Geoffrey Tabin

Late Recurrences and the Necessity for Long-term Follow-up in Corneal and Conjunctival Intraepithelial Neoplasia

PURPOSE The purpose of the study was to elucidate the natural history of corneal-conjunctival intraepithelial neoplasia (CIN) and suggest treatment and follow-up guidelines. METHODS The records of all histologically proven cases of CIN at the Royal Victorian Eye and Ear Hospital between 1979 and 1994 were reviewed. RESULTS Seventy-nine eyes of 76 patients had a pathologic diagnosis of CIN and were observed for up to 15 years. The lesion recurred in 31 eyes (39%) overall. There was no statistical difference shown in the likelihood of recurrence based on histologic classification. Complete excision was attempted in each case. In 18 eyes, dysplastic cells were evident at the excision margin. Ten (56%) of these tumors recurred, compared to a 33% recurrence rate in completely excised lesions. The time to the first recurrence ranged from 33.0 days to 11.5 years between the first and second surgeries, with 11 lesions recurring after more than 4 years. Incompletely excised lesions reappeared more rapidly (average, 2.5 years) than did those with clear surgical margins (average, 3.8 years). Seven cases progressed to invasive squamous cell carcinoma and four cases led to blindness or removal of the eye. CONCLUSIONS This study suggests that excision margin at the time of surgery is the most important factor in predicting recurrence. The slow growth of the recurrent lesions combined with the ever-present malignant potential leads the authors to suggest that all patients with a history of CIN warrant annual follow-up for the remainder of their lives.

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.

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.

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

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

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.

Penetrating keratoplasty in Nepal

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 </=1/60 in all the patients. There was a significant improvement in vision in six eyes postoperatively (P = 0.013). The corneal clarity was grade 2+ or better in five eyes and 1+ in four eyes. No recurrence of corneal vascularization or signs of rejection were seen in any eye during the mean follow-up of 7.4 +/- 3.2 months. Causes of no improvement of vision included the presence of subepithelial nebulomacular haze in one eye caused by persistent epithelial defect and residual stromal haze. CONCLUSIONS Large-diameter lamellar keratoplasty is a useful therapeutic modality in cases of severe alkali burns. It is a single-stage procedure that provides a stable ocular surface because of stem cell supplementation and may visually rehabilitate the patient.

Astigmatic change 1 year after excimer laser treatment of myopia and myopic astigmatism

Purpose: To identify indications and outcomes in a large series of penetrating keratoplasty surgeries performed in Nepal. Methods: A retrospective case series of 472 consecutive penetrating keratoplasty surgeries (408 patients) performed at Tilganga Eye Center, Kathmandu, Nepal from June 1994 to September 1999. Results: Mean recipient age was 39.2 years (± 19.7 years). Main indications for PKP were corneal scar (37%), adherent leukoma (35%), perforation or impending perforation (9%), pseudophakic bullous keratopathy (6%), keratoconus (4%), and aphakic bullous keratopathy (3%). Mean duration of follow-up was 27.6 ± 25.1 months. Sixty-five percent of available grafts were clear at 6 months, and 70% of available grafts were clear at 3 years. Six months postoperatively, 15% of patients had acuity better than 6/18, 37% had acuity between 6/18 and 6/60, and 17.7% had acuity between 6/60 and 3/60. Common causes of graft failure were endothelial failure (43%), increased intraocular pressure (15%), ulcer (14%), and trauma (7%). Conclusions: The corneal diseases and indications for transplant surgery in Nepal are different from those in the Western world. Despite these differences, penetrating keratoplasty is a successful and reasonable way to reduce corneal blindness in developing nations.

Corneal superinfection in acute hemorrhagic conjunctivitis.

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.

Atypical presentation of Acanthamoeba keratitis.

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.

Etiologic diagnosis of corneal ulceration at a tertiary eye center in Kathmandu, Nepal.

Purpose. To present two cases of minimal pain Acanthamoeba keratitis to alert clinicians to remember Acanthamoeba when evaluating atypical cases of keratitis. Methods. The histories of two cases were reviewed with attention to clinical presentation subjective complaints, treatment, and long-term outcome. Results. In case 1, a 24-year-old man presented with decreased vision and an irritated feeling in his eye. He did not wear contact lenses. His initial diagnosis was adenoviral conjunctivitis. One month later, he was diagnosed with atypical herpes simplex keratitis and started on acyclovir. Two weeks later, he was referred to the Cornea Service. Further history revealed the patient to be a professional triathlete who trained by swimming in a fresh water pond. He was found to have an unusually high pain tolerance. Biopsy revealed Acanthamoeba. He was admitted for intensive therapy with neomycin, propamidine isethionate, and polyhexamethylene biguanide. Two years after diagnosis, he has best-corrected visual acuity of 20/100. In case 2, a 28-year-old man with known herpes simplex keratitis presented with decreased vision. He was started on topical trifluridine. After 6 weeks without improvement, he was referred for corneal evaluation. His eye always remained comfortable. Corneal sensation was markedly decreased. Further history revealed that he swam in fresh water. Biopsy was positive for Acanthamoeba. After 1 year of therapy with polyhexamethylene biguanide and neomycin, visual acuity was 20/200, and the patient underwent a corneal transplant. Conclusion. Acanthamoeba keratitis must be considered in the differential diagnosis of keratitis, even without the classic presentation of severe pain and predisposing corneal trauma, including contact lens wear.