PubMed Health⌕ Search

Biomedical subjects

C A Puliafito

Publications and source records attributed to C A Puliafito.

126 records · Page 7Linked to original sources

Laser surgery of the lens. Experimental studies.

The authors used high peak power nanosecond (Q-switched) and picosecond (mode-locked) pulses from the neodymium-YAG laser to perform experimental anterior and posterior capsulotomy in rabbits. The morphology of laser anterior capsulotomy was studied using scanning electron microscopy. Ultrastructural studies revealed no evidence of morphologic abnormality in the corneal endothelium in eyes in which laser capsulotomy had been performed. The critical factors for the prevention of inadvertent retinal injury during laser surgery in the anterior segment of the eye were identified as pulse energy and cone angle of incident laser radiation. Using wide angle fundus photography and fluorescein angiography, intentional retinal injury during laser surgery of the lens was experimentally documented when retinal radiant energy exposure exceeded injury threshold.

Animals↗

Uveal melanoma in China.

We reviewed 65 cases of uveal melanoma from the Shanghai Eye, Ear, Nose, and Throat Hospital between 1956 and 1979. These 65 cases occurred at a rate of 4.5 cases per 10,000 inpatients on the ophthalmology service. Uveal melanoma is more frequently encountered in China than previous reports have suggested. In China, as in the United States, uveal melanoma is the most frequently occurring primary intraocular neoplasm in adults. We observed a strikingly younger age distribution of our cases; almost 20 percent of cases in our series involved patients between the ages of 19 and 30. The largest number of cases was seen in the fifth decade. However, only 5 cases (8 percent) were seen in the sixth decade. Fundus lesions, which were observed to stimulate choroidal melanoma, are similar to those encountered in the United States. One contrast was the importance of inflammatory lesions in the differential diagnosis of choroidal melanoma. Management of cases was surgical in all instances. A lower percentage of spindle cell tumors and a higher percentage of epitheloid tumors were seen than in most Western series.

Adult↗

Infectious endophthalmitis. Review of 36 cases.

A three-year retrospective study of 36 cases of infectious endophthalmitis seen at a large referral eye center between 1977 and 1980 was conducted. The criterion for infectious endophthalmitis was the culture of microorganisms from aqueous or vitreous on at least two media. The most frequent pathogen was Staphylococcus epidermis; it was isolated from 18 (50%) of the cases. In cases of infectious endophthalmitis following recent cataract extraction, S. epidermidis was isolated from 10 to 17 eyes (58.8%). Complete loss of visual function occurred in 16 of the 36 eyes (44.4%); a visual acuity of 20/400 or better as recorded in 15 eyes (41.6%) and 20/100 or better in eight (22.2%). Fifty percent of the cases were treated with vitrectomy and intraocular antibiotics. Poor visual outcome was associated with gram-negative organisms or delay of vitrectomy more than 24 hours after the initial diagnosis. In cases of postoperative S. epidermidis endophthalmitis, the most favorable visual outcomes were associated with use of intraocular antibiotics and vitrectomy; 80% of cases so treated had a final visual acuity of 20/400 or better and 60% had a visual acuity of 20/100 or better.

Adult↗

Optic atrophy and visual loss in craniometaphyseal dysplasia.

Four members of one family had craniometaphyseal dysplasia. Two of the four had severe optic atrophy with profound loss of vision as a complication of this disorder. Optic nerve decompression attempted in one patient may have caused a reduction in the vision of that eye. Eight years later this patient underwent craniofacial surgery uneventfully for contouring of her facial and cranial bones, but osteotomies and intracranial surgery were specifically avoided because of bony over-growth in the foramen magnum region.

Adolescent↗

Clinical trial comparing timolol ophthalmic solution to pilocarpine in open-angle glaucoma.

A ten-week, double-masked, randomized, clinical trial compared timolol ophthalmic solution and pilocarpine in the therapy of open-angle glaucoma. Timolol decreased the intraocular pressure at least as much as pilocarpine and did not induce miosis, accommodative spasm, or other annoying side effects. The pulse was slowed by timolol, but blood pressure was unaffected. Significant decreases in intraocular pressure were still present after ten weeks of maintenance therapy with the same concentration of drug.

Adult↗

Long-term experience with timolol ophthalmic solution in patients with open-angle glaucoma.

