Central Corneal Edema Research Articles

First Day Review after Uncomplicated Phacoemulsification: Is it Necessary?

To determine whether first day follow-up is necessary after routine uncomplicated phacoemulsification cataract surgery. Data collected prospectively at day 1 postoperative review. In 510 consecutive cases, serious complications occurred in 8 (1.6%) (wound leak [4], corneal abrasion [2], iris prolapse [1], hyphema [1]). Intraocular pressure (IOP) >30 mmHg was found in 26 (5.1%) and was strongly associated with a diagnosis of pre-existing glaucoma or ocular hypertension (odds ratio [OR] 7.7). Symptoms of headache or ocular discomfort occurred in 40 (7.8%), mostly in association with raised IOP, and were also associated with pre-existing glaucoma or ocular hypertension (OR 4.7). Central corneal edema was found in 61 (12.0%). In the absence of corneal edema, IOP was >30 mmHg in only two cases (0.39%). Few sight-threatening complications were detected on the morning after an uncomplicated procedure. First day follow-up may be safely omitted if adequate patient counseling is undertaken and there is provision of adequate access to eye services. Review prior to discharge on the day of surgery would provide an opportunity to detect these few surgical complications and for counseling. A diagnosis of glaucoma or ocular hypertension is a risk factor for significantly raised next day IOP and these patients are more likely to experience postoperative discomfort. They may benefit from prophylactic treatment.

Small-incision manual extracapsular cataract surgery in Ghana, West Africa

Purpose To evaluate the results of small-incision manual extracapsular cataract extraction surgery (ECCE) in a district hospital in West Africa. Setting Margret Marquart Catholic Hospital, Ghana, West Africa. Methods This prospective study consisted of 200 eyes of 193 patients who had small-incision manual ECCE between January 1999 and May 2000. For comparison, the charts of 32 patients (32 eyes) operated on between July and December 1998 using a limbal incision (control group) were retrospectively analyzed. Outcome measures included intraoperative and postoperative complications, postoperative visual acuity, and refractive astigmatism. Results In the small-incision ECCE group, self-sealing wounds were achieved in 129 eyes (64.5%). Vitreous loss occurred in approximately 3% of eyes in both the small-incision and control groups. The final visual acuities were similar between the 2 groups, with more than 90% of eyes in both groups achieving a final best corrected visual acuity of at least 20/60. Eyes in the small-incision group had faster visual recovery ( P < .001), a lower incidence of fibrinous iritis ( P = .02), and were more likely to have round pupils ( P < .001) than eyes in the control group. The main complication of small-incision surgery was moderate corneal edema, which persisted until at least the 1-week visit in 14 eyes (7%). At the most recent visit, 1 eye in the small-incision group (0.5%) had bullous keratopathy. Conclusion In a district hospital in West Africa, small-incision manual ECCE surgery yielded faster visual rehabilitation and had a lower incidence of fibrinous iritis than standard ECCE surgery.

Vitreoretinal surgery for retained lens fragments after phacoemulsification.

To evaluate the prognostic factors, effect of timing and outcomes of vitreoretinal surgery for removal of retained lens fragments after phacoemulsification. A retrospective review of 43 eyes of 43 patients who had vitreoretinal surgery for retained lens fragments after phacoemulsification, between January 1998 and November 2000. Seven of the 43 patients underwent vitrectomy on the same day as cataract surgery, 20 in the first week, and 23 after the first week, with a mean of 14.8 days (0-90). Initial visual acuity was < or = 20/400 in 27 (75%, n=36) and intraocular pressure (IOP) > or = 25 mmHg in 22 (61%, n=36) eyes with or without medication. The mean preoperative IOP was 27.4 mmHg. Initial ocular findings included moderate or severe corneal edema in 17 patients (40%), uveitis in 14 (33%), retinal detachment in 1 (2%) and vitreous hemorrhage in 2 (5%). After a mean follow-up of 8.4 months, final best-corrected visual acuity (BCVA) was > or = 20/40 in 24 patients (56%) and < or = 20/400 in 7 (16%). Persistent corneal edema (one eye), cystoid macular edema (four eyes), age-related macular degeneration (one eye) and suprachoroidal hemorrhage (one eye) were the causes of BCVA < or = 20/400. Final mean IOP was 15.2 mmHg and only one case had IOP > 25 mmHg. Uveitis disappeared in all cases (p<0.001), and corneal edema persisted in only one eye. Both the BCVA and IOP differences were significant (p<0.001), but no correlation was found between pre- and postoperative BCVA and IOP as regards vitreoretinal surgery timing, posterior or anterior removal sites and IOL implantation sites or procedures. Vitreoretinal surgery is effective for removing retained lens fragments after phacoemulsification, lowering the IOP and reducing the uveitic reaction and corneal edema. BCVA > or = 20/40 can be reached in at least half the patients.

