Repeat penetrating keratoplasty: indications, graft survival, and visual outcome.

AIM: To determine graft survival and visual outcome after repeat penetrating keratoplasty (PKP). METHODS: Retrospective review of the medical records patients who underwent repeat PKP at the King Khaled Eye Specialist Hospital (KKESH) between 1 January 1991 and 31 December 2002. RESULTS: 243 repeat PKP performed in 210 eyes of 208 patients, who had also had initial PKP at KKESH, were included in the study. The mean follow up was 43 months (range 1-170). At the most recent examination, 114 (54.3%) grafts were clear. The overall survival rate was 98% at 1 year, 83% at 2 years, and 49% at 5 years. The best graft survival was in eyes with an original diagnosis of keratoconus (93.8%) and the worst was in eyes with Fuchs' dystrophy (23.1%). Overall, 29.6% of eyes achieved a final visual acuity greater than 20/200, while only 4.8% were 20/40 or better. The best visual prognosis was in eyes with an original diagnosis of stromal dystrophy and keratoconus. CONCLUSION: Although the prognosis for repeat PKP is poorer than that of initial PKP, reasonable outcomes can be obtained with repeat PKP with careful case selection.

Heterotransplantation of human choroidal melanoma into the athymic "nude" mouse.

The investigation of the structure and behavior of malignant melanoma of the uveal tract in man has been limited by the lack of a ready source of human tumor and an animal model in which the tumor resembles that in the human choroid. We now report the observation that fresh surgical specimens of human choroidal melanoma can be successfully transplanted into the posterior segment of the "nude" mouse (a homozygous mutant, nu/nu, with a defect in cellular immunity) and can be serially transplanted. This model utilizing human melanoma should be useful for the study of the natural history of this disease, as well as the response to various chemotherapeutic agents.

Polymorphonuclear neutrophils delay corneal epithelial wound healing in vitro.

Using an in vitro system for measuring epithelial wound healing, we studied the effect of polymorphonuclear neutrophils (PMNs) and PMN lysate on rat corneal epithelial wound healing. After 22 hr of organ culture, epithelial defects that were originally 3 mm in diameter (7.06 mm2) measured 0.41 mm2 (range, 0.17-0.72 mm2) in control rat corneas, 2.11 mm2 (range, 0.81-3.91 mm2) in corneas incubated in medium containing 5 X 10(6) PMN/ml, and 2.49 mm2 (range, 2.21-2.76 mm2) in corneas incubated with lysate obtained from an equivalent number of PMNs. Scanning and transmission electron microscopy showed similar morphology in the three groups. PMNs selectively adhered to the leading edge of the wound in corneas incubated with PMNs. These data indicate that PMNs and PMN lysate significantly slow corneal epithelial wound healing in vitro.

The incidence of metastases from untreated ciliary body and choroidal melanoma.

A large survey was conducted to identify patients with choroidal and ciliary body melanomas in whom preoperative evaluation for the presence of metastases was performed. Twenty-nine (2.47%) of 1,214 patients were found to have metastases prior to surgical manipulation of the globe. Liver function enzymes combined with liver-spleen scanning is the most effective means for screening for the presence of metastases in these patients and should be performed in all cases in which surgical manipulation of the globe is anticipated.

Long-term comparison of epikeratoplasty and penetrating keratoplasty for keratoconus.

The results of epikeratoplasty for keratoconus in ten patients with long-term follow-up (mean, 25 months; range, 19 to 31 months) vs ten patients with contemporaneous penetrating keratoplasty for keratoconus (mean, 33 months; range, three to 81 months) indicate a similar level of postoperative spectacle visual acuity (20/32 vs 20/27, respectively) and similar refractive and keratometric results. The healing period until achieving best corrected visual acuity averaged 12 months for epikeratoplasty vs three months for penetrating keratoplasty. Compared with penetrating keratoplasty, epikeratoplasty offers the advantages of maintaining an intact globe surgically and postoperatively in a young, active population, while avoiding potential immune rejection. The major disadvantages are a prolonged healing period and undefined limits in the extent of the cone that would define suitable candidates preoperatively.

