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Biomedical subjects

E I Assia

Publications and source records attributed to E I Assia.

At least 37 records · Page 2Linked to original sources

Preventing expulsive hemorrhage using an anterior chamber maintainer to eliminate hypotony.

We describe a method in which constant infusion inflow through an anterior chamber maintainer (ACM) is used to maintain positive intraocular pressure (IOP) during cataract extraction through a self-sealing tunnel incision. A retrospective review of patient records showed that the difference in the incidence of intraoperative suprachoroidal hemorrhage was significantly greater in eyes in which IOP was not constant throughout surgery than in eyes in which IOP was maintained using the ACM system.

Anterior Chamber↗

Utilizing gravity in the removal of a large intraocular foreign body.

This article describes an unconventional technique for the removal of a nonmagnetic intraocular foreign body that is too large or too smooth to be grasped by intraocular forceps and does not float on perfluorocarbon liquids. By flipping the patient to a face-down position and allowing the gravitational forces to help remove the object, one can hope to avoid further ocular damage. This approach should be considered in similar cases of very large and smooth intravitreal foreign bodies to avoid severe and irreversible damage to the retina.

Adult↗

A safety suture for implantation of posterior chamber intraocular lenses in complicated cases.

Implantation of a posterior chamber intraocular lens can be difficult and risky in complicated cases such as a large tear in the posterior capsule, a cloudy cornea, or a small pupil. The author describes a technique for performing a safe implantation. The intraocular lens is supported by a suspension suture, which is threaded through a positioning hole or tied to the lens haptic. The suture is removed once a stable fixation is achieved.

Humans↗

Effect of capsulorhexis diameter on glare disability.

PURPOSE: To determine whether the diameter of the anterior capsulorhexis has an effect on postoperative glare. SETTING: Sapir Medical Center, Meir Hospital, Kfar Saba, Israel. METHODS: Forty patients had extracapsular cataract extraction (manual or phacoemulsification) through an intact continuous curvilinear capsulorhexis (CCC) of various sizes. The CCC diameter was measured and the opacity of the anterior and posterior capsules was evaluated before and after dilation of the pupils. Glare test (Miller-Nadler glare tester) was performed with the eyelid in a normal position and after lid elevation. RESULTS: The diameter of the CCC ranged from 3.50 to 7.00 mm (mean 4.87 mm). The anterior capsule was always opaque in the area of contact with the IOL material. None was graded clear; 60% were graded as +3. Mean glare disability prior to pupil dilation was 12.1 +/- 8.8 (SD) and after dilation, 17.3 +/- 9.7. There was no correlation between glare disability and the diameter of the capsulorhexis, the width of the exposed opacified capsular ring, or the grading of capsule opacification (anterior and posterior). Dilation of the pupil significantly increased glare disability (P = .016), unrelated to CCC diameter. CONCLUSION: A CCC larger than 3.5 mm does not induce significant glare.

Aged↗

The capsular bag after short- and long-term fixation of intraocular lenses.

PURPOSE: To investigate the effect of posterior chamber intraocular lens (PC IOL) size and construction on the capsular bag in human cadaver eyes. METHODS: Studies were done at two timeframes: (1) short term (prospective)--the effect of 12 different IOLs on the capsular bag configuration after experimental implantation; and (2) long term--(retrospective) analysis of eyes with PC IOLs obtained post-morterm. RESULTS: The short-term study showed the maximal diameter of the capsular bag to be 11.0 mm for IOLs with total diameter of 12.0 mm and 11.5 mm for 13.5- to 14.0-mm IOLs. Longer IOLs caused more ovaling of the bag with stress lines (striae) on the posterior capsule. Secondary processes such as proliferation of epithelial cells (Soemmering ring) and capsular fibrosis caused the capsular bag to resume a more circular shape with irregular contour. The area of contact between the IOL loops and the capsular equator was significantly lower in eyes with radial tears and IOLs with the J-loop design compared with the C-loop design. In both the short- and long-term groups, maximal capsular diameter did not exceed 12.0 mm. CONCLUSIONS: The results of this study suggest that using the capsulorrhexis technique, a 12.0-mm total diameter IOL is sufficient to provide stable capsular fixation.

Aged↗

Management of Descemet's membrane detachment.

Detachment of Descemet's membrane is a rare but serious complication of cataract surgery. Most surgeons attempt to reposition the membrane by injecting air, slow-reabsorbing gases, or viscoelastic substances into the anterior chamber. We describe five cases of subtotal detachment without rolled scroll. These cases recovered spontaneously after two to three months. We believe that conservative treatment in such cases is indicated and has a good chance of favorable outcome.

Aged↗

Clinicopathologic study of ocular trauma in eyes with intraocular lenses.

