Radial keratotomy: background and how to manage these patients nowadays.

In this review, we presented the principles of radial keratotomy (RK), its evolution, enhancement, and complications, and strategies to manage the consequences of RK in the present day. It is essential to understand the RK procedure f, the theoretical background that supported this surgery, the current effect on the cornea, and how to approach patients needing vision improvement. These patients are developing cataracts that need to be handled well, from the IOL calculation to the surgical procedure. Guided keratorefractive surgery is the most accurate procedure to improve these patient's vision and life. Nevertheless, some patients may need other approaches, such as sutures, penetrating keratoplasty, corneal rings, and pinhole implants, depending on the degree of irregularity of the cornea, ablation depth for guided surgery or if the sutures are open.

Late Spontaneous Postradial Keratotomy Corneal Perforation After Scleral Contact Lens Use-Case Report.

PURPOSE: To describe a case of late spontaneous postradial keratotomy corneal perforation after scleral contact lens (SCL) wear for optic correction. SETTING: Tertiary referral center for corneal pathology. DESIGN: Case report. RESULTS: A 64-year-old man presented the consequences of a late radial keratotomy (RK) surgery performed for myopia correction 26 years ago. His ophthalmologic history was a RK in both eyes (BE), previous Lasik surgery in BE and Lasik enhancement in the right eye (RE), and pterygium excision with conjunctival transplantation in RE. To improve visual acuity, SCL were fitted in both eyes. After 8 months of use, on a certain day, when removing the lens from the RE, the patient reported experiencing intense eye pain and reduced visual acuity. On ophthalmologic examination, the RE cornea was perforated in one of the previous RK incisions. An urgent corneal transplant was performed in the RE, followed by cataract surgery in the same eye. CONCLUSION: Corneal instability caused by RK scars and daily manipulation with the SCL use may have led to ocular perforation.

Cataract Surgery after Radial Keratotomy with Non-Diffractive Extended Depth of Focus Lens Implantation.

Radial keratotomy was a popular surgical procedure used to treat myopia. Patients who underwent radial keratotomy several years ago, are currently reporting to the ophthalmologist due to worsening of vision associated with age-related cataracts. In this case report we present a case of a 60-year-old woman who underwent radial keratotomy with 16 incisions in the right eye and 12 incisions in the left eye. The patient reported to an ophthalmologist due to a deterioration of vision caused by a cataract. We described, in detail, the difficulties encountered during the diagnostic procedures, differences in the calculation of intraocular lens, and intraoperative difficulties as compared to patients who had not undergone radial keratotomy. We also present the obtained postoperative results.

Descemet membrane endothelial keratoplasty in a patient with iris-fixated intraocular lens and prior radial keratotomy: a case report.

BACKGROUND: Anterior segment surgeries such as cataract surgery, intraocular lens (IOL) repositioning, and radial keratotomy (RK) may hasten endothelial dysfunction, particularly in the context of pre-existing Fuchs dystrophy, necessitating future corneal transplantation. CASE PRESENTATION: A 68-year-old woman with a history of RK with associated irregular astigmatism in both eyes and iris-fixated intraocular lens (IF-IOL) in the left eye presented with six months of decreased vision in the left eye. She was found to have Fuchs dystrophy and underwent DMEK surgery. She had an uncomplicated postoperative course, with uncorrected visual acuity improving to 20/20 three months after surgery. CONCLUSION: To our knowledge, this is the first reported case of a highly successful DMEK surgery in a patient with prior RK and IF-IOL.

Scleral Lens-Induced Corneal Edema After Radial Keratotomy.

ABSTRACT: This case series examines the magnitude and regional variation in scleral lens-induced corneal edema in postradial keratotomy (RK) eyes. Scheimpflug imaging was used to measure corneal thickness across the central 6 mm before and after scleral lens wear in nine post-RK eyes (median age 64 years). Variations in corneal edema were examined as a function of distance from the corneal center (six 0.5-mm annuli) and from 0° to 360°. The median central corneal edema was 2.19% (interquartile range 1.03%-3.18%; P=0.02) and increased in magnitude and variability further from the central cornea (from 1.30% in the central 0-0.5 mm to 3.12% in the 2.5-3.0 mm midperiphery) (P=0.02). Scleral lens-induced corneal edema in post-RK eyes was greater in magnitude further from the corneal center and at the approximate location of corneal incisions.

