-
Asia-Pacific Journal of Ophthalmology... 2016Myopia is a generally benign refractive error with an increasing prevalence worldwide. It can be corrected temporarily with glasses and contact lenses and permanently... (Review)
Review
Myopia is a generally benign refractive error with an increasing prevalence worldwide. It can be corrected temporarily with glasses and contact lenses and permanently with laser vision correction. The 2 main procedures currently being performed for myopia correction are photorefractive keratectomy and laser-assisted in situ keratomileusis. Each technique has its advantages, but they appear to yield similar visual outcomes 1 year after surgery. Laser vision correction for myopia was considered a paradigm shift because healthy eyes could now undergo a surgical procedure to permanently and safely correct the error by altering the center of the cornea, which was previously off limits because of the potential for loss of transparency. Customized ablation using wavefront aberrometry and its optimized profiles were created to correct higher-order aberrations and give more vision quality to patients. Topography-guided ablation, initially used for complex retreatments, shows potential to make vision even better than glasses and contact lenses in a recent study on previously untreated eyes. One major concern is to identify corneas that are at risk of developing ectasia after the procedure. Topographic and tomographic screening indices have been implemented clinically, but there is still much to learn about corneal biomechanics. A more recently developed procedure for myopia correction is small-incision lenticule extraction, in which a lenticule is created in the cornea's stroma with a femtosecond laser and extracted through a small corneal incision. Long-term outcomes and new complication risks need to be better understood as this procedure develops.
Topics: Astigmatism; Cornea; Corneal Stroma; Humans; Keratomileusis, Laser In Situ; Lasers, Excimer; Myopia; Photorefractive Keratectomy
PubMed: 27898448
DOI: 10.1097/APO.0000000000000237 -
International Ophthalmology Aug 2022To evaluate the intraocular pressure (IOP) trend and risk factors for IOP rise after myopic photorefractive keratectomy (PRK). (Randomized Controlled Trial)
Randomized Controlled Trial
PURPOSE
To evaluate the intraocular pressure (IOP) trend and risk factors for IOP rise after myopic photorefractive keratectomy (PRK).
PATIENTS AND METHODS
One eye of each patient undergone PRK for myopia was randomly assigned to this study. All eyes underwent tonometry by CorVis Scheimpflug Technology (CST) tonometer (Oculus Optikgeräte GmbH, Wetzlar, Germany) 1 week, 2 weeks, 1 month, 2 months, 3 months and 4 months after surgery. The eyes with IOP rise more than 5 mmHg and the risk factors were evaluated by Kaplan-Meier graph and multiple Cox regression analysis.
RESULTS
A total of 348 eyes of 348 patients were enrolled in this study. Forty-three eyes (12.35%) experienced a steroid-induced IOP rise of more than 5 mmHg. Eyes with IOP rise had higher baseline IOP (Median 19 mmHg (IQR 18-22) versus Median 15 mmHg (IQR 14-16); p < 0.001). Baseline central corneal thickness (CCT) was higher in eyes without IOP rise (Median 520 µm (IQR 509-541) versus Median 535 µm (IQR 518-547); p = 0.009). In multivariate Cox regression analysis, higher baseline IOP was a risk factor for IOP rise (Hazard Ratio (HR) 1.59 (95% CI 1.43-1.77); p < 0.001) while higher baseline CCT was protective (HR 0.97 (95% CI 0.95-0.98); p < 0.001).
CONCLUSION
Eyes with higher baseline IOP and lower baseline CCT are at increased risk of IOP rise after PRK and should be monitored more frequently.
Topics: Cornea; Humans; Intraocular Pressure; Lasers, Excimer; Myopia; Photorefractive Keratectomy; Tonometry, Ocular
PubMed: 35059929
DOI: 10.1007/s10792-022-02228-2 -
Current Opinion in Ophthalmology Jul 2015Since the introduction of photoablative procedures, postoperative pain management has been a major challenge for both the patient and the surgeon. Over the years,... (Review)
Review
PURPOSE OF REVIEW
Since the introduction of photoablative procedures, postoperative pain management has been a major challenge for both the patient and the surgeon. Over the years, significant advances have been made in our ability to overcome this challenge. The purpose of this article is to discuss the most current strategies for pain control after photorefractive keratectomy and phototherapeutic keratectomy.
