Intraoperative enoxaparin minimizes inflammatory reaction after pediatric cataract surgery

Double trouble in DMEK surgery: Learning experience and review of the literature

PURPOSE

To report a challenging Descemet Membrane Endothelial Keratoplasty (DMEK) case, complicated by intraoperative aqueous misdirection and spontaneous anterior chamber fibrin reaction.

METHODS

A 70-year-old female affected by corneal edema due to Fuchs endothelial dystrophy underwent a triple procedure (cataract extraction - IOL implantation - DMEK surgery) in her left eye. This report illustrates the management of the intraoperative complications of aqueous misdirection syndrome and anterior chamber fibrin reaction.

RESULTS

Despite the optimal management of the posterior pressure and the thorough removal of the fibrinous reaction during the case, the DMEK graft was not completely unfolded and centred at the end of the surgical procedure. Nonetheless, the patient showed good long-term anatomical and functional recovery: at the last follow-up (2 years after surgery), central corneal thickness was 526 µm with a best corrected visual acuity of 20/25 and an endothelial cell density of 1112 cell/mm2.

CONCLUSION

Early recognition and prompt management of intraoperative aqueous misdirection syndrome and anterior chamber fibrin reaction during DMEK surgery is essential to ensure good functional and anatomical outcomes.

Use of ultrasound biomicroscopy to predict the outcome of anterior segment reconstruction in congenital fibrovascular pupillary membrane with secondary glaucoma

AIMS

To evaluate the efficacy and safety of anterior segment reconstruction (ASR) in congenital fibrovascular pupillary membrane-induced secondary glaucoma (CFPMSG) basing ultrasound biomicroscopy (UBM) classification.

METHODS

This ambispective cohort study enrolled patients with CFPMSG who underwent ASR between January 2014 and September 2020. Comprehensive ophthalmic examinations and UBM were performed before surgery and postoperatively. The patients were classified into three types according to the UBM configurations. Anterior chamber recovery (ACR) was defined as deepening in anterior chamber (≥1.5 mm all through final follow-up (FFU), while success following ASR was defined as ACR and intraocular pressure (IOP)≤21 mm Hg.

RESULTS

25 eyes of 25 patients underwent ASR (average age at operation 5.8±5.0 months, 48% girls) with FFU 15.8±16.9 months. Enrolled subjects were classified into type Ⅰ (11 eyes), type Ⅱ (11 eyes) and type Ⅲ (3 eyes). After ASR, 23 eyes (92%) achieved ACR, and the mean ACD increased in all groups (p=0.006, <0.001 and 0.003, respectively). Eyes with types Ⅰ and Ⅱ demonstrated a reduction of IOP (p=0.009 and 0.002, respectively). ASR success rate was highest in type Ⅰ (72.9%) compared with types Ⅱ and Ⅲ (18.2% and 0%, respectively; p=0.011). ASR led to decreased number of antiglaucoma medications for type Ⅰ CFPMSG at FFU (p=0.016). No vision-threatening postoperative complications occurred.

CONCLUSIONS

ASR for CFPMSG results in increased ACD and improvement in IOP. Postoperative IOP control was best in type Ⅰ CFPMSG but not as effective in types Ⅱ and Ⅲ. UBM-based classification helps to predict the surgical outcome of ASR in CFPMSG.

Treatment of visual axis opacification and secondary membranes with Nd:YAG laser after pediatric cataract surgery under intranasal sedation

Purpose

To describe neodymium-doped yttrium-aluminum-garnet (Nd:YAG) laser treatment of visual axis opacification and secondary membranes in pediatric patients with cataracts under intranasal dexmedetomidine sedation.

Methods

Twenty eyes of 17 patients with secondary membrane formation after cataract extraction were enrolled in this study. Intranasal dexmedetomidine sedation (3 ug/kg) was administered, and Nd:YAG laser (Ellex Super Q, Adelaide, Australia) procedures were performed with children in the sitting position with their chin supported on a laser delivery slit lamp. Preoperative and postoperative visual acuities were documented, and medical records were reviewed.