[Radial keratotomy: history and current state]. / Radial'naya keratotomiya: istoriya i real'nost'.

Results of clinical use of the radial keratotomy (RK) surgery are presented in the format of a lecture and a summary. The analysis encompasses the mechanism of changes in corneal refraction, immediate intra- and postoperative complications, so-called secondary symptoms and long-term effects (addition of various pathological processes, influence of corneal changes on the results of diagnostic tests and treatment methods) of the surgery.

Case Report: Acute Hydrops with Descemet Membrane Schisis in Corneal Ectasia after Radial Keratotomy.

SIGNIFICANCE: As patients with previous radial keratotomy (RK) are still occasionally encountered, recognition of the anatomy of post-RK corneas and management of their complications remain relevant. High-definition anterior segment optical coherence tomography (AS-OCT) is a very useful tool to assess these postsurgical corneas. PURPOSE: To describe a case of acute corneal hydrops with Descemet membrane schisis after RK with observation by AS-OCT. CASE REPORT: A 43-year-old woman presented with a 9-day history of sudden vision loss, foreign body sensation, and photophobia in her left eye. She had undergone bilateral RK 25 years ago at her local hospital. Slit-lamp examination revealed marked corneal edema and stromal clefts in the central cornea along with radial surgical scars in her left eye. Pentacam imaging showed the typical pattern of a post-RK cornea with ectasia in her right eye. Multiple dilacerations of collagen lamellae and fluid-filled intrastromal cysts together with epithelial edema were observed in her left eye using AS-OCT. A Descemet membrane detachment with schisis was also shown by AS-OCT. After 5 months of medication with topical 0.1% fluorometholone eye drops four times daily together with 3% ofloxacin eye ointment once daily, the corneal edema, Descemet membrane detachment, and Descemet membrane schisis had completely resolved resulting in pan-stromal scarring. CONCLUSIONS: This report describes acute corneal hydrops with Descemet membrane schisis after RK imaged using high-definition AS-OCT. The acute hydrops was possibly caused by corneal ectasia or underlying keratoconus, which was aggravated by RK. High-definition AS-OCT is a useful tool to demonstrate the details of different corneal layers and to observe the resolving process of acute hydrops. Topical medications consisting of antibiotic, lubrication, and corticosteroid can be used to treat the acute event effectively.

Mini-Scleral Lenses for Correction of Refractive Errors After Radial Keratotomy.

OBJECTIVE: To evaluate the factors affecting clinical outcomes of correcting cumulative refractive errors or irregular astigmatism after radial keratotomy (RK) using mini-scleral lenses. METHODS: We retrospectively analyzed 36 eyes receiving mini-scleral lenses after RK from July 2011 to June 2016. Analyses included age, refractive errors, best spectacle-corrected visual acuity (BSCVA), best contact lens-corrected visual acuity (BCLCVA), topographic indices, RK treatment zone diameter (TZD), power difference (PrD) within the RK treatment zone, and decentration distance (DD) of the RK treatment zone center. An increase of three lines or more of Snellen visual acuity was considered a successful fitting. RESULTS: Of the eyes fitted with mini-scleral lenses, the BCLCVA (logarithm of the minimum angle of resolution [logMAR] 0.19±0.22) was significantly better than the BSCVA (logMAR 0.47±0.30). Twenty-three patients (64%) had a successful fitting. There was no statistically significant difference between successful and unsuccessful fittings with regard to age, prefitting refractive error, BSCVA, corneal astigmatism, simulated steep/flat K values, surface regularity index, TZD, or PrD. However, successful fittings had better centration of treatment zones with an average DD of 0.54±0.44 mm compared with a DD of 0.92±0.53 mm in the unsuccessfully fitted eyes. In addition, our case series showed that there was a negative impact on fitting outcomes in the presence of small central clear zones resulting from central incisions or scars. CONCLUSIONS: Although decentration of the RK treatment zone and small central clear zones were related to less optimal fitting results, mini-scleral lenses are a feasible option to correct cumulative refractive errors and irregular astigmatism in post-RK patients.

