Large-diameter lamellar keratoplasty in severe ocular alkali burns: A technique of stem cell transplantation.

PURPOSE: To evaluate the efficacy of large-diameter lamellar keratoplasty in cases of severe ocular alkali burns. DESIGN: Prospective, noncomparative, interventional case series. PARTICIPANTS: Nine eyes of nine patients with severe ocular alkali burns (grade III/IV) exhibiting corneal vascularization, conjunctivalization, and chronic inflammation were recruited from the Cornea Clinic of Dr. Rajendra Prasad Centre for Ophthalmic Sciences, New Delhi, a tertiary eye care center. INTERVENTION: Large-diameter lamellar keratoplasty was performed using McCarey-Kaufman media-preserved donor corneas. The patients were followed up for a minimum of 6 months. MAIN OUTCOME MEASURES: Symptomatic relief, time to epithelialization, best-corrected visual acuity, Schirmer I, tear film break-up time, and central corneal clarity were the parameters evaluated. RESULTS: The mean duration between the injury and surgery was 29.5 +/- 19.4 months. No intraoperative complications were seen. Successful epithelialization of the ocular surface was achieved in all but one eye, and the mean time to epithelialization was 5.2 +/- 4.9 days. One eye had a persistent epithelial defect which was managed with a bandage soft contact lens. All patients achieved symptomatic relief. The preoperative best-corrected visual acuity was

Low-cost high-volume extracapsular cataract extraction with posterior chamber intraocular lens implantation in Nepal.

OBJECTIVE: To improve current clinical practices and ways of thinking about the problem of curable Third-World blindness resulting from cataract. DESIGN: A two-site prospective, nonrandomized, comparative clinical trial. PARTICIPANTS: Patients from 2 distinct surgical venues underwent cataract surgery following the same carefully outlined protocol: 62 consecutive cases from the Tilganga Eye Centre in Katmandu, Nepal, and 207 cases from a remote eye camp in rural Chaughada, Nepal. INTERVENTION: Extracapsular cataract extraction with posterior chamber intraocular lens (IOL) implantation surgery using a technique developed by Dr. Sanduk Ruit of the Tilganga Eye Centre in conjunction with the Medical Directorate of the Fred Hollows Foundation of Australia. Also presented is the teaching method used to help make local doctors proficient in this technique. MAIN OUTCOME MEASURES: Visual acuity recorded at 2 months after surgery as well as surgical complications. RESULTS: Preoperative visual acuities for the 62 patients from the Tilganga Eye Centre ranged from 20/60 to light perception only (4 patients were untested). At 2 months after surgery, 87.1% had a best-corrected visual acuity of 20/60 or better. There were zero major surgical complications reported from the Tilganga group. Of the 207 patients at the Chaughada eye camp, preoperative visual acuities (recorded for 177 [85.5%]) ranged from 20/200 or greater to light perception only. One hundred eighty-nine (91.3%) of the patients returned for an examination at 2 months after surgery, at which time 54.5% had an uncorrected visual acuity of 20/60 or greater, improving to 74.1% with correction. There were six (2.9%) surgical complications documented at Chaughada. CONCLUSIONS: Because the average operative time using the technique presented here is less than 10 minutes per case and the cost per surgery is less than $20, the surgical results are significant in addressing the massive problem of cataract blindness in the Third World. With some changes in preoperative care, a simplified surgical technique, the development of local lens factories, and the implementation of teaching programs, effective lens implantation cataract surgery can be done in high volume at affordable costs in remote areas of underserved nations.

High-altitude retinopathy and altitude illness.

OBJECTIVE: To determine the relationship between high-altitude retinopathy (HAR) and other altitude-related illnesses and establish a classification system for HAR. DESIGN: Observational case series. PARTICIPANTS: All 40 climbers among 3 Himalayan expeditions who ascended to altitudes between 16,000 and 29,028 feet above sea level (summit of Mt. Everest) were examined for signs of HAR and altitude illness (AI). METHODS: All subjects had dilated fundus examinations before the ascent, intermittent fundus, and medical examinations during the climb and a dilated fundus and medical examination within 2 days after attaining their highest altitude. MAIN OUTCOME MEASURES: Careful fundus drawings or fundus photography or both were obtained for all participants. All subjects gave a subjective assessment of their symptoms of acute mountain sickness (AMS) and were assessed clinically for signs of high-altitude cerebral edema (HACE). RESULTS: Nineteen of 21 climbers who ascended above 25,000 feet developed HAR. Fourteen of 19 climbers who attained altitudes between 16,000 and 25,000 feet were found to have retinopathy. A grading system for HAR describing the severity of the retinopathy was developed. Correlation of the retinopathy with other AI showed that AMS was endemic and that a statistically significant correlation exists between HAR and HACE (P = 0.0240). CONCLUSION: Recognizing advancing grades of HAR may allow physicians to recommend initiating empiric treatment with oxygen, steroids, diuretics and immediate descent to prevent HAR progression, macular involvement, or potentially fatal HACE. High-altitude retinopathy is both a significant component of and a predictor of progressive AI.

