Alfredo Castillo

Endothelial damage with cataract surgery techniques

Purpose: To evaluate intraoperative endothelial damage after planned extracapsular cataract extraction (ECCE) with different capsulotomy techniques and phacoemulsification. Settings: San Carlos University Hospital, Castroviejo Institute, Madrid, Spain. Methods: In this prospective, randomized study, 60 patients with senile cataract scheduled for cataract surgery were divided into three groups of 20 each: Group 1 had phacoemulsification; Group 2, planned ECCE with continuous curvilinear capsulorhexis; and Group 3, ECCE with letter‐box capsulotomy. Preoperatively and 3 months postoperatively, endothelial cell density, percentage of hexagonality, and the cell size variation coefficient were determined by contact specular microscopy; endothelial permeability was examined by anterior segment fluorophotometry and central comeal thickness, by ultrasonic pachymetry. Results were analyzed using the two‐tailed Students t‐test and analysis of variance. Results: In all three groups, endothelial permeability and cell loss increased significantly from the preoperative values, but there were no significant differences among the postoperative values. Mean cell loss was 11.8% in Group 1, 12.8% in Group 2, and 10.1% in Group 3. There were no differences between the preoperative and postoperative morphometric indexes. Postoperative pachymetric measurements were not significant. Conclusions: Endothelial response was not statistically significantly different among the surgical techniques, although endothelial damage was lower in Group 3, which could indicate a protective effect of the anterior capsule during cataract extraction. Endothelial barrier function remained disturbed despite the apparent morphological stabilization.

Peripheral melt of flap after laser in situ keratomileusis

BACKGROUND Laser in situ keratomileusis (LASIK) is an effective procedure to correct myopia. It may have complications related to the flap, such as epithelial ingrowth and stromal melt. METHODS We report on a patient who developed extensive epithelial ingrowth and partial keratolysis of the flap following LASIK. This complication was treated by lifting the flap and removing the epithelium from within the interface. RESULTS Progressive keratolysis (stromal melt) can result in irregular astigmatism and loss of vision as well as photophobia and ciliary injection. The pathogenesis is not completely understood although the epithelial ingrowth in the interface is always present, and epithelial-stromal interaction with production of proteases may be involved. CONCLUSION Epithelial ingrowth may develop in the lamellar interface after LASIK and be associated with melting of the edge of the flap. This undesirable complication can be successfully managed with early surgical removal of the epithelium and proper attachment of the flap.

Endothelial morphological and functional evaluation after cataract surgery.

Purpose To assess endothelial barrier function, morphological appearance and corneal thickness three months after cataract surgery in order to evaluate intraoperative endothelial damage. Methods Endothelial permeability was examined by fluorophotometry, and contact specular microscopy and corneal pachymetry measurements were made in 40 patients (40 eyes) with senile, non-complicated cataracts one month before and three months after cataract surgery. Twenty eyes underwent uneventful phacoemulsification (Group 1) and 20 uneventful extracapsular cataract extraction (ECCE) with continous curvilinear capsulotomy (Group 2). Results were analyzed using the two-tailed Students t test, analysis of variance, and multifactorial and regression analysis. Results There was a significant postoperative increase in endothelial permeability in both groups (p<0.001), but no real differences between the postoperative values (p=0.07). Mean cell loss was 15.2% in ECCE and 18.3% in phacoemulsification (p=0.4). There was a significant linear correlation between ultrasound time, cell loss and functional damage. Postoperative pachymetric measurements were not significant. Conclusions Endothelial response showed no differences between the surgical techniques. Endothelial barrier function remained disturbed in spite of the apparent morphological stabilization. Corneal pachymetry is not useful for assessing postoperative endothelial changes.

Circadian IOP-lowering efficacy of travoprost 0.004% ophthalmic solution compared to latanoprost 0.005%

