Ocular telemedicine between Nepal and the USA: prevalence of vitreoretinal disease in rural Nepal.

This study is aimed at reporting experiences with telemedicine between Nepal and the USA and at reporting the prevalence of age-related macular degeneration (AMD) and diabetic retinopathy (DR) in rural Nepal. AMD and DR are becoming more significant factors for non-reversible vision loss in rural Nepal due to increasing life expectancy and urbanisation. The prevalence of DM is low compared with the developed world, but the percentage of diabetics with DR is high, presumably due to limited access to healthcare. The higher prevalence of DM in Hetauda is explained as being due to a more urban lifestyle, dietary habits (more deep-fried food) and more advanced age.

Malattia leventinese presenting with subretinal neovascular membrane and hemorrhage.

PURPOSE: To report a case of malattia leventinese involving subretinal hemorrhage. METHODS: Case report. RESULTS: Two weeks after initial presentation, the visual acuity of this 34-year-old man decreased to LE: 20/100. Funduscopic evaluation revealed a subretinal hemorrhage involving the center of the foveal in the left eye that was interpreted as secondary to a neovascular membrane on fluorescein angiography. The patient did well after the removal of the submacular material by pars plana vitrectomy. CONCLUSION: Patients with malattia leventinese may occasionally present with submacular hemorrhage. Prompt diagnosis and intervention may enhance the patient's chance for visual improvement.

Irreversible silicone oil adhesion to silicone intraocular lenses. A clinicopathologic analysis.

PURPOSE: To report a newly defined complication of foldable intraocular lenses (IOLs), namely silicone oil-silicone IOL interaction. This is a complication not generally seen by the implanting cataract surgeon but, rather, at a later stage in a patient's postoperative course, by a vitreoretinal surgeon. METHODS: Three clinical case histories, including two explanted silicone IOLs, were submitted for analysis. The submitted silicone lenses were photographed under water, and the nature of the silicone oil coating was documented. RESULTS: In each instance, the silicone coating was manifest as a thick coating with droplet formation on the lens surface that was tenaciously adherent and could not be dislodged by instruments or injection of viscoelastics. CONCLUSION: The use of silicone IOLs in patients with current vitreoretinal disease or those who are at high risk for future vitreoretinal disease that may require silicone oil as part of the therapy should be reconsidered. The authors recommend that information regarding the existence and significance of this complication be printed on all silicone oil and silicone IOL packages and inserts (if not as a warning, at least as an informative comment regarding the existence of this condition). This is a rare but clinically significant complication that will affect the occasional patient treated with both of these modalities.

Branch retinal artery occlusion as the initial sign of giant cell arteritis.

PURPOSE: To describe a patient whose initial sign of giant cell arteritis was a branch retinal artery occlusion. METHODS: We examined a 77-year-old woman who developed arteritic anterior ischemic optic neuropathy three weeks after an isolated non-embolic branch retinal artery occlusion occurred in the same eye. RESULTS: The diagnosis of giant cell arteritis was confirmed by temporal artery biopsy after the patient was treated with intravenous corticosteroids. CONCLUSIONS: Although a rare cause of branch retinal vascular occlusion, giant cell arteritis should be considered in the differential diagnosis of a non-embolic branch retinal artery occlusion in elderly patients.

Laser photocoagulation for stage 3+ retinopathy of prematurity.

Twenty-two infants with "threshold" stage 3+ retinopathy of prematurity (ROP) were entered into a prospective, randomized clinical trial to compare the efficacy of transscleral cryotherapy versus laser photocoagulation delivered by the indirect ophthalmoscope. Eighteen infants have been followed for at least 3 months. Fifteen of 16 eyes randomized to laser and 9 of 12 eyes randomized to cryotherapy showed regression. The results suggest that laser therapy is as effective as cryotherapy in the treatment of ROP (P = 0.285).

Inadvertent globe perforation during retrobulbar and peribulbar anesthesia. Patient characteristics, surgical management, and visual outcome.

The authors report a series of 20 eyes from 20 patients in whom inadvertent perforation of the globe occurred during local anesthesia for ocular surgery. Perforation resulted from retrobulbar anesthesia in 18 eyes and from peribulbar anesthesia in 2 eyes. Nine (45%) of 20 eyes had an axial length greater than or equal to 26.00 mm. Combining this figure with axial length data for the general population and estimates for the risk of globe perforation during local anesthesia yields an approximate incidence of perforation in eyes with axial length greater than or equal to 26.00 mm of 1 in 140 injections. Proliferative vitreoretinopathy (PVR) developed in 8 of the 20 eyes (40%) in this series. Overall, 15 (75%) of the 20 eyes were successfully repaired, and, in five eyes (25%), the final visual acuity was 20/70 or better.

Surgical removal of massive subretinal hemorrhage associated with age-related macular degeneration.

