Erbium:YAG laser vitrectomy: clinical results

PURPOSE: To evaluate the intraoperative use of a new erbium:yttrium aluminum garnet (YAG) laser vitrectomy system. METHODS: An erbium:YAG laser combined with an infusion-suction system (Wavelight Laser Technology, Erlangen, Germany), equipped with a flexible fiber optic and a hand piece with a 20-gauge end tip and a side opening of 0.6 mm was used. Cutting rates were 2 to 30 Hz, and energies were 20 to 40 mJ. Between January 1998 and January 1999 the erbium:YAG laser system was used in 67 consecutive patients (68 eyes) where vitrectomy was indicated. The patients had a complete eye examination before surgery and postoperatively at 1 to 3 days, 1 week, 3 weeks, and 6 weeks. During surgery, the total time needed for vitrectomy, the laser time itself, amount of energy used, cutting rate, suction, and perfusion, as well as manipulative difficulties and/or complications, were documented. RESULTS: The average laser time was 4.5 minutes for a basic vitrectomy with a setting of 20 mJ, 20 Hz, and suction 100 to 200 mm Hg. Hemorrhages, loose intravitreal, and preretinal membranes of different densities were cut well with adjustment of energy. After a minimal observation time of 6 months (median, 12.7 months) no laser-associated complications were found. CONCLUSIONS: The erbium:YAG laser, combined with an infusion-suction system, offers a new technology for vitreous surgery. Its advantages, compared with mechanical vitrectomy cutters, are higher cutting rates and the modulation of energy. Modifications of the end tip are needed to develop this system further.     

Micro-endoscopy of the lacrimal apparatus combined with Erbium YAG laser: an anatomical study. New methods of imaging]

PURPOSE: To study the anatomic structure and the endoscopic aspect of the lacrimal drainage system and to evaluate the efficacy of the Erbium laser with microendoscope in lacrimal obstruction. METHODS: Twenty lacrimal ducts from ten fresh cadaver heads were used to lead a special rigid probe of 1.1. mm diameter (Endognost Schwind). This probe combined a flexible endoscopic probe of 500 mu, an Erbium laser fiber of 375 mu and an irrigation. The probe was introduced through the inferior canaliculus. Progressing in the lacrimal system, all the images were analysed. Then, we used the laser fiber to open the lacrimal sac mucosa and the lacrimal bone. RESULTS: The anatomo-endoscopic analysis was performed using endoscopic data. We appreciated essentially the walls of valves and sinuses that appeared only functional when increasing the irrigation flow. The laser could easily open the mucosa and the lacrimal bone but not the maxilla. DISCUSSION: The small size of the cannula allows to use the system for the diagnosis of lacrimal obstructions. The combined laser allows to treat at same time canalicular obstructions and lower obstructions. CONCLUSION: The endocanalicular study of the lacrimal drainage system can diagnose the type of obstruction and can treat it. A clinical study is requested to confirm these results.     

Erbium:YAG laser emulsification of the cataractous lens

PURPOSE: To evaluate the clinical effectiveness and safety of the erbium:YAG (Er:YAG) laser for cataract extraction surgery. SETTING: Visual Sciences Institute, Madrid, Spain. METHODS: In this prospective randomized study, 65 eyes of 50 patients scheduled for cataract extraction were divided into 2 groups based on the type of lens emulsification: Er:YAG laser (40 eyes) or ultrasound (US) (25 eyes). The laser procedure was converted to the US technique in cases with potential complications. All patients received a foldable posterior chamber intraocular lens. A complete ophthalmologic examination including topographic analysis, pachymetry, and endothelial cell count was performed preoperatively and 1 day, 2 weeks, and 1, 3, 6, and 12 months postoperatively. All patients had fluorescein angiography at 1 month to rule out subclinical cystoid macular edema (CME). RESULTS: There were no significant differences between the techniques in any parameter at any time. In both groups, visual acuity significantly increased and endothelial cell count significantly decreased postoperatively (P <.01). The only serious complication was subclinical CME in 2 patients 1 month after the laser procedure. CONCLUSIONS: Emulsification of the lens using the Er:YAG laser was effective for performing small incision cataract surgery in eyes with soft and medium nuclei. The small ablation zones created can help prevent damage to surrounding ocular structures. The Er:YAG technique used less ablation energy than US emulsification and did not result in thermal injury.     