Mucoepidermoid carcinomas of the lacrimal sac.

Mucoepidermoid carcinoma is a malignant tumor containing both neoplastic mucin-producing cells and epidermoid cells. To the only reported case arising in the lacrimal sac, we add three additional cases. All three were locally aggressive and required orbital exenterations. No deaths from metastatic disease occurred.

Chemical injuries of the eye: current concepts in pathophysiology and therapy.

Chemical injuries of the eye may produce extensive damage to the ocular surface epithelium, cornea, and anterior segment, resulting in permanent unilateral or bilateral visual impairment. Pathophysiological events which may influence the final visual prognosis and which are amenable to therapeutic modulation include 1) ocular surface injury, repair, and differentiation, 2) corneal stromal matrix injury, repair and/or ulceration, and 3) corneal and stromal inflammation. Immediately following chemical injury, it is important to estimate and clinically grade the severity of limbal stem cell injury (by assessing the degree of limbal, conjunctival, and scleral ischemia and necrosis) and intraocular penetration of the noxious agent (by assessing clarity of the corneal stroma and anterior segment abnormalities). Immediate therapy is directed toward prompt irrigation and removal of any remaining reservoir of chemical contact with the eye. Initial medical therapy is directed promoting re-epithelialization and transdifferentiation of the ocular surface, augmenting corneal repair by supporting keratocyte collagen production and minimizing ulceration related to collagenase activity, and controlling inflammation. Early surgical therapy if indicated, is directed toward removal of necrotic corneal epithelium and conjunctiva, prompt re-establishment of an adequate limbal vascularity, and re-establishment of limbal stem cell population early in the clinical course, if sufficient evidence exists of complete limbal stem cell loss. Re-establishment of limbal stem cells by limbal autograft or allograft transplantation, or by transfer in conjunction with large diameter penetrating keratoplasty, may facilitate development of an intact, phenotypically correct corneal epithelium. Limbal stem cell transplantation may prevent the development of fibrovascular pannus or sterile corneal corneal ulceration, simplify visual rehabilitation, and improve the visual prognosis. Advances in ocular surface transplantation techniques which allow late attempts at visual rehabilitation of a scarred and vascularized cornea include limbal stem cell transplantation for incomplete transdifferentiation and persistent corneal epithelial dysfunction, and conjunctival and/or mucosal membrane transplantation for ocular surface mechanical dysfunction. Rehabilitation of the ocular surface may be followed, if necessary, by standard penetrating keratoplasty if all aspects of ocular surface rehabilitation are complete, or by large diameter penetrating keratoplasty if successful limbal stem cell transplantation cannot be achieved but other ocular surface rehabilitation is complete.

Choroidal halo nevus occurring in a patient with vitiligo.

A halo nevus of the ocular fundus is described in a patient with vitiligo and history of malignant melanoma of the calf excised six years previously. The significance of halo nevi is discussed.

Intracorneal hematoma in Mooren ulceration.

PURPOSE: To report a case of intracorneal hematoma occurring in association with Mooren ulceration. METHOD: Case report. RESULTS: In an 81-year-old man with bilateral Mooren ulceration, a dense intracorneal hemorrhage occurred in the right eye secondary to peripheral corneal neovascularization and was followed by slow resolution over a 3-year period. Following subsequent lamellar and penetrating keratoplasty, histopathologic examination demonstrated the association between the stromal neovascularization and the residual interlamellar hemorrhage, as well as phagocytosis of residual hemosiderin by macrophages. CONCLUSION: Intracorneal hematoma with spontaneous resolution has been documented clinically and histopathologically in an eye with Mooren ulceration.

Meesmann corneal epithelial dystrophy in a Saudi Arabian family.