Cluster of diplopia cases after periocular anesthesia without hyaluronidase.

PURPOSE: To describe a cluster of cases of iatrogenic diplopia after cataract surgery that occurred in 1998, when hyaluronidase was unavailable for use in periocular anesthetic regimens. SETTING: The clinical practices of the authors. METHODS: This study comprised a retrospective chart review. RESULTS: Twenty-five cases of transient or permanent diplopia were reported. Of these, 13 eyes had retrobulbar and 10 had peribulbar injections; in 2 cases the injection technique was unknown. The inferior rectus was affected in 19 eyes; of these, 1 had a temporary palsy and 18 had permanent restriction. Temporary paresis developed in the lateral rectus in 5 cases and the superior rectus in 2. Eleven cases were submitted by 4 anterior segment surgeons, who collectively had a zero incidence of iatrogenic postoperative diplopia in the preceding 4 to 11 years of practice (approximately 6900 cases). CONCLUSION: Hyaluronidase may be more important than previously suspected in preventing anesthetic-related damage to the extraocular muscles. The inferior rectus muscle is particularly vulnerable, presumably because of the injection technique.

Oversized grafts in children.

OBJECTIVE: To evaluate the efficacy of oversized corneal grafts in the pediatric age group. DESIGN: Prospective, nonrandomized clinical trial. PARTICIPANTS AND INTERVENTION: Forty pediatric patients with unilateral or bilateral corneal opacification of congenital or acquired origin underwent corneal grafting surgery over a period of 2 years using donor corneal buttons oversized by 1 mm. MAIN OUTCOME MEASURES: The parameters evaluated were indications for keratoplasty, graft clarity, visual acuity, keratometry, spherical equivalent, anterior chamber depth, and complications. RESULTS: Corneal ulceration was the most common cause of corneal opacification (25%), followed by trauma (20%) and sclerocornea (20%). At 1 year, clear grafts were achieved in 85% of the cohort. The average keratometry at the end of 1 year was 43.28 +/- 1.65 diopters (D) in the congenital opacity group and 43.04 +/- 2.20 D in the acquired group. The keratometric astigmatism was 3.60 +/- 2.60 D in the congenital group and 2.52 +/- 2.20 D in the acquired group. Oversized grafts provided an adequate anterior chamber depth of 2.20 +/- 0.612 mm in the congenital group and 2.36 +/- 0.302 mm in the acquired group. Visual acuity of 20/80 or better was recorded in only 30% of cases in the congenital group as opposed to 47% with acquired opacities. Nine cases had episodes of graft rejection. CONCLUSION: Oversizing donor buttons by 1 mm provides adequate anterior chamber depth and increases the morphologic success of corneal grafting in children.

Comparison of the effects of enucleation and orbital reconstruction using free-fat grafts, dermis grafts, and porous polyethylene implants in infant rabbits.

Twenty-nine infant rabbits from four litters were randomly assigned to three groups. No surgery was performed on left eyes. All right eyes were enucleated. Group 1, the control group, had no right-socket reconstruction. Group 2 had reconstruction using free-fat and dermis grafts. Group 3 had reconstruction using porous polyethylene implants. On attaining adult size, rabbits were killed, decapitated, and prepared for measurements. Orbital volume measurements were performed twice and orbital entrance areas were determined once. No significant differences were noted between first and second measurements of orbital volumes. Right orbital volumes were significantly smaller than left orbits in all groups except for the second measurement of the polyethylene implant group. Right orbital entrance areas were significantly smaller than left areas in the control and the free-fat and dermis graft groups. Right orbital entrance areas of the polyethylene group were not significantly smaller than the corresponding left orbital entrance areas. The use of free-fat and dermis grafts for orbital reconstruction in anophthalmic infant rabbits did not significantly stimulate orbital bone growth. In one trial, the polyethylene implant group displayed right orbital volumes and orbital entrance areas that were not significantly smaller than controls.

Corneal superinfection in acute hemorrhagic conjunctivitis.

