Treatment of retinal breaks with large-spot diode laser photocoagulation.

A new technique is described for treating peripheral retinal breaks using large-spot, diode laser retinopexy. A large-spot (1.2 to 3.0 mm) diode laser (810 nm) was used to treat patients with breaks in attached retina. Powers between 800 and 1,200 mW produced a uniform retinal photocoagulation beyond the break margins. Patients were observed monthly until an adequate chorioretinal scar had formed. Eleven eyes were treated using this technique. Satisfactory retinopexy was obtained in all cases. The efficiency of large-spot diode laser photocoagulation for retinal breaks and its advantages over conventional laser and cryopexy techniques justifies further studies into this technique.

Results 28 months following transpupillary thermotherapy for classic and occult choroidal neovascularization in patients with age-related macular degeneration.

BACKGROUND AND OBJECTIVE: To report the outcome of patients 28 months following treatment with transpupillary thermotherapy (TTT) for classic and occult choroidal neovascularization (CNV) secondary to age-related macular degeneration. PATIENTS AND METHODS: A nonrandomized pilot trial of 36 eyes of 33 patients was performed. Eyes with angiographically defined CNV, 11 predominantly classical and 25 predominantly occult, were treated with large spot diode laser (810 nm) TTT for 1 minute, the end point being no or minimal visible change. Outcome was assessed with best-corrected LogMAR visual acuity, clinical examination, and fluorescein angiography. RESULTS: Patients were observed for a mean of 28.7 months (range, 18 to 40 months). The mean change in LogMAR visual acuity for predominantly classic membranes was -1.91 (standard deviation [SD] = 4.3) and 5 of 11 (45.5%) eyes had a loss of 3 or more LogMAR lines. Predominantly classic membranes were closed in 9 of 11 eyes and stabilized in 2 of 11 eyes. The mean change in LogMAR visual acuity for predominantly occult membranes was -1.48 (SD = 6.3) and 10 of 25 (40%) patients had a loss of 3 lines or more. Predominantly occult CNV was stabilized in 25 of 25 cases, and recurrence developed in 2 of 25 cases; one of the latter developed classic CNV. CONCLUSIONS: The medium-term results for patients treated with TTT for both occult and classic CNV show good stability, with little visual loss and few recurrences. These data confirm the original findings of this study.

Transpupillary thermotherapy (TTT) for the treatment of choroidal neovascularisation.

AIM: To assess the effectiveness of transpupillary thermotherapy (TTT) for the treatment of classic and occult choroidal neovascularisation (CNV). METHOD: In a retrospective, case selected, open label trial 44 eyes of 42 patients with CNV secondary to age related macular degeneration (ARMD) were studied. 44 eyes with angiographically defined CNV were treated with diode laser (810 nm) TTT. Laser beam sizes ranged between 0.8 and 3.0 mm and power settings between 250-750 mW. Treatment was given in one area for 1 minute, the end point being no visible change, or a slight greying of the retina. Outcome was assessed with Snellen visual acuity and clinical examination; in 24/44 patients angiographic follow up was available. RESULTS: 12 predominantly classic CNV and 32 predominantly occult membranes were followed up for a mean of 6.1 months (range 2-19). Mean change in vision for classic membranes was -0.75 (SD 1.75) Snellen lines and occult membranes was -0.66 Snellen lines (2.1) (p>0.05). Predominantly classic membranes were closed in 75% (95% CI: 62.5-87.5) of eyes, remained persistent in 25% (95% CI: 12.5-37.5); no recurrences occurred. Predominantly occult membranes were closed in 78% (95% CI: 70.1-85.3) of eyes, remained persistent in 12.5% (95% CI: 6.6-18.5), and were recurrent in 5.1% (95% CI: 4.2-14.3). CONCLUSIONS: Transpupillary thermotherapy is a potential treatment for CNV. It is able to close choroidal neovascularisation while maintaining visual function in patients with classic and occult disease. Further trials of TTT are needed to compare this intervention with the natural history and other treatment modalities.

Transscleral diode laser in the treatment of retinopathy of prematurity.