Results

The age of the patients ranged from 5 to 83 months (31.82 ± 27.73). Nineteen (95.0%) eyes had congenital cataracts and one (5.0%) had a traumatic cataract. Nd:YAG laser treatment of VAO with ten (50.0%) eyes, pupillary membranes with three (15.0%) eyes, pupillary cortical proliferation with six (30.0%) eyes, and anterior capsule contraction with one (5.0%) eye. Five (25.0%) eyes demonstrated visual acuity improvement, whereas six (30.0%) eyes remained unchanged after laser treatment. The recurrence rate was 30.0% and four eyes underwent a second Nd:YAG membranectomy. No side effects or tolerances due to sedative drugs were observed.

Conclusion

Nd:YAG laser membranectomy under intranasal dexmedetomidine sedation was safely performed in children as young as 5 months old in a sitting position. This approach facilitates patient convenience, doctor proficiency, and cost reductions. Patients with recurrence can be treated by repeating the procedure.

Characterization of postoperative "fibrin web" formation after canine cataract surgery

PURPOSE

To describe the occurrence and associated factors for "fibrin web" (FW) formation following phacoemulsification in dogs.

METHODS

A retrospective review of medical records of all dogs undergoing phacoemulsification (MU-Veterinary Health Center, 2014-2018) was conducted to associate FW formation with signalment, systemic co-morbidities, cataract stage, surgeon (resident vs faculty), phacoemulsification time, IOL, and intracameral injections including viscoelastic type. Both univariate and multivariate statistical analyses were performed to evaluate associations among variables with FW formation.

RESULTS

Data from 398 eyes on 201 dogs were included; 4 left eyes (4 dogs) developed presumptive endophthalmitis and were excluded from further analysis. Forty-eight eyes did not have cataract surgery. Hence, 350 eyes on 201 dogs were included in the analyses. Among these, 84 eyes (59 dogs) developed a FW. Univariate analyses showed that the odds of FW increased with age and phacoemulsification time. Additionally, FW web was associated lens type, lens brand, and viscoelastic type. Multivariate analyses showed that when comparing lens types in combination with a particular viscoelastic, viscoelastic impacted the estimated prevalence of FW formation the most. In contrast, when the data were analyzed by lens brand, lens brand impacted prevalence more than viscoelastic type. Diabetes mellitus was not associated with FW formation.

CONCLUSIONS

Based on the available data, intraocular lens implantation, viscoelastic type, dog age, and phacoemulsification time were associated with FW formation. Diabetes mellitus, gender, cataract stage, surgeon, intracameral injections other than viscoeleastic, and intra- and postoperative complications were not associated with FW formation.

Intraoperative fibrin formation during Descemet membrane endothelial keratoplasty

Purpose

To describe Descemet membrane endothelial keratoplasty (DMEK) cases complicated by spontaneous intraoperative fibrin formation.

Methods

DMEK surgeries performed at two centers using a standardized technique were reviewed retrospectively for the occurrence of intraoperative fibrin formation. Cases were assessed for recipient medical history, donor age, best spectacle-corrected visual acuity (BSCVA), intraoperative unscrolling time, 6-month endothelial cell loss (ECL), and the course of the mate donor cornea.

Results

In this review of 868 cases of standardized DMEK surgery with surgical peripheral iridotomy, 32 eyes of 29 patients (3.7%) were complicated by the formation of intraoperative fibrin formation, including 3 patients that developed fibrin in both eyes. Three of the 32 grafts failed (9.4%). None of the mate corneas transplanted (n = 27) developed complications related to fibrin. The donor age ranged from 51 to 75 years and recipient age ranged from 49 to 82 years (median, 66 years). Unscrolling time ranged from 1 to 105 min (median, 15 min). Nine eyes required one rebubble procedure. No eyes had vision-limiting comorbidities, and the 6-month BSCVA was ≥20/40 in all eyes. Six-month ECL ranged from 19% to 73% (median, 44%).

Conclusions

We conclude that fibrin formation during DMEK surgery is an uncommon but important complication that can make graft manipulation more difficult, and may have deleterious effects on endothelial cell density and graft survival.

