Alginate inserts loaded with epidermal growth factor for the treatment of keratoconjunctivitis sicca.

We developed and tested ocular inserts containing epidermal growth factor (EGF) for a causal treatment of keratoconjunctivitis sicca (KCS). The inserts, consisting of different alginates with hydroxyethylcellulose (HEC) as a lubricant and release modifier, released EGF over time periods ranging from a few hours up to several days. The stability of EGF was high, having a protein half-life of approximately 548 days. A clinical pilot study suggests an amelioration of both the main symptoms and the objective criteria: tear film break-up (BUT) time and lissamine green score. Our results show that EGF treatment of KCS is highly promising.

Tear film function and corneal sensation in the early postoperative period after LASEK for the correction of myopia.

PURPOSE: Subepithelial nerves and stromal nerves of the cornea are damaged during LASEK surgery for the correction of myopia. This leads to a reduction in corneal sensation and to alterations of the tear film function in the early postoperative period. The aim of this study was to evaluate tear film function, corneal sensation and subjective symptoms of dry eye in the early postoperative period after LASEK for the correction of myopia. METHODS: LASEK surgery was performed in 20 eyes of 10 consecutive patients for the correction of myopia (-1.0 to -9.0 D, mean -4.86 D). Subjective symptoms of a dry eye were evaluated with a standardised questionnaire. Schirmer test with and without local anaesthesia, tear film break-up time, fluorescein staining of the cornea and corneal esthesiometry (Cochet-Bonnet) were performed before surgery and 1 week, 1 month, 2 months and 3 months after LASEK. Additionally corneal staining and subjective symptom severity scores were assessed 3 days after surgery. RESULTS: Corneal sensation was reduced 1 week after LASEK and recovered during the first month after LASEK. The tear film break-up time was reduced 1 week and 1 month after LASEK and reached preoperative values 2 months after surgery. Fluorescein staining was increased 3 days and 1 week after LASEK. Subjective symptom severity scores were increased 3 days, 1 week, 1 month and 2 months after LASEK. Schirmer tests values with local anaesthesia were significantly reduced at 3 months after surgery, but not at 3 days, 1 month, or 2 months. Schirmer test values without local anaesthesia were significantly decreased 2 and 3 months after LASEK, but not after 3 days and 1 month after LASEK. CONCLUSIONS: LASEK alters ocular surface haemostasis and reduces corneal sensation in the early postoperative period. Subjective symptoms of dry eye were described during the first 2 months after surgery.

Fundus autofluorescence in acute and chronic-recurrent central serous chorioretinopathy.

PURPOSE: Central serous chorioretinopathy (CSC) affects mostly young and middle-aged adults. Typically, a serous retinal detachment occurs with a focal leakage point in fluorescein angiography. Fundus autofluorescence (AF) is related to the lipofuscin within the retinal pigment epithelium (RPE). As CSC is thought to be associated with RPE disorders, AF measurements might be able to detect distinct changes within the RPE level. The purpose of this study was to compare AF patterns in acute and chronic-recurrent CSC and to evaluate the potential value of AF as a non-invasive monitoring tool. METHODS: From 85 patients diagnosed with CSC (mean age 43 years), AF images were retrospectively evaluated and compared with angiographic and ophthalmoscopic findings. Fluorescein angiography and AF measurements were performed using a Heidelberg retina angiograph. Autofluorescence was excited at a wavelength of 488 nm and detected above 500 nm. RESULTS: Acute CSC as determined by an acute decrease in visual acuity (VA) within the last 6 weeks, focal point leakage and neurosensory retinal detachment was diagnosed in 39 patients. In 36 of those patients (92%), a significantly decreased AF at the leakage point (72%) and/or decreased AF in the area of neurosensory detachment (77%) were observed. Regarding chronic-recurrent CSC as determined by a decrease in VA for longer than 6 weeks and mottled hyperfluorescent appearance in angiography, abnormalities in AF were observed in 44/46 patients (96%). In those patients, decreased or mottled AF was observed at the leakage point itself (76%), whereas significantly increased AF was seen in the area of residual neurosensory retinal detachment (85%). CONCLUSIONS: In acute CSC, decreased AF is presumably due to a blockage caused by oedema, whereas in chronic-recurrent forms, irregular and increased AF is observed, possibly reflecting reactive RPE changes secondary to RPE defects and neurosensory detachment. If these findings could be systematically underlined by prospective clinical studies, AF might be an interesting non-invasive tool for monitoring RPE changes in CSC and for performing differential diagnosis.