Oedematous Corneal Response of the Fellow Control Eye to Lotrafilcon A and Vifilcon A Hydrogel Contact Lenses in the Rabbit

Purpose: To compare central corneal swelling after 24 h in eyes wearing Lotrafilcon A (high Dk silicone hydrogel) and Vifilcon A (low Dk hydrogel) lenses and the fellow control eyes of rabbits. Methods: 24 New Zealand albino rabbits, free of corneal and conjunctival disease, were anaesthetised with ketamine and xylazin. In 12 rabbits, the right eye was fit with the high Dk Lotrafilcon A silicone hydrogel lens. In the other 12 rabbits, the right eye was fit with the low Dk Vifilcon A hydrogel lens, whereas the left eyes were kept as control eyes. Thereafter, the lens-fitted eyes had partial tarsorrhaphy that left a central gap of approximately 4 mm in length. After 24 h the eyelids were opened and the lenses removed. Central corneal thickness was measured using an ultrasonic pachymeter (Mentor O&O-Advent). Results: Central corneal oedema induced by Vifilcon A lens was significantly higher than that with the Lotrafilcon A lens (p < 0.0001). The oedema of the fellow eyes paired with the Vifilcon A lens-wearing eyes was also higher than that of the fellow eyes paired with the Lotrafilcon A lens-wearing eyes (p < 0.01). Conclusions: The Lotrafilcon A lens induced significantly less corneal oedema than the Vifilcon A lens. Corneal oedema of the fellow eyes appears to be influenced by the swelling of the contralateral lens-wearing eyes. The oedema of the fellow control eye was significantly lower when there was less oedema in the contralateral eye wearing a high Dk silicone hydrogel lens. This may be a sympathetic physiological response. The presence of silicone in the high Dk hydrogel lens may suppress corneal oedema in the lens-wearing eye, thus affecting the fellow eye.

Phacoemulsification in spherophakia with corneal touch

A phacoemulsification procedure with implantation of a foldable acrylic intraocular lens in a 31-year-old man with spherophakia is described. The procedure was necessitated by anterior dislocation of the spherophakic lens, with corneal endothelial contact and development of central corneal edema. With a careful approach, the procedure was uneventful and the outcome successful. Modern small-incision cataract surgery techniques are of great benefit in this type of complicated case.

Cataract surgery in a patient with Brown-McLean syndrome

The Brown-McLean syndrome is defined by corneal edema that involves the peripheral 2.0 to 3.0 mm of cornea, sparing the central cornea. This syndrome is usually associated with previous cataract surgery but has been reported rarely in patients with other predisposing factors such as angle-closure glaucoma or spontaneous lens absorption with iridodonesis. We describe the clinical course of a 50-year-old man with myotonic dystrophy who had Brown-McLean syndrome with no identifiable predisposition for peripheral corneal edema. Although this syndrome appears to be the result of peripheral endothelial dysfunction, this patient was able to tolerate cataract extraction without developing central corneal edema.

The Effect of Propolis Extract in Experimental Chemical Corneal Injury

Purpose: To investigate the effect of propolis, a natural resin produced by honeybees, in the treatment of alkali-injured rabbit eyes. Method: A corneal alkali burn was induced by applying filter paper immersed in 1 N NaOH on the central axis of the right corneas of 24 rabbits for 30 s. The animals were divided into three treatment groups: group 1 (control) was given 0.3% tobramycin and phosphate-buffered solution; group 2 was treated with antibiotic coverage and topical 1% ethanolic extract of propolis; group 3 received antibiotic coverage and topical 1% dexamethasone. The dexamethasone-treated group was maintained as the positive control. Drugs were instilled 4 times a day for 7 days. The corneal inflammation was evaluated by calculating the average inflammatory index obtained from clinical observation of the ciliary hyperemia, central and peripheral corneal edema at 24 h, 48 h, on day 5 and day 7, before sacrificing the animals. Then, the corneas underwent routine histological examination. Results: The effects of dexamethasone and propolis on healing of injured corneas were similar (p > 0.05) and significantly better than controls at 24 h (p < 0.01, p < 0.05, respectively), and on day 7 (p < 0.05) with respect to the inflammatory index. On histological observation, inflammatory cell infiltration was lower as compared to control in both the dexamethasone and propolis groups (p < 0.001) and similar with each other (p > 0.05). Conclusions: Our study shows that propolis has an anti-inflammatory effect comparable to dexamethasone in chemical corneal injury.