RECENT FINDINGS
Methods for pain control can be targeted locally or systemically and can be pharmacological or nonpharmalogical. Options include anesthetics, NSAIDs, opiates, and anticonvulsants, as well as bandage contact lenses and corneal cooling.
SUMMARY
Literature and experience provide insight on the efficacy and safety of the many options for post-photorefractive keratectomy pain control. Generally, refractive surgeons are using a combination approach to achieve pain control with excellent results.
Topics: Eye Pain; Humans; Pain Management; Pain, Postoperative; Photorefractive Keratectomy
PubMed: 26058021
DOI: 10.1097/ICU.0000000000000170 -
Klinische Monatsblatter Fur... Jun 2016
Review
Topics: Corneal Transplantation; Diagnosis, Differential; Humans; Keratoconus; Photorefractive Keratectomy; Treatment Outcome; Ultraviolet Therapy
PubMed: 27315288
DOI: 10.1055/s-0042-107167 -
Arquivos Brasileiros de Oftalmologia 2021To compare postoperative pain and discomfort between mechanical and transepithelial photorefractive keratectomies.
PURPOSE
To compare postoperative pain and discomfort between mechanical and transepithelial photorefractive keratectomies.
METHODS
This prospective comparative study included 190 eyes of 95 patients with hyperopia (up to +4.00 D), astigmatism (up to -5.00 D), and myopia (up to -8.00 D) who underwent mechanical photorefractive keratectomy in one eye and transepithelial photorefractive keratectomy in the contralateral eye using Wavelight Allegretto EX500 excimer laser. The patients were unaware of the side treated with each technique. The interval between operations in the same patient was 15-30 days. Both eyes had similar refraction before surgery, with a maximum of 15-µm difference in ablation. Postoperative questionnaires were administered on days 1 and 7 to assess the patients' level of discomfort (0=no discomfort to 5=extreme discomfort) with the following symptoms: pain, burning sensation, itchiness, tearing, photophobia, eye redness, foreign body sensation, and eyelid swelling. Patients were also asked about which method they preferred.
RESULTS
The sample consisted of 61 women (64.21%) and 34 men (35.79%). The mean (SD) patient age was 31.66 (6.69) years (range, 22-54 years). On postoperative day 1, the patients reported significantly less discomfort in terms of pain (1.9 ± 1.74 vs 2.5 ± 1.83; p=0.017), burning sensation (1.8 ± 1.56 vs 2.5 ± 1.68; p=0.004), tearing (2.3 ± 1.71 vs 3.1 ± 1.69; p=0.001), and foreign body sensation (1.9 ± 1.77 vs 2.5 ± 1.86; p=0.024) in the eye that received mechanical photorefractive keratectomy than in the eye that received transepithelial photorefractive keratectomy. No significant differences were found between the mechanical and transepithelial photorefractive keratectomies on postoperative day 7. Fifty-nine patients (62.10%) preferred mechanical photorefractive keratectomy, while 32 (33.68%) preferred transepithelial photorefractive keratectomy. Four patients (4.22%) expressed no preference.
CONCLUSIONS
Our results showed that pain scores were significantly lower in the mechanical photorefractive keratectomy-treated eyes than in the transepithelial photorefractive keratectomy-treated eyes on postoperative day 1, which may have provided greater patient comfort after surgery and led patients to prefer the mechanical photorefractive keratectomy technique.
Topics: Adult; Female; Foreign Bodies; Humans; Lasers, Excimer; Male; Middle Aged; Pain, Postoperative; Photorefractive Keratectomy; Prospective Studies; Refraction, Ocular; Young Adult
PubMed: 34431901
DOI: 10.5935/0004-2749.20220026 -
Journal of Cataract and Refractive... Jan 2024To compare photorefractive keratectomy (PRK) outcomes in patients with different corneal steepness.
PURPOSE
To compare photorefractive keratectomy (PRK) outcomes in patients with different corneal steepness.
SETTING
Care-Vision Laser Center, Tel-Aviv, Israel.
DESIGN
Retrospective comparative chart review.
METHODS
Patients included in this study underwent wavefront optimized myopic PRK between January 2013 and December 2019. Patients were divided into 3 groups based on the steepness of the cornea (steep keratometry) (flat: <42 diopters [D], normal: 42 to 46 D and steep: >46 D). One to one matching was performed to verify that baseline parameters (age, preoperative visual acuity and refractive error) were similar between groups. Primary outcome measures were: postoperative corrected/uncorrected distance visual acuity (CDVA/UDVA), efficacy index (postoperative UDVA/preoperative CDVA), safety index (postoperative CDVA/preoperative CDVA), spherical equivalence (SEQ) and cylinder.