Neutrophil extracellular traps (NETs) contribute to pathological changes of ocular graft-vs.-host disease (oGVHD) dry eye: Implications for novel biomarkers and therapeutic strategies

PURPOSE

To investigate the role of neutrophil extracellular traps (NETs) and NET-associated proteins in the pathogenesis of oGVHD and whether dismantling of NETs with heparin reduces those changes.

METHODS

Ocular surface washings from oGVHD patients and healthy subjects were analyzed. Isolated peripheral blood human neutrophils were stimulated to generate NETs and heparinized NETs. We performed in vitro experiments using cell lines (corneal epithelial, conjunctival fibroblast, meibomian gland (MG) epithelial and T cells), and in vivo experiments using murine models, and compared the effects of NETs, heparinized NETs, NET-associated proteins and neutralizing antibodies to NET-associated proteins.

RESULTS

Neutrophils, exfoliated epithelial cells, NETs and NET-associated proteins (extracellular DNA, Neutrophil Elastase, Myeloperoxidase, Oncostatin M (OSM), Neutrophil gelatinase-associated lipocalin (NGAL) and LIGHT/TNFSF14) are present in ocular surface washings (OSW) and mucocellular aggregates (MCA). Eyes with high number of neutrophils in OSW have more severe signs and symptoms of oGVHD. NETs (and OSM) cause epitheliopathy in murine corneas. NETs (and LIGHT/TNFSF14) increase proliferation of T cells. NETs (and NGAL) inhibit proliferation and differentiation of MG epithelial cells. NETs enhance proliferation and myofibroblast transformation of conjunctival fibroblasts. Sub-anticoagulant dose Heparin (100 IU/mL) dismantles NETs and reduces epithelial, fibroblast, T cell and MG cell changes induced by NETs.

CONCLUSION

NETs and NET-associated proteins contribute to the pathological changes of oGVHD (corneal epitheliopathy, conjunctival cicatrization, ocular surface inflammation and meibomian gland disease). Our data points to the potential of NET-associated proteins (OSM or LIGHT/TNFSF14) to serve as biomarkers and NET-dismantling biologics (heparin eye drops) as treatment for oGVHD.

Use of a Juvenile Rabbit Animal Model to Evaluate Therapeutic Interventions for Postoperative Inflammation and Fibrin Formation After Lensectomy

Purpose

We used the juvenile rabbit as a model for investigating therapeutic interventions for postoperative inflammation and fibrin formation following intraocular lens (IOL) insertion for management of pediatric cataracts.

Methods

Twelve 6- to 7-week-old, 600 to 900 g rabbits underwent bilateral clear-cornea lensectomy via irrigation and aspiration with IOL insertion. Following wound closure, enoxaparin 8 mg (n = 6 eyes), preservative-free triamcinolone 0.5 mg (n = 6), 8 mg enoxaparin plus 0.5 mg triamcinolone (n = 6), or balanced salt solution (n = 6) was injected into the anterior chamber. Slit-lamp examinations and optical coherence tomography (OCT) scans were performed postoperatively on days 3 through 7, and 14 to characterize levels of inflammation and fibrin. Using 17 additional rabbits, enzyme-linked immunosorbent assays (ELISAs) with 100 μL of aqueous humor were performed to quantify the amount of fibrinogen and fibrin preoperatively and on postoperative day 3. Immunohistochemistry was performed to confirm the presence of fibrin.

Results

Enoxaparin alone and combined with triamcinolone reduced the amount of fibrin present in the anterior chamber compared to untreated eyes, which corresponded to an increase in OCT signal strength. Despite the clear visual axis shown in clinical images, the combination treatment group had the highest levels of soluble fibrin when assessed by ELISA. Immunohistochemistry confirmed the presence of insoluble fibrin seen clinically.

Conclusions

A combination of enoxaparin and triamcinolone appears to provide the most therapeutic benefit by reducing fibrin formation and postoperative inflammation.

Translational Relevance

The juvenile rabbit is an excellent model to investigate inflammation and fibrin formation following lensectomy with IOL insertion and possibly any intraocular surgery in children.

Diagnostic and Therapeutic Approach in a Case of Severe Post-Traumatic Hyphema with Subtotal Iridodialysis

Purpose

To report our diagnostic ultrasound-based approach and surgical strategy in a case of severe blunt trauma with complete hyphema, 270° iris disinsertion, and traumatic subluxated cataract.

