Keratotomy Wounds Research Articles

Management of pterygium in a case of post radial keratotomy

<p class="abstract"><span lang="EN-IN">This study is a case of post radial keratotomy who underwent pterygium excision and its management</span>. <span lang="EN-IN">A 44 old high myope who underwent radial keratotomy more than a decade earlier underwent pterygium excision and conjunctval autograft. 6 months follow-up showed no recurrence of pterygium and improvement in corneal irregulalrity</span>. <span lang="EN-IN">Careful and meticulous dissection of pterygium over keratotomy wounds helps in prevention seroius complications during surgery. </span></p>

Simultaneous penetrating keratoplasty and artificial iris‐lens diaphragm implantation

AbstractMaterials and methods: Forty four eyes of 44 patients with aniridia after penetrating corneal injuries and traumatic post radial keratotomy wound dehiscences have undergone penetrating keratoplasty (PKP) and simultaneous artificial iris‐lens diaphragm (ILD) implantation. The average age was 36 years (8‐60 years). Time since trauma ranged from 3 months to 17 years. In 27 eyes intraocular pressure (IOP) was normal preoperatively, while 17 eyes were diagnosed with glaucoma. IOP was managed medically in 9 of these eyes, and 8 eyes had been operated for glaucoma before PKP + ILD. PKP was performed with the assistance of femtosecond laser in 10 eyes, and 34 eyes were operated with the use of Barron vacuum trephine. Five eyes had previous successful retinal detachment surgery, and 8 eyes had subtotal vitrectomy for vitreous hemorrhage. Results: Preoperatively mean non‐corrected distance visual acuity (NCDVA) was 0.03 ± 0.04 (m ± SD), corrected distance visual acuity (CDVA) was 0.04 ± 0.07, preoperative corneal astigmatism was 8.3 ± 5.8 diopters (D). Twelve months after the surgery mean NCDVA after traditional PKP was 0.08 ± 0.09, CDVA was 0.2 ± 0.19, corneal astigmatism was 4.7±3.9 D; and after femtolaser‐assisted PKP NCDVA was 0.1 ± 0.12, CDVA 0.3 ± 0.28, corneal astigmatism was 3.9 ± 3.1 D. In the group of 8 eyes previously operated for glaucoma only 1 eye experienced worsening of IOP control, requiring 2 extra filtering procedures including drainage device implantation. In the glaucoma medical management group of 9 eyes 1 eye required filtering surgery 1 month after PKP + ILD, while four more had to be operated for glaucoma as late as 9 to 24 months. Due to transplant failure cornea had to be regrafted in 6 of 9 patients in the glaucoma medical management group, and only in 2 of 8 patients who were previously operated for glaucoma. Conclusion: In patients after simultaneous penetrating keratoplasty and artificial iris‐lens diaphragm implantation surgery corneal transplant failure rate increases with IOP decompensation. Previous glaucoma surgery improves IOP control.

Dehiscence of Radial Keratotomy Wounds Without Globe Rupture Following Explosion Injury

To report a case of explosive trauma to a patient with a history of radial keratotomy (RK), which resulted in multiple wound dehiscences but not globe rupture. A 29-year-old male underwent radial keratotomy 1 year before he sustained facial trauma from a gasoline tank explosion. Corneal abrasions were treated with copious irrigation, topical antibiotics, corticosteroids, and scopolamine. He did not have a ruptured globe in either eye. The incision sites from radial keratotomy had evidence of anterior dehiscence in both eyes. One month following the injury, the patient had corrected visual acuity of 20/20-1 in the right eye and 20/25+1 in the left eye. At that time, the RK wounds were well healed with minimal irregularity over the incision sites. This case demonstrates the excellent recovery of visual acuity in a patient with a partial thickness traumatic wound rupture 12 months following radial keratotomy.