Phacofracture versus phacoemulsification in eyes with age-related cataract

Purpose: To compare manual phacofracture and phacoemulsification techniques.Setting: Dr. Rajendra Prasad Centre for Ophthalmic Sciences, New Delhi, India.Methods: This prospective, randomized study comprised 60 cases of age-related cataract randomly divided into 2 groups: 30 eyes had phacoemulsification and 30, manual phacofracture using a trisection technique. Postoperative evaluation was at I day, 1 and 6 weeks, and 3 months. The parameters evaluated were amounts of viscoelastic material and irrigating fluid used, the time required to manage the nucleus postoperative best corrected visual acuity, endothelial cell loss, and complications.Results: Mean viscoelastic material used intraoperatively (3.69 mL -± 0.81 [SD] versus 1.76 ± 0.54 mL) and the time required to manage the nucleus (7.78 ± 2.07 minutes versus 2,53 ± 1.18 minutes) were significantly greater in the phacofracture than in the phacoemulsification group, respectively. Best corrected visual acuity was significantly better in the phacoemulsification group on the first postoperative day; 64% had a visual acuity of 6/9 or better versus 37% in the phacofracture group. Endothelial cell loss at 3 months was 17.66 ± 3.65% in the phacofracture group and 12.03 ± 3.06% in the phacoemulsification group and central corneal edema persisting for more than 1 week, 7 and 0 cases, respectively. The differences between groups were statistically significant.Conclusion: More experience in and further modification of the manual phacofracture technique are' required before it can be recommended as a safe alternative to phacoemulsification.

Incorporation of a fluorocarbon polymer implanted at the posterior surface of the rabbit cornea.

An implant of porous expanded polytetrafluoroethylene (PTFE) in the corneal stroma allows fast cell colonization and can become translucent. We studied the behavior of the same polymer implanted in the anterior chamber of the rabbit eye and sutured to the posterior surface of the cornea. The expanded tetrafluoroethylene was provided as 200-micron thick sheets in 3 pore diameters (20, 50 and 80 microns). Disks (5 mm) were implanted in the anterior chambers of 20 rabbits and sutured to the posterior surface of the cornea. Histological and ultrastructural studies were performed after 3 and 4 months. Quantimetry was done on TEM images to analyze the fibrillar structure of the intercellular matrix inside and around the implanted polymer. The material was well tolerated. In all cases there was mild central corneal edema, which disappeared after 1 month. Mild neovascularization occurred in five cases, decreasing after 1 month. The polymer became translucent after 8 days. Keratocytes from the corneal stroma colonized the implant via breaks in the Descemet's membrane along the sutures. Quantimetry showed three types of fibrils inside and beside the polymer. Corneal endothelial cells regenerated over the fibroblasts and the polymer. This fluorocarbon polymer implanted in the anterior chamber and sutured to the posterior surface of the cornea was well tolerated, and there was real incorporation, with keratocytes producing collagen fibrils inside the polymer and endothelial cells forming a posterior cell monolayer. This is promising for the development of a keratoprothesis with posterior fixation.

Incorporation of a fluorocarbon polymer implanted at the posterior surface of the rabbit cornea

An implant of porous expanded polytetrafluoroethylene (PTFE) in the corneal stroma allows fast cell colonization and can become translucent. We studied the behavior of the same polymer implanted in the anterior chamber of the rabbit eye and sutured to the posterior surface of the cornea. The expanded tetrafluoroethylene was provided as 200-micron thick sheets in 3 pore diameters (20, 50, and 80 microns). Disks (5 mm) were implanted in the anterior chambers of 20 rabbits and sutured to the posterior surface of the cornea. Histological and ultrastructural studies were performed after 3 and 4 months. Quantimetry was done on TEM images to analyze the fibrillar structure of the intercellular matix inside and around the implanted polymer. The material was well tolerated. In all cases there was mild central corneal edema, which disappeared after 1 month. Mild neovascularization occurred in five cases, decreasing after 1 month. The polymer became translucent after 8 days. Keratocytes from the corneal stroma colonized the implant via breaks in the Descemet's membrane along the sutures. Quantimetry showed three types of fibrils inside and beside the polymer. Corneal endothelial cells regenerated over the fibroblasts and the polymer. This fluorocarbon polymer implanted in the anterior chamber and sutured to the posterior surface of the cornea was well tolerated, and there was real incorporation, with keratocytes producing collagen fibrils inside the polymer and endothelial cells forming a posterior cell monolayer. This is promising for the development of a keratoprothesis with posterior fixation. © 1996 John Wiley & Sons, Inc.