Case Report

A 70-year-old male was referred to our hospital for a blunt trauma in his right eye. A complete examination revealed visual acuity consisting in light perception, a complete hyphema, and an intraocular pressure of 45 mm Hg with moderate pain. Our diagnostic approached was ultrasound based with B-scan examination showing some vitreous hemorrhage and ultrasound biomicroscopy showing a large iris disinsertion of 270° with the iris entirely dislocated in the inferior sector of the anterior chamber. The patient was hospitalized and a systemic and topical treatment was started to lower intraocular pressure. Our surgery consisted in a single-step approach with removal of traumatic cataract with scleral fixation of an intraocular lens and iridoplasty.

Conclusion

In our patient, the single-step surgery, supported by anterior and posterior ultrasound imaging, achieved a satisfactory anatomical and functional outcome.

Non-anticoagulant effects of low molecular weight heparins in inflammatory disorders: A review

Low molecular weight heparins (LMWHs) are produced by chemical or enzymatic depolymerization of unfractionated heparin (UFH). Besides their well-known anticoagulant effects, LMWHs have also been reported to exhibit numerous anti-inflammatory properties. Previous studies have, however, shown that different production processes result in unique structural characteristics of LMWHs. The structural variations may help explain the different therapeutic spectrums in disease treatment for non-anticoagulant effects. In the present review, we summarize major advances in understanding and exploiting the anti-inflammatory disorder activities of LMWHs, based on mechanistic studies, preclinical experiments and clinical trials. We highlight differences in these activities of commercially available LMWHs produced using different manufacturing processes. We stress the importance of structure-activity relationship (SAR) studies on the non-anticoagulant effects of LMWHs and discuss strategies for exploring new clinical indications.

The effects of enoxaparin on the liver in experimental pneumoperitoneum model

PURPOSE:

To investigate the potential protective effects of enoxaparin against the adverse events of carbon dioxide (CO2) pneumoperitoneum.

METHODS:

Thirty four rats were divided into three groups: Group 1 (sham) underwent insertion of Veress needle into the abdomen and 90 min of anesthesia with no gas insufflation. The animals in control and enoxaparin groups were subjected to 90 min of 14 mmHg CO2 pneumoperitoneum. Enoxaparin (100 u/kg) was administered subcutaneously to the rats in enoxaparin group one hour before the operation. After 90 min of pneumoperitoneum, the rats were allowed for reperfusion through 60 min. Blood and liver samples were obtained for biochemical and histopathological examination.

RESULTS:

Treatment with enoxaparin decreased the histopathological abnormalities when compared with the control group. The highest levels of oxidative stress parameters were found in control group. The use of enoxaparin decreased the levels of all oxidative stress parameters, but the difference between the control and enoxaparin groups was not statistically significant.

CONCLUSION:

Enoxaparin ameliorated the harmful effects of high pressure CO2 pneumoperitoneum on the liver.

The effect of enoxaparin-containing irrigation fluid used during cataract surgery on postoperative inflammation in patients with diabetes

PURPOSE

To investigate effects of enoxaparin on postoperative inflammation in patients with moderate nonproliferative diabetic retinopathy (NPDR) and nuclear cataract.

DESIGN

Prospective masked controlled trial.

METHODS

setting: Institutional practice. study population: The study included 51 eyes of 51 diabetes mellitus (DM) patients with moderate NPDR and grade 2-3 nuclear cataracts. Group 1 included randomly selected patients who received enoxaparin in balanced salt solution (BSS) during cataract surgery, while standard BSS was used in Group 2. observation procedure: Patients were followed up 1 day, 1 week, and 1 and 2 months after the surgery. main outcome measures: Anterior chamber cell and flare.

RESULTS

Postoperatively, 20 patients from Group 1 and 4 patients in Group 2 had less than a mean of 10 cells at day 1 (P = .012). At the first week, 20 patients from Group 1 and 10 patients from Group 2 had less than a mean of 10 cells (P = .004). When compared for flare, 20 patients from Group 1 and 8 patients from Group 2 had a flare between 0 and +1 at postoperative day 1 (P < .001). By the end of postoperative first week, 24 patients from Group 1and 18 patients from Group 2 had a flare between 0 and +1 (P = .012). There was no difference between groups in terms of postoperative inflammation at the first and second months after the surgery.