Autofluorescence imaging after selective RPE laser treatment in macular diseases and clinical outcome: a pilot study

AIM: Selective retinal pigment epithelium (RPE) laser treatment is a new technique which selectively damages the RPE while sparing the neural retina. One difficulty is the inability to visualise the laser lesions. The aim of the study was to investigate whether fundus autofluorescence (AF) is changed because of the RPE damage, and thus might be used for treatment control. Additionally, the clinical course of patients with various macular diseases was evaluated. METHODS: 26 patients with macular diseases (diabetic maculopathy (DMP), soft drusen maculopathy (AMD), and central serous retinopathy (CSR)) were treated and followed up for at least 6 months. Treatment was performed with a train of repetitive short laser pulses (800 ns) of a frequency doubled Nd:YAG laser (parameters: 532 nm, 50 and 500 pulses at 100 and 500 Hz, retinal spot diameter 200 micro m, pulse energies 75-175 micro J). AF was excited by 488 nm and detected by a barrier filter at 500 nm (HRA, Heidelberg Engineering, Germany). Patients were examined by ophthalmoscopy, fluorescein angiography, and autofluorescence measurements at various times after treatment (10 minutes, 1 hour, 1 and 6 weeks, 3, 6, and 12 months). RESULTS: Fluorescein angiography showed leakage from the irradiated areas for about 1 week after treatment. None of the laser lesions was ophthalmoscopically visible during treatment. Identification of the lesions was possible by AF imaging showing an intensity decay in the irradiated area in 22 out of 26 patients, predominantly in patients with CSR and AMD. Lesions could be identified 10 minutes after treatment as hypoautofluorescent spots, which were more pronounced 1 hour later. During follow up the laser spots became hyperautofluorescent. In patients with DMP some AF images were less helpful because of diffuse oedema and larger retinal thickness. In these cases ICG angiography was able to confirm therapeutic success very well. Most of the patients have had benefit from the treatment, with best results obtained for CSR patients. CONCLUSION: Imaging of non-visible selective RPE laser effects can be achieved by AF measurements predominantly in patients without retinal oedema. Therefore, AF may replace invasive fluorescein angiography in many cases to verify therapeutic laser success. Selective laser treatment has the potential to improve the prognosis of macular diseases without the risk of laser scotomas.     

无痛准分子激光角膜上皮瓣下磨镶术的临床研究

目的探讨控制准分子激光上皮瓣下角膜磨镶术（LASEK）术后疼痛及炎症反应的方法,评价无痛LASEK的可能性。方法常规LASEK为2006年6月1日至2007年6月1日手术者;无痛LASEK为2008年6月1日至2009年6月1日手术者。应用了更为熟练而稳妥的操作,增加了术前、术中、术后非类固醇消炎药普拉洛芬滴眼液的应用等措施。两组各160例（320眼）,随访时间均为1a。观察两组畏光、流泪、异物感、疼痛以及裂隙灯显微镜观察的情况,各项指标得分相加后得到综合评分,比较两组在术后即刻、术后2d,术后6d,术后14d在综合评分差异。结果无痛LASEK组和常规LASEK组综合评分在术后即刻,术后2d差别有统计学意义。术后6d及14d差别无统计学意义。症状消失的天数差别有统计学意义。结论无痛性LASEK控制LASEK术后疼痛及炎症反应有效而安全。可以达到无痛LASEK的要求。     