Data on 41 cases (37 intraocular lenses and four globes) of intraocular lenses explanted or expulsed after ocular trauma were retrieved from over 5,000 intraocular lenses and 1,200 globes. The age of the male and female donors varied significantly (male, 64.4 +/- 13.1 years; female, 75.5 +/- 12.6 years; P = .0334). Twenty-two were posterior chamber, 11 were anterior chamber, and eight were iris-fixated lenses. The mean implant durations were 0.66 +/- 0.9 years for posterior chamber intraocular lenses, 4.0 +/- 3.4 years for anterior chamber lenses, and 9.0 +/- 4.9 years for iris-fixated lenses. Accidental falling was the most common trauma in 14 of 21 cases (67%). In the posterior chamber intraocular lens group, trauma was more severe and resulted in rupture of the globe in 19 of 22 cases (86%) and expulsion of the intraocular lens in 15 of 22 cases (68%). Rupture usually occurred at the surgical wound, even when the trauma happened five years postoperatively. In contrast, most of the eyes with anterior chamber intraocular lenses and iris-fixated intraocular lenses did not rupture, but a minor trauma often resulted in intraocular lens dislocation and secondary complications that necessitated intraocular lens explantation. The pathologic findings were nonspecific (proteinaceous deposits, blood and pigment adherent to the intraocular lens). Severity of trauma and pathologic findings were not correlated. Posterior chamber intraocular lenses are more resistant to minor ocular trauma compared to anterior chamber and iris-fixated intraocular lenses.

Adult↗

Using an anterior chamber maintainer to control intraocular pressure during phacoemulsification.

We describe a phacoemulsification technique that uses an anterior chamber maintainer (ACM) to control intraocular pressure. Continuous irrigation through the ACM maintains pressurized intraocular conditions throughout surgery and when the automated system is not activated. Intraocular pressure is stabilized at predetermined levels with minor fluctuations. Viscoelastics can be used in conjunction with the ACM.

Anterior Chamber↗

Hydroexpression of subluxated lenses using a glide.

During the past 8 years, 15 patients (20 eyes) underwent a variety of operations to remove a subluxated lens. In six of these eyes, a new technique, featuring an anterior chamber maintainer and a plastic glide, was used for intracapsular cataract extraction (ICCE). The results achieved in these eyes were compared with those in 8 eyes in which cryo extraction was used, in 1 in which pars plana lensectomy was used, in 4 in which aspiration of lens material and peeling of the capsule was used, and in 1 in which a viscoelastic material and spatula were used. Using the glide, the lens is extracted through a scleral tunnel incision or a limbal opening. The length of the opening is somewhat smaller than the diameter of the lens and is significantly smaller than that used in traditional ICCE. The visual outcomes achieved with these various techniques were essentially identical. The proposed technique is simple and relatively safe for these complicated cases.

Adult↗

Clinicopathologic study of the effect of radial tears and loop fixation on intraocular lens decentration.

PURPOSE: The purpose of this study is to determine the effect of loop fixation and anterior capsular tears on intraocular lens (IOL) decentration. METHODS: A retrospective measurement of IOL decentration was performed on 144 human eyes with posterior chamber (PC) IOLs obtained after death. RESULTS: Decentration in eyes with asymmetrical bag-sulcus fixation (mean +/- standard deviation, 0.64 +/- 0.39 mm) was significantly higher than eyes with symmetrical fixation. In the presence of radial tears, symmetrically fixated IOLs in either the capsular bag or the ciliary sulcus decentered to a similar degree, 0.35 +/- 0.25 mm and 0.4 +/- 0.26 mm, respectively. The least decentration was observed with capsular fixation and no radial tears (0.18 +/- 0.09 mm). This was significantly less decentration than with any other form of fixation in the presence of radial tears. CONCLUSION: This study shows that capsular fixation with no radial tears, as can be achieved by using the continuous curvilinear capsulorhexis, is associated with the least decentration.

Adult↗

The gliding nucleus.

The lens glide is a disposable sterile plastic piece designed to achieve smooth, easy, safe expression of the nucleus in planned extracapsular cataract extraction. The advantages of the technique include prevention of iris prolapse or iris trauma, controlled nucleus extraction without sudden nucleus expulsion, direction of the nucleus toward the external opening, and prevention of malengagement of the nucleus to the anterior chamber angle or vitreous cavity. Using the glide facilitates extraction of a nucleus through a small limbal or scleral incision. Combining the glide with other modern surgical techniques, such as scleral tunnel small incision, capsulorhexis, and hydrodissection, results in a no-stitch low astigmatic wound and stable intraocular lens fixation in the capsular bag.

Cataract Extraction↗

Inhibition of posterior capsule opacification: the effect of colchicine in a sustained drug delivery system.