The authors report on 11 patients with age-related macular degeneration associated with massive subretinal hemorrhage, who were treated with surgical removal of the hemorrhage and associated fibrosis. Preoperative visual acuity ranged from 20/400 to hand motions. Postoperative visual acuity ranged from 20/200 to light perception with a minimum of 3 months of follow-up. Complications included partial or total retinal detachment in four patients (36%) and cataract in four patients (36%). Four of 11 patients showed some improvement in vision (36%). All four of these patients had surgery within 1 week of the onset of severe visual loss. Although surgical removal of large subretinal hemorrhages is technically feasible, visual recovery is limited, even in uncomplicated cases, by macular degenerative changes.

Extensive peripheral retinectomy combined with posterior 360 degrees retinotomy for retinal reattachment in advanced proliferative vitreoretinopathy cases.

Posterior 360 degrees retinotomy in conjunction with extensive peripheral retinectomy was necessary for retinal reattachment in 18 eyes. A visual acuity of 20/400 or better was achieved in 22% of the patients; in patients with rubeosis, regression was found in 89%. Of the hypotonus eyes, preoperatively 78% were normotensive postoperatively after removal of anterior proliferative vitreoretinopathy (PVR) covering ciliary epithelium. The major intraoperative complication was hemorrhage, which could be readily controlled. Recurrent retinal detachment (RD) occurred in 39% and reproliferation in 50% of the patients.

Cutis marmorata telangiectatica congenita associated with bilateral congenital retinal detachment.

Cutis marmorata telangiectatica congenita is a rare congenital vascular disorder of the skin, characterized by persistent telangiectasia of the cutaneous blood vessels often associated with cutaneous ulcers. The only previously recognized ophthalmic association with this condition has been rare instances of unilateral congenital open angle glaucoma. The authors report their observations in a child in whom this cutaneous disorder was associated with congenital bilateral total retinal detachments and secondary neovascular glaucoma. The retinal detachments produced bilateral leukocoria simulating retinoblastoma. The cutaneous disorder and the ocular findings were confirmed histopathologically.

Semiconductor diode laser endophotocoagulation.

We successfully used a semiconductor diode laser to deliver endophotocoagulation burns to the retina of a rabbit. The diode laser employed emits light at a wavelength of 817 nm (near infrared). It has a power output of up to 1.0 W in the continuous-wave mode, equivalent to the capability of current argon laser endophotocoagulators. A standard, commercially available fiberoptic endophotocoagulation probe was used to deliver the laser burns. We used power settings ranging from 300 mW to 400 mW and exposure times of 0.1 to 0.2 seconds to produce chorioretinal burns that appeared clinically and histopathologically indistinguishable from those induced with conventional wavelengths. This new laser system has the decided advantages over traditional endophotocoagulators of being much smaller, less costly, and requiring no water cooling, without sacrificing power output or ease of delivery.

Laser sclerostomy ab interno using a continuous wave Nd:YAG laser.

We report the use of a continuous wave Nd:YAG (CW-YAG) laser focused through a sapphire crystal to create a filtering bleb by ab-interno sclerostomy. A 2-mm clear corneal incision was made in each eye of five anesthetized Dutch Belted rabbits, and the 30-mm-long sapphire crystal with a 0.2-mm focal tip was passed across the anterior chamber until it came in contact with the opposite angle. Between two and three pulses of 0.8 J were required to produce a filtering bleb in each of the 10 eyes. The overlying conjunctiva was not damaged; the procedure time was under five minutes. Histological examination revealed a surrounding area of scleral melting that extended an average of 0.06 mm from the sclerostomy. These data suggest that the CW-YAG laser may be useful in performing glaucoma filtering surgery with minimal damage to surrounding ocular tissues.

In vitro inhibition of lens epithelial cell growth by continuous wave Nd:YAG laser.

Bovine lens epithelial cells were suspended in MEM medium and subjected to continuous wave, low power, pulsed neodymium:yttrium-aluminum-garnet (Nd:YAG) laser irradiation. The temperature of each suspension was maintained at 36 degrees C. Laser applications ranged from 1 to 10 watts and from 100 to 2000 seconds, but the total dose to each of the epithelial cell suspension was 2000 J. Six to thirty-nine percent of the cells were dead immediately after irradiation. Surviving cells, cultured for 15 days, showed decreased attachment and failed to grow. These preliminary results suggest that the Nd:YAG laser may be used during cataract surgery to prevent subsequent lens epithelial cell proliferation and the resulting vision reduction and glare.

The role of inflammation in CW Nd:YAG contact transscleral photocoagulation and cryopexy.

Cyclodestructive modalities in humans have been shown to be effective when applied 3.5 mm or more posterior to the limbus. Therefore, CW Nd:YAG contact transscleral laser and cryopexy were applied 6 mm posterior to the limbus of pigmented rabbits. The intraocular pressure (IOP), flare, iritis, cells and conjunctival hyperemia were monitored clinically up to 3 weeks. The pressure lowering effect was -7.5 +/- 7.7 mm Hg for laser retinopexy and -14.2 +/- 6.0 mm Hg for retinocryopexy at 3 weeks and was comparable to application of the same modalities directly over the ciliary body. Similarly, induction of intraocular inflammation by injecting 10 micrograms of endotoxin intravitreally lowered IOP significantly. These findings suggest that hypotension may not be directly due to cyclodestruction but may be related to the ocular irritative response and extent of neuroepithelial defect, irrespective of its distance from the limbus.