Management of the corneal flap in laser in situ keratomileusis after previous radial keratotomy

PURPOSE: To report a method of managing the corneal flap in patients having laser in situ keratomileusis for the treatment of residual refractive errors after radial keratotomy. DESIGN: Retrospective case series. METHODS: Intraoperative dehiscence of radial keratotomy wounds occurred in 7 eyes of 6 patients treated with laser in situ keratomileusis for residual myopia or astigmatism or hyperopia 5 to 15 years after radial keratotomy. To minimize extension of these tears, the flap was initially rolled like a carpet toward the hinge before the ablation and then rolled away from the hinge to its original position after the ablation. RESULTS: Using this method of managing the laser in situ keratomileusis flap in patients with previous radial keratotomy, all eyes had successful laser in situ keratomileusis, with 1-year postoperative uncorrected visual acuity ranging between 20/16 and 20/25. No eye had loss of spectacle-corrected vision or interface epithelial ingrowth. CONCLUSIONS: Laser in situ keratomileusis has proved to be an effective treatment for correction of residual refractive errors after radial keratotomy. The surgical technique used in these cases was targeted at minimizing shearing forces in lifting the corneal flap to avoid extension of radial keratotomy wound dehiscence, which could lead to epithelial ingrowth and loss of best-corrected vision.

Minoxidil-induced alteration of corneal topography after radial keratotomy

Purpose: To determine the antiproliferative effect of minoxidil on human corneal epithelium (hCE) proliferation in vitro and to assess whether topical minoxidil can significantly alter corneal topography after radial keratotomy (RK) by inhibiting myofibroblast activity in the keratotomy wound.Setting: Corneal Research Laboratory, University of Chicago, Illinois, USA.Methods: In the in vitro evaluation, proliferating hCE was exposed to minoxidil (0.1 to 2.0 mM) for 96 hours to determine the minimum inhibitory dose. Human corneal epithelium cell proliferation was assessed by the incorporation of bromodeoxyuridine (BRDU) into DNA. In the in vivo analysis, eight New Zealand albino rabbits had an eight-incision bidirectional RK on one eye and were divided into two groups. The control eyes (n = 3) received tobramycin and dexamethasone (TobraDex®), ciprofloxacin hydrochloride (Ciloxan®), and balanced salt solution (BSS®) drops four times a day for 3 weeks, while the treatment eyes (n = 5) received TobraDex, Ciloxan, and minoxidil 1.0 mM drops four times daily for 3 weeks. The net change in corneal curvature at 3 weeks was analyzed with corneal topography. Myofibroblast activity in the keratotomy wound was assessed using alpha smooth muscle actin staining techniques.Results: At concentrations of 1.0 mM and above, minoxidil caused a statistically significant, dose-dependent reduction in hCE cellular proliferation ranging from 29 to 44% (P < .05). Minoxidil (1.0 mM) caused a statistically significant central corneal flattening effect of 4.66 diopters (D) after RK in the treatment eyes compared with 1.11 D in the control eyes (P = .05). Histologically, minoxidil-treated keratotomy wounds lacked cells with contractile elements consistent with myofibroblast differentiation. Corneal epithelial wound healing was similar in both groups.Conclusion: At the appropriate dose, topical minoxidil may be a useful adjunctive treatment that can reduce the number of undercorrections after mini-RK without apparent toxicity to the corneal epithelium.

Assessment of stress fiber orientation during healing of radial keratotomy wounds using confocal microscopy.