Corneal sensation after laser epithelial keratomileusis for the correction of myopia.

BACKGROUND: Subepithelial nerve fibre bundles and stromal nerves are damaged during laser epithelial keratomileusis (LASEK). The aim of this study was to investigate the recovery of corneal sensation after LASEK for the correction of myopia. METHODS: Corneal sensation was evaluated in 40 eyes of 20 patients using a Cochet-Bonnet aesthesiometer before surgery and 3 days, 14 days, 1, 3 and 6 months after LASEK for the correction of mild to moderate myopia (range -2.5 D to -8.0 D). At every examination corneal sensation was tested in the apex of the cornea and in one point each at the 12, 3, 6 and 9 o' clock positions 2 mm from the centre of the cornea. RESULTS: Corneal sensation was significantly reduced at 3 days and 14 days after surgery (P<0.01). The loss of corneal sensation was greatest 3 days after surgery and corneal sensation increased during the first month after LASEK. After 1 month, 3 months and 6 months no significant difference was found between preoperative and postoperative sensation. There was no significant difference in sensation between different areas of the cornea after LASEK. CONCLUSIONS: Corneal nerves are disrupted during LASEK surgery and the procedure results in a significant reduction in corneal sensation. During the first month after surgery the depressed corneal sensation improved and subsequently went back to preoperative values, staying stable 3 months and 6 months after surgery.

Wavefront-guided laser epithelial keratomileusis with the wavelight concept system 500.

PURPOSE: Laser epithelial keratomileusis (LASEK) is a technique of refractive surgery for treatment of myopia. More than 90% of patients are within the intended correction of +/-0.50 diopters (D), without any unwanted side effects. After conventional refractive surgery, higher-order aberrations are induced. To reduce these aberrations, we used wavefront-guided ablation. METHODS: Twenty patients with visual problems in ambient light were included. The primary surgery was 141 to 463 days before the retreatment. LASEK was performed with the Camellin technique with 20% EtOH for 30 seconds. Before surgery, the root mean square (RMS) values were measured and the laser treatment was performed with the WaveLight Concept System 500 (WaveLight Laser Technologie AG). The preoperative spherical equivalent refraction was -1.22 D (SD 0.57 D) and the astigmatism was -0.42 D (SD 0.25 D). Preoperatively and 6 months postoperatively, a comprehensive examination was performed. RESULTS: All retreatments were performed without any intra- or postoperative complications. All patients reported an improvement of vision. The 6-month postoperative refraction was 0.25 D (SD 0.36 D). RMS decreased significantly from 0.72 to 0.47. RMS fourth order also decreased significantly from 0.60 to 0.30 and the spherical aberration decreased significantly from 0.57 to 0.28. CONCLUSIONS: In earlier studies, patients reported reduction of contrast vision, even after resurgery. Our patients showed a significant reduction of higher-order aberrations and better contrast vision after retreatment with wavefront guided LASEK. Retreatment with wavefront-guided LASEK has the potential to correct night vision problems after excimer laser surgery.

Elliptical ELSA (LASEK) instruments for the treatment of astigmatism.

