Sebastião Cronemberger

Ultrasound biomicroscopic study of anterior segment changes after phacoemulsification and foldable intraocular lens implantation

PURPOSE To report quantitative changes in the anterior segment configuration after clear corneal incision phacoemulsification and foldable intraocular lens (IOL) implantation by means of ultrasound biomicroscopy (UBM). DESIGN Prospective, nonrandomized, comparative (self-controlled) trial. PARTICIPANTS Twenty-one eyes of 19 patients with senile or presenile cataracts and no other ocular illness. METHODS Patients were examined with UBM before and 1 and 3 months after surgery. At each UBM examination, axial images of the anterior chamber and radial sections of the angle at the superior, lateral, inferior, and medial quadrants were obtained. MAIN OUTCOME MEASURES Central anterior chamber depth (ACD), iris-lens contact distance, iris-lens angle (ILA), angle opening distance at points 250 (AOD250) and 500 microm (AOD500) from the scleral spur, trabecular-iris angle (TIA), iris thickness 500 microm from the scleral spur (IT), trabecular-ciliary process distance (TCPD), iris-ciliary process distance (ICPD), iris-zonule distance, iris-sclera angle (ISA), and ciliary process-sclera angle (CPSA). After surgery, central anterior chamber depth was also measured from the cornea to the IOL (ACD) and from the cornea to the pupillary plane (ACD2). Each variable was measured twice in different days by the same observer. RESULTS The variables IT, TCPD, ICPD, IZD, and CPSA did not significantly change after surgery (P > 0.01). Central anterior chamber depth increased approximately 30% after surgery (approximately 850 microm; P < 0.001), by both measurement methods used (ACD x ACD and ACD x ACD2). Anterior chamber angle significantly increased, by approximately 50% of the initial value, by the three measurement methods used: AOD250 (P <or= 0.002), AOD500 (P < 0.001), and TIA (P <or= 0.003). The ISA increased by approximately 10 degrees (30%) after surgery (P < 0.001). The ILCD and ILA did not exist after surgery, except in two eyes. CONCLUSIONS After phacoemulsification and foldable IOL implantation, UBM revealed that the iris diaphragm shifted backward, deepening the anterior chamber by approximately 850 microm and widening its angle by approximately 10 degrees. These findings may be of clinical significance in eyes with angle-closure glaucoma or with occludable angles.

Ultrasound biomicroscopic imaging of posterior chamber phakic intraocular lens

BACKGROUND Phakic intraocular lens (IOL) implantation represents a major technique for the correction of high myopia. The STAAR collamer posterior chamber phakic IOL--trade named Implantable Contact Lens--is an emerging technology in refractive surgery. We studied the relative position of the posterior chamber phakic IOL using ultrasound biomicroscopy. METHODS The posterior chamber phakic intraocular lens was inserted in 9 eyes of 8 patients with high myopia. Ultrasound biomicroscopy was performed before and after implantation of the phakic IOL to assess its relative position in the anterior segment of the eye. The parameters measured and compared were anterior chamber depth, angle opening distance 500 microns from the scleral spur, iris-crystalline lens contact distance, iris-IOL contact distance, and IOL-crystalline lens distance. RESULTS Ultrasound biomicroscopy showed contact between the iris and the IOL in all eyes and between the IOL and the crystalline lens in 8 eyes. Reduction in the anterior chamber depth and localized narrowing of the angle opening were observed in all eyes. CONCLUSION IOL-iris touch, IOL-crystalline lens touch, and anterior chamber shallowing raise concerns of pigmentary dispersion, cataractogenesis, and narrow angle glaucoma following posterior chamber phakic intraocular lens implantation. Clinical data are needed to determine if these problems occur.

Bimatoprost-Loaded Ocular Inserts as Sustained Release Drug Delivery Systems for Glaucoma Treatment: In Vitro and In Vivo Evaluation