The Induction of Anterior Chamber Inflammation by Factors Released from Hydrogen Peroxide-Injured Corneas: Effect of Dexamethasone and Indomethacin

Studies from our laboratory have demonstrated the release of high levels of neutrophil chemotactic factors (NCF) from isolated rabbit corneas injured by hydrogen peroxide (H2O2). The purpose of the present study was to determine the biological activity of these factors and to test the hypothesis that the intracameral injection of these factors can induce inflammation of the anterior segment. Under sterile conditions, the epithelial surfaces of isolated rabbit corneas were incubated with a 300 ul mixture of glucose (G) (1mg/ml) and glucose oxidase (GO) (20 U/ml) at 37 degrees C for 6 hours. This supernatant solution was collected and a 100 ul sample containing NCF, but not H2O2, was injected into the anterior chamber of anesthetized rabbit eyes (n = 8). Anterior chamber inflammation, characterized by moderate corneal edema associated with a fibrinous anterior chamber reaction, was evident 2 and 4 hours after injection. Aqueous humor analysis revealed the presence of fibrin and a large number of neutrophils (32 +/- 5 x 10(4) cells/ml). Control eyes, on the other hand, showed normal morphology and low levels of neutrophils after the injection of 100 ul minimum essential medium (MEM) (n = 8) (1.2 +/- 0.14 x 10(4) cells/ml), G/GO mixture (n = 8) (5 +/- 0.86 x 10(4) cells/ml), or supernatant solutions collected from MEM-treated corneas (n = 8) (15 +/- 2 x 10(4) cells/ml). To determine whether the inflammatory reaction observed was due to a direct effect of the chemoattractants or mediated through stimulation of arachidonic acid (AA) metabolites, we pretreated rabbit eyes with a sterile solution of 0.1% dexamethasone (n = 8 eyes) or with a sterile solution of 3.4% indomethacin (n = 8 eyes) three times a day, for one day, prior to the injection of NCF supernatant solution. Examination 2 hours and 4 hours after injection revealed inflammation characterized by mild-to-moderate corneal edema associated with a fibrinous anterior chamber reaction was observed with or without prior treatment with AA metabolite inhibitors. No difference in the degree of inflammation was detected clinically. Results of these studies suggest that NCF released from H2O2-injured corneas can directly induce inflammation of the anterior segment, and that metabolites of AA are not mediating the observed in vivo response.

Immunohistochemical evaluation of murine HSV-1 keratouveitis

The intraocular inflammatory reaction in a murine model of herpes simplex keratouveitis was studied using immunohistochemical techniques. 5 x 10(5) PFU of HSV-1 (Stewart strain) was applied to the abraded cornea of BALB/c mice. The subsequent development of keratouveitis was documented by sequential examination, conventional histology and immunohistochemical staining of frozen sections with the following monoclonal antibodies: Thy-1, Lyt-1, Lyt-2, Ia, Mac-1 and Lyb-8.2. At one week (in the early stage) there was moderate central corneal edema with inflammatory cell infiltration, consisting of a predominance of polymorphonuclear leukocytes, with the appearance of helper/inducer T-cells(Th/i). At two weeks (in the middle stage), a geographic corneal ulcer developed and the majority of inflammatory cells were still polymorphonuclear leukocytes. However, there was a further increase in the Th/i cell population, with the first appearance of B-cells. At three weeks (in the late stage), a dense stromal corneal scar was observed and there was a decrease in the inflammatory cell population, with the predominant cell being the B-cell. Throughout the evolution of HSV-1 keratouveitis, a mild inflammatory reaction was observed in the uvea. However, the number of inflammatory cells present was too small to allow more definitive characterization. Patchy Ia staining which is noted in the normal choroid increased markedly throughout the keratouveitis.