CONCLUSION

The results of the study suggest that enoxaparin added into the infusion fluid may reduce postoperative inflammation in patients with DM, and this result supports the anti-inflammatory effect of enoxaparin.

Effect of low molecular weight heparin (enoxaparin) on congenital cataract surgery

AIM

To assess the efficacy of intracameral enoxaparin (a low-molecular-weight heparin) infusion, in variable doses on postoperative inflammatory response in congenital cataract surgery.

METHODS

It is a prospective, randomized controlled trial. Eighty eyes of 53 children with congenital cataract were enrolled in this study. Every eye had primary posterior capsulorrhexis and intraocular lens (IOL) implantation after lens aspiration. The eyes were divided into 4 equal groups. In group 1 balanced salt solution (BSS) without enoxaparin was used as an irrigation solution. Whereas in group 2, 3 and 4, 40mg, 20mg and 10mg enoxaparin in 500mL BSS was used respectively. The inflammatory response in the anterior chamber was compared among the groups with slit-lamp biomicroscopy.

RESULTS

The mean follow-up period was (17.75±3.95) months in group 1, (18.00±5.15) months in group 2, (19.20±5.47) months in group 3 and (18.65±5.16) months in group 4. Mean number of inflammatory cells in the anterior chamber in group 1 was significantly higher than that of group 2, 3, 4 (P<0.001). There was fibrin formation in the anterior chambers of 3 eyes in group 1 and one eye in group 4. There was synechiae formation in 3 eyes of group 1 and one eye of group 4. There was no significant difference among the groups by means of fibrin or synechiae formation (P>0.05). There were IOL precipitates in 4 eyes of group 1 and 2 eyes of group 4. IOL precipitate formation was significantly higher in group 1 than that of group 2 and 3 in which there was no IOL precipitate (P=0.048). There was IOL subluxation in only one eye of group 1, 3 and 4 while no subluxation was observed in group 2 (P>0.05). There was no statistically significant difference detected about IOL subluxation occurance in all 4 groups (P>0.05).

CONCLUSION

Complications of cataract surgery in congenital cataract patients associated with postoperative inflammatory response found to be decreased with the use of enoxaparin in intraocular infusion solutions. Furthermore according to our results the anti-inflammatory effect of enoxaparin was dose dependant.

Anti-inflammatory effect of low-molecular-weight heparin in pediatric cataract surgery: a randomized clinical trial

PURPOSE

To determine if intraocular infusion of low-molecular-weight heparin (enoxaparin) reduces postoperative inflammation in pediatric eyes undergoing cataract surgery with IOL implantation.

DESIGN

Prospective masked randomized controlled trial.

METHODS

setting: Private, institutional practice. study population: Twenty children (40 eyes) undergoing bilateral cataract surgery with IOL implantation were randomized to receive enoxaparin in the intraocular infusion fluid (BSS) (Group I) or not to receive enoxaparin (Group II). The first eye was randomly assigned to 1 of the 2 groups and the second eye received alternate treatment. observation procedure: Patients were followed up in the first week and 1 and 3 months after surgery. main outcome measures: Anterior chamber flare and cells (Hogan's criteria), cell deposits on IOL, posterior synechiae.

RESULTS

One week postoperatively, no eyes had >grade 2 flare/cells. Proportion of eyes with grade 2 cells was higher in eyes that did not receive enoxaparin (Group II: 80% vs Group I: 40%, P = .009). In the first week >10 small cell deposits were noted in the eyes that received enoxaparin (Group I: 20%, Group II: none, P = .005). Large cell deposits first appeared at 1 month in 40% of eyes in Group I and 55% of eyes in Group II (P = .34) and increased at 3 months (60% in both groups, P > .999). Posterior synechiae were seen in 10% of eyes in Group I at 1 month, which persisted at 3 months; no eyes in Group II showed posterior synechiae (P = .14).