The purpose of the present study was to develop and assess a novel sustained-release drug delivery system of Bimatoprost (BIM). Chitosan polymeric inserts were prepared using the solvent casting method and characterized by swelling studies, infrared spectroscopy, differential scanning calorimetry, drug content, scanning electron microscopy and in vitro drug release. Biodistribution of 99mTc-BIM eye drops and 99mTc-BIM-loaded inserts, after ocular administration in Wistar rats, was accessed by ex vivo radiation counting. The inserts were evaluated for their therapeutic efficacy in glaucomatous Wistar rats. Glaucoma was induced by weekly intracameral injection of hyaluronic acid. BIM-loaded inserts (equivalent to 9.0 µg BIM) were administered once into conjunctival sac, after ocular hypertension confirmation. BIM eye drop was topically instilled in a second group of glaucomatous rats for 15 days days, while placebo inserts were administered once in a third group. An untreated glaucomatous group was used as control. Intraocular pressure (IOP) was monitored for four consecutive weeks after treatment began. At the end of the experiment, retinal ganglion cells and optic nerve head cupping were evaluated in the histological eye sections. Characterization results revealed that the drug physically interacted, but did not chemically react with the polymeric matrix. Inserts sustainedly released BIM in vitro during 8 hours. Biodistribution studies showed that the amount of 99mTc-BIM that remained in the eye was significantly lower after eye drop instillation than after chitosan insert implantation. BIM-loaded inserts lowered IOP for 4 weeks, after one application, while IOP values remained significantly high for the placebo and untreated groups. Eye drops were only effective during the daily treatment period. IOP results were reflected in RGC counting and optic nerve head cupping damage. BIM-loaded inserts provided sustained release of BIM and seem to be a promising system for glaucoma management.

Late Needling of Flat Filtering Blebs with Adjunctive Mitomycin C: Efficacy and Safety for the Corneal Endothelium

PURPOSE To assess the efficacy of needle revision using mitomycin C (MMC) for reviving failed filtering blebs during the late postoperative period and its safety for the corneal endothelium. DESIGN Prospective interventional case series. PARTICIPANTS We recruited 125 eyes from 98 patients with uncontrolled glaucoma. All had at least 1 failed trabeculectomy, a flat filtering bleb, and a patent internal ostium on gonioscopy. The average time between the last trabeculectomy and needle revision was 5.3±5.3 years (range, 6 months to 30 years). INTERVENTION Needling revision with a subconjunctival injection of 8 μg of MMC. MAIN OUTCOME MEASURES Intraocular pressure (IOP) and number of hypotensive medications at latest visit, central corneal thickness (CCT), corneal endothelial cell density (ECD), coefficient of variation of cell size (CV), and hexagonality before and after needling. RESULTS We performed 186 needling procedures on 125 eyes (mean, 1.5±0.6 procedures/eye). Seventy-three eyes (58.4%) were needled once, 44 eyes (35.2%) were needled twice, 7 eyes (5.6%) were needled 3 times, and 1 eye (0.8%) was needled 4 times. We reestablished aqueous flow and obtained a raised bleb in 115 eyes (92%). After an average follow-up of 20.8±12.0 months, the mean IOP decreased from 20.1±5.2 mmHg preoperatively to 13.2±6.8 mmHg (P<0.001), and the mean number of hypotensive medications per eye decreased from 2.4±1.1 to 0.8±1.3 (P<0.001) at the latest visit. The overall success rate (IOP ≤16 mmHg) was 76% (58.4% without medication and 17.6% with hypotensive medications). Kaplan-Meier survival rates were 91.2% at the 1-month follow-up, 84.5% at 6 months, 81.0% at 1 year, 74.6% at 2 years, and 66.3% at 3 years. We studied the corneal endothelium in 42 eyes of 36 patients. There was no statistically significant difference between preoperative CCT, ECD, CV, or hexagonality and postoperative measurements at 1 week and 1, 3, 6, and 12 months. CONCLUSIONS Needling revision with adjunctive MMC is effective for reviving flat filtering blebs and controlling IOP, even several years after the original trabeculectomy, and seems to be safe for the corneal endothelium.

Oculodentodigital dysplasia: study of ophthalmological and clinical manifestations in three boys with probably autosomal recessive inheritance

Oculodentodigital dysplasia (ODDD) is a rare inherited disorder affecting the development of the face, eyes, teeth, and limbs. The majority of cases of ODDD are inherited as an autosomal dominant condition. There are few reports of probable autosomal recessive transmission. Affected patients exhibit a distinctive physiognomy with a narrow nose, hypoplastic alae nasi, and anteverted nostrils, bilateral microphthalmos, and microcornea. Sometimes iris anomalies and secondary glaucoma are present. There are malformations of the distal extremities such as syndactyly. In addition, there are defects in the dental enamel with hypoplasia and yellow discoloration of the teeth. Less common features include hypotrichosis, intracranial calcifications, and conductive deafness secondary to recurrent otitis media. We describe three brothers with ODDD. Their parents are first cousins and present no features of ODDD. These data are in favor of autosomal recessive inheritance and suggest genetic heterogeneity for this entity.

