Effects of irrigation solutions on corneal endothelial function

Effect of Irrigation Solution Temperature on the Corneal Endothelial Functions in Posterior Vitrectomy: Room Temperature Versus Cooled

PURPOSE

To compare the effects of cooled and room temperature irrigation on the preoperative and early postoperative corneal endothelial parameter values in posterior vitrectomy.

MATERIALS AND METHODS

In this prospective, randomized, comparative study, 68 patients underwent a standard 3-port, 23-G posterior vitrectomy operation by a single surgeon. Cooled irrigation solution was applied to 36 patients during surgery (group 1), and room temperature irrigation solution was applied to 32 patients (group 2). The patients were also divided into four groups according to their history of noncomplicated cataract surgery (phakic or pseudophakic) and the types of tamponade used (silicone or gas). The central corneal thickness (CCT), endothelial cell density (ECD), mean cell area (MCA), hexagonal cell percent, and coefficient of variation of cell area (CV) parameter values of the groups at preoperative and postoperative 1 month were compared.

RESULTS

There were no statistically significant differences between the preoperative and postoperative corneal parameter values in groups 1 and 2 ( P >0.05). However, it was remarkable that the percentage of preoperative-postoperative change in all the corneal parameter values was higher in group 2. When the results of the subgroup analyses of the patients who were pseudophakic and used gas tamponade (Group D) in group 2 were examined, it was determined that the negative effects were significantly higher in the postoperative values for the ECD, MCA, CV, and CCT parameters compared with the preoperative values ( P <0.05).

CONCLUSION

In patients with pseudophakia and gas tamponade, cooled irrigation was found to be more advantageous for corneal parameters.

Subpalpebral Antibiotic Lavage as Safe, Emergent, and Cost-Effective Management of Acute Infectious Keratitis Related to Contact Lens Overwear: Case Report and Literature Review

PURPOSE

The aim of this study is to describe the technique of subpalpebral antibiotic lavage (SAL), which is a highly therapeutic, efficient, and cost-effective method for managing severe bacterial keratitis.

METHODS

This case report describes a 26-year-old woman with severe bacterial keratitis in the right eye due to contact lens overwear, with progressive corneal thinning, a hypopyon, impending perforation, and marked visual loss to perception of light despite treatment with intensive topical antibiotics. This was managed with SAL that involves the insertion of a cannula transcutaneously into the upper conjunctival fornix to provide continuous antibiotic irrigation of the ocular surface.

RESULTS

By 11 weeks after presentation, the cornea and anterior chamber appeared clinically quiescent, and visual acuity improved to 20/40 corrected in the right eye.

CONCLUSIONS

Bacterial keratitis is a potentially blinding condition for which contact lens wear is an important risk factor. Most cases are successfully managed with topical medications; however, in cases of treatment failure, a second-line approach such as SAL can be sight-saving. SAL uses readily available equipment for the delivery of high concentrations of antibiotics to the ocular surface, thus increasing therapeutic efficacy and reducing nursing staff workload. Despite its advantages, the literature reveals apparent underutilization of this technique.

Evaluation of limbal and pars plana silicone oil removal in aphakic eyes

PURPOSE

To compare limbal and pars plana silicone oil removal (SOR) in aphakic eyes and to evaluate the acute effect of silicone oil flow to the corneal endothelium.

METHODS

Sixteen aphakic patients with silicone oil endotamponade requiring SOR were recruited for this prospective study and randomly scheduled for limbal or pars plana SOR. The central corneal thickness (CCT), visual acuity (VA) and intraocular pressure were measured preoperatively, on the first postoperative day and 4 months after surgery. Endothelial cell density (ECD) was measured preoperatively and at the end of follow-up. The in vitro study was performed on ten enucleated porcine eyes. Corneoscleral discs were prepared and fixed on artificial anterior chamber followed by 2.5-mm limbal incision and 5-ml silicone oil injection in six cases and 5 ml balanced salt solution (BSS) in four cases.

RESULTS

The ECD decreased by 239.2 ± 86.7 (13.9%) and 86.7 ± 22.4 cells/mm(2) (5%) after limbal (n = 8) and pars plana SOR (n = 8), respectively (p < 0.001 for both). The difference between the groups was significant (p < 0.001). A significant increase in CCT and corresponding decrease in VA was noted on the first postoperative day using both procedures. At the end of follow-up, the CCT and VA were comparable to initial values. Postoperative hypotony (≤6 mmHg) was observed more frequently after limbal SOR. In the experiment, lamellar abrasions of corneal endothelium were observed after silicone oil injection, whereas no changes were observed after BSS injection.

