Laser in situ keratomileusis (LASIK) is currently one of the most common methods for treatment of myopia and astigmatism. The technique of LASIK has been much improved since it was first introduced in mid-1980s. The LASIK procedure has shown quite acceptable outcomes and its future is very promising. However, long-term follow-up studies have shown unexpected complications. Therefore, understanding of the LASIK procedure and evaluating the risks and benefits thereof are needed for better outcomes and satisfaction on the patients' side.
Astigmatism ; Follow-Up Studies ; Keratomileusis, Laser In Situ* ; Myopia ; Risk Assessment

We examined 60 eyes of 60 patients after excimer photorefractive keratectomy(PRK) for myopia and analyzed the changes of central island on corneal topography for 6 months prospectively. These patients were divided into two groups according to the degree of myopia, group 1(26 eyes, 6 diopters or below by spherical equivalent) and group 2 (34 eyes, over 6 diopters). The occurrence rate of central island was 76.4% collectively, 87.5% in group 1, 67.7% in group 2 at 2 weeks after PRK. It decreased to 30.4%, 43.5%, and 21.1% respectively at 6 months after PRK and was lower in group 2 than group 1. However there was no statistically significant correlation between the reduction of central island size and improvement of corrected visual acuity in both groups. In conclusion, the central island disappeared and decreased the amount for six months follow-up period after PRK and seems to be no effect on the corrected visual acuity.
Corneal Topography ; Follow-Up Studies ; Humans ; Myopia* ; Photorefractive Keratectomy* ; Prospective Studies ; Visual Acuity*

Recent cataract surgery has a trend to use clear corneal incision that does not require conjunctival peritomy and has fewer complications such as hyphema and ciliary body damage etc. Clear corneal incision also provides less corneal astigmatism and thereby better naked visual acuity. However the side effects of clear corneal incision such as includes wound leakage and associated endophthalmitis, endothelisal cell damage, irregular corneal astigmatism and instability of wounds have been reported continuously. Thus, we have introduced the 3.5mm sized mid limbal incision technique which may compensate the above complications and have rapid visual rehabilitation. Postoperative corneal astigmatism and uncorrected visual acuity of patients with clear corneal incision were compared with the results of scleral pocket incision. The corneal astigmatic changes of both group showed trivial against- the-rule change(0.44-0.12D) in early post operative period. Mid limbal incision group presented a little highter against-the-rule change at post operative 1 wee, but no significiant diffeence was noted sice postoperative 1 month. Uncorrected visual acuity showed no difference between two groups. From these results, we conclude mid limbal incision is an effective procedure that can compensate the disadvantage of both clear corenal incision and scleral pocket incision.
Astigmatism ; Cataract* ; Ciliary Body ; Endophthalmitis ; Humans ; Hyphema ; Rehabilitation ; Visual Acuity ; Wounds and Injuries

Excimer laser photorefractive keratectomy(PRK) has been used as a good treatment modality for myopia. However many surgeon reported its complications, especially loss of best corrected visual acuity(BCVA) after PRK with an incidence of 0~12%. Thus we studied the causes and incidence of BCVA loss in myopic eyes that were followed up at least 12 months after PRK. We defined `BCVA loss` as 2 or more lines decrease by Snellen chart comparing to preoperative visual acuity. We found that 16 of 313 eyes(5.1%) lost BCVA during follow up period after PRK. High myopes, 8.25diopters or more, developed BCVA loss(8.8%) more commonly than myopes below 8.00 diopters(3.3%) (P<0.05). But BCVA loss recovered after post-operative 2 years except one eye. The causes of BCVA loss were corneal haze, irregular astigmatism, incidental cataract and steroid-induced glaucoma. According to the corneal haze scoring, average corneal haze was greater in eyes(1.47 score) with BCVA loss than eyes(0.36) without BCVA loss (P<0.01). However average cornea haze score in eyes with BCVA loss gradually decreased with time.As a result, main causes of BCVA loss after PRK was corneal haze, irregular astigmatism. High myopia more than 8.25 diopters showed greater BCVA loss than myopia less than 8.00diopters after PRK, but BCVA loss recovered with time.
Astigmatism ; Cataract ; Cornea ; Follow-Up Studies ; Glaucoma ; Incidence ; Lasers, Excimer* ; Myopia ; Photorefractive Keratectomy* ; Visual Acuity*

To determine amount of surgically induced outcome of 3.5mm clear corneal incisin, 30 eyes(30 patients) were evaluted retrospectively. Corneal curvature was measured using cmputerized videokeratography, and the induced astigmatism was calculated with using the Holladat-Cravy-Koch formula. The corneal flattening was significantly more prominent at distances of 0.5, 1.5 and 2.5mm along 90-degree meridian and 270 degree meridian at one week 1 month postoperatively but decreased at 6 months. Surgically induced astigmatism was -0.5D at one week, -0.12D at 1 month, and -0.13D at 6 month in groups using keratometry and in group using toography. At 1 month postoeratively surgically induced astigmatism in topography was statically sigmificant(p<0.05).
Astigmatism ; Cataract* ; Corneal Topography* ; Retrospective Studies