PURPOSE: To assess the outcome of contact transscleral diode laser (TSDL) in the treatment of threshold retinopathy of prematurity (ROP). METHOD: TSDL was performed in 14 eyes of 8 babies who presented to the paediatric ophthalmic service at King's College Hospital between 1996 and 1997 with threshold ROP (median post-conceptual age 26 + 1 weeks, median birthweight 835 g) by a single surgeon. Follow-up ranged from 9 to 41 weeks (median 21 weeks). RESULTS: In 11 eyes (79%) regression of ROP occurred after a single laser treatment with a good anatomical outcome. In 3 eyes (21%) there was an unfavourable response with the development of traction retinal detachment. These include both eyes of one baby who rapidly progressed to stage IV ROP. One other eye developed a fibrotic band a few months after treatment. No significant complications of laser treatment were observed. CONCLUSION: These initial results indicate that TSDL photocoagulation is an effective and technically straightforward alternative to cryotherapy in the treatment of ROP.

Diode laser trabeculoplasty versus argon laser trabeculoplasty in the control of primary open angle glaucoma.

A randomised prospective study was carried out to determine whether diode laser trabeculoplasty (DLT) is as effective as argon laser trabeculoplasty (ALT) in the control of primary open angle glaucoma (POAG). Forty eyes of 40 patients with uncontrolled intraocular pressure (IOP) despite maximum topical medication were entered into the study. Twenty eyes received DLT, spot size 100 µm, exposure time 0.2 s, mean power 1034 (±56.4) mW. Twenty eyes received ALT, spot size 50 µm, exposure time 0.2 s, mean power 528 (±44.7) mW. They were reviewed at 2 h, 2 and 8 weeks, and 3, 6, 12, 18 and 24 months after laser treatment. Two eyes were withdrawn from the DLT group and four from the ALT group because of uncontrolled IOP during follow-up. Of the remaining eyes in the trial, mean IOP reductions for DLT and ALT, respectively, were: 6 months 7.42 (±2.36) mmHg and 6.36 (±2.3) mmHg; 12 months 7.02 (±2.6) mmHg and 6.28 (±2.2) mmHg; 18 months 6.86 (±2.8) mmHg, 5.98 (±2.02) mmHg; 24 months 6.50 (±2.72) mmHg, 5.92 (±2.02) mmHg. There was a significant reduction in each laser group when IOP at each stage was compared with baseline (p<0.001) (paired Student's t-test), but no significant difference between the two groups. In the ALT group peripheral anterior synechiae developed in four eyes and post laser pain in seven eyes. These complications were not noted following DLT. We conclude that DLT and ALT are equally effective in IOP control, but DLT is associated with less anterior segment inflammation.

Long-term results after drainage of premacular subhyaloid hemorrhage into the vitreous with a pulsed Nd:YAG laser.

OBJECTIVE: To investigate the effects of drainage of premacular subhyaloid hemorrhage into the vitreous with an Nd:YAG laser in a large series of patients with long-term follow-up. METHODS: A retrospective review was conducted on 21 eyes with a circumscribed premacular subhyaloid hemorrhage of various causes. These eyes were treated with a pulsed Nd:YAG laser to drain the entrapped blood into the vitreous. The period of review ranged from 12 to 32 months (mean, 22 months). RESULTS: In 16 eyes, visual acuity improved within 1 month. Four eyes had persistent, dense, nonclearing vitreous opacity for at least 3 months and finally required vitrectomy. One clotted hemorrhage did not drain into the vitreous. Final visual outcome was determined by the underlying diagnosis, such as Valsalva retinopathy (7 eyes), diabetic retinopathy (7 eyes), branch retinal vein occlusion (4 eyes), and retinal macroaneurysm, Terson syndrome, or blood dyscrasia (1 eye each). Eyes with Valsalva retinopathy fared the best. Complications included a macular hole in 1 eye and a retinal detachment from a retinal break in a myopic patient. CONCLUSIONS: Drainage of premacular subhyaloid hemorrhage into the vitreous with an Nd:YAG laser is a viable treatment alternative for eyes with recent bleeding. However, a macular hole and a retinal detachment were observed as complications. Thus, to establish Nd:YAG laser treatment as a routine procedure, the risks and benefits have to be weighed in a randomized trial and compared with those of deferral of treatment or primary vitrectomy.

Systemic risk factors for idiopathic macular holes: a case-control study.