CONCLUSION

Limbal SOR causes more considerable damage to the corneal endothelium than the pars plana approach because of mechanical abrasion.

Comparison of corneal changes after phacoemulsification using BSS Plus versus Lactated Ringer's irrigating solution: a prospective randomised trial

Background/aims

To compare two intraocular irrigating solutions, Balanced Salt Solution Plus (BSS Plus) versus Lactated Ringer's (Ringer), for the preservation of corneal integrity after phacoemulsification.

Methods

110 patients undergoing phacoemulsification were randomised to either BSS Plus (n=55) or Ringer (n=55) as the irrigating solution. Patients were examined at baseline and at 1, 8, 15, 30 and 60 days postoperatively. Evaluations included specular microscopy to evaluate endothelial cell density (ECD) and endothelial cell size variability (CV), and corneal pachymetry for central corneal thickness (CCT) measurement.

Results

Groups were well balanced regarding baseline ECD, CV and CCT (p>0.05). There was no statistically significant difference between ECD reduction in group BSS Plus 13.1±2.0% and Ringer 9.2±1.9% (p<0.05) at day 60 or in any study visit. There was no statistically significant difference between CV increase in group BSS Plus 23.0±3.0% and Ringer 20.2±4.0% (p<0.05) at day 60 or in any study visit. CCT was significantly increased (p<0.05) at 1, 8, 15 and 30 days postoperatively, returning to baseline at 60 days in both groups. There was no significant difference in CCT increase in both groups at any visit. Interestingly, there were statistically significant correlations between ECD loss and phacoemulsification time (p<0.0001) and ECD loss and irrigation solution volume (p<0.0001) in the Ringer group, but not in the BSS Plus group.

Conclusions

Ringers solution was similar to BSS Plus for corneal preservation in atraumatic cataract surgery. However, our study demonstrates that there is a trend towards lower postoperative endothelial cell density for surgeries with longer phacoemulsification time and higher irrigation volumes if Ringer is used.

Trial registration number

NCT00801358.

Comparison between Ringer's lactate and balanced salt solution on postoperative outcomes after phacoemulsfication: a randomized clinical trial

Aim:

To compare the effects of balanced salt solution (BSS) and Ringer's lactate (RL) on corneal thickness, endothelial morphology, and postoperative anterior chamber inflammation in eyes undergoing phacoemulsification.

Setting:

Iladevi cataract and IOL research center, Ahmedabad, India.

Materials and Methods:

This prospective randomized study comprised 90 consecutive patients with age-related cataract who were randomly assigned to either Group 1 (n = 45) with BSS or Group 2 (n = 45) with RL. Observations made included measurement of central corneal thickness (CCT), presence of anterior chamber flare and cells, endothelial cell loss, and change in coefficient of variation (CV). Data was analyzed using Mann Whitney test and test of proportion.

Results:

Mean increase in CCT on postoperative Day 1 was 58 µm and 97 µm in Groups 1 and 2 respectively (P = 0.01). Increase in CCT at one month was 10µm and 11µm in Groups 1 and 2 respectively (P = 0.99); increase in CCT at three months was 3 µm and 6 µm in Groups 1 and 2 respectively (P = 0.86). Number of eyes with flare grades in a range of 0 to 3 was statistically higher in Group 2 on postoperative Day 1 (P = 0.004, 0.016, <0.001, 0.047 for Grade 0, 1, 2 and 3 respectively). Number of eyes with cells of Grade 3 on first postoperative day was significantly higher in Group 2 as compared to Group 1 (P = 0.004). Three months postoperatively, endothelial cell loss was 5.5% and 7.8% in Groups 1 and 2 (P = 0.21) and change in CV was 3 and 5.4 in Groups 1 and 2 (P = 0.20) respectively.

Conclusion:

BSS offers a significant advantage over RL in terms of increase in corneal thickness and postoperative inflammation on the first postoperative day in patients undergoing phacoemulsification.

Confocal microscopy imaging of the cornea in patients with silicone oil in the anterior chamber after vitreoretinal surgery

OBJECTIVE

Evaluation of corneal morphology by confocal microscopy after vitreoretinal surgery complicated by passage of silicone oil into the anterior chamber. Design Case series (case control study).