PURPOSE: Meesmann corneal epithelial dystrophy is a dominantly inherited disorder that was originally reported in Germany and later in descendants of German immigrants to the United States. We report Meesmann corneal epithelial dystrophy in a family that cannot be traced to Germanic origin. METHODS: A 17-year-old Saudi boy from the Al-Qahtani tribe of the Asir region of the kingdom came to the King Khaled Eye Specialist Hospital with classic clinical findings of Meesmann corneal epithelial dystrophy. We examined all members of the immediate family of the index case and members of five branches of the extended family. RESULTS: Meesmann corneal epithelial dystrophy was present in the father and one sister of the index case. Four additional affected individuals were identified in three generations of one branch of the extended family. All but one of the seven affected individuals were aged 17 years or older. Our findings are consistent with previous reports of an autosomal dominant pattern of inheritance, with probable incomplete penetrance or delayed onset of phenotypic expression. CONCLUSION: We report Meesmann corneal epithelial dystrophy in a family without German ancestry.

Pseudomonas corneoscleritis.

We evaluated three cases of Pseudomonas aeruginosa corneoscleritis, one associated with the use of contaminated eyedrops; another in an elderly, debilitated patient; and the third in a patient who had previously undergone penetrating keratoplasty. In the first two cases, control of the infection was achieved by intensive antibiotic therapy alone. The third case required evisceration of the eye following spontaneous perforation at the site of scleral involvement. Histopathologic findings showed persistence of the organism in the sclera despite intensive antibiotic therapy for six days.

Clinical analysis of excimer laser photorefractive keratectomy using a multiple zone technique for severe myopia.

PURPOSE: In an investigational procedure, excimer laser photorefractive keratectomy for severe myopia was performed at three clinical trial centers to determine the effectiveness of the multiple zone technique. METHODS: A VisX Model Twenty/Twenty excimer laser (VisX, Santa Clara, California) was used to perform photorefractive keratectomy on 14 severely myopic eyes (-10.37 to -24.5 diopters) of 12 patients by using a multiple zone technique. Postoperative follow-up ranged from six months to two years; retreatments were performed on four patients, with a follow-up of at least nine months. RESULTS: At six months postoperatively, before retreatment, three of the 14 eyes were within 2 diopters and seven of the 14 eyes were within 4 diopters of attempted correction. Regression of effect to more severe myopia was worse in five eyes treated with nitrogen gas blowing. Retreatments also demonstrated considerable myopic regression. Three patients had loss of two or more lines of best-corrected visual acuity, and these patients also had moderate or severe levels of haze. CONCLUSION: Excimer laser photorefractive keratectomy for severe myopia using a multiple zone technique is associated with considerable regression, haze, and loss of best-corrected visual actuity, especially when performed in association with nitrogen gas blowing.

New observations on vitiligo and ocular disease.

We examined 223 consecutive patients with vitiligo for ocular disease and 154 consecutive patients with uveitis for vitiligo to better determine the nature of the relationship between vitiligo and ocular disease. Of the 129 patients whose uveitis had an unknown cause, seven (5.4%) had cutaneous depigmentation, poliosis, or early graying of hair. The incidence is 0.5% in the general population (P less than .02). None of the 25 patients whose uveitis had a known cause had vitiligo. Eleven (4.8%) of 223 patients with vitiligo had uveitis at the time of the study or had had it within the previous two years. Of 27 patients in whom vitiligo was associated with cutaneous melanoma, five (18.5%) had had uveitis within the previous two years. In three of these five, the uveitis began within one month of the appearance of cutaneous changes. Evidence of old chorioretinal scars were present in 69 of 223 patients with vitiligo (30.9%) but in only two of 148 control patients (P less than .001). Sixty of 223 patients with vitiligo (26.9%) had evidence of hypopigmentation or atrophy of the retinal pigment epithelium, or both, not related to old chorioretinitis or macular degeneration but only six of 148 controls did (P less than .001).

Phototherapeutic keratectomy for macular corneal dystrophy.

PURPOSE: To report a case of early intervention with phototherapeutic keratectomy for treatment of macular corneal dystrophy. METHODS: We report a 21-year-old Saudi male with early macular corneal dystrophy, recurrent erosions, and decreased visual acuity, who underwent phototherapeutic keratectomy in the right eye and penetrating keratoplasty in the left eye with more than 2 years of follow-up. RESULTS: Following phototherapeutic keratectomy, uncorrected visual acuity in the right eye improved from 20/80 to 20/30. Following penetrating keratoplasty in the left eye, uncorrected visual acuity deteriorated from 20/80 to 20/120 due to irregular astigmatism; the eye was not amenable to improvement with spectacle correction, and the patient declined contact lens therapy. In the right eye, there has been no anterior recurrence, although some mid- to deep stromal haze, which is not visually significant, has developed. CONCLUSIONS: Early intervention for symptomatic, anterior macular corneal dystrophy with phototherapeutic keratectomy is relatively safe and preferable to observation or penetrating keratoplasty.