CONCLUSION

The results of our study suggest that there does not seem to be a benefit of using enoxaparin in the infusion fluid with respect to early postoperative inflammation.

Effect of intracameral cefuroxime on fibrinous uveitis after pediatric cataract surgery

PURPOSE

To determine whether intracameral cefuroxime reduces postoperative fibrin formation after pediatric cataract surgery.

METHODS

Children aged 3 months to 10 years with bilateral congenital or developmental cataracts who underwent surgery between February and July 2008 were eligible for inclusion in this prospective double-masked study. The same surgical technique was used in each eye. The intraocular lens was placed in either the bag or sulcus in both eyes. The same intraocular lens type was used in both eyes (polymethylmethacrylate). One eye was randomized to receive intracameral cefuroxime at the end of surgery and the fellow eye received saline. The surgeon was masked to the treatment assignment. The amount of fibrin formation in the anterior chamber of each eye was assessed by a masked grader on the fourth postoperative day.

RESULTS

Seventy eyes of 35 children were included in the study. Fibrin formation was noted on the fourth postoperative day in 14 of 70 eyes (20%), 7 in the cefuroxime group and 7 in the saline group. The mean fibrin score was 0.57 ± 1.31 in the cefuroxime group and 0.49 ± 1.07 in the saline group. There was no statistically significant difference in the amount of fibrin formation between groups (P = .857, Wilcoxon ranked signs test).

CONCLUSION

Intracameral cefuroxime did not significantly reduce postoperative fibrin formation in this study. Fibrin formation does not appear to be due to bacterial contamination in most cases of pediatric cataract surgery.

The effect of low molecular weight heparin (dalteparin) on duration and initiation of labour

It has recently been reported that women treated with low molecular weight heparin (LMWH) during pregnancy had 3 h shorter duration of delivery. The aim of the present study was to evaluate whether LMWH (dalteparin) affects labour. From January 1996 to December 2005, 217 consecutive pregnancies, out of 34 216 newborn (prevalence 0.6%) that were given thromboprophylaxis with dalteparin (usually 5,000 IU once daily). These 217 consecutive pregnancies were compared to an unselected control group (n = 1,499) of gravidae. Main outcome was time in first and second stage of labour and gestational age at delivery. Among nulliparous women, there were significantly fewer women with prolonged first stage of labour as compared to controls (4.1% vs. 8.5%, P = 0.047). In addition, the duration of first stage of labour was 1 h shorter among those treated with LMWH (5.2 vs. 6.2 h, P = 0.06). There were no such differences among parous women. The risk of prematurity, profuse blood loss, and postpartum anaemia was almost doubled among those treated with LMWH (11.5% vs. 5.9%, P = 0.002, 10.6% vs. 5.9%, P < 0.001, and 12.9% vs. 8.7%, P = 0.048, respectively). Treatment with a prophylactic dose of LMWH (dalteparin) during pregnancy was related to fewer women with prolonged first stage of labour, but also to an increased risk of prematurity and blood loss complications.

Successful treatment of ligneous conjunctivitis with topical cyclosporine and heparin

Ligneous conjunctivitis is a rare disease characterized by wood-like pseudomembranes developing on the ocular and extraocular mucosae. We present a case of ligneous conjunctivitis and cataracts in a 10-year-old boy with a positive family history of the disease and consanguinity. His condition was managed with topical cyclosporine, heparin, and steroids.

Effect of heparin in the intraocular irrigating solution on postoperative inflammation in the pediatric cataract surgery

Purpose:

To evaluate the influence of irrigation of the anterior chamber with heparin sodium on postoperative inflammation after pediatric cataract surgery.

Setting:

Kartal Training and Research Hospital, First Eye Clinic, Istanbul, Turkey.

Design:

Randomized prospective double-blind study.