Erbium:YAG laser cataract removal: role of fiber-optic delivery system

PURPOSE: To review the properties of energy delivery systems and to evaluate the efficiency of zirconium-fluoride-based and sapphire fibers delivering erbium:YAG (Er:YAG) laser energy in a clinical laser cataract surgery system. SETTING: Department of Ophthalmology, Medical College of Virginia Campus of Virginia Commonwealth University, and Veterans Affairs Medical Center, Richmond, Virginia, USA. METHODS: Thirty-two patients had Er:YAG laser cataract extraction. Preoperative visual acuity ranged between finger counting and 20/40 secondary to cataract. The endothelial cell count was measured preoperatively and 6 weeks after surgery. A zirconium-fluoride-based fiber was used in 23 patients and a sapphire fiber in 9 patients. RESULTS: Of the patients examined after 3 months (n = 31), 90.3% (n = 28) had a visual acuity of 20/30 or better and 9.7% (n = 3), of 20/40 or 20/50. Mean endothelial cell loss at 6 weeks was 7.6% +/- 12.8 (SD). Posterior capsule rupture with vitreous loss occurred in 3 cases; 1 was attributed to laser damage to the capsule. Conversion to ultrasound phacoemulsification was required in 13 cases. Suitable fiber materials for Er:YAG laser delivery are sapphire, zirconium fluoride, silica, and germanium oxide. Toxicity of the latter is under investigation. CONCLUSION: The Er:YAG laser emulsified the lens nucleus safely and effectively. These early results include a higher than acceptable posterior capsule rupture rate and reflect the surgeon's learning curve with a new technology. Effective power delivery can be achieved with sapphire- and zirconium-fluoride-based fiber optics through a silica tip. The optimal energy delivery system has not been determined.     

Use of Erbium:YAG laser in the treatment of palpebral xanthelasmas

OBJECTIVE: In light of the research and the use of lasers in the therapy of xanthelasmas, the authors report their experience in the treatment of this pathology with Erbium:YAG laser. MATERIALS AND METHODS: In 30 patients, all female, 70 xanthelasmas were treated with Erbium:YAG laser, 65 (93%) of which were on the upper eyelid and 5 (7%) on the lower eyelid, varying from 1 x 1.5 mm to 11 X 20 mm in size. Spots with a diameter of 1.6 mm, energy of 300 mJ, frequency of 1-5 Hz and in a number varying were used in relation to the extent of the pathology. RESULTS: In all cases, the appearance and functional results were good, without leaving scars and/or dyschromia. CONCLUSIONS: Erbium:YAG laser, in the treatment of xanthelasmas, is a parasurgical method that is simple to perform and because of the successful aesthetic and functional results, is a valid alternative to the more traditional treatment methods.     

Macular translocation with chorioscleral outfolding: a pilot clinical study

PURPOSE: A new surgical technique to translocate the macula was used to treat patients with subfoveal choroidal neovascularization secondary to age-related macular degeneration (AMD). DESIGN: Prospective, interventional case series. METHODS: Twenty-five eyes of 25 patients underwent macular translocation with either circumferential or radial chorioscleral outfolding using three clip sizes: 2-mm, 3-mm, and 4-mm. Postoperative photocoagulation was performed on only those eyes that had an extrafoveal choroidal neovascular membrane following surgery. RESULTS: The surgery successfully displaced the fovea in 22 (88%) of the eyes. The median postoperative foveal displacement was 1142 microm (range 0 to 3200 microm). Patients who had radial outfolding with 4-mm clips had the greatest displacement of the fovea (range 1644 to 3200 microm median 1977 microm). The fovea was successfully displaced to a location outside the choroidal neovascular membrane in 17 (68%) of the 25 eyes. The best-corrected visual acuity improved in 11 eyes (median, 17 letters), remained unchanged in 4 eyes, and decreased in 10 eyes (median, 12 letters). Visual acuity increased by a median of 2 letters. The final best-corrected visual acuity was 20/64 in 3 eyes; 20/80 in 3 eyes; 20/100 in 4 eyes; 20/126 in 4 eyes; 20/200 in 4 eyes; 20/250 in 4 eyes; and 20/400 in 3 eyes. CONCLUSIONS: Macular translocation with radial chorioscleral outfolding using 4-mm clips resulted in the best foveal displacement and improvement in visual function, and was associated with the least amount of vision loss and complications. Further refinements are needed to make this surgical procedure more predictable, and more research (randomized clinical trials) is needed to determine the role of macular translocation in the treatment of subfoveal choroidal neovascularization in patients with AMD.     