Following reports on successful ocular surface reconstruction using amniotic membrane, many trials of amniotic membrane transplantation are being doing to treat various ocular surface diseases. We treated pterygium with amniotic membrane transplantation and assessed the effectiveness of this method. Pterygia in 15 eyes of 15 patients were surgically excised during December 1996 to January 1997. Over the bare sclera, amniotic membrane was attached with sutures. After a mean follow-up of 72+/-20 days. 3 cases were recurred (rate 20%). The complications encountered were: persistent conjunctival injection in 10 cases (67%); pyogenic granuloma in one case (7%); loss of transplanted membrane (7%). No other serious complications were noted. Considering a short follow-up period, the recurrence rate is not low and there is also possibility of recurrence in 10 cases of persistent conjunctival injection. Therefore, this approach appears ineffective compared with other method.
Amnion* ; Follow-Up Studies ; Granuloma, Pyogenic ; Humans ; Membranes ; Pterygium* ; Recurrence ; Sclera ; Sutures ; Transplantation

Causative bacterias of keratitis due to mishandling of contact lenses are mainly Gram negative rods, and large percentage of them are Pseudomonas. We experienced 6 cases of culture-proven Pseudomonas keratitis due to mishandling of soft contact lenses and wetting solution can be cultured. They are lack of education as how handle the contact lenses safely. And they did not done disinfection of the soft contact lens cases. To prevent contact lens related keratitis, we think it is very important for users to know its possible complication and how to use it and disinfect it safely.
Bacteria ; Contact Lenses ; Contact Lenses, Hydrophilic* ; Disinfection ; Education ; Keratitis* ; Pseudomonas*

We reviewed the outcome of combined penetrating keratoplasty and intraocular lens implantation surgery in 24 patients (25 eyes). All patiets underwent keratoplasty and posterior chamber lens implantation or intraocular lens exchange. Mean follow-up time was 20.5 months (range, 2 to 63 months). Visual acuity of 0.5 or better Was obtained in 5 patients (20%) and visual improvement was achieved in 60% of patients over all postoperatively. The success rate of keratoplasty was 56% according to corneal clarity during the follow-up periods. Immediate postoperative hyphema (1 eye), glaucoma (9 eyes), Graft failure (7 eyes), recurred Herpetic or newly developed bacterial keratitis (3 eyes), macular degeneration (1 eye). and retinal detachment (1 eye) were occurred as complications at postoperative periods. These combined operations allow faster visual rehabilitation without increasing the incidence of complications, compared to multi-step modalities of treatment.
Corneal Transplantation ; Follow-Up Studies ; Glaucoma ; Humans ; Hyphema ; Incidence ; Keratitis ; Keratoplasty, Penetrating* ; Lens Implantation, Intraocular* ; Lenses, Intraocular* ; Macular Degeneration ; Postoperative Period ; Rehabilitation ; Retinal Detachment ; Transplants ; Visual Acuity

Microbial growth(including fungal growth in 6 cases) was detected in 8 soft contact lenses Among the contact lens wearers who visited the Department of Ophthalmology, Asan Medical Center, between May, 1990 and Nov, 1990, contact lens deposits were easily recognized with naked eye and it was not removed by conventional cleaning methods, such as chemical cleaners and enzymatic agents. We examined these deposits under the microscope and found them microbial colonies. Isolation of microorganisms from the contact lenses and storage solutions was attempted in order to identify them. Direct microscopic observation of colonies grown in the contact lenses made it possible to identify 5 out of 10 cases. Growths of four cases were identified as Actinomyces sp., Trichothecium sp., Dermatophilus congolensis, Alternaria sp., and one case was found mixed growth of Humicolor sp. and Fusarium sp. Other 3 cases were highly suspected as fungus. Culure of the eight storage solutions were all revealed Serratia marcescens Our patients showed foreign body sense and redness in all 8 cases, superficial punctate keratitis in 1 case, and corneal erosion in 1 case.
Actinomyces ; Alternaria ; Chungcheongnam-do ; Contact Lenses ; Contact Lenses, Hydrophilic* ; Foreign Bodies ; Fungi ; Fusarium ; Humans ; Keratitis ; Ophthalmology ; Serratia marcescens

We studied the healing course and histologic change of ablated rabbit cornea following excimer laser photorefractive keratectomy using three different corneal wound healing methods; pressure patch, T-lens, collagen shield. Nine rabbits(18 eyes) were divided into three different groups according to its treatment method. Corneal status including the corneal haze, conjunctival injection, discharge amount at postoperative 1st day, 2nd day and 3rd day were the same, irrespective to the treatment method and corneal wound healing rate show no significant differentces in all the groups. The histologic feature revealed irregular epithelial hyperplasia and keratacyte infiltration in the superficial stromal layer on postoperative 3rd day and 7th day. These reactions lessened at postoperative 1 month. The cornea treated with pressure patch group revealed more severe tissue reaction when compared with the other groups, T-lens and collagen shield. These results suggest that the corneal wounds produced by excimer laser can be managed by T-lens as an another alternative method of wound treatment.
Collagen* ; Cornea* ; Hyperplasia ; Lasers, Excimer* ; Photorefractive Keratectomy* ; Wound Healing* ; Wounds and Injuries*