METHODS

Eight patients (eight eyes) who had undergone vitreoretinal surgery and had silicone oil in the anterior chamber but no clinically evident corneal abnormalities made up the patient group. The control group consisted of eight patients (eight eyes) who had undergone vitreoretinal surgery with application of silicone oil tamponade but who had no silicone oil clinically observable in the anterior chamber. In vivo examination of the cornea using a ConfoScan 3 (Nidek Technologies) confocal microscope equipped with the standard 40x immersion lens was performed. Central, upper, and lower parts of the cornea were assessed separately. High-magnification evaluation of the status of corneal layers and endothelial cell density in upper parts of the cornea directly in contact with silicone oil in the anterior chamber and in parts of the cornea not in direct contact with silicone oil was carried out.

RESULTS

Alterations in corneal morphology, especially in endothelium and posterior and medium stroma, were observed. In all cases, changes were more advanced in the upper part of the cornea. Endothelial cell density was significantly decreased in upper parts of the cornea.

CONCLUSIONS

In patients with silicone oil in the anterior chamber, confocal microscopy imaging reveals early morphological alterations of the cornea before their clinical manifestation.

Viscoanesthesia. Part I: toxicity to corneal endothelial cells in a rabbit model

PURPOSE

To evaluate the toxicity of a solution combining sodium hyaluronate 1.5% with lidocaine (0.5%, 1.0%, or 1.65%) to the rabbit corneal endothelium.

SETTING

Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA.

METHODS

Each rabbit cornea was excised, and the endothelium was exposed to 1 of the following solutions for 20 minutes: viscoanesthetic solution (0.5%, 1.0%, or 1.65% lidocaine in sodium hyaluronate 1.5%; 5 corneas each), sodium hyaluronate 1.5% (n = 5), balanced salt solution (BSS(R)) (n = 5), mitomycin-C 0.02% (n = 2), dextran 15% (n = 2), or distilled water (n = 2). The endothelium was then stained with trypan blue and alizarin red. Two corneas were stained immediately after excision. Cell morphology and damage to the corneal endothelium were analyzed by microscopic examination.

RESULTS

The endothelium in the corneas of the viscoanesthetic groups was comparable to that in the sodium hyaluronate 1.5% and the BSS groups and to the corneas not exposed to any solution. In some areas of the 1.0% and the 1.65% viscoanesthesia groups, the corneal endothelial cells presented irregular intercellular borders. Staining with trypan blue, which indicates cellular damage, was observed in some linear areas corresponding to corneal folds in all groups. The folds were probably caused during manipulation for corneal excision and staining. The corneal endothelium was destroyed in the mitomycin group. In the dextran and distilled-water groups, morphological alterations probably resulting from osmotic changes were observed.

CONCLUSIONS

The 3 concentrations of viscoanesthetic solutions appeared to be safe to rabbit corneal endothelium.

Effect of corneal wetting solutions on corneal thickness during ophthalmic surgery

PURPOSE

To measure the changes in corneal thickness with wetting solutions used in ophthalmic surgery.

SETTINGS

Ege University, School of Medicine, Department of Ophthalmology, Izmir, Turkey.

METHODS

Thirty-one adult pigmented rabbits that weighed about 2.5 kg each were anesthetized with pentobarbital sodium. The rabbits were randomly divided into 3 groups to receive 3 wetting solutions: Group 1, Ringer's lactate; Group 2, balanced salt solution (BSS); and Group 3, BSS with glutation (BSS Plus). The solutions were dropped on the right cornea of the rabbits at a rate of 6.0 cc in 12 minutes using an intravenous infusion pump. Corneal thickness was measured by ultrasonic pachymetry before and after the procedure, and the between-group changes in corneal thickness were compared.

RESULTS

The corneal thickness before and after the procedure was 361.27 microm +/- 19.3 (SD) and 380.00 +/- 25.0 microm, respectively, in Group 1 (P =.000); 372.10 +/- 18.8 microm and 388.60 +/- 24.1 microm, respectively, in Group 2 (P =.003); and 358.10 +/- 26.5 microm and 360.10 +/- 24.1 microm, respectively, in Group 3 (P =.316).

CONCLUSION

As a corneal wetting solution, BSS Plus resulted in significantly fewer changes in corneal thickness than Ringer's lactate or BSS. This should be considered in cases involving long intraocular surgery.

Effect of irrigating solution and irrigation temperature on the cornea and pupil during phacoemulsification

PURPOSE

To evaluate the effect of irrigation solution and temperature on pupil diameter, corneal endothelium, and corneal pachymetry during and after phacoemulsification.