A comparison of CW Nd:YAG contact transscleral cyclophotocoagulation with cyclocryopexy.

The cyclodestructive and inflammatory effects of CW Nd:YAG contact laser were compared to those of conventional cryopexy. CW Nd:YAG light transmitted by fiber optic cable and sapphire crystal was applied transsclerally to the ciliary body of pigmented and albino rabbits. Cyclocryopexy was given to a comparable second group. The intraocular pressure (IOP), flare, iritis, cells and conjunctival hyperemia were monitored clinically up to 3 weeks. The breakdown of the blood-aqueous barrier and time course of ocular inflammation was similar for both modalities and IOP was -12.2 +/- 4.2 mm Hg for laser cyclopexy and -15.1 +/- 5.4 mm Hg for cyclocryopexy at 3 weeks. Ciliary body lesions were noted in both groups. Overall, albino rabbits showed less histological damage and faster recovery of IOP. Contact cyclophotocoagulation and cyclocryopexy can be considered models of ocular injury. The similarities in ocular irritative response suggest a similar pathophysiologic mechanism underlying the pressure behavior in both thermal mode injuries.

Contact neodymium:YAG laser. Experimental studies and oculoplastic applications.

Contact Nd:YAG laser surgery offers a new method of delivering laser energy to a target tissue site. Nd:YAG, a near-infrared laser, can be transmitted through an optical fiber delivery system to a synthetic sapphire probe. This sapphire probe can be used as a surgical scalpel to cut, vaporize, or coagulate tissues. The contact laser scalpel offers many advantages over conventional steel scalpel surgery and the system overcomes many of the limitations encountered with noncontact Nd:YAG lasers. A review of the history, biophysics, and experimental studies is presented. Clinical oculoplastic applications are reviewed.

Contact transscleral retinopexy using a sapphire crystal probe.

To examine the laser-tissue interactions for contact transscleral irradiation, argon and CW Nd:YAG light was delivered through a synthetic sapphire crystal which was held in direct conjunctival contact perpendicular to the peripheral retina. The threshold for retinal whitening was 0.5 J in the rabbit, 1.0-1.5 J in the monkey, and 1.0-4.0 J in human eyes. Histologic examination of the acute injury and at 2 days, 1, 3, 6, and 12 weeks, showed coagulative lesions centered around the pigmented layers in the rabbit. While severe chorioretinal disruption and hemorrhage did occur depending on species, energy level, and probe location, no scleral perforation was noted at any setting. These preliminary studies suggest that transscleral contact lasers may be used safely in clinical situations where selective ablation of the peripheral retina or pigmented tissues is the primary objective.

Surgical dilation of the pupil during pars plana vitrectomy.

Adequate pupillary dilation is essential to dissect and excise peripheral tractional proliferative tissue during vitreous surgery. Most surgical dilating procedures involve an incision or excision of iris tissue, that is either inadequate or irreversible. We describe a modification of a previously devised technique for stretching the pupil that ensures an excellent view of the peripheral retina. The technique has been used in aphakic and pseudophakic eyes in over 50 cases with no postoperative morbidity or problems with glare or poor cosmesis.

Complications associated with the use of silicone oil in 150 eyes after retina-vitreous surgery.

Complicated retinal detachments (RDs) were successfully managed in 150 eyes of 170 consecutive patients by one surgeon (JLF) using silicone oil in conjunction with modern pars plana vitrectomy. Long-term postoperative complications were observed between 6 months and 5 years of follow-up. Cataracts developed in all phakic eyes and all corneas with oil-endothelial touch showed band keratopathy within 6 months. Recurrent detachments were noted in 22% of eyes during silicone oil tamponade and occurred in 13% of eyes after the oil had been removed. Other complications associated with the use of oil for vitreous surgery included pupillary block glaucoma (3%), closure of the inferior iridectomy (14%), fibrous epiretinal and subretinal proliferations (15%), pain (5%), and subconjunctival deposits of oil (3%). Without exception, within a period of 1 year the intraocular silicone oil showed some degree of emulsification, suggesting that the physicochemical characteristics of the oil injected may be an important variable in long-term complications.

Contact laser: thermal sclerostomy ab interna.

An experimental technique utilizing a sapphire contact laser probe for thermal sclerostomy ab interna is described. The contact laser probe with a tip diameter of 0.2 mm is brought in contact with the trabecular meshwork. Using 3.50 watts of cw Nd:YAG at 0.1 second duration, three to five exposures established communication between anterior chamber and subconjunctival space in pigmented rabbits.