PURPOSE: This study aimed to evaluate the clinical profile, microbial spectrum, management modalities, and visual outcome in cases of corneal superinfection that occurred after an epidemic of acute hemorrhagic conjunctivitis. METHOD: A retrospective analysis of 14 eyes of 13 patients who were referred to a tertiary eye-care center with corneal ulceration after an episode of acute hemorrhagic conjunctivitis was undertaken. The parameters analyzed were age, sex, prior use of topical medications, predisposing factors, ulcer characteristics, organisms isolated, success of medical therapy and surgery, and visual outcome. RESULTS: A definite history of topical corticosteroid use to treat acute hemorrhagic conjunctivitis was elicited in 12 (86%) eyes. Cultures were positive in 86% (12/14) eyes. Organisms isolated were Pseudomonas aeruginosa (three eyes, 25%), Fusarium species (three eyes, 25%), Aspergillus species (two eyes, 16%), and Staphylococcus aureus (two eyes, 16%). Mixed infection occurred in two patients. After discontinuation of topical corticosteroids, all patients received antimicrobial therapy. The keratitis resolved in seven eyes. Therapeutic penetrating keratoplasty was required in five eyes. Two patients were lost to follow-up. CONCLUSIONS: Corneal superinfection may occur after acute hemorrhagic conjunctivitis. Use of topical corticosteroids to treat acute hemorrhagic conjunctivitis may predispose an already compromised cornea to develop microbial keratitis and such a practice should be discouraged.

Refractive versus corneal changes after photorefracive keratectomy for astigmatism.

PURPOSE: To define measures of assessing success and subsequent ways to improve excimer laser treatment of astigmatism. METHODS: We studied 97 eyes of 79 patients, followed for 12 months, that underwent photorefractive keratectomy (PRK) for myopia and astigmatism with a VISX 20/20 excimer laser. Preoperative spherical equivalent refraction at the corneal plane was between -1.00 and -15.00 D. Mean preoperative refractive astigmatism at the spectacle plan was -2.17 +/- 1.05 D (range, -1.25 to -6.00 D), which is -1.81 +/- 0.86 D (range -1.04 to -4.97 D) when calculated at the corneal plane. All patients were examined before and after surgery; examination included refraction, keratometry, and topography measurement. RESULTS: The success in treatment of astigmatism appeared measurably less than the treatment of sphere when analogous indices were used for assessment. Success in astigmatism surgery improved, as measured by all parameters, after an additional 20% was applied to astigmatism treatment magnitude indicated by the VISX computer algorithm. The sequential modes of treatment undercorrected astigmatism magnitude to a greater extent than elliptical, but equivalent success rates were present in view of the greater astigmatic changes attempted using the sequential mode. The elliptical mode tended to produce a greater undercorrection of associated sphere (p = 0.313). Results measured by refraction showed a larger change than those measured by topography and keratometry. CONCLUSION: During PRK with the VISX 20/20 laser, adjustment for undercorrection of astigmatism treatment achieves a fuller correction of astigmatism. When measuring astigmatic changes, results are different when comparing refractive astigmatism changes with corneal astigmatism changes measured by keratometry and topography.

Astigmatic change 1 year after excimer laser treatment of myopia and myopic astigmatism. Melbourne Excimer Laser Group.

PURPOSE: To evaluate the surgically induced astigmatism (SIA) 1 year after excimer laser photorefractive astigmatic keratectomy (PARK) and photorefractive keratectomy (PRK). SETTING: Royal Victorian Ear and Eye Hospital, Melbourne, Australia. METHODS: This study comprised 333 PARK patients and 155 PRK patients treated with a VISX 20/20 excimer laser and followed prospectively for 12 months. Vector analysis of the change in astigmatism was used to calculate the SIA in the PRK group and the percentage of astigmatism corrected in the PARK group. RESULTS: Among patients with low cylinders astigmatic correction varied greatly, particularly in those treated for large amounts of myopia. The spherical PRK treatments yielded a mean induced postoperative astigmatism of 0.47 diopter. There was a linear relationship between this inadvertent SIA and increasing myopia. CONCLUSION: Excimer laser surgery for myopia creates a low degree of random, unpredictable SIA that may be the result of irregular epithelial thickening during postoperative healing. This creates a background noise of astigmatic change upon which the targeted astigmatic correction is superimposed.

Predictive leg strength values in immediately prepubescent and postpubescent athletes.

Sixty healthy, athletic children were treated on a Cybex II Dynamometer to obtain values for the relative strengths of the major muscle groups of the lower extremity. Prepubescent and postpubescent boys and girls were tested. Of the anthropometric parameters measured, lean body weight correlated best with maximal torque force development. In prepubescent children, the mean maximal quadriceps torque force, measured in foot-pounds at 60 deg/sec, is equal to 70% of the lean body weight. In postpubescent subjects, the mean peak quadriceps torque equalled 80% of the lean body weight in girls and 90% of the lean body weight in boys. Correlations can be established between the maximal torque force generated by the quadriceps and the strength of the hamstrings, ankle dorsiflexors, and plantar flexors. The values obtained are useful in planning training and rehabilitation programs and in determining when an injured young athlete can safely return to his or her sport.