Gonioscopic ab interno laser sclerostomy. A pilot study in glaucoma patients.

PURPOSE: The purpose of this study is to evaluate the safety and efficacy of gonioscopic ab interno laser sclerostomy (GLS) in patients with glaucoma. METHODS: The technique of GLS involves iontophoresis of methylene blue dye (1%) at the limbus to focally dye the sclera and to provide subsequent delivery of 10-microsecond pulsed laser energy to the dyed area through a goniolens. The laser emits at 660 nm, a wavelength that is maximally absorbed by the methylene blue dye. Patients were evaluated for fistula formation, intraocular pressure (IOP) reduction, and adverse sequelae. Thirty-eight treatments were performed in 35 eyes. RESULTS: Successful complete sclerostomies were achieved in 21 eyes (55%), which was associated with an acute mean reduction in IOP of 23 mmHg. Mean preoperative IOP for all patients was 35 mmHg, and 1 hour after treatment it was reduced to 18.5 mmHg. In 4 of the 38 treatments, there was no acute IOP reduction, and these eyes were judged as failures. The mean follow-up time was 8.2 months with a maximum follow-up of 15 months. By 9 months, 50% of patients had an IOP of 22 mmHg or lower. The number of antiglaucoma medications decreased from 3.1 to 1.7 for all eyes over the 15-month follow-up period. Hyphemas (13%) were the only major complication, and these resolved spontaneously. In only one case did the IOP increase after the procedure. CONCLUSION: The results of this trial indicate that GLS is technically feasible, and preliminary results of IOP control are promising.     

Human excimer laser lamellar keratectomy. A clinical study

The first ten blind human eyes in the United States to receive excimer laser (ArFl 193 nm) lamellar keratectomy (reprofiling) are presented. Seven of these patients were followed 6 to 12 months after ablation. All eyes are grossly clear in the region of ablation. Results of slit-lamp examination of all flattened ablated areas show mild superficial haze at the epithelial/stromal interface. This haze might not interfere significantly with vision in patients 7 to 10. Serial pachymetry and keratometry measurements, refraction, and digital keratoscopy show a progressive filling in of the excavated area by approximately two thirds but a loss of initial diopteric correction of only one third. Histopathologic analysis was obtained for four eyes. Transmission electron microscopy of three eyes enucleated 3 to 12 days after ablation shows 40-microns ablation depths through Bowman's layer and superficial stroma with minimal adjacent tissue damage and no inflammatory cells. The epithelium is increased in thickness by 50%, and firmly attached to the underlying stroma. A 4-month postablation specimen shows keratocyte activation with increased protein synthesis (presumed collagen and ground substance).     

Mycophenolate mofetil after penetrating high risk keratoplasty. A pilot study]

AIM: Mycophenolate mofetil (MMF, CellCept) has become a successful part of the standard immunosuppression regimes after solid organ transplantation. It was the aim of this study to compare the efficacy and the safety of MMF after penetrating high-risk keratoplasty with our standard immunosuppression, i.e. systemic cyclosporin A (CSA), in a pilot study. PATIENTS AND METHODS: Sixteen patients after penetrating high-risk keratoplasty were randomized to be treated either with MMF or with CSA for six months postoperatively. MMF was administered in an oral dose of two times 1 g daily whereas the CSA dose varied according to the blood trough levels of 120-150 ng/ml (monoclonal TDx) between 100 and 500 mg daily. RESULTS: During this first follow-up period of 11.4 (5-18) months neither in the MMF- nor in the CSA-group irreversible graft failure was observed. One serious acute endothelial immune reaction was observed in the CSA-group after systemic immunomodulation had been tapered. It was treated successfully with systemic and topical corticosteroids. In one patient CSA-prophylaxis had to be stopped five months postoperatively because of elevated liver enzymes. Side-effects did not occur in the MMF-group. CONCLUSIONS: Up to now MMF has been evaluated to be as efficacious as CSA and safe. If these results are confirmed in the long run in this study MMF may become an armament to avoid immune reactions in high-risk penetrating keratoplasty patients who must not receive systemic CSA.     