PURPOSE/BACKGROUND: The idiopathic full-thickness macular hole (IFTMH) is an important cause of poor vision in the elderly affecting predominantly women over the age of 60 years. While it is accepted that vitreoretinal traction is an important local factor in the development of IFTMH, the underlying cause is not known. The aim of this study was to identify possible systemic risk factors for the development of IFTMH. METHODS: Two hundred and thirty-seven patients with IFTMH (cases) attending the Macular Hole Clinic at Moorfields Eye Hospital were identified. These were compared with 172 patients without macular holes (controls) attending other clinics in the same hospital. Cases and controls were frequency-matched by sex. The prevalence of the following factors in both groups was ascertained by interview: ethnic origin, place of birth, housing tenure, any systemic diseases, current and lifetime consumption of medication, severe dehydrational episodes, menstrual and obstetric history, onset and severity of menopause and use of exogenous oestrogens (in women only), osteoporosis, vegetarianism, use of vitamin supplementation, and smoking and alcohol consumption. Height and weight were measured for all participants. RESULTS: Cases of IFTMH macular holes were predominantly women (67%) and aged 65 years and older (74%). We found very few systemic risk factors that were significantly associated with IFTMH. There was a higher prevalence of diabetes in controls (12% vs 5%). There was no association between the majority of indicators of oestrogen exposure in women and macular holes, but cases had a more difficult menopause as judged by the severity of hot flushes at menopause: odds ratio 2.6 (1.4-4.6). CONCLUSIONS: In common with other studies, we found only a few systemic factors associated with IFTMH. The study did confirm, however, that IFTMH is a strongly gender-related disease. There is some evidence for the role of sudden changes in hormonal balance, as seen by the increased reporting of severity of symptoms around the menopause along with (statistically non-significant) increased risks associated with hysterectomy and oophorectomy. The particular aetiological factor which puts women at increased risk of macular holes requires further studies.

Assessment of liposomal transfection of ocular tissues in vivo.

A possible route to the treatment of inherited retinal degenerations such as retinitis pigmentosa (RP) is the application of somatic gene therapy by the transfer and expression of corrective functional genes in ocular tissue. Cationic liposomes are established vehicles for the delivery and expression of exogenous genes in mammalian cells both in vitro and in vivo1. We report here a preliminary assessment of liposome-mediated transfer of a plasmid carrying the reporter gene lacZ (encoding the enzyme beta-galactosidase) into tissues of the adult rabbit eye.

Long-term follow-up of diode laser trabeculoplasty for primary open-angle glaucoma and ocular hypertension.

BACKGROUND: Initial studies of laser trabeculoplasty using infrared energy (810 nm) emitted by diode semi-conductor lasers have been encouraging. A 2-year study of diode laser trabeculoplasty (DLT) in the control of primary open-angle glaucoma (POAG) and ocular hypertension has been completed. METHODS: Patients with uncontrolled POAG or ocular hypertension were treated with DLT to one half of the trabecular meshwork using a trabeculoplasty lens. Spot size was 100 microns, exposure time was 0.2 second, and mean power was 1096 mW (+/- 46.5 mW). The desired endpoint was a mild blanching of the meshwork only. RESULTS: Twenty-five eyes of 16 patients were treated. Mean intraocular pressure reduction was 9.24 mmHg (+/- 3.4 mmHg) at 6 weeks, 9.32 mmHg (+/- 3.6 mmHg) at 3 months, 9.34 mmHg (+/- 3.8 mmHg) at 6 months, 8.42 mmHg (+/- 2.62 mmHg) at 12 months, 8.14 mmHg (+/- 3.42 mmHg) at 18 months, and 7.9 mmHg (+/- 3.63 mmHg) at 24 months. No pressure peaks (> 5 mmHg) were recorded after therapy. Inflammation and discomfort were minimal after laser treatment. Of 16 eyes examined at 2 years, there were no peripheral anterior synechiae. During the course of the study, six eyes became uncontrolled, despite one session of DLT. Four eyes regained control with a further session of DLT, but two required trabeculectomy. CONCLUSION: Diode laser trabeculoplasty is an effective form of therapy in POAG and ocular hypertension. Hypotensive effects and success rates are comparable with argon laser trabeculoplasty (ALT). Reduced inflammation after laser treatment may be due to reduced absorption of infrared energy by the melanin of the anterior segment. The portable nature of these lasers may allow for laser delivery in developing countries and remote situations.

Comparison of the anterior chamber inflammatory response to diode and argon laser trabeculoplasty using a laser flare meter.