Multicenter study of photorefractive keratectomy for myopia of 6.00 to 8.00 diopters. VISX Moderate Myopia Study Group.

PURPOSE: To summarize the initial results of excimer laser photorefractive keratectomy (PRK) on 89 eyes of 80 patients with moderate myopia (myopia of -6.00 to -8.00 diopters [D]; mean -6.98 +/- 0.90 D) at nine investigational sites. METHODS: All treatments used an argon fluoride excimer laser (VISX, Inc, Santa Clara, Calif) using standard settings. Sixty eyes received single-zone 6.0-millimeter ablations and 29 eyes received two-zone ablations. Follow up ranged from 1 month (n = 89) to 6 months (n = 46). RESULTS: At 3 months, uncorrected visual acuity measured 20/40 or better in 75% and 20/20 or better in 18%; 78% were within +/- 1.00 D of intended correction, 38% were within +/- 0.50 D, and 9% lost two or more lines of spectacle-corrected visual acuity. At 6 months, uncorrected visual acuity measured 20/40 or better in 74% and 20/20 or better in 17%; 67% were within 1.00 D of intended correction, 38% within 0.50 D, and 2% (1/46) lost two lines of spectacle-corrected visual acuity. CONCLUSIONS: PRK for moderate myopia with large diameter ablation zones appears safe and more predictable than that done using smaller ablation zone diameters. Longer follow up is needed to better define stability, the effects of postoperative corticosteroids, and the use of single-versus double-zone ablations.

Penetrating keratoplasty vs. epikeratoplasty for the surgical treatment of keratoconus.

PURPOSE: Penetrating keratoplasty and epikeratoplasty have been utilized in the surgical treatment of keratoconus. Comparison of the relative efficacy of each procedure in achieving visual outcomes has not been achieved due to limited numbers of cases and follow-up in previous series. METHODS: All patients who underwent either penetrating keratoplasty or epikeratoplasty for keratoconus between January 1987 and December 1997, and for whom at least 24 months of postoperative follow-up data for visual acuity was documented in the medical record, were included in this retrospective, nonrandomized, sequential comparative trial. The sole criteria for outcome in each group, as well as for comparison of the two groups, was Snellen visual acuity measured at the time of each follow-up with the presenting optical aid. RESULTS: Inclusion criteria were met for 443 eyes treated with penetrating keratoplasty and 161 eyes treated with epikeratoplasty. Mean follow-up was 4.3 years for penetrating keratoplasty and 4.5 years for epikeratoplasty. In each group, approximately 50% of the patients chose rehabilitation with optical correction with either spectacles or contact lenses and 50% chose no optical correction. Final median logMAR visual acuity for all patients, irrespective of means of visual rehabilitation, was 0.30 (20/40) for penetrating keratoplasty and 0.40 (20/50) for epikeratoplasty (P < .00005). In 209 penetrating keratoplasty and 77 epikeratoplasty eyes with optical correction, the final median logMAR visual acuity was 0.18 (20/30) for penetrating keratoplasty and 0.40 (20/50) for epikeratoplasty (P < .00005). The final median logMAR visual acuity in 234 penetrating keratoplasty and 84 epikeratoplasty eyes without optical correction was 0.48 (20/60) in both groups (P-value was not statistically significant). CONCLUSIONS: Although penetrating keratoplasty was statistically superior to epikeratoplasty with respect to visual outcome, results with epikeratoplasty were adequate to recommend its use as a surgical alternative in cases when it is not desirable to perform penetrating keratoplasty.

Bacterial keratitis following phototherapeutic keratectomy.