PURPOSE: To investigate newly designed, elliptical ELSA (excimer laser subepithelial ablation) instruments for the treatment of astigmatism. SETTING: University Eye Clinic Regensburg, Regensburg, Germany, and the Rayne Institute, Department of Ophthalmology, St. Thomas' Hospital, London, United Kingdom. METHODS: The new ELSA instrument set consists of an elliptical microtrephine (11.0 mm x 8.0 mm) with a 70 microm calibrated blade and an elliptical alcohol cone (11.5 mm x 8.5 mm). With this instrument set, ELSA (the laser-assisted subepithelial keratectomy [LASEK] described by Camellin) was performed in 34 astigmatic eyes. The cylindrical correction was between 1.00 diopters (D) and 3.50 D and the spherical correction, between -0.75 D and -8.75 D. In all eyes, the follow-up was 6 months. The postoperative refractive outcome was analyzed using Alpins vector analysis. RESULTS: Excimer laser subepithelial ablation was performed without intraoperative complications in all eyes. At 6 months, the mean spherical correction was -0.04 D +/- 0.27 (SD) (range +0.75 to -0.75 D) and the mean cylindrical correction, 0.27 +/- 0.23 D (range 0 to 0.75 D). The mean index of success was 0.18 +/- 0.15. CONCLUSIONS: With the elliptical instruments, ELSA was an effective and safe surgical procedure for astigmatism.

Laser-assisted subepithelial keratectomy enhancement of residual myopia after primary myopic LASEK: six-month results in 10 eyes.

PURPOSE: To determine whether residual myopia after primary laser-assisted subepithelial keratectomy (LASEK) can be corrected by repeated LASEK and whether this procedure is safe and effective. SETTING: University Eye Clinic, University of Regensburg, Regensburg, Germany. METHODS: Laser-assisted subepithelial keratectomy was performed in 10 eyes that had had primary LASEK for myopia. The initial mean spherical equivalent (SE) was -6.2 diopters (D) (range -2.5 to -8.0 D), and the residual mean SE was -1.6 D (range -1.0 to -3.0 D). The retreatment ratio was 7.6%. The exposure time of the corneal epithelium to alcohol (20% ethanol) was 30 seconds plus an additional 10 to 15 seconds in cases of strong epithelial adherence. Laser ablation was performed with a Keracor 117 excimer laser (Chiron Technolas). The follow-up after the second LASEK treatment was 6 months. RESULTS: The epithelial flap for repeated LASEK was successfully created in all 10 eyes. The postoperative course in the eyes was uneventful. Six months after LASEK enhancement, the SE refraction was within +/-0.5 D in all eyes. No eye lost more than 1 line of best corrected visual acuity, and the uncorrected visual acuity was 20/20 or better in 8 eyes. Significant haze was not observed after repeated LASEK (mean 0.35 before and 6 months after LASEK enhancement). CONCLUSIONS: Laser-assisted subepithelial keratectomy enhancement appears to be safe and effective for the correction of residual myopia after primary LASEK. Repeated epithelial flap preparation is possible without technical modifications.

Vitality of epithelial cells after alcohol exposure during laser-assisted subepithelial keratectomy flap preparation.

PURPOSE: To evaluate the vitality of epithelial cells after various exposure times to 20% ethanol and epithelial flap preparation in laser-assisted subepithelial keratectomy (LASEK) using the trypan blue dye test. SETTING: University Eye Clinic Regensburg, Regensburg, Germany, and the Rayne Institute, Department of Ophthalmology, St. Thomas' Hospital, London, United Kingdom. METHODS: Five human cadaver eyes were exposed to 20% ethanol for 15, 30, 45, 60, and 120 seconds, respectively. After an epithelial flap (as in LASEK) was prepared, the flap was deliberately cut off. The flaps were soaked in a trypan blue 0.1% solution at 37 degrees C. After 3 washes with phosphate-buffered saline (PBS), the specimens were reincubated for 30 minutes in culture medium containing 10% fetal calf serum at 37 degrees C. After an additional wash with PBS, the cells were observed with a standard inverted light microscope. RESULTS: After 15- and 30-second exposure to 20% ethanol, most epithelial cells were vital. This changed substantially after 45 seconds, when vital and dead cells were approximately equal. Longer exposure times (60 seconds and 120 seconds) showed predominantly dead epithelial cells. CONCLUSIONS: Exposure to 20% ethanol should be 20 to 30 seconds as the number of vital epithelial cells rapidly decreased after that. Vitality of the epithelial flap is probably a crucial factor in the dampened wound response in LASEK compared to that in photorefractive keratectomy.