BACKGROUND: Diode laser trabeculoplasty (DLT) has a similar hypotensive action to argon laser trabeculoplasty (ALT). However, anterior chamber inflammatory response and laser-induced discomfort are less pronounced with DLT. The authors compared the breakdown of the blood-aqueous barrier after DLT and ALT over the time course of 1 week and the hypotensive action over 8 weeks. METHODS: Twenty-five patients with uncontrolled intraocular pressure (IOP) were randomized to either DLT or ALT. If two eyes required treatment, then the second eye would be treated with the alternative laser to the first. Flare values were measured at 1, 3, 24, 48, 72, 96, and 168 hours using a laser flare and cell meter. Intraocular pressures were measured at similar intervals and at 8 weeks. RESULTS: Of 38 eyes treated, 21 underwent ALT and 17 DLT. Both forms of treatment induced a similar hypotensive effect with a significant reduction in IOP at 8 weeks compared with initial IOP (P < 0.01) (paired Student's t test). However, there was a significantly greater disruption of the blood-aqueous barrier with ALT when compared with DLT at 1, 3, and 24 hours (P < 0.001) and at 48, 72, and 96 hours (P < 0.01) (unpaired Student's t test). By 1 week, however, there was no significant difference in flare values between the two groups. Postlaser pain occurred in seven eyes treated with ALT but in no eyes treated with DLT. In addition, peripheral anterior synechiae occurred in four eyes after ALT by 8 weeks but none occurred in the DLT group. CONCLUSION: Argon laser trabeculoplasty produces a greater disruption of the blood-aqueous barrier than DLT. This may be associated with the development of complications in the anterior segment.

The effects of subconjunctival betamethasone on the blood aqueous barrier following cataract surgery: a double-blind randomised prospective study.

The aim of this double-blind randomised prospective study was to assess the effect of subconjunctival Betnesol (betamethasone sodium phosphate 0.1%) on the recovery of the blood aqueous barrier (BAB) following cataract surgery in uncomplicated eyes. Twenty patients [10 male, mean age 71.4 (SD 12.7) years] admitted for routine cataract surgery were randomised into two groups. All patients recruited into the study were free of other ocular disease and were not taking any anti-inflammatory medication. Group A received a subconjunctival injection of cefuroxime (125 mg) alone while group B received a subconjunctival injection of both cefuroxime and Betnesol. All surgery was performed by a single surgeon using a standardised surgical technique and all patients received the same postoperative medication. The Kowa laser flare cell meter was used to measure aqueous flare and cells preoperatively and on the first, second, and seventh postoperative day, and at 1 and 3 months following surgery. The code was broken only after all patients had been followed-up for 3 months postoperatively. There was no significant difference between the two groups in aqueous flare and cells at any of the postoperative visits. In this study we were unable to demonstrate any beneficial effect of subconjunctival betamethasone on damage to and recovery of the BAB following cataract surgery in the uncomplicated eye.

Perforation of the globe--a complication of peribulbar anaesthesia.

Peribulbar anaesthesia has been recommended as a safer alternative to retrobulbar anaesthesia. We report a case of perforation of the globe sustained during peribulbar anaesthesia which resulted in blindness. Orbital injections are potentially dangerous, be they peribulbar or retrobulbar. To minimise the risk, short, blunt needles are advocated for the peribulbar route.

Initial clinical experience using a diode laser in the treatment of retinal vascular disease.

A pilot study has been carried out to investigate the clinical use of an infrared diode laser in the treatment of a number of retinal vascular conditions. A hand-held device was employed initially and subsequently a further prototype was developed for use in conjunction with a standard slit lamp microscope. Thirty-three eyes in thirty patients were treated for conditions such as proliferative diabetic retinopathy, exudative retinopathy and branch and central retinal vein thrombosis. Regression of neovascularisation was observed in 13 of 16 eyes (81%) with proliferative diabetic retinopathy and in six of eight eyes (75%) with branch retinal vein occlusion. Four eyes were successfully treated for established or incipient rubeosis iridis following central vein thrombosis. Focal photocoagulation applied to five eyes for diabetic exudative maculopathy resulted in partial resorption of the exudates. These results are presented together with information on the ease of use of the laser and its reliability. The implications of the development of this instrument in the context of its place in ophthalmic therapy are discussed.

Changing patterns of early complications in cataract surgery with new techniques: a surgical audit.

We have undertaken a retrospective review of samples of case records from patients undergoing cataract surgery at St Thomas's Hospital over the years of the introduction of new extracapsular techniques and the widespread use of intraocular lens implants. We found no significant change in the proportion of patients achieving a corrected visual acuity of better than or equal to 6/12 three months after surgery. However, the pattern of complications was found to have changed in three respects. Firstly, there was a fall in the frequency of raised intraocular pressure requiring treatment associated with the abandonment of intracapsular surgery and the use of chymotrypsin. Secondly, a considerable number of patients who had had extracapsular extractions suffered from visually disabling posterior capsular thickening (13%). Thirdly, there was a downward trend in the rates of vitreous loss and of reduced vision at three months due to vitreous haemorrhage, vitritis, and retinal detachment in the patients undergoing extracapsular cataract surgery.