Optometrists' perspectives on cross-cultural encounters in clinical practice: a pilot study

Background: There is growing awareness that cultural background influences health beliefs and practices and can impact on the patient–practitioner encounter. However, in relation to optometry there is little known about the implications of cultural diversity for clinical decision‐making and how optometrists address culturally based understandings of health. This pilot study examines how culturally based differences in health practices and beliefs impact on patient–optometrist interactions and how optometrists negotiate and manage these differences. Methods: Semi‐structured interviews were conducted with 10 optometrists. A qualitative analysis was undertaken regarding the optometrists' experiences of cultural diversity and how these impact their decision‐making and clinical interactions. Results: Emergent themes were:

• 1 Culture can influence and impact on patient–optometrist clinical encounters.
• 2 Culturally based differences in health practices and beliefs can have a negative impact on clinical encounters.
• 3 Culturally based differences, beliefs and values (related to eye health) can be difficult to negotiate.
• 4 Optometrists might benefit from additional training and strategies to deal with culturally based differences in health beliefs and practices.

Conclusions: This pilot study provides data about some of the issues that arise as a result of cultural differences between patients and health care practitioners. The findings from this study contribute to an understanding of the impact of cultural diversity and might assist the development of training and further research in the area.     

Experimental autoimmune uveitis--a clinical and pathological study]

Experimental autoimmune uveitis (EAU) was induced in 95% of guinea pigs after immunization by a single intradermal injection of homologous retinal tissue in Freund's complete adjuvant and subcutaneous injection of dead pertussis bacilli. The clinical features were circumcorneal injection, cells and flare in the anterior chamber, vasodilation in the iris, and marked cellular exudate in the vitreous. The pathological changes were characterized by diffuse proliferative granulomatous panuveitis, consisting of lymphocytes, macrophages, and epithelioid cells. The outer layers of the retina were disrupted or missing in areas where the pigment epithelium was damaged.     

Choroidal neovascularization, experimental and clinical study]

As a special lecture at the 95th annual Congress of the Japanese Ophthalmological Society in 1991, we presented experimental studies on choroidal neovascularization (ChNV), and clinical studies on senile disciform macular degeneration (exudative age-related macular degeneration). We produced experimentally ChNV on monkey eyes using intense photocoagulation with krypton laser. We showed the retinal pigment epithelium (RPE) played a heavy role as inducer or inhibitor for ChNV at different stages of development or involution of experimental ChNV. Senile disciform macular degeneration is becoming a leading cause of blindness in the elderly in Japan. We examined 473 eyes in 398 cases of this disease during the past 5 years. Nineteen percent were bilaterally affected, males were affected 3 times prevalent than in female, and average age was 67 in years. Predisposing signs were degeneration or atrophy of RPE, hard or soft drusen, and serous detachment of RPE in the macula. In early stage, serous retinal detachment stage appeared and showed good outcome by laser treatment. Subretinal hematoma form showed next better outcome in acute onset and acute course. Advanced form of disciform lesion showed worse outcome. A form (subretinal cystic form) associated with large serous RPE detachment showed the worst outcome and scarcely indicated for laser treatment. We describe clinical features of each form and stages of the disease and clinical course. Early detection, early correct diagnosis and early laser treatment must be essential for prevention of blindness due to this disease.     