RESULTS
After matching, 650 eyes were included in each group, which were similar in baseline parameters. There were no significant postoperative differences between flat, normal, and steep corneas in terms of safety index (1.02 vs 1.03 vs 1.03, P = .28), efficacy index (1.01 vs 1.01 vs 1.02, P = .57), logMAR CDVA (0.01 vs 0.02 vs 0.01, P = .76), logMAR UDVA (0.02 vs 0.03 vs 0.02, P = .68), %SEQ within 0.50 D (73.9% vs 74.2% vs 74.6%, P = .95) or 1.00 D of target (91.9% vs 92.5% vs 92.2%, P = .92), %cylinder within 0.50 D (82.8% vs 82.2% vs 81.4%, P = .81) or 1.00 D of target (96.9% vs 97.1% vs 97.2%, P = .95).
CONCLUSIONS
No significant differences were found between flat, normal and steep corneas following wavefront-optimized myopic PRK. Thus, this procedure may be safely and effectively performed in both flat and steep corneas.
Topics: Humans; Photorefractive Keratectomy; Lasers, Excimer; Retrospective Studies; Follow-Up Studies; Cornea; Refraction, Ocular; Myopia; Treatment Outcome
PubMed: 38048136
DOI: 10.1097/j.jcrs.0000000000001307 -
Der Ophthalmologe : Zeitschrift Der... Jun 2019To analyze and assess the refractive outcome after transepithelial photorefractive keratectomy (TransPRK). (Review)
Review
OBJECTIVE
To analyze and assess the refractive outcome after transepithelial photorefractive keratectomy (TransPRK).
MATERIAL AND METHODS
The treatment was performed with the AMARIS 1050RS laser (SCHWIND eye-tech-solutions GmbH, Kleinostheim, Germany). The method used an aspheric, aberration-neutral ablation profile and a standardized epithelial tissue removal of 55 µm in the center and 65 µm at a radius of 4 mm as well as SmartPulse technology. Only spherical and/or cylindrical refraction values were treated. Only untreated eyes with preoperative best corrected visual acuity equal to or better than 0.8 were included in the cohort. Follow-up examinations were performed after 1 and 4 days, after 1 and 3 months and after 1 year RESULTS: A total of 939 consecutive TransPRK laser treatments performed in the period from December 2014 to December 2016 were retrospectively analyzed. The mean age of the patients was 34 years. The preoperative sphere had a range of -7.75 D up to +3.00 D and cylinders up to 5.00 D. The 3‑month follow-up control was performed in 728 eyes (77.5%). The predictability showed 89% of eyes within the target correction of less than 0.50 D and 99% of eyes less than 1.00 D. The astigmatic correction showed 91% of eyes with less than 0.50 D. In the safety 1% of eyes showed a visual loss of 2 Snellen lines because of haze. In 26 eyes (2.7%) follow-up treatment was performed with renewed TransPRK laser treatment, in the myopic cohort in 1.8% and in the hyperopic cohort in 13.0%. A residual refraction occurred in 20 eyes without haze and 6 eyes showed a residual refraction with signs of haze.
CONCLUSION
The TransPRK led to similar results to intrastromal refractive surgery techniques but with fewer clinical complications.
Topics: Adult; Astigmatism; Cornea; Follow-Up Studies; Germany; Humans; Lasers, Excimer; Photorefractive Keratectomy; Refraction, Ocular; Retrospective Studies; Treatment Outcome
PubMed: 30406472
DOI: 10.1007/s00347-018-0814-x -
International Ophthalmology Jul 2021To assess the safety and effectiveness of transepithelial photorefractive keratectomy (T-PRK) in patients with mild myopia using the Schwind Amaris 750 s Excimer laser...
PURPOSE
To assess the safety and effectiveness of transepithelial photorefractive keratectomy (T-PRK) in patients with mild myopia using the Schwind Amaris 750 s Excimer laser system which take corneal epithelium variability in consideration during ablation.
METHODS
A prospective case series study of patients with mild myopia with or without astigmatism (spherical equivalent ≤ -3 diopters), who underwent T-PRK as a single-step treatment, was carried out at King Abdulaziz University Hospital, Riyadh between May 2017 and January 2018. The main outcomes included postoperative uncorrected distance visual acuity (UDVA), residual refraction (manifest refraction) and complications.