Espessura central e periférica da córnea: influência na medida da pressão intra-ocular pelo Tonopen

PURPOSE To assess the influence of central and peripheral corneal thickness on the IOP measurement by Tonopen. METHODS The IOP of 58 eyes from suspected and glaucomatous patients was evaluated by Goldmanns tonometry (GT) and, by Tonopen XL on the central (TC) and peripheral (TP) regions of the cornea. Using the DGH 5100e pachymeter, we also measured the corneal thickness in its central (CCT) and peripheral (at 6:00 h) regions (PCT). Patients with any corneal changes were excluded. The mean values of all measurements was comparatively analyzed (GT x TC; GT x TP; TC x TP; CCT x PCT) by the paired t test and by regression and correlation analysis. RESULTS The means (+/- standard deviation) of IOP obtained with GT, TC and TP were respectively 14.6 (+/-) mmHg; 18.9 (+/-2.9) mmHg and 20.7 (+/-3.7) mmHg with a statistical highly significant difference (p<0.001). The means (+/- standard deviation) of central and peripheral corneal thickness were respectively 526 (+/-42.3) and 639 (+/-52.9) microm, also with a statistical highly significant difference (p<0.001). The correlation coefficients (r) between the measurements were 0.71 (p<0.001) for GT and TC; 0.65 (p<0.001) for GT and TP and 0.64 (p<0.001) for TC and TP. CONCLUSIONS There was a positive correlation between the measurements performed with Tonopen XL and Goldmanns tonometer at the central region of the cornea and the mean IOP was higher with Tonopen XL. The mean IOP obtained by TP was higher than that obtained by TC. These data showed that Tonopen XL, besides providing higher IOP readings than those with Goldmanns tonometer, is influenced by the corneal thickness presenting higher IOP readings in the periphery than in the central region of the cornea.

New comparative ultrasound biomicroscopic findings between fellow eyes of acute angle closure and glaucomatous eyes with narrow angle.

PURPOSE To compare morphometric features between fellow acute primary angle-closure (APAC) eyes and glaucomatous or suspect eyes with narrow angle (NA). METHODS Fellow eyes of 30 patients with unilateral APAC and 30 with NA were evaluated by ultrasound biomicroscopy (UBM) under light and dark conditions. UBM parameters such as anterior chamber depth (ACD), angle opening distance at 250 microm/500 microm from the scleral spur (AOD250/AOD500), trabecular ciliary process distance (TCPD) and iris-lens contact distance (ILCD) were measured in the superior (SQ) and inferior (IQ) quadrants. RESULTS Significant differences between APAC fellow and NA eyes were found in ACD, P<0.001; AOD250 at SQ and IQ, P<0.001; AOD500 at SQ and IQ, P<0.001; TCPD light, P=0.010 and TCPD dark at SQ, P=0.031; and TCPD light at IQ, P=0.010. Significant differences between light and dark examinations of APAC fellow eyes were found in ILCD (P=0.009) at SQ and ILCD at IQ (P=0.006), and of NA eyes in ILCD at SQ (P=0.047) and ILCD at IQ (P<0.001). CONCLUSIONS APAC fellow eyes have a more crowded anterior segment and shallower ACD than NA eyes. ILCD decreases in both groups when the illumination conditions change from light to dark.

Intraocular pressure and ocular rigidity after LASIK

PURPOSE To assess the intraocular pressure (IOP) and ocular rigidity (E) at 1, 3, 6 and 24 postoperative months in eyes that underwent LASIK. METHODS The IOP measured by Goldmann applanation tonometer (GAT) and by the 5.5 and 10 gm. weights of a standardized Schioetz tonometer (ST) and the E measured by differential tonometry (the 5.5 and 10 gm. of ST) were assessed before and after LASIK (at 1, 3, 6 and 24 month) in 23 eyes. The volume of the corneal indentation (Vc) and IOP with ST resting on the eye (tonometric pressure - Pt) were also evaluated. RESULTS The average IOP (GAT) at 6 and 24 months after LASIK was lower than at 1 and 3 months and before LASIK. A statistically significant difference of E was found at 1, 3, 6 and 24 months. The reduction of the central corneal thickness (CCT) by LASIK was the cause of increasing values of Vc and decreased values of Pt. In turn, the changes in Vc and Pt were responsible for the lower IOP measurements by GAT and E changes. CONCLUSIONS LASIK reduces IOP readings by GAT but not the ones by ST (differential tonometry). LASIK also diminishes E. IOP (GAT) values are lower at 6 and 24 months. IOP evaluation by ST is more accurate than that by GAT. At 6 months, Vc, Pt and E parameters are stabilized (no changes relatively to 24 months measurements.