Methods:

Fourteen consecutive eyes from 14 patients aged 8.9 ± 5.9 years, (range 3–18 years) (group 1) and 19 eyes from 19 patients aged 9.1 ± 5.2 (range 1.5–18 years) (group 2) underwent pediatric cataract surgery. Five patients in group 1 were between three and five years old. One patient was 1.5 years old and six patients in group 2 were between three and five years old. During the procedure, group 1 received anterior chamber irrigation with heparin sodium (5 IU/cc) and 1 ml of heparin sodium (concentration 10 IU/ml) added to the irrigating balanced salt solution (BSS Plus; Alcon Laboratories, Inc., Fort Worth, TX, USA) while group 2 received BSS without heparin sodium only. Cases aged under three years received anterior vitrectomy in addition to posterior capsulorrhexis. One eye received anterior vitrectomy in group 1 and two eyes received anterior vitrectomy in group 2. Cases with preoperative complications were not included in the study. Early and late postoperative inflammatory complications, including fibrin formation, anterior and posterior synechia, cyclitic and pupillary membrane formation were recorded and compared.

Results:

Mild anterior chamber reaction was observed in three patients in Group 1, while nine cases in group 2 experienced marked anterior chamber reaction. In four of nine patients from group 2, anterior chamber reaction was severe and resulted in pupillary membrane and synechia despite treatment in the postoperative 7th day, while in all three cases in group 1, reaction disappeared by the 7th day.

Conclusion:

Anterior chamber irrigation with heparin during pediatric cataract surgery may minimize early inflammatory reaction and decrease the number of postoperative inflammatory related complications.

Emmetropization and eye growth in young aphakic chickens

PURPOSE

To establish a chick model to investigate the trends of eye growth and emmetropization after early lensectomy for congenital cataract.

METHODS

Four monocular treatments were applied: lens extraction (LX); sham surgery/-30 D lens; LX/+20 D lens; and LX/+30-D lens (nine per group). Lens powers were selected to slightly undercorrect or overcorrect the induced hyperopia in LX eyes and to induce comparable hyperopia in sham-surgery eyes. Refractive errors and axial ocular dimensions were measured over a 28-day period. External ocular dimensions were obtained when the eyes were enucleated on the last day.

RESULTS

The growth patterns of experimental (Exp) eyes varied with the type of manipulation. All eyes experiencing hyperopia initially grew more than their fellow eyes and exhibited myopic shifts in refraction. The sham/-30 D lens group showed the greatest increase in optical axial length, followed by the LX group, and then the LX/+20 D lens group. The Exp eyes of the LX/+30 D lens group, which were initially slightly myopic, grew least, and showed a small hyperopic shift. Lensectomized eyes enlarged more equatorially than axially (i.e., oblate), irrespective of the optical treatment applied.

CONCLUSIONS

The refractive changes observed in young, aphakic eyes are consistent with compensation for the defocus experienced, and thus emmetropization. However, differences in the effects of lensectomy compared to those of sham surgery raise the possibility that the lens is a source of essential growth factors. Alterative optical and mechanical explanations are offered for the oblate shapes of aphakic eyes.

Enoxaparin does not ameliorate limb ischemia-reperfusion injury

OBJECTIVE

Since low molecular weight heparin has greater bioavailability and sustained serum levels in vivo than unfractionated heparin, it has been used to supplant unfractionated heparin to achieve therapeutic anticoagulation in humans. These studies were designed to determine whether treatment with enoxaparin could protect murine skeletal muscle from ischemia reperfusion injury.

METHODS

C57BL6 mice were divided into four groups. Sham control animals underwent 90 min of anesthesia alone. All other groups underwent 90 min of unilateral hindlimb ischemia. At the onset of reperfusion, animals received either normal saline (control and saline) or 4 mg/kg of enoxaparin subcutaneously twice daily. Groups were followed for 24 or 48 h reperfusion. Hindlimb skeletal muscle blood flow was measured by laser Doppler, and muscle was removed for histological and protein analysis. Tissue thrombosis was evaluated by thrombin antithrombin III (TAT III), local inflammation by measurement of proinflammatory cytokines (macrophage inflammatory protein-2: MIP-2, monocyte chemoattractant protein-1: MCP-1), and neutrophil infiltration by myeloperoxidase (MPO) using enzyme-linked immunosorbent assay. Plasma levels of Factor Xa were measured during reperfusion to confirm therapeutic levels of anticoagulation. Comparisons were calculated using analysis of variance.