Radial keratotomy (RK) is a refractive surgical procedure in which partial thickness incisions are made in the cornea in order to alter its shape. Previous studies suggest that RK wounds undergo changes in wound gape in response to the ingrowth of myofibroblasts which mediate subsequent wound contraction and may modulate changes in corneal curvature seen after RK. A recent quantitative analysis of f-actin organization in full-thickness incisional wounds in the rabbit demonstrated that microfilament bundles (stress fibers) present in myofibroblasts align parallel to the long axis of the wound during wound contraction. To investigate whether the same pattern of alignment occurs after RK, a similar analysis of f-actin organization was undertaken using the cat RK model. Radial keratotomy wounds were studied from 10 to 28 days after surgery using en block staining with fluorescein isothiocyanate (FITC) phalloidin, and three-dimensional (3-D) datasets (z-series of en face optical sections) were collected using laser confocal microscopy at various regions within the wound. In addition, conventional en face sections were double-labeled using combinations of phalloidin and antibodies to fibronectin and alpha 5 beta 1 integrin. Myofibroblast ingrowth started in the bottom of the wound and progressed anteriorly. At 10 to 14 days, f-actin was predominantly distributed in long, thick bundles (stress fibers) within the wound. These fibers appeared to be randomly oriented anteriorly, but became progressively more aligned with the long axis of the wound posteriorly. At 21 days, the stress fibers were predominantly oriented parallel to the long axis of the wound at all levels. F-actin, fibronectin and integrin were coaligned at both the 14 and 21 day time points. Since the majority of wound closure occurs between 14 and 28 days after surgery, we conclude that parallel alignment of the actin filament-fibronectin-integrin assembly in the cat RK model is associated with wound contraction.

Photodynamic biologic tissue glue to enhance corneal wound healing after radial keratotomy

Purpose: To evaluate the effect of photodynamic biologic tissue glue (PBTG) on corneal wound healing after radial keratotomy (RK).Setting: Cornea Research Laboratory, The University of Chicago, Chicago, Illinois, USA.Methods: Bidirectional, eight-incision RK was done in one eye of eight Dutch pigmented rabbits. Then, PBTG was inserted into the RK incisions and activated with an argon blue-green laser in four treatment eyes. The rabbits were divided into three groups: early, in which corneal wound healing was assessed at 1 and 3 weeks; late, in which corneal wound healing was assessed at 8 weeks; enhancement.Results: The PBTG-treated keratotomy wounds had a more prominent epithelial healing response immediately after RK and a decreased propensity for wound dehiscence. Collagen fiber arrangement in the PBTG-treated incisions was sagittal to the keratotomy wound 1 to 3 weeks after RK and then changed to a transverse orientation across the keratotomy wound by 8 weeks. The control keratotomy wounds had a less prominent epithelial healing response and developed late disorganization of the posterior keratotomy wound at 8 weeks. Keratometry measurements 2 months after RK showed corneal flattening of 1.0 diopter (D) in the PBTG-treated eye and 6.5 D in the control eye, which is consistent with histologic studies showing more advanced wound healing in the PBTG-treated eyes. After RK enhancement, the PBTG-treated eye resisted further corneal flattening and had 4.5 D of corneal steepening; the control eye had 2.0 D of additional corneal flattening.Conclusion: The nontoxic, laser-activated adhesive PBTG accelerated corneal wound healing after RK and simulated the placement of sutures into the RK wound. Thus, PBTG may be an alternative to sutures to correct hyperopia after RK in humans.

Ruptured Globes Following Radial and Hexagonal Keratotomy Surgery-Reply

In reply We support the concept that long-term, prospective, inclusive collection of data on all traumatic ruptured globes is needed to answer the important question of whether refractive surgery that is not medically necessary predisposes the eye to traumatic rupture. Such a study was proposed to leaders of the refractive surgery community, but did not progress further. We believe that these cases indicate only a potential hazard that is underreported in the peer review literature and does not represent a complete case count, thus, cannot be used as a basis to determine the incidence of traumatic RK and hexagonal keratotomy wound rupture. Remember, many of our cases were of eyes ruptured following minor trauma that would not ordinarily cause a globe rupture, let alone loss of an eye. Because every eye ruptured through the RK or hexagonal keratotomy incision as much as 10 years postoperatively, these cases may be a

Ruptured globes following radial and hexagonal keratotomy surgery.