The effects of fenestrating soft contact lenses on corneal swelling: a re‐examination

Previous studies have suggested that central corneal oedema during hydrogel lens wear can be reduced by placing peripheral fenestrations in the lens. In this study, optical pachometry was used to monitor central and peripheral corneal swelling in response to a peripherally fenestrated hydrogel lens. The experiment was conducted in a double-masked, randomized manner on 10 unadapted subjects. Fenestrations did not alter central corneal oedema, but peripheral corneal oedema was reduced by 34% (p > 0.001). Fenestrations may therefore provide a useful strategy for minimizing lens-induced corneal oedema. Clinical trials with fenestrated lenses are now indicated.

Topographical corneal oedema.

Corneal thickness changes were monitored across the cornea in 10 subjects during 7 days continuous wear of 3 types of hydrogel contact lenses of different back vertex powers. Analysis of topographical corneal thickness changes indicates that the periphery of the cornea swells significantly less than the central cornea. The effect is more dramatic with higher levels of central corneal oedema, and with lenses of higher minus power, in spite of their thicker lens periphery. An anoxic stimulus was also found to produce greater central than peripheral corneal swelling, indicating that tear exchange under the periphery of the contact lens is not a significant factor in limiting peripheral corneal swelling. It was concluded that the topographical swelling profile is not contact lens-related, but reflects a reduced swelling capability of the peripheral cornea, due to physical restraint in the limbal region.

Pre-keratoplasty Potential Acuity Evaluation: Laser interferometer and Potential Acuity Meter

Twenty-three patients who underwent penetrating keratoplasry were evaluated preoperatively for potential retinal acuity utilizing the Randwal Laser Interferometer and the Mentor Potential Acuity Meter. When compared with Snellen visual acuity during the early postoperative period (1–6 months), both instruments were useful as qualitative predictors of maculae function when used in the presence of mild to moderate corneal edema. The laser interferometer was somewhat more accurate in the severe cases of corneal edema.

The Corneal Toxicity of Presurgical Skin Antiseptics

In a study of the corneal toxicity of some commonly used presurgical skin antiseptics, we used biomicroscopy, corneal pachymetry, healing studies, and electron microscopy to compare tincture of iodine (2% iodine, 2.35% sodium iodine, and 46% ethanol), Hibiclens (4% chlorhexidine and 4% isopropyl alcohol with detergent), pHisoHex (3% hexachlorophene and detergent), Lavacol (70% ethanol), 7.5% povidone iodine scrub (with a detergent), and 10% povidone iodine solution (without a detergent) in rabbits. Five minutes after application, moderate corneal epithelial edema was noted in all groups except the saline control group. After three hours there was marked corneal de-epithelialization, conjunctival chemosis, and anterior stromal edema in all groups except those treated with 10% povidone iodine solution and 0.9% sodium chloride. After one week all corneas had returned to normal. Accidental instillation of 7.5% povidone iodine scrub into the tear film of a 33-year-old man resulted in almost immediate chemical chemosis despite prompt irrigation, demonstrating the corneal toxicity of this substance. These results indicated that a 10% povidone iodine solution without detergent causes minimal corneal toxicity whereas the other presurgical skin antiseptics tested are toxic to the cornea.

The effect of peripherally fenestrated contact lenses on corneal edema.

To determine the effect of peripherally fenestrated contact lenses on central corneal edema, 6 subjects (12 eyes) wore steeply fitted lenses of identical dimensions but with various numbers of 0.1-mm diameter peripheral fenestrations for 3-hr periods. At the end of the wearing periods, thickening, steepening, and central clouding of the cornea were generally reduced as the number of fenestrations was increased. However, 20 fenestrations were required before the edema was reduced to a clinically acceptable level.

Nevoxanthoendothelioma (juvenile xanthogranuloma) of the iris. Diagnosis by biopsy and treatment with x-ray.

Report of a Case This 6-month-old white girl was first seen Nov. 3, 1958. Three weeks previously the parents had noticed a yellow spot on the left iris. A few days later, fresh blood was seen on the iris. This bleeding recurred 4 days prior to examination. The past history was negative except for having been slightly premature. The birth weight was 5 lb. 3 oz. Examination revealed a yellowish-pink mass over the peripheral portion of the left iris from 3 to 6 o'clock (Fig. 1). Coagulated blood was present on the surface of the lesion. The adjacent iris was vascular and slightly greenish in color. Moderate corneal edema permitted a hazy view of an apparently normal fundus. Intraocular tension measured 27 mm. Hg (Schiotz, 1955). Gonioscopy showed flocculent tumor tissue spread along the angle, over the surface of the lens, and on the back of the cornea. The right