RESULTS
A total of 42 patients (84 eyes) underwent bilateral T-PRK with a preoperative spherical equivalent ranging from - 0.75 to - 3.00 D. Median spherical equivalent before Trans-PRK was - 1.75 (- 1.25to - 1.75). The spherical equivalent six months after Trans-PRK was 0.0 (- 0.25 to 0.5). All patients had a postoperative UDVA of 20/20 or better in the last follow-up. Transient postoperative corneal haze was observed in five eyes (6%).
CONCLUSION
T-PRK appears to be safe and effective in patients who have mild myopia, with or without astigmatism. The normal variation in corneal epithelial thickness seems not to affect the outcomes.
Topics: Astigmatism; Humans; Lasers, Excimer; Myopia; Photorefractive Keratectomy; Prospective Studies; Refraction, Ocular; Treatment Outcome
PubMed: 33761045
DOI: 10.1007/s10792-021-01816-y -
Aerospace Medicine and Human Performance May 2024This article documents the stability of photorefractive keratectomy (PRK) and laser-assisted in situ keratomileusis (LASIK) in two astronauts during 6-mo missions to...
This article documents the stability of photorefractive keratectomy (PRK) and laser-assisted in situ keratomileusis (LASIK) in two astronauts during 6-mo missions to the International Space Station. Ocular examinations including visual acuity, cycloplegic refraction, slit lamp examination, corneal topography, central corneal thickness, optical biometry (axial length/keratometry), applanation tonometry, and dilated fundus examination were performed on each astronaut before and after their missions, and in-flight visual acuity testing was done on flight day 30, 90, and R-30 (30 d before return). They were also questioned regarding visual changes during flight. We documented stable vision in both PRK and LASIK astronauts during liftoff, entry into microgravity, 6 mo on the International Space Station, descent, and landing. Our results suggest that both PRK and LASIK are stable and well tolerated during long-duration spaceflight.
Topics: Humans; Aerospace Medicine; Astronauts; Keratomileusis, Laser In Situ; Myopia; Photorefractive Keratectomy; Space Flight; Visual Acuity
PubMed: 38715272
DOI: 10.3357/AMHP.6368.2024 -
BMC Ophthalmology Feb 2022To assess transepithelial photorefractive keratectomy (tPRK) in terms of corneal epithelial healing rate, postoperative pain, postoperative discomfort, and visual and... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
To assess transepithelial photorefractive keratectomy (tPRK) in terms of corneal epithelial healing rate, postoperative pain, postoperative discomfort, and visual and refraction outcomes compared to mechanical epithelial debridement PRK (mPRK) and alcohol-assisted PRK (aaPRK).
METHODS
In this double-masked, randomized clinical trial, thirty-nine patients underwent tPRK in one eye and mPRK in the fellow eye (arm A), and 33 patients underwent tPRK in one eye and aaPRK in the contralateral eye (arm B). All surgical procedures were done using the Schwind Amaris excimer laser. The area of corneal epithelial defect in all eyes was captured and analyzed using ImageJ software.
RESULTS
Mean epithelial healing time was respectively 3.74 ± 0.82 and 3.59 ± 0.79 days in tPRK versus mPRK (P = 0.21) in arm A, and 3.67 ± 0.92 and 3.67 ± 0.74 days in tPRK versus aaPRK (P = 1.00) in arm B. Accounting for the initial corneal epithelial defect area, the epithelial healing rate was faster in conventional PRK groups compared to tPRK (both P<0.001) in both arms. However, there was no significant difference in safety, efficacy, spherical equivalent refractive accuracy, or corneal haze development between tPRK and conventional PRK groups (all P > 0.05).
CONCLUSIONS
All three methods are effective in terms of visual and refractive outcomes. However, although time to complete re-epithelialization was similar with the three methods, the epithelial healing rate was faster in conventional PRK considering the initial corneal epithelial defect area, and the patients experienced less pain and discomfort in the first postoperative day.
TRIAL REGISTRATION
IRCT, IRCT20200317046804N1 . Retrospectively registered 5 May 2020.
Topics: Astigmatism; Epithelium, Corneal; Humans; Lasers, Excimer; Pain, Postoperative; Photorefractive Keratectomy; Refraction, Ocular; Treatment Outcome
PubMed: 35148689
DOI: 10.1186/s12886-022-02293-2