ABSTRACT Purpose: The primary objective of this study was to determine the intraocular pressure- (IOP) lowering efficacy over two consecutive 24-h periods of travoprost 0.004% ophthalmic solution (Travatan†) compared to latanoprost 0.005% (Xalatan†) dosed once daily in patients with primary open-angle glaucoma or ocular hypertension. † Travatan is a registered trademark of Alcon Laboratories Inc., Fort Worth, TX, USA ‡ Xalatan is a registered trademark of Pfizer Inc., New York, NY, USA Methods: This was a double-masked trial conducted at the Hospital Clínico San Carlos, Madrid, Spain. The primary objective of this study was to determine the IOP lowering efficacy of travoprost and latanoprost. During the eligibility visit, patients’ IOP was measured throughout two consecutive 24‐h periods every 4 h. Patients were then randomized to travoprost or latanoprost (one drop at 8 p.m. daily for 2 weeks). Sixty-two patients were randomized (travoprost n = 32; latanoprost n = 30). IOP was measured at week 2 every 4 h throughout two 24‐h periods. All measurements were taken in both supine and sitting positions with the aid of Perkins applanation tonometry. Limitations of the study include a small sample size (due to the difficulty in recruiting patients in a study of this type) which enrolled only Caucasian patients and a short study duration. However, with 25 subjects per group, there was at least 90% power to detect a mean IOP change from baseline of 2.9 mmHg and 80% power to detect a difference of 2.5 mmHg between treatments. Results: Patients on travoprost therapy showed lower mean IOP levels than those on latanoprost. This difference was statistically significant ( p < 0.05) at 12, 16, 20, 24, 36, 40, and 48 h after the last dose for the supine position. The mean IOPs in the supine position throughout the first and the second 24‐h period of the week 2 visit as well as for the 48‐h visit were statistically lower ( p < 0.05) for the travoprost group. Adverse events were mild and included hyperemia and corneal staining. Travoprost and latanoprost were both well tolerated. Conclusion: Mean IOP values were significantly lower for patients on travoprost for the majority of time points in the supine position.

Concomitant administration of travoprost and brinzolamide versus fixed latanoprost/timolol combined therapy: three-month comparison of efficacy and safety

SUMMARY Purpose: To compare the efficacy and safety of the concomitant administration of travoprost 0.004% once daily and brinzolamide 0.1% twice daily with those of a fixed combination of latanoprost 0.005%/timolol 0.5% once daily. Research, design and methods: Forty-four patients with primary open-angle glaucoma or ocular hypertension with elevated IOP insufficiently responsive to monotherapy were randomly assigned to one of the two treatment groups: concomitant administration of travoprost 0.004% once daily and brinzolamide 0.1% twice daily (TB group: 22 patients) or latanoprost 0.005% plus timolol 0.5% once daily (LT group: 22 patients). Visits were undertaken at screening (current ocular hypotensive therapy was discontinued), baseline (randomization), and after 2 weeks, 1 month, 2 months and 3 months of therapy. Main outcome measures: IOP was determined at 9 a.m., 12 p.m. and 4 p.m. at each study visit, and diurnal IOP was calculated as the mean of these recordings. Adverse events were recorded at each visit. Results: IOP at the baseline visit was similar in both groups. Overall mean IOP was significantly lower in the TB as compared to the LT group after 1 month, 2 month and 3 month follow-up; only 9 a.m. measurements were significantly different, reaching a maximum difference (16.9 ± 0.9 mmHg vs 18.4 ± 1.8 mmHg, p < 0.001) at the 3 month check. The percentage of responders (IOP decrease ≥ 30%) was higher in the TB group. Both treatments were well tolerated and there were no cases of withdrawal from treatment. Conclusions: Travoprost 0.004% and brinzolamide 0.1% concomitant therapy showed a greater efficacy than the fixed latanoprost 0.005%/timolol 0.5% combination in terms of absolute IOP decreases. Travoprost/brinzolamide therapy also offered the advantages of a greater percentage of responders.

Management and Treatment of Central Steep Islands after Excimer Laser Photorefractive Keratectomy

BACKGROUND Permanent central steep islands are an undesirable phenomenon that cause distorted images and a significant reduction in visual acuity. We describe treatment of central steep islands with repeat excimer laser photoablation in the central cornea. METHODS Three patients with preoperative refractions of -7.50 -2.50 x 170 degrees D (right eye), -8.00 -2.25 x 10 degrees D (right eye) and -6.00 -1.50 x 90 degrees (right eye) developed central steep islands which persisted more than 12 months. All patients lost more than two lines of spectacle-corrected visual acuity and complained of visual disturbances. We retreated the central steep islands with a VISX 20/20 excimer laser PRK ablation that matched the size of the central island measured on videokeratography. RESULTS Symptomatic glare and distortion were significantly reduced and the central steep islands were resolved. Several weeks after reablation, spectacle-corrected visual acuity improved to the preoperative level. CONCLUSION Central steep island, an infrequent complication of excimer laser photorefractive keratectomy, can be safely removed with a repeat laser ablation that matches the central circular steep area.