RESULTS

At 24 h reperfusion, there was increased expression of MIP-2, MCP-1, MPO, and TAT III in saline and enoxaparin treated mice compared with control (*P < 0.05). By 48 h reperfusion, all parameters measured remained greater than control except for the enoxaparin treated mice whose TAT III levels were significantly less than untreated mice (P < 0.05). Despite documented therapeutic anticoagulation and decreased levels of markers of thrombosis in enoxaparin treated mice, there was no difference in tissue cytokines, inflammatory markers, degree of muscle fiber injury (31% +/- 8% versus 30% +/- 5%) or muscle flow between ischemia-reperfusion groups (2447 +/- 141 versus 2475 +/- 74 flux units) at 48 h reperfusion.

CONCLUSIONS

Post hoc administration of enoxaparin did not affect local tissue thrombosis, inflammatory markers, or muscle necrosis. This suggests that despite its potent in vivo activity, enoxaparin did not modulate skeletal muscle injury, thrombosis, or inflammatory following ischemia reperfusion. enoxaparin may not be useful in mediating skeletal muscle injury when administered in a clinically relevant scenario.

Effect of a Low Molecular Weight Heparin Molecule, Dalteparin, on Cellular Apoptosis and Inflammatory Process in an Incisional Wound-Healing Model

PURPOSE

In this study we aimed to test the effect of a low molecular weight heparin molecule, namely dalteparin, on the inflammation and cellular apoptosis in an incisional wound-healing model in rats.

METHODS

Eighteen male Sprague-Dawley rats were randomly assigned to three groups (n = 6 for each group). Two full-thickness skin incisions were made over cervical and lumbar regions of all rats. Group 1 (sham group) received no treatment, group 2 (control group) received 0.01 ml/g saline subcutaneously 12 h two times daily from 0 to 10th postoperative day, and group 3 (dalteparin group): received 1 IU/g dalteparin subcutaneously two times daily from 0 to 10th postoperative day. A histological evaluation was done by light microscopy. Apoptosis was detected immunohistochemically by anti-poly (ADP-ribose) polymerase p85 fragment pAb.

RESULTS

The early inflammatory response and related tissue edema were depressed on day 3 in the dalteparin group when compared with those in the other groups (P < 0.05). Fibroblast proliferation was also depressed on day 10 in the dalteparin group compared to the others (P < 0.05). Furthermore, increased apoptosis was detected in the dalteparin group both on day 3 and day 10.

CONCLUSION

Our results showed that dalteparin may adversely affect the incisional wound healing by suppressing the early inflammatory process and increasing cellular apoptosis; however, further studies are warranted to confirm the results.

Inhibition of intraocular fibrin formation after infusion of low-molecular-weight heparin during combined phacoemulsification–trabeculectomy surgery

PURPOSE

To evaluate the effect of intraocular infusion of dalteparin, a low-molecular-weight heparin (LMWH) administered in the infusion fluid to prevent early postoperative fibrin formation in combined phacoemulsification-trabeculectomy surgery (phacotrabeculectomy).

SETTING

Farabi Eye Hospital, Tehran, Iran.

METHODS

Standard combined phacotrabeculectomy was performed prospectively in a masked fashion in 60 eyes; 35 eyes received 5 IU/mL LMWH in the infusate and 25 eyes served as controls. Masked postoperative examinations assessed visual acuity, intraocular pressure (IOP), anterior chamber cell and flare, and fibrin formation with slitlamp examinations 1, 3, 7, 30, and 90 days after surgery.

RESULTS

The rate of intraocular fibrin/membrane formation was significantly lower in the LMWH group than in the control group at each follow-up (P<.001, Student t test) . The amount of IOP was lower in LMWH group at each follow up (P<.01, Student t test). Final visual acuity was better in LMWH group (P = .03, Student t test). The frequency of synechia formation was lower in the LMWH group on day 90 (P = .002, chi-square test).

CONCLUSIONS

Infusion of dalteparin, a LMWH, may be an effective inhibitor of postoperative fibrin formation in phacotrabeculectomy surgery. It may reduce the frequency of synechia formation and improve visual acuity. It may not be associated with increased risk for intraoperative or postoperative complications at the tested dose. This drug may be a useful adjunct in combined surgery.