To ascertain if cases of radial keratotomy wound rupture were occurring and whether the globes ruptured through the corneal incisions. Cases of traumatic ruptured globe after incisional corneal refractive surgery were collected from ophthalmologists and from peer-reviewed and other ophthalmic literature. Twenty-eight human eyes (eight previously unreported) are known to have ruptured through refractive corneal incisions in activities of daily living (n = 12), assault (n = 7), motor vehicle accidents (n = 5), and sports (n = 4). Two patients died of their injuries. Of the remaining 26 ruptured eyes, eight (31%) recovered 20/40 or better visual acuity. Six eyes (23%) were totally blinded, six (23%) were legally blinded, and six (23%) had best corrected visual acuity of 20/40 to 20/100 despite multiple surgical procedures. As radial keratotomy becomes more popular the pool of patients who may experience traumatic ruptured globe will grow. Every patient who has had radial keratotomy should be aware that the surgery has weakened the eye(s).

Air Bag-related Corneal Rupture After Radial Keratotomy

We studied a case of air bag-associated corneal rupture in a patient who had previously undergone radial keratotomy surgery. The patient was struck in the right eye when his driver's side air bag inflated during a low-speed collision. Inflation of the air bag resulted in rupture of the patient's right cornea. The rupture involved all but one of his old radial keratotomy wounds. Patients who have undergone radial keratotomy may be at increased risk for corneal rupture caused by air bag trauma. These patients may benefit by wearing protective eyewear while driving cars equipped with air bags.

Healing of reopened-and-sutured radial keratotomy wounds

We designed a study to evaluate healing in reopened-and-sutured (RAS) keratotomy wounds to determine the efficacy of reoperations in treating radial keratotomy overcorrections. Using light and transmission electron microscopy, we compared stromal scar tissue organization (transverse fibroblast orientation and collagen fiber continuity across the wound) in RAS wounds and in sutured and unsutured control wounds in 18 monkey eyes one to nine weeks after surgery. Wound healing morphology of RAS wounds varied with the interval between reoperation and termination of the experiment. Scar tissue organization was sagittal at one week postoperatively, transverse in the anterior and mid regions after four weeks, and transverse over the entire wound after nine weeks. Sutured wounds showed a similar pattern of healing, although transverse scar tissue organization was restricted to the anterior and mid regions in the late healing phases. In contrast, unsutured wounds showed a temporary, transverse scar tissue organization over the entire wound depth at two to four weeks and a progressive reorientation of the mid and posterior scar tissue sagittal to the wound at later intervals. The results suggest that reopening and suturing keratotomy incisions to treat radial keratotomy overcorrections may be effective through a myopic shift induced by sutured wound apposition and long-term wound remodeling, contraction, or both.

Epithelial-Stromal Interactions in Human Keratotomy Wound Healing

To evaluate epithelial-stromal interactions in the healing of stromal wounds and the relationship of such interactions to regional variations in healing throughout keratotomy wounds. Ten radial keratotomy autopsy specimens were studied by using light and transmission electron microscopy. Underneath epithelial plugs, the epithelial-stromal interface was characterized by three adjacent morphological zones: a duplicated basement membrane complex, a zone that resembled Bowman's layer, and a third zone with collagenous fiber orientation parallel to the plugs. Scar tissue orientation was transverse at the base of the plug, and sagittal in deeper wound regions. Basement membrane duplication and a Bowman's layer-like region underneath a plug may result from complicated epithelial-stromal interaction. Asymmetrical organization of the scar, with subepithelial transverse and sagittal deeper scar tissue orientation, may characterize radial keratotomy wound healing, and may relate to variations in final refractive effect.

Scar tissue orientation in unsutured and sutured corneal wound healing.

This study aimed to evaluate stromal wound healing morphology in short term unsutured compared with sutured corneal wounds, to define regional variation in healing within radial keratotomy wounds. Stromal scar tissue orientation (fibroblast and collagen fibre orientation) was analysed in unsutured and adjacent sutured keratotomy wounds in monkeys, 2 to 9 weeks after surgery, using light and transmission electron microscopy. At 2 to 4 weeks, scar tissue orientation was transverse to the wound edge in unsutured wounds, but sagittal in sutured wounds. At 5 to 9 weeks, a reorientation of scar tissue sagittal to the wound was seen in the unsutured wounds, proceeding from the posterior to anterior wound regions. In sutured wounds, a scar tissue reorientation transverse to the wound was seen, proceeding from the anterior wound region in a posterior direction. Within the same cornea, sutured and unsutured wounds showed opposite patterns of healing. Sutured wounds initially healed more slowly, but obtained pseudolamellar continuity over time. In contrast, healing of unsutured wounds was characterised by an early approximation towards lamellar repair that was followed by an ineffective reorganisation of the scar. This latter pattern of healing, that may be associated with a variable weakening of the wound, may relate to the clinical findings of unpredictability and/or progression of refractive effect following radial keratotomy.