[Laser epithelial keratomileusis (LASEK): histological investigation for vitality of corneal epithelial cells after alcohol exposure]. / Laserepitheliale Keratomileusis (LASEK): Histologische Untersuchungen zur Vitalität der kornealen Epithelzellen nach Alkoholexposition.

BACKGROUND: Laser epithelial keratomileusis (LASEK) is a new surgical procedure to treat myopia. An epithelial flap is created after the exposure to 20 % alcohol and following the laser ablation the epithelium is repositioned to its original location. The advantage of LASEK is that the ablated corneal surface is covered by a full thickness epithelium immediately after surgery. It is hypothesised that this epithelial coverage inhibits the wound healing response of the cornea. However, this concept will only work if the epithelial cells are still vital after the exposure to alcohol. MATERIAL AND METHODS: The vitality of the corneal epithelial cells was investigated in 6 human cadaver eyes after the exposure to 20 % alcohol over 15 to 60 s. The vitality of the corneal epithelial cells was assessed by soaking the specimen in a 0.1 % trypan blue solution and incubated at 37 degrees C for 2 min. After a wash with BSS the specimen were re-incubated at 37 degrees C for 30 min in culture medium. After one more wash with BSS the cells were observed with a standard light microscope. Cells which retained the blue colour would be dead and vital cells would appear clear. Light microscopy and transmission electron microscopy was used to detect morphological changes. RESULTS: Mainly vital corneal epithelial cells were seen for an alcohol exposure time of up to 30 s. In particular the basal epithelial cells appeared alive. With a exposition time of 60 s most cells were dead. CONCLUSION: In LASEK the exposure time of 20 % alcohol is between 20 and 30 s. Based on our results we can conclude that after such exposure time most cells are alive, which is essential for the postoperative wound healing response.

[Excimer laser subepithelial ablation (ELSA) or laser epithelial keratomileusis (LASEK) - a new kerato-refractive procedure for myopia. Surgical technique and first clinical results on 24 eyes and 3 months follow-up]. / Excimer Laser Subepitheliale Ablation (ELSA) bzw. Laser Epitheliale Keratomileusis (LASEK) - Ein neuartiges refraktiv-chirurgisches Verfahren zur Myopiekorrektur. Operationstechnik und erste klinische Ergebnisse an 24 Augen und nach 3 Monaten.

BACKGROUND: Laser epithelial keratomileusis (LASEK) is a new keratorefractive surgical procedure to treat myopia and possibly other refractive errors, which combines the advantages while eliminating the disadvantages of both PRK (pain, corneal haze) and LASIK (flap complications, interface complications). Our results with LASEK are very promising and because this technique is currently not very popular in Germany we here with introduce the surgical technique and our first clinical results. PATIENTS AND METHODS: We treated 24 eyes (18 patients) by LASEK. The preoperative myopia was between - 1.50 and - 6.00 D with an astigmatism less than 1.00 D. Surgery starts with an incision in the epithelium by using a special microtrephine. After the application of 20 % ethanol for 20 seconds a hinged epithelial flap is created and the laser ablation performed with a Keracor 117 excimer laser. Finally, the epithelial flap is repositioned and secured using a bandage contact lens and artificial tears for 3 days. RESULTS: In all eyes the creation of the epithelial flap and its repositioning presented no problems. None of the eyes showed any postoperative epithelial instability. However, one eye lost the contact lens and the epithelial flap during the first postoperative day. Postoperatively, none of the patients complained of significant pain; however, the contact lens caused some foreign body sensation. After 3 months all eyes were within +/- 1.0 D and 20/24 eyes (84 %) within +/- 0.50 D of emmetropia (spherical equivalent). None of the eyes showed significant haze. CONCLUSIONS: Although, the number of treated eyes is small and the postoperative follow-up is short LASEK seems to be an effective and safe procedure for the treatment of myopia.