Refractive results of photorefractive keratectomy comparing trans-PRK and PTK-PRK for correction of myopia and myopic astigmatism.
International ophthalmology
PURPOSE:To compare refractive outcomes after transepithelial photorefractive keratectomy (tPRK) and combined phototherapeutic keratectomy (PTK-PRK) procedure using two different excimer laser platforms for correction of myopia and myopic astigmatism. METHODS:In this retrospective multicenter study, we compared the results of two different PRK methods. The first group received a tPRK treatment with the Amaris750 excimer laser (Schwind eye-tech solutions). The second group received a combined PTK-PRK treatment with the MEL90 excimer laser (Carl Zeiss). Only healthy eyes with no previous surgery and a spherical equivalent (SE) of -1 to -8 diopters (D) were included. Preoperative spherical equivalent (SE), age, and sex were matched among the two groups. All treatments were performed by the same surgeon in different clinics. This study was approved by the local Ethics Committee (No. 2022-1980). RESULTS:We included 154 eyes of 86 patients in our study. There was no difference in predictability of SE between the two groups. Efficacy and safety indices were equally high in both groups. Similarly, no significant differences were seen in change of higher order aberrations (HOA) between the two groups (p > 0.05). No complications occurred. CONCLUSION:Both investigated methods provide safe and effective refractive results. The combination of PTK with PRK may be a suitable option to the already used one-step tPRK for the correction of myopia.
10.1007/s10792-024-02999-w
Update on phototherapeutic keratectomy.
Stasi Kalliopi,Chuck Roy S
Current opinion in ophthalmology
PURPOSE OF REVIEW:To review all recent publications on the use of phototherapeutic keratectomy (PTK). RECENT FINDINGS:Recent studies confirm the beneficial outcomes of PTK in a variety of anterior corneal disorder: anterior stromal scars, dystrophies of the corneal epithelium and the anterior stroma, and elevated corneal lesions. They also try to evaluate the biomechanical properties of eyes with granular corneal dystrophy undergoing PTK, in an effort to prevent iatrogenic ectasia. The different genotypes in patients with transforming growth factor, beta-induced linked corneal dystrophies have recently been correlated to the surgical outcome after PTK. An extensive review of recurrent corneal erosion syndrome identified PTK as the most effective treatment. In the developing world, the most common indication for PTK is still bullous keratopathy, as PTK can be successfully used while waiting for penetrating keratoplasty. SUMMARY:PTK can successfully treat a variety of conditions of the anterior cornea. New studies may further expand its use.
10.1097/ICU.0b013e32832b4f44
A Standardized Protocol of Simultaneous Transepithelial Phototherapeutic Keratectomy (PTK) Followed by Corneal Collagen Crosslinking for Keratoconus.
Cornea
PURPOSE:To report outcomes in patients with progressive keratoconus who underwent a standardized protocol of transepithelial phototherapeutic keratectomy (t-PTK) laser followed by accelerated corneal collagen crosslinking (CXL). METHODS:All patients with progressive keratoconus undergoing our protocol at a London clinic between 2019 and 2023 were included. The protocol involved t-PTK at 58-μm central ablation depth at a 9-mm treatment zone on the Schwind Amaris 1050RS platform. Preoperative K readings of 43.0D (both K1 and K2) were inputted for all cases. Patients then underwent CXL with a pulsed-light accelerated protocol (30 mW/cm2 for 8 minutes of UVA exposure time with 1 second on/1 second off). RESULTS:Seventy-nine eyes from 55 patients were included with an average follow-up of 12 months (range 6-24 months). Both mean uncorrected distance visual acuity (UDVA) and best spectacle-corrected visual acuity improved significantly from 0.42 preoperatively to 0.29 postoperatively (P < 0.01) and 0.11 to 0.06 postoperatively (P < 0.01), respectively. The refractive cylinder reduced significantly from -3.07D to -2.63D (P < 0.05). The mean Km improved from 46.15D to 45.44D (P < 0.01) and mean Kmax from 54.03D to 52.52D (P < 0.01). 77% of eyes (n = 61) exhibited Kmax improvement postoperatively, and 56% showed an improvement in UDVA (n = 44). 16% (n = 13) had worsening of vision, but of these, only 1 patient had visual loss of more than 2 lines. No eyes had corneal haze reported at the final follow-up, and none required additional treatment. CONCLUSIONS:This standardized simultaneous t-PTK and CXL protocol is safe and effective for the treatment of progressive keratoconus, providing visual, refractive, and topographic improvements.