Rupture of Radial and Arcuate Keratotomy Scars by Blunt Trauma 91 Months After Incisional Keratotomy

We studied a case in which blunt trauma caused dehiscence of radial and arcuate corneal scars 91 months after incisional keratotomy. The ruptured incisions did not extend beyond the corneoscleral limbus. Incisional refractive surgery renders the cornea susceptible to blunt traumatic rupture. This vulnerability results from the intrinsic weakness of the keratotomy wounds. Our case documents that this weakness persists up to 91 months after the operation.

Immunohistochemical analysis of unsutured and sutured corneal wound healing.

In the unsutured partial thickness penetrating wounds of the cornea, the epithelium migrates over the wounded stromal surface prior to the onset of stromal regeneration. To determine the possible affects of the epithelial ingrowth on the organization of the stromal scar tissues, the healing of unsutured and sutured wounds was compared immunohistochemically. Immunostaining patterns for fibronectin, types III, VI and VII collagen, keratan sulfate proteoglycan (KSPG), and intermediate filament-associated protein (IFAP 130) in fibroblasts, were analyzed in unsutured and adjacent sutured keratotomy wounds in monkeys, at 2-9 weeks after surgery. At 2-4 weeks, fibronectin, type III and type VI collagen showed a lamellar interweaving pattern across unsutured wounds that was absent in sutured wounds. Type VII collagen was detected along the entire depth of regenerated stroma in unsutured wounds, but not in sutured wounds indicating that the epithelium had formerly been present in the regenerated stroma in unsutured wounds. Fibroblasts in both types of wounds expressed IFAP 130, but staining was more pronounced in sutured wounds. At 5-9 weeks, cellular re-activation, as judged from the expression for IFAP 130, was concomitant with a loss of lamellar interweaving with fibronectin, type III and type VI collagen across unsutured wounds, and proceeded in a posterior to anterior direction. In contrast, in sutured wounds, lamellar interweaving was established in anterior to posterior direction. At all postoperative times, unsutured and sutured wounds showed minimal staining for KSPG in the anterior scar.(ABSTRACT TRUNCATED AT 250 WORDS)

Perforation By a Foreign Body Through a Pre-Existing Radial Keratotomy Wound

A case is presented demonstrating selective perforation of a foreign body through a pre-existing partial thickness radial keratotomy wound. This is the initial documentation of a distinct type of injury to which an eye is susceptible following corneal refractive procedures. Despite the excellent outcome, the occurrence of this injury in a soldier during a field training exercise provides additional justification for current Army policy of barring the induction of enlistees who have undergone corneal surgery to correct refractive errors.

Perforation By a Foreign Body Through a Pre-Existing Radial Keratotomy Wound

A case is presented demonstrating selective perforation of a foreign body through a pre-existing partial thickness radial keratotomy wound. This is the initial documentation of a distinct type of injury to which an eye is susceptible following corneal refractive procedures. Despite the excellent outcome, the occurrence of this injury in a soldier during a field training exercise provides additional justification for current Army policy of barring the induction of enlistees who have undergone corneal surgery to correct refractive errors.

Late Wound Complications after Circular Keratotomy for Zoster Keratitis

We observed spontaneous melting and separation of circular keratotomy wounds in two zoster patients 8 and 23 years, respectively, after surgery. In one case, it could be demonstrated that the upper part of the unaffected keratotomy wound was formed by a large epithelial plug. It is probable that this type of wound may cause late complications under unfavorable conditions.