Soemmering's ring, although communication with the anterior chamber was limited by the capsular bend. Fluid was seen between the lens and posterior capsule.

Effect of microkeratome suction during LASIK on ocular structures.

PURPOSE: To study the effect of microkeratome suction on ocular structures during LASIK. DESIGN: Observational, prospective case series. PARTICIPANTS: Twenty-one eyes of 11 patients with myopia or astigmatic myopia (8 females, 3 males) were included. The mean patient age was 36.3 years (median, 37 years; range, 24-48 years), and the mean spherical equivalent was -5.03 diopters (D) (median, -4.63 D; range, -2.38 to -8.38 D). METHODS: We performed preoperative and intraoperative A-scan ultrasonography during application of suction using the Hansatome microkeratome (Bausch & Lomb Surgical, Munich, Germany) to create corneal flaps during LASIK. We also performed preoperative and postoperative B-scan ultrasonography of the posterior ocular segment with special attention to the presence and size of posterior vitreous detachment (PVD). MAIN OUTCOME MEASURES: We measured changes in the axial length, anterior chamber depth, lens thickness, and vitreous distance (distance from the posterior lens capsule to the posterior pole) during application of the microkeratome suction ring and recorded new occurrences of or increases in the size of the PVD after surgery. RESULTS: The lens thickness decreased (mean change, -0.20 mm; P = 0.001; 95% confidence interval [CI], -0.11 to -0.30) in 18 eyes during application of the suction ring. The vitreous distance increased (mean change, 0.20 mm; P = 0.004; 95% CI, 0.08-0.32) in 16 eyes. No statistically significant changes were found in the anterior chamber depth (P = 0.75) or axial length (P = 0.51). After surgery, 3 of 14 eyes (21.4%) experienced PVD that did not have echographic signs of PVD before surgery. Of 7 eyes with preoperative PVD, the PVD enlarged in 1 eye (14.3%). CONCLUSIONS: During application of microkeratome suction, the lens thickness decreases, whereas the vitreous distance increases, suggesting anterior traction on the posterior segment. The relationship between the observed PVD and LASIK merits further investigation.

Congenital double crystalline lenses.

We report an unusual case of an eye with 2 congenital crystalline lenses; ie, a duplicated lens. The horizontal axis of the eye was obliquely placed. One lens was situated in the upper temporal quadrant and the other, in the lower nasal quadrant. One lens was larger than the other.

Traumatic lens abscess with chornic endophthalmitis successfully treated with pars plana lensectomy and vitrectomy.

Intralenticular abscess is a rare entity and has been infrequently reported after surgery, metastatic infection, or trauma. We report a case of post traumatic lens abscess with low-grade endophthalmitis following a penetrating eye injury with a splinter of wood. The patient was successfully treated with a pars plana lensectomy and vitrectomy. Despite thorough microbiological investigations, no causative organism could be isolated.

Ultrasonographic measurement of induced myopia associated with capsular bag distention syndrome.

OBJECTIVE: To determine the causes of postoperative myopia associated with capsular bag distention syndrome (CBDS) and characterize the associated findings. DESIGN: Prospective, multicenter, nonrandomized, comparative (self-controlled) trial. PARTICIPANTS: Six eyes from six patients had CBDS develop after phacoemulsification and posterior chamber intraocular lens implantation. METHODS: Keratometric values, axial length, visual acuity, and manifest refraction were assessed in each eye. Using 20-MHz (I3SYSTEM-ABD, Innovative Imaging Inc, Sacramento, CA) and 50-MHz (Ultrasound Biomicroscope, Zeiss Humphrey Systems, Dublin, CA) ultrasonographic probes, images and measurements of the anterior segment were obtained. After neodymium:yttrium-aluminum-garnet (Nd:YAG) capsulotomy, these measures were repeated and correlated with predicted and actual refractive changes. MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), manifest refraction, and anterior chamber depth before and after treatment of CBDS. RESULTS: Although intended postoperative refraction averaged -0.58 diopters (D) (range, -0.12 to -1.63 D), eyes with CBDS had an average spherical equivalent refraction of -2.35 D (range, +0.13 to -4.50 D), P < 0.05 (one-tailed, paired t test). BCVA averaged 20/24 (range, 20/15-20/40-1), but UCVA averaged 20/133 (range, 20/60 to 20/400). Average distance from the corneal surface to the anterior intraocular lens (IOL) optic surface was 3.55 mm in eyes with CBDS, and 4.30 mm after Nd:YAG capsulotomy. Posterior movement of the IOL optic after capsulotomy accounted for 1.23 D of hyperopic shift or 82% of the CBDS-induced myopia. Treatment of CBDS resulted in both improved UCVA and BCVA. Nd:YAG capsulotomy also released the colloidal suspension within the capsular bag posterior to the IOL optic. The incidence of CBDS was 0.3% in one of the practices reviewed. CONCLUSIONS: Capsular bag distention syndrome includes unexpected myopia and poor UCVA after cataract surgery with lens implantation in cases involving a continuous capsulorhexis. A dramatic posterior distention of the posterior capsule is observed, as well as anterior chamber shallowing, tight apposition of the iris to the IOL, and anterior bowing of the iris. A slightly turbid colloidal suspension behind the IOL implant and late posterior capsular fibrosis are also observed. Timely treatment of CBDS can correct unwanted myopia, improve UCVA and BCVA, and restore normal anatomic relationships in the eye.