A Case of Late Spontaneous Post-Radial Keratotomy Corneal Perforation Managed With Specialty Lenses.

PURPOSE: To describe a case of spontaneous wound dehiscence 29 years after radial keratotomy (RK) and to illustrate how specialty contact lenses were used for tectonic support and optic correction. SETTING: Tertiary referral center for corneal pathology. DESIGN: Case report. RESULTS: In November 2014, a 62-year-old woman presented to the emergency department with a spontaneous corneal perforation in her left eye. Her ocular history was significant only for uncomplicated RK surgery performed in 1985 to correct myopia (-5.50 D) in both eyes. At the slit-lamp pronounced, bullous edema was seen in the inferotemporal quadrant of the left cornea with internal opening of the 3.30- and 5-o'clock positions incisions and severe localized thinning and aqueous leakage at the 5-o'clock position incision. There was no history of trauma. A conservative approach was adopted: application of a standard bandage lens was effective in tamponading the leakage, allowing the anterior chamber to reform; a custom-made soft lens was worn for tectonic support over a period of 4 months. Finally, visual acuity was restored to 20/20-by fitting a scleral lens. CONCLUSION: Spontaneous corneal perforation is a rare but more dramatic long-term complication after RK. The pivotal role of appropriately fitted soft bandage lenses in the conservative management of this type of complex perforation is highlighted. For optical correction, a scleral lens was fitted with excellent visual result, illustrating the added value of specialty contact lenses as an alternative to surgery in the management of postrefractive corneas.

Correction of hyperopia with astigmatism following radial keratotomy with daily disposable plus spherical contact lens: a case report.

PURPOSE: To report the refractive correction in a case of hyperopia and astigmatism following radial keratotomy. METHODS: A case report. RESULTS: A 47-year-old woman, who had undergone refractive surgery for radial keratotomy in both eyes 22 years before the present study, presented to our clinic with blurred vision. Her best corrected visual acuity, with spectacle correction of +3.50 DS/-1.50 DCX130° in the right eye and +3.75 DS/-1.50 DCX80° in the left eye, was 0.2 logMAR and 0.3 logMAR, respectively. Her keratometric readings were 35.75 D/36.75 D at 74° and 35.25 D/36.25 D at 61°, respectively. Prompted by intolerance to glasses, the patient requested for contact lenses. First, we applied a rigid, gas-permeable contact lens. However, we noted poor fitting due to central corneal flattening. Subsequently, we applied a conventional plus spherical soft contact lens (PSSCL), which is thick in the center and can therefore correct hyperopia and low-grade astigmatism simultaneously. The conventional PSSCL showed slightly inferior decentration, with good movement, and the patient was satisfied with it. After ascertaining the patient's living habits, we decided that a daily disposable soft contact lens would most meet her needs. The final prescription was a daily disposable PSSCL; the patient was satisfied with her corrected visual acuity of 0.0 logMAR in the right eye and 0.0 logMAR in left eye. Her daily disposable PSSCL-corrected visual acuity was stable during the 10-month follow-up. CONCLUSION: For patients displaying hyperopia with astigmatism following radial keratotomy, the PSSCL may confer better corrected visual acuity and acceptability.

[Progressive hyperopic shift after radial keratotomy: possible causes].