激光治疗中心性浆液性脉络膜视网膜病变86例

目的:评价激光治疗中心性浆液性脉络膜视网膜病变(CSC)的疗效。方法:选择2003-01/2005-03间我院门诊就诊的经眼底荧光血管造影检查确诊的CSC患者86例(92眼),并应用激光对眼底荧光渗漏点进行直接光凝。结果:激光治疗CSC治愈率高达88%,而且平均视力有了很大的提高。结论:激光治疗中心性浆液性脉络膜视网膜病是一种有效和可靠的治疗方法。它封闭渗漏点准确,能明显缩短病程,提高视力和治愈率,改善视功能,降低复发率。     

LASEK术中应用丝裂霉素C的临床研究

目的探讨准分子激光上皮瓣下角膜磨镶术（LASEK）术中应用丝裂霉素C（MMC）抑制术后角膜上皮下雾状浑浊（haze）的疗效。方法中高度近视（-5．00～-10．00D）LASEK60例（120眼）术中应用0．02％MMC的30例（60眼）者为试验组,术中未用MMC的30例（60眼）为对照组。分别于术后1月、3月、6月观察其角膜haze的发生及发展情况。结果试验组中高度近视者术后不同时期haze发生程度较对照组低,差异具有统计学意义（P〈0．05）。结论丝裂霉素C对中高度近视LASEK术后haze的形成具有明显的抑制作用。     

Nd:YAG laser posterior capsulotomy: a clinical study

As a postoperative complication to cataract surgery [extracapsular extraction (ECCE), phacoemulsification (KPE)], the posterior capsule (PC) of the lens often becomes opacified with plaque, Elschnig's pearls, or fibrotic bands, resulting in decreased visual acuity (VA). A Q-switched Nd:YAG ophthalmic laser was used to perform noninvasive micropuncturing of the posterior capsule. Two hundred thirteen patients (195 with existing intraocular lenses) underwent laser capsulotomy within a 14-month clinical study. These patients were followed over a 6-month postcapsulotomy period. Findings indicate excellent restored VA with minimal ocular complications.     

Morphology of the trabecular meshwork three years after Erbium:YAG laser trabecular ablation.

Laser trabecular ablation (LTA) is an abinterno approach with the purpose to improve outflow facility by removing trabecular tissue and open Schlemm's canal. In a blind eye with secondary glaucoma following silicone oil surgery, Erbium:YAG LTA had been performed applying 12 neighboring single laser pulses (5-7 mJ pulse energy, 200 micros pulse duration) to the trabecular meshwork. Enucleation was performed three years after the procedure that did not achieve pressure control. Light-microscopy revealed neither marked scarring nor endothelial proliferation in the treated trabecular meshwork. However, most of the recognizable ablation craters failed to open Schlemm's canal. Although limited scar formation within the trabecular meshwork after LTA is a promising aspect, the present technique of Er:YAG LTA still needs technical and surgical improvements to guarantee reliable and reproducible openings of Schlemm's canal.     

Photoablative filtration surgery with the excimer laser for primary open-angle glaucoma: a pilot study

We have performed ab-externo photoablative filtration surgery on 19 patients affected by uncontrolled primary open-angle glaucoma. All cases had wide open angles, were previously treated with argon laser trabeculoplasty and were considered good candidates for trabeculectomy. After topical and peribulbar anesthesia, a limbus-based conjunctival flap was dissected. Photoablation of a rectangular area at the limbus was performed with an argon fluoride excimer laser (193 nm), at 180mJxsq cm fluence. The beam was shaped in the appropriate fashion using a custom-made metal mask. Photoablation was continued until aqueous appeared percolating through the juxtacanalicular tissue at the bottom of the crater; a water-tight closure of conjunctiva was then performed. Postoperatively, the anterior chamber reaction was minimal; in no case a flat chamber or choroidal detachment was observed. In 18 of the 19 cases the IOP was significantly lowered, and a filtering bleb developed. Mean preoperative IOP was 26.4 (±7) mmHg. At a median follow-up of 9 months (range 4–15) the IOP is<18 mmHg on no medications in 16 (84%) of the eyes, with a mean value of 13.3 (±6) mmHg. Our short-term results support excimer laser photoablative filtration as a relatively safe and effective procedure for primary open-angle glaucoma.