10.1097/ICO.0000000000003595
Phototherapeutic keratectomy: Indications, methods and decision making.
Deshmukh Rashmi,Reddy Jagadesh C,Rapuano Christopher J,Vaddavalli Pravin K
Indian journal of ophthalmology
Phototherapeutic keratectomy (PTK) involves treating anterior corneal lesions by superficial corneal ablation using an excimer laser (193 nm). Some of the commonly treated conditions include recurrent corneal erosions (RCE), corneal dystrophies, spheroidal degeneration, keratoconus, and corneal scars. We discuss various techniques of PTK including large area PTK, focal PTK, and multifocal PTK and alternatives to PTK. Masking agents like hyaluronate, methylcellulose, and dextran are recommended to help achieve a better outcome when ablating irregular corneal surfaces. Antifibrotic agents like mitomycin C reduce the chances of recurrence of the disease, apart from minimizing the postoperative scarring. Some of the complications include induced hyperopia and irregular astigmatism, haze, recurrence, and corneal thinning. However, earlier postoperative recovery, possibility of a repeat procedure, and ability to control the depth of ablation make PTK a promising, minimally invasive alternative to keratoplasty in cases with anterior corneal pathologies.
10.4103/ijo.IJO_1524_20
Phototherapeutic keratectomy: who are the best candidates and how do you treat them?
Rapuano Christopher J
Current opinion in ophthalmology
PURPOSE OF REVIEW:To discuss the primary types of lesions most amenable to excimer laser phototherapeutic keratectomy (PTK) and the specific techniques to best treat each of these disorders. RECENT FINDINGS:Elevated and anterior stromal lesions respond best to PTK. PTK can also be used to effectively treat recurrent erosions. Smoothing agents and intraoperative mitomycin C can be helpful for certain disorders. SUMMARY:The preoperative evaluation is very important in order to establish whether the eye is a good candidate for excimer laser PTK. Careful slit lamp evaluation and ancillary testing can not only determine how good a candidate they are but just as importantly, the best surgical approach. Surgeons and patients need to understand the limitations of PTK for proper informed consent. PTK is a minimally invasive procedure that is often successful in delaying or avoiding more aggressive corneal surgeries.
10.1097/ICU.0b013e32833a8e0d
Transepithelial phototherapeutic keratectomy for treatment-resistant recurrent corneal erosion syndrome.
Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie
BACKGROUND:To evaluate the efficacy and safety of trans-epithelial phototherapeutic keratectomy (TE-PTK) as a treatment for recurrent corneal erosion syndrome (RCES) in patients with symptoms refractory to conventional treatments. METHODS:All patients who received TE-PTK treatment for RCES had failed 3 or more conventional treatments and were reviewed, and if met criteria, approved by healthcare workers of the British Columbia public health authority (Medical Services Plan (MSP). A retrospective chart review and telephone survey were conducted at the Pacific Laser Eye Centre (PLEC). Exclusion criteria were ocular co-morbidities potentially affecting treatment efficacy. RESULTS:This study included 593 eyes of 555 patients (46.2% male; 50.9 ± 14.2 years old) who underwent TE-PTK. The leading identified causes of RCES were trauma (45.7%) and anterior basement membrane dystrophy (44.2%). The most common pre-PTK interventions were ocular lubricants (90.9%), hypertonic solutions (77.9%), and bandage contact lenses (50.9%). Thirty-six eyes had undergone surgical interventions such as stromal puncture, epithelial debridement, or diamond burr polishing. Post-PTK, 78% of patients did not require any subsequent therapies and 20% required ongoing drops. Six patients (1.1%) reported no symptom improvement and required repeat TE-PTK for ongoing RCES symptoms after initial TE-PTK. All 6 eyes were successfully retreated with TE-PTK (average time to retreatment was 11.3 ± 14.9 months). There was no significant difference in best corrected visual acuity pre- vs. post-operatively. The mean post-operative follow-up was 60.5 months (range: 5-127 months). CONCLUSION:TE-PTK has a good efficacy and safety profile for treatment-resistant RCES. The third-party public health-reviewed nature of this study, the low recurrence rate of RCES, and the low PTK retreatment rate suggest that TE-PTK might be considered for wider use in the management of RCES.
10.1007/s00417-024-06482-1
Phototherapeutic keratectomy.