Timolol was used by 37 glaucoma patients from 1 to 18 months. Of those 37 patients, 31 used timolol for three months or longer and 7 used timolol for over one year. Timolol produced sustained reductions in intraocular pressure with continuous administration and did not induce miosis, accommodative spasm, or other annoying side effects. Systemic absorption produced a mild slowing of resting pulse rate. In some patients, timolol's ocular hypotensive effects are additive to miotics and carbonic anhydrase inhibitors.

Adult↗

Laser interactions with the cornea.

Principles of laser-tissue interactions in the eye are reviewed. Corneal structure and function are summarized, with particular regard for features related to laser treatment. A summary of argon and carbon dioxide laser techniques in the cornea is presented, followed by a review of studies on corneal response to ultraviolet radiation. A detailed description is then given of the characteristics of excimer laser tissue ablation. Potential applications of this process in corneal and keratorefractive surgery are reviewed.

Argon↗

Plasma-mediated excimer laser ablation of bone: a potential microsurgical tool.

A pulsed ultraviolet excimer laser was used to ablate bone in vitro at 193, 248, 308, and 351 nm and in vivo at 193 nm. Ablation was dependent on sufficient fluence (energy delivered per unit area per pulse) for plasma formation at the target site at all wavelengths. Adjacent tissue damage at various fluences for each wavelength was examined using a light microscope. Damage was minimal at 193 nm (1 to 3 microns) and most extensive at 351 nm (60 to 75 microns). This is in sharp contrast to the 1 to 3 mm of adjacent thermal damage produced when carbon dioxide lasers are used to ablate bone. Differences in the degree and type of damage to adjacent tissues among the wavelengths studied indicated that other ablation mechanisms and tissue interactions are involved in addition to simple plasma vaporization of bone. Bleeding during and after ablation demonstrated that the use of this laser does not cause thermal damage, which would cauterize adjacent vessels. Pre- and post-mortem lesions made at identical power and pulse settings were of equal depth, indicating that bleeding does not affect the ablation rate. The excimer laser has potential as a microsurgical instrument for the precise removal of bone with minimal damage to adjacent structures.

Animals↗

Clinical strategies for excimer laser therapeutic keratectomy.

BACKGROUND: Surgical therapy for superficial corneal scars, dystrophies, or surface irregularities with the 193 nm excimer laser shows great promise. Depending upon the character of the pathology to be treated, different surgical strategies are required. METHODS: Treatment strategies for three patients with diverse corneal pathology are presented. Focal surface irregularities are treated with small laser spot sizes leaving the epithelium intact. Smooth, uniformly distributed subepithelial anterior stromal pathology is best removed with a large spot size through intact epithelium. When scattered scarring of variable thickness is present, selective epithelial debridement permits improved exposure of irregularities in Bowman's layer and the anterior stroma. RESULTS: Guidelines for selective debridement of epithelium and protection of adjacent and underlying stroma with moderate viscosity solutions enhances the surgeons's ability to obtain a smooth and clear surface while minimizing corneal thinning. Even with these strategies and use of plano disc ablation, net hyperopic shift generally occurs with broad large area therapeutic ablation. CONCLUSIONS: Superficial corneal opacities and irregularities can be surgically treated with the excimer laser as an alternative to the more invasive procedure of lamellar keratoplasty. Treatment failures can then go on to lamellar keratoplasty while successfully treated patients are more rapidly rehabilitated at lower total cost than a lamellar graft. Refinement of treatment strategies to minimize the hyperopic shift and facilitate masking around irregularities will further improve the results.

Adult↗

Indocyanine green angiography for recurrent choroidal neovascularization in age-related macular degeneration.

BACKGROUND AND OBJECTIVE: Recurrence of choroidal neovascular membranes (CNV) occurs frequently following laser photocoagulation. Recurrent CNV can be difficult to treat because they may not be well defined by fluorescein angiography. PATIENTS AND METHODS: The fluorescein and indocyanine green (ICG) angiograms of 58 eyes of 57 patients who presented with clinically suspected recurrence were evaluated retrospectively. RESULTS: In 14 eyes (24%), a well-defined recurrent CNV could be identified by evaluating the fluorescein angiogram. In 6 (14%) of the remaining 44 eyes, a well-defined recurrent CNV was identifiable by ICG angiography. CONCLUSION: A role for ICG angiography in the care of patients with suspected recurrent CNV is discussed.

Aged↗