AIM: To describe possible causes of progressive hyperopia in patients who underwent radial keratotomy. MATERIAL AND METHODS: The study enrolled 33 subjects who underwent radial keratotomy earlier in their lives, of them 15 controls (29 eyes, group 1) with no refractive error and 18 patients (35 eyes, group II) with progressive hyperopia. The number and type of keratotomy scars was determined during biomicroscopy. Biomechanical properties of the cornea were assessed by means of bidirectional applanation (Ocular Response Analyzer). Dynamic contour tonometry (Pascal) was also used for intraocular pressure (IOP) measurement. Evaluation of the optic nerve head and retina included standard automated perimetry (Humphrey Field Analyzer) and confocal scanning laser ophthalmoscopy with Heidelberg Retinal Tomograph (HRT III). RESULTS: Group II showed reliable signs of low corneal rigidity, namely reduction of CH and CRF values (by 2.4 and 1.6 mmHg respectively) and central corneal thickness (by 56 microns) as compared to the controls. Tonometry results differed inconsiderably showing a tendency toward hypertension in both groups. The interquartile range of IOP was 17.8 ÷ 22.4 mmHg in group II and 16.3 ÷ 20.6 mmHg in group I. Changes in retinal light sensitivity and optic nerve head parameters were more pronounced in the controls. CONCLUSION: Several reasons for lowering of corneal rigidity can be suggested: initial biomechanical parameters of the cornea, surgical interference, and age-related changes. We think that hyperopic shift results from the combination of low corneal rigidity and increased IOP, i.e. not the lamina cribrosa but the cornea becomes the target of ocular hypertension. Thus, patients with weakened corneal refraction after radial keratotomy are at risk for developing glaucoma in the late postoperative period.

Acute hydrops with secondary bacterial keratitis: sequelae of paediatric refractive surgery.

A 24-year-old male patient with bilateral high myopia presented to our outpatient department with sudden onset of pain and diminution of vision in his right eye. He had sequentially undergone bilateral trabeculectomy and photorefractive keratectomy at the age of 6 years in both eyes. This was followed by radial keratotomy in right eye at the age of 8 years. The slit lamp examination demonstrated the presence of infiltrates in central cornea with an underlying fluid cleft, along with 14 radial keratotomy scars. Anterior segment optical coherence tomography confirmed the presence of intrastromal cleft in communication with anterior chamber. Bacterial culture revealed coagulase-negative Staphylococcus. The patient was successfully treated with fortified antibiotics in conjunction with the sensitivity report. This case underlines the need for a cautious approach towards refractive surgery in paediatric age group and highlights the long-term sequelae of retreatments in these cases.

Corneal ectasia secondary to LASIK after arcuate keratotomy.

PURPOSE: To present a case of corneal ectasia after LASIK in a patient with previous arcuate keratotomy. METHODS: Case report. RESULTS: The patient underwent arcuate keratotomy in both eyes in 1997 for with-the-rule regular hyperopic astigmatism and uneventful bilateral LASIK for residual astigmatism 5 years later. Visual acuity and refraction remained stable for 5 years, when the patient noticed worsening visual acuity. Corneal topography showed progressive inferior steepening, confirming the diagnosis of ectasia. Corneal high-resolution optical coherence tomography revealed a normal LASIK flap. The patient had no risk factors for corneal ectasia other than previous incisional surgery. CONCLUSIONS: This case suggests that isolated arcuate keratotomy can be a significant risk factor for the development of corneal ectasia after LASIK.

Ray tracing biometry in post radial keratotomy eye.

OBJECTIVE: To report a case of post radial keratotomy (RK) cataract in a 55-year-old lady wherein biometry was done by ray-tracing method incorporated in scheimpflug topographer (Sirius + Scheimpflug Analyzer, CSO, Italy). METHOD: In our case, we performed intraocular lens (IOL) power calculation using a recent concept of ray tracing with scheimpflug topographer and compared with traditional methods available at American Society of Cataract and Refractive Surgery(ASCRS) website (www.ascrs.org) for eyes with prior RK. Phacoemulsification was performed and a monofocal + 24.5D IOL implanted in the capsular bag. RESULT: Manifest refraction at six weeks postoperative period was + 1.0DS/-2.0DC × 75° with spherical equivalence of 0. On comparison of all the methods used to calculate IOL power, the absolute errors of ray tracing and Barrett true K were found to be the least, 0.14 and 0.18 respectively. CONCLUSION: Ray tracing biometry with scheimpflug topographer seems to provide accurate IOL power in post RK eyes.

Therapeutic visual rehabilitation in a patient with high hyperopia and flat cornea years after radial keratotomy.