Rathi Varsha M,Vyas Sharadini P,Sangwan Virender S
Indian journal of ophthalmology
Phototherapeutic keratectomy (PTK) is done regularly for anterior corneal diseases such as corneal dystrophies, corneal degenerations, scars, and band-shaped keratopathy. The various indications include both therapeutic and visual. The aim of this article is to discuss the therapeutic indications for PTK, the specific technique pertaining to a specific etiology, the various other procedures like amniotic membrane graft combined with PTK or PTK being done for recurrences in the grafts, and PTK done before cataract surgery when the anterior corneal pathology coexists with the cataract. Post PTK management such as healing of an epithelial defect, use of steroids in the post PTK period, recurrences of primary disease pathology, and infections, will be discussed. Methods of literature search: A Medline search was carried out for articles in the English language, with the keywords, phototherapeutic keratectomy, band-shaped keratopathy, spheroidal degeneration, scars, bullous keratopathy, and corneal dystrophy. The relevant references are mentioned here.
10.4103/0301-4738.91335
Phototherapeutic keratectomy.
Gill K S,Sitbon J R,Trocmé S D
AORN journal
The US Food and Drug Administration recently approved the 193-nm excimer laser for the treatment of superficial corneal pathology and surface irregularities--a procedure called phototherapeutic keratectomy (PTK). Indications for PTK include corneal dystrophies, degenerations, and scars that impair corneal transparency, thus compromising visual acuity. In some cases, PTK may offer a better treatment modality than corneal transplant surgery. This article reviews the basic fundamentals of PTK, including indications for surgery, the surgical procedure, preoperative and postoperative patient evaluation and care, and possible complications.
Myopic outcomes after excimer laser phototherapeutic keratectomy (PTK).
Tobalem S,Panthier C,Moran S,Debellemaniere G,Gatinel D
Journal francais d'ophtalmologie
PURPOSE:To evaluate refractive outcomes following excimer laser phototherapeutic keratectomy (PTK). METHODS:A retrospective non-randomized review of refractive outcomes of 146 consecutive eyes treated with excimer laser PTK at the Rothschild Foundation, Paris, France. Inclusion criteria were all patients undergoing PTK laser using a flying spot excimer laser system (Wavelight Allegretto, Alcon Surgical, Inc.) from October 2016 to June 2018. Exclusion criteria were incomplete data, irregular astigmatism and dystrophies of uncertain diagnosis. Preoperative diagnoses included recurrent corneal erosion syndrome without dystrophy and Cogan corneal dystrophies. The primary outcome measure was the change in spherical equivalent (SEQ) at M1 post PTK. The secondary outcome measure was the creation of a regression equation for predicting refractive outcomes after PTK, by analyzing the effect of ablation depth (AD) and optical zone (OZ) diameter. RESULTS:Fifty-eight eyes of 54 patients were included. The mean OZ was 7.352 mm±0.622. The mean AD was 18.362μm±21.406. At M1 postoperatively, the mean SEQ was -2.485 D±2.628 and mean final SEQ was -1.052 D±1.260. Both OZ and AD were independent variables with significant effects on the final visual outcome. A regression equation for predicting refractive outcomes was established. No complications were observed. CONCLUSION:The Wavelight flying spot excimer laser system produces myopic outcomes following PTK. Both OZ and AD are significant variables. A regression equation was created and may aid in prediction of refractive outcomes following PTK.
10.1016/j.jfo.2020.03.024
Management of Corneal Haze After Photorefractive Keratectomy.
Ophthalmology and therapy
Photorefractive keratectomy (PRK) is a safe and popular corneal surgery performed worldwide. Nevertheless, there is potential risk of corneal haze development after surgery. Proper management of post PRK haze is important for good visual outcome. We performed a comprehensive review of the literature on the various risk factors and treatments for PRK haze, searching the PubMed, Google Scholar, SCOPUS, ScienceDirect, and Embase databases using relevant search terms. All articles in English from August 1989 through April 2023 were reviewed for this study, among which 102 articles were chosen to be included in the study. Depending on the characteristics of and examination findings on post PRK haze, different management options may be preferred. In the proposed framework, management of PRK haze should include a full workup that includes patient's subjective complaints and loss of vision as well as visual acuity, biomicroscopy, anterior segment optical coherence tomography, epithelial mapping, and Scheimpflug densitometry. Topical steroid treatment for haze should be stratified based on early- or late-onset haze. Mechanical debridement or superficial phototherapeutic keratectomy (PTK) may be used to treat superficial corneal haze. Deep PTK and/or PRK can be used to treat deep corneal haze. Mitomycin-C and topical steroids are prophylactic post-surgery agents to prevent recurrence of haze.
10.1007/s40123-023-00782-1