We investigated the effect of colchicine in a sustained drug delivery system on posterior capsule opacification (PCO) in rabbit eyes. A polymer matrix wafer, which diffused colchicine at a steady rate, was implanted in the capsular bag of 34 eyes after the lens material was removed by endocapsular phacoemulsification. Three different drug concentrations were used in the rabbit eyes, which were compared with control eyes containing the polymer matrix wafer without colchicine. The mean PCO score was highest in the control group without colchicine and increased steadily over 12 weeks. The rate of PCO formation in all eyes treated with colchicine was significantly lower than in the control group. There was no statistically significant improvement in PCO inhibition with the higher colchicine dosages. Side effects included inflammatory anterior chamber reaction and corneal and retinal complications and were most notable with the highest drug concentration. Slow release of colchicine reduces PCO formation in the rabbit. The optimal biocompatible dosage must be carefully determined and warrants further investigation.

Animals↗

[Configuration of the capsular sack after implantation of posterior chamber lenses].

The effect of posterior chamber intraocular lenses (PC-IOLs) on the capsular bag was investigated in human cadaver eyes. Short-term changes were observed with different PC-IOLs directly after experimental implantation. Long-term results were obtained from postmortem eyes with PC-IOLs. Mean implant duration was 2.5 years. The average diameter of the capsular bag in the loop axis was 11.0 mm for 12.0 mm IOLs and 11.5 mm for 13.5-14.0 mm IOLs in the short-term study. Longer loops caused more ovaling of the bag with stress lines on the posterior capsule. The average diameter of the capsular bag in the long term study was 10.6 mm. Secondary processes such as capsular fibrosis and lens epithelial cell proliferation caused the capsular bag to shrink and thus to assume a more circular configuration. The area of contact between the IOL loops and the capsular equator was significantly lower in eyes with radial tears and IOLs with J-loop design when compared to C-loops. The maximal capsular diameter in both the long-term and short-term observations never exceeded 12.0 mm. The results of our study suggest that a 12.0 mm total diameter IOL is sufficient for stable fixation, provided that capsular bag implantation can be assured.

Aged↗

Recurrent hyphema associated with IOL loop displacement treated with argon laser photocoagulation.

Recurrent late hyphema following cataract surgery and implantation of a posterior chamber intraocular lens (PC-IOL) is a rare complication, since there is usually no contact between the IOL and the anterior iris. If treatment with miotics or mydriatics fails, surgical removal of the IOL is often necessary. We report a patient with recurrent hyphema in his only myopic eye who had undergone two retinal detachment operations. A loop of the PC-IOL dislocated anteriorly through a peripheral iridectomy and caused localized pressure and recurrent bleeding. Conservative treatment with argon laser photocoagulation obviated more complex surgery in a high-risk patient.

Cataract Extraction↗

Side-view analysis of the lens. I. The crystalline lens and the evacuated bag.

A new technique for studying the anatomy of the lens and other anterior chamber structures in human eyes obtained post mortem is described. An oblique or side view is achieved by creating a uveoscleral window. This provides a clear three-dimensional view of such structures as the crystalline lens, zonular apparatus, and ciliary body. The crystalline lens is shown to be approximately 4.5 mm thick and 9.5 mm in diameter. The equator of the lens is 0.2 to 0.3 mm from the center of the ciliary body. After removal of lens substance, the capsular bag collapses, its thickness approaches zero, and the total diameter increases to 10.5 mm. Filling of the capsular bag with a viscoelastic material restores the configuration of the lens to its original state. This technique is also useful for demonstrating the dynamics of surgical procedures during cataract operation.

Anterior Chamber↗

Side-view analysis of the lens. II. Positioning of intraocular lenses.

The uveoscleral window technique is useful for studying the position and fixation of posterior chamber intraocular lenses (IOLs). Studies using this technique show that the configuration of an IOL in the capsular bag largely depends on three factors: size, shape, and relative rigidity of the IOL. The general configuration of the capsular bag is that of a flattened saucer created by radial expansion of the haptic. Zonules at the fixation site are relaxed, eliminating the possibility of accommodation with thin IOLs. Downsized IOLs (total diameter of 12.0 mm) provide stable fixation with less tension on the capsule than larger IOLs.

Cataract Extraction↗

Posterior continuous curvilinear capsulorhexis. An experimental study with clinical applications.

The posterior continuous curvilinear capsulorhexis technique has been advocated in cases of posterior capsule rupture during extracapsular cataract extraction. The authors compared posterior continuous curvilinear capsulorhexis with posterior capsular sharp-edged tears. Two different types of forces were experimentally created on the posterior capsule of 30 human eyes obtained after death: (1) implantation and dialing of posterior chamber intraocular lenses (PC IOLs) and (2) increased intravitreal pressure by injection of balanced salt solution. All posterior capsular tears extended toward the equator, causing major capsular defects. In contrast, the posterior continuous curvilinear capsulorhexis remained intact in all cases. This experimental study proves that in cases where an inadvertent posterior capsular tear occurs, a posterior continuous curvilinear capsulorhexis is useful in preventing further capsular damage. Also, in cases where a posterior capsulotomy is indicated, a smooth edge created by a posterior continuous curvilinear capsulorhexis may be useful to maintain the integrity of the capsular bag for PC IOL capsular implantation.

Aged↗