Plateau iris configuration in eyes with narrow-angle: an ultrasound biomicroscopic study

PURPOSE To investigate, through ultrasound biomicroscopy images, the presence of plateau iris configuration in eyes with narrow-angle from patients with open-angle glaucoma and in eyes with previous acute primary angle-closure and compare the biometric features of eyes with plateau iris configuration with those of normal eyes. METHODS Ultrasound biomicroscopic images from 196 patients with open-angle glaucoma and narrow-angle and 32 patients with acute primary angle-closure were retrospectively analyzed. The inclusion and specific criteria for the diagnosis of plateau iris configuration was the presence of an anterior positioning of the ciliary processes, supporting the peripheral iris so that it was parallel to the trabecular meshwork; the iris root had a steep rise from its insertion point, followed by a downward angulation from the corneoscleral wall; presence of a central flat iris plane; an absent (complete plateau iris configuration) or partially absent (incomplete plateau iris configuration) ciliary sulcus. The ultrasound biomicroscopic parameters were compared between complete and incomplete plateau iris configuration. The same parameters of both groups were compared with those of normal eyes. The following measurements were performed: anterior chamber depth; angle opening distance at 500 microm from the scleral spur; peripheral iris thickness at 500 microm from the scleral spur; iris-ciliary process distance; trabecular-ciliary process distance and angle recess area. RESULTS Plateau iris configuration was found in 33 eyes of 20 (10.2%) out of 196 patients with open-angle glaucoma and narrow-angle and in 4 eyes of 2 (6.3%) out of 32 patients with acute primary angleclosure. Seventeen (77.3%) patients with plateau iris configuration were female and 5 (22.7%) male. Twenty-three (62.2%) out of 37 eyes had complete plateau iris configuration, and 14 (37.8%) had incomplete plateau iris configuration. Complete and incomplete plateau iris configuration presented similar biometric features with the exception of the iris-ciliary process distance. All plateau iris configuration eyes showed biometric parameters completely different from those of normal eyes except for peripheral iris thickness at 500 microm from the scleral spur. CONCLUSIONS Plateau iris configuration was present in 10.2% of patients with open-angle glaucoma and narrow-angle and in 6.3% of patients with acute primary angle-closure. Biometric features were similar in eyes with complete and incomplete plateau iris configuration with the exception of iris-ciliary process distance. Compared to normal eyes, all plateau iris configuration eyes showed biometric parameters completely different except for peripheral iris thickness at 500 microm from the scleral spur.

Ocular Inserts for Sustained Release of the Angiotensin-Converting Enzyme 2 Activator, Diminazene Aceturate, to Treat Glaucoma in Rats

The aim of this study was to develop and evaluate the effects of chitosan inserts for sustained release of the angiotensin-converting enzyme 2 (ACE2) activator, diminazene aceturate (DIZE), in experimental glaucoma. Monolayer DIZE loaded inserts (D+I) were prepared and characterized through swelling, attenuated total reflectance Fourier transformed infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC) and in vitro drug release. Functionally, the effects of D+I were tested in glaucomatous rats. Glaucoma was induced by weekly injections of hyaluronic acid (HA) into the anterior chamber and intraocular pressure (IOP) measurements were performed. Retinal ganglion cells (RGC) and optic nerve head cupping were evaluated in histological sections. Biodistribution of the drug was accessed by scintigraphic images and ex vivo radiation counting. We found that DIZE increased the swelling index of the inserts. Also, it was molecularly dispersed and interspersed in the polymeric matrix as a freebase. DIZE did not lose its chemical integrity and activity when loaded in the inserts. The functional evaluation demonstrated that D+I decreased the IOP and maintained the IOP lowered for up to one month (last week: 11.0±0.7 mmHg). This effect of D+I prevented the loss of RGC and degeneration of the optic nerve. No toxic effects in the eyes related to application of the inserts were observed. Moreover, biodistribution studies showed that D+I prolonged the retention of DIZE in the corneal site. We concluded that D+I provided sustained DIZE delivery in vivo, thereby evidencing the potential application of polymeric-based DIZE inserts for glaucoma management.