Impact of intraocular pressure after filtration surgery on visual field progression in primary open-angle glaucoma.

Purpose. To compare visual field progression after trabeculectomy in eyes showing a postoperative intraocular pressure (IOP) less than or equal to 16 mmHg and eyes with an IOP of 17 to 21 mmHg. Methods. A retrospective cohort study design was used. A total of 101 eyes of 101 consecutive patients undergoing trabeculectomy for primary open-angle glaucoma (POAG) with a postoperative IOP less than or equal to 21 mmHg were divided into two groups: Group 1 included eyes showing a postoperative IOP less than or equal to 16 mmHg at all visits and Group 2 included eyes with a postoperative IOP between 17 and 21mmHg. In turn, each of these groups was divided into two subgroups according to whether treatment was required for IOP control. Glaucomatous visual field control during follow-up was compared between the subject groups. Results. Kaplan-Meier analysis revealed glaucomatous visual field control in 98.53% of the eyes in Group 1 and 89.06% of those in Group 2 at 5 years, the difference between the groups being significant. Conclusions. Glaucomatous disease progression is less frequent when IOP is less than or equal to 16 mmHg in all the follow-up visits after trabeculectomy. The results indicate a definite benefit of low IOP in visual field control.

Laser in situ keratomileusis enhancement after photorefractive keratectomy

OBJECTIVE To describe the safety, effectiveness, and predictability of laser in situ keratomileusis (LASIK) for correcting residual myopia after primary photorefractive keratectomy (PRK). DESIGN A retrospective, noncomparative case series. PARTICIPANTS AND INTERVENTION Thirty-six consecutive eyes of 30 patients underwent LASIK after primary PRK. A Multiscan Schwind excimer laser was used for LASIK enhancement. MAIN OUTCOME MEASURES Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity, refraction, videokeratography, and complications were determined before and after LASIK retreatment. Follow-up was at least 12 months. RESULTS Before LASIK, 11.11% of eyes showed a UCVA of 20/40 or better. This increased to 94.44% 12 months after LASIK. A UCVA of 20/25 or better was achieved in 0% before and in 72.22% after retreatment. Refraction +/-0.5 diopters (spherical equivalent) represented 0% of eyes before and 77.78% of eyes after enhancement. Before LASIK, two eyes had significant haze. Haze remained in these two eyes and appeared in another eye. CONCLUSIONS Laser in situ keratomileusis proved to be safe and effective for treating residual myopia after PRK. Care must be taken when considering LASIK retreatment in patients with significant haze after primary PRK.

Influence of topical Cyclosporine A and dissolvent on corneal epithelium permeability of fluorescein

The corneal stroma is the major barrier to penetration for the lipophilic Cyclosporine A (CsA) molecule and prevents the use of the common ophthalmic solvents. At present, corn oil, castor oil and olive oil are the three most commonly used vehicles. The aim of this study was to determine the effect that topically applied CsA dissolved in different oils has on corneal epithelial permeability measured by fluorophotometry. Forty healthy volunteers, with absence of ocular or systemic disease and not receiving topical or systemic drugs were enrolled. Measurements were taken before and 45 min after the instillation of 40 microliters of a 2% aqueous solution of sodium fluorescein without preservatives. Basal corneal permeability and the permeability 24 h after the instillation of 2% CsA-olive oil, olive oil alone, 2% CsA-castor oil, castor oil alone, 2% CsA-corn oil and corn oil alone, were calculated. To prepare the topical 2% CsA, a Sandimmun oral solution (Sandoz, Basel, Switzerland) was employed under sterile conditions. We found that epithelial permeability 24 h after the instillation of any CsA formulations or solvents increased more than 6.62 times (p < 0.001). No differences in corneal permeability values were found between any of the CsA formulations and the vehicles. We conclude that oils used to dissolve CsA are mainly responsible for the increased corneal epithelial permeability. No differences were found in the effects of the tested solvents on corneal epithelial permeability.

Respiratory Arrest After 0.75% Bupivacaine Retrobulbar Block

Respiratory arrest is an uncommon complication of retrobulbar anesthesia. We present a case in which it occurred following a 0.75% bupivacaine and 2% lidocaine retrobulbar block and analyze the possible causes. We conclude that the most important of these were the relatively high concentration and volume of the anesthetic and a faulty technique.