BACKGROUND: Phototherapeutic keratectomy (PTK) is effective in the treatment of many superficial corneal disorders. The incidence of bacterial keratitis following PTK has not been assessed in a large, prospective clinical trial. METHODS: We report three cases of bacterial keratitis that occurred in a prospective study of 258 consecutive PTK procedures at King Khaled Eye Specialist Hospital. RESULTS: Three (1.2%) of 258 eyes developed bacterial keratitis during a period of follow up ranging from 1 to 24 months. All three cases were in 183 eyes (1.6%) with a diagnosis of climatic droplet keratopathy, while no cases were observed in 75 eyes with other anterior corneal disorders. Gram-positive species (Streptococcus pneumonia in two, coagulase-negative Staphylococcus in one) were the predominant species isolated from all three cases. Two of the cases were polybacterial. The final visual outcomes ranged from 20/125 to 20/400. CONCLUSIONS: The risk of bacterial keratitis following treatment of superficial corneal disorders with PTK is low but its occurrence may adversely affect the final visual outcome.

Phototherapeutic keratectomy for climatic droplet keratopathy, KKESH Excimer Laser Study Group. King Khaled Eye Specialist Hospital.

BACKGROUND: Phototherapeutic keratectomy (PTK) is an effective treatment for many superficial corneal disorders. The efficacy of PTK for the treatment of climatic droplet keratopathy (CDK) has not been reported. METHODS: We report the results of excimer laser (Summit Technology, Inc, Waltham, Mass) PTK on 75 eyes (67 patients) with "smooth" climatic droplet keratopathy (55 eyes) and "irregular" climatic droplet keratopathy (20 eyes) in whom more than 6 months of follow up are available. RESULTS: PTK was successful in reducing corneal opacification in both smooth (98%) climatic droplet keratopathy and irregular (80%) climatic droplet keratopathy. Achievement of a clear or mildly hazy cornea following PTK was more likely to occur with smooth (80%) climatic droplet keratopathy than irregular (25%) climatic droplet keratopathy (P = 0.01). Eyes with smooth climatic droplet keratopathy were more likely to obtain more than one line of improved uncorrected (56% vs. 25%) or spectacle-corrected visual acuity (61.8% vs. 21.2%) than those with irregular climatic droplet keratopathy (P = 0.03 and 0.005, respectively). Delayed re-epithelialization (longer than 14 days) was more common in irregular CDK (21%) than in smooth CDK (9%), as was the incidence of secondary microbial keratitis (10.0% vs. 1.8%). CONCLUSIONS: PTK is effective in reducing superficial corneal opacification in CDK, although serious complications may occur, especially in advanced irregular CDK.

Vitiligo and disorders of the retinal pigment epithelium.

The association of vitiligo with inflammation of the uveal tract is well established. The relationship between vitiligo and hypopigmentation and/or degeneration of the retinal pigment epithelium (RPE) not secondary to ocular inflammation has not been adequately investigated. Sixty (27%) of 223 consecutive patients with vitiligo were found to have some evidence of RPE hypopigmentation ranging from mild, focal areas of involvement in most cases to extensive RPE degeneration with a retinitis pigmentosa-like syndrome in one patient. Fifteen (25%) patients complained of night blindness. Only 6 (4%) of 148 patients in a control group had similar funduscopic findings (p less than 0.001). None of these patients were symptomatic. There have been isolated reports of vitiligo occurring with tapetoretinal degeneration. We report 2 patients with both vitiligo and retinitis pigmentosa.

Pterygium in young members of one family.

PURPOSE: To report a family with aggressive, early-onset pterygium. METHODS: We examined all living relatives (with one exception) of a Saudi Arabian family and found three members with pterygium (onset occurred when the patients were at early 20s, 6, and 4 years of age). RESULTS: Multiple attempts at surgical removal, even in conjunction with application of topical mitomycin C and use of conjunctival autograft, failed to prevent recurrent pterygium, which advanced across the visual axis and produced profound visual disability in the three cases. CONCLUSION: Contrary to previously published reports of familial pterygium, two of the three cases had childhood age at onset and all three had an aggressive clinical course after the onset of recurrent pterygium after surgical resection; genetic identification may be beneficial.