A 51-year-old man was referred for refractive surgery evaluation. Spectacle dependence and poor visual quality in both eyes was his chief complaint. He cannot tolerate contact lenses. Corrected distance visual acuity (CDVA) was 20/40 in both eyes. Manifest refraction was +5.25 -2.25 @ 90 (20/40) in the right eye and +6.25 -2.25 @ 105 (20/40) in the left eye. The patient had a history of radial keratotomy (RK) almost 30 years ago in both eyes and at the slitlamp presented 8 RK incisions, proportionally spaced between one another. All incisions were closed, and there were no relevant signs of scarring. The patient denied any history of ocular trauma, systemic disease, or medications. Corneal topography with different technologies revealed an irregular pattern with marked central flattening in both eyes, with some points below 30 diopters (D) (Supplemental Figures 1 and 2, available at http://links.lww.com/JRS/A862 and http://links.lww.com/JRS/A863, respectively). There were no signs of cataract, and fundus examination was normal. Optical coherence tomography (OCT) of the right eye revealed a more homogeneous thickness pattern, little variation between the thinnest and thickest areas, and adequate transparency (Figure 1JOURNAL/jcrs/04.03/02158034-202306000-00018/figure1/v/2023-05-31T172126Z/r/image-tiff). In the left eye, there is wide variability between the thinnest and thickest stromal points, with annular thinning and central thickening (Figure 2JOURNAL/jcrs/04.03/02158034-202306000-00018/figure2/v/2023-05-31T172126Z/r/image-tiff). Both eyes show marked epithelial irregularity. Considering this patient's current ocular status, how would you reach visual rehabilitation? Because he is contact lens intolerant, would you consider surface ablation, for example, photorefractive keratectomy (PRK) with mitomycin-C (MMC)? If that were the case, would you think of an optimized or a topography-guided (TG) treatment? Would you immediately consider a corneal transplant option? Would you instead consider a more conservative approach? Which one and why?

Rare case of corneal keloid following radial keratotomy for myopia.

An adult male in his 50s presented with complaints of glare and gradual, painless, progressive diminution of vision in the right eye (RE). Visual acuity in RE was noted to be 2/60, and slit lamp biomicroscopy revealed a pearly grey-white elevated corneal opacity measuring 4 mm × 3 mm, obscuring the visual axis. There was no history of ocular trauma or infection. The patient had undergone bilateral radial keratotomy for myopia correction 25 years ago. Anterior segment optical coherence tomography imaging demonstrated increased corneal thickness of 1080 µm at the site of lesion and the height of the epicorneal mass was noted to be 493 µm. The patient underwent fibrin glue-aided anterior lamellar keratoplasty. Histopathological examination of the excised host tissue confirmed the diagnosis of corneal keloid.

Is topography-guided ablation profile centered on the corneal vertex better than wavefront-guided ablation profile centered on the entrance pupil?

PURPOSE: To illustrate the hypothesis that corneal vertex centration is superior to entrance pupil centration when guiding an ablation by wavefront. METHODS: In one case example of therapeutic retreatment for treatment zone decentration after primary radial keratotomy (RK) centered on the entrance pupil (line of sight), both a whole-eye wavefront-guided ablation profile (WASCA data) and a topography-guided ablation profile (Atlas data) were generated using the CRS-Master (Carl Zeiss Meditec) and compared. The patient had a large vertical angle kappa. Corneal topography demonstrated that the zone of flattening was decentered superiorly with reference to the corneal vertex and the patient reported severe night vision disturbances. RESULTS: The wavefront-guided profile, centered on the line of sight, was symmetrical because the wavefront was dominated by spherical aberration induced by the primary RK treatment. On the other hand, the topography-guided profile, centered on the corneal vertex, was asymmetric with an inferior region of ablation, which would logically improve the topographic decentration. The topography-guided profile was chosen for photorefractive keratectomy using the MEL 80 excimer laser (Carl Zeiss). Ten months after the procedure, the treatment zone was topographically well centered on the corneal vertex. Whole-eye higher order root-mean-square (RMS) was reduced by 43% and corneal higher order RMS was reduced by 61%. The patient reported large subjective improvement in the quality of vision and marked reduction in night vision disturbances. CONCLUSIONS: This case provides evidence that wavefront data centered on the entrance pupil center may not represent the patient's view and the treatment zone should preferably be centered on the corneal vertex rather than the entrance pupil center.