SETTING

Klinik Dardenne, Bonn, Germany.

METHODS

Eighty patients who had cataract surgery by phacoemulsification were assigned to 1 of 4 cross-classified groups and had intraoperative irrigation with room-temperature or refrigerated fortified balanced salt solution (BSS Plus) or modified Ringer's solution. Pupil diameters were recorded at different stages during the surgery. Epithelial cell counts and pachymetry were determined before and 1 day after surgery.

RESULTS

The solution temperature did not affect any parameter. The type of solution did not influence endothelial cell loss; however, the solution had a significant effect on corneal pachymetry 1 day postoperatively. The corneas irrigated with BSS Plus were less swollen than the corneas irrigated with Ringer's solution. By day 14, corneal thickness was equal among all groups.

CONCLUSION

Long-term results were equally favorable in all 4 groups. However BSS Plus induced less short-term corneal swelling than Ringer's solution. From these findings, it appears that BSS Plus may decrease corneal risk in cases with compromised corneas or prolonged surgery.

The tolerability of lactated Ringer's solution and BSS plus for ocular irrigation with and without the Morgan therapeutic lens

OBJECTIVE

To evaluate two solutions, lactated Ringer's (LR) and a balanced salt solution (BSS Plus, Alcon Laboratories, Ft. Worth, TX), compared with normal saline solution (NSS), for ocular irrigation in healthy adult volunteers with and without the Morgan therapeutic lens (MTL).

METHODS

This was a prospective, double-blind, randomized study of healthy volunteers who were at least 18 years of age. Exclusion criteria included the use of analgesics within four hours of the study. A complete ophthalmologic examination was performed at baseline and at the completion of the study. Following randomization and prior to any intervention, baseline discomfort scores were obtained by means of a verbally administered, horizontal, 100-mm, unnumbered analog discomfort scale. Both eyes of each volunteer were irrigated simultaneously for 15 minutes, with additional discomfort scores being recorded every 5 minutes using the same 100-mm, unnumbered analog discomfort scale. A global evaluation to assess the method of irrigation and the solutions used for irrigation was completed by both the physician blinded to the treatment groups and the volunteers. The volunteers were continuously monitored for any adverse effects resulting from the irrigation solutions or MTL.

RESULTS

Sixty-three volunteers were recruited into the study, with 61 entered in the final analysis. Age and gender were balanced within each group. There was no significant difference in discomfort scores between the two groups; however, all discomfort scores decreased over time (p = 0.008). A lens-solution interaction was identified, with LR being the most tolerated when administered with the MTL. A statistically higher ocular pH difference was seen between the pre- and postirrigation readings for the control eye in volunteers irrigated with MTL (p = 0.046). Analysis of the global evaluations for each group revealed no difference in the distributions of physician and volunteer scores. No adverse event was reported in either group.

CONCLUSION

There does not appear to be any difference in discomfort scores between the ocular irrigation fluids when used without the MTL. Overall, the use of the MTL appears well tolerated by healthy, adult volunteers. However, there does appear to be a significant lens-solution effect on volunteers' discomfort scores, with LR having significantly lower discomfort scores when used for ocular irrigation with the MTL. The authors conclude that the use of the MTL for ocular irrigation is well tolerated and recommend using LR as the irrigation solution for maximal patient comfort.

Toxicity of Xylocaine to rabbit corneal endothelium

PURPOSE

To assess the toxicity of lidocaine hydrochloride (Xylocaine) to the corneal endothelium.

SETTING

Department of Ophthalmology, Hôtel-Dieu Hospital, Paris, France.

METHODS

Rabbit corneas were excised and the endothelium was exposed to balanced salt solution (BSS), Xylocaine 1%, or Xylocaine 5% (5 corneas/group) for 20 minutes. The endothelium was then stained with trypan blue and alizarin red, and 5 photomicrographs were taken of each cornea at a standard magnification and analyzed with a digital imaging system (Biocom 200).

RESULTS

Xylocaine solutions produced changes in endothelial cell morphology, but there was no cell staining with trypan blue. Corneas exposed to Xylocaine 5% had more marked cell alterations. Small areas of cells were lost from all 15 corneas, mainly at the periphery, but the differences among the 3 groups of corneas were not significant.

CONCLUSION

Exposure of rabbit corneal endothelium to Xylocaine solutions in vitro was not associated with trypan blue staining of endothelial cells.