Factors predicting the visual outcome of intracorneal ring segment for keratoconus.

OBJECTIVES: To identify predictive factors and to construct predictive models using epidemiological and clinical preoperative factors for the visual acuity change after intracorneal ring segment (ICRS) implantation in patients with keratoconus. METHODS: The medical records of 287 keratoconic eyes of 230 patients implanted with ICRS at Chula Refractive Surgery Center of a tertiary university hospital (Bangkok, Thailand) between January 2012 and March 2022 were retrospectively reviewed for epidemiological and clinical preoperative variables, including those derived from Scheimpflug tomography. After randomly excluding one eye for each bilateral case, the remaining 230 eyes were randomized into two groups: a training group (184 eyes) and a validation group (46 eyes). In the training group, the correlation between the interesting variables and postoperative uncorrected and corrected distance visual acuity change (ΔUDVA and ΔCDVA; logMAR scale) at 6 months was explored, and then the multiple linear regression analysis was used to develop the predictive models. The obtained models were tested using the validation group. RESULTS: There were 5 and 14 preoperative variables that statistically correlated with ΔUDVA and ΔCDVA respectively. Only the preoperative corrected distance visual acuity (CDVAp) strongly correlated with ΔCDVA (Beta = -0.746). Using multiple regression, the preoperative uncorrected distance visual acuity (UDVAp) and front mean keratometry were selected in the proposed model for ΔUDVA (adjusted R2 = 38.8%), while the CDVAp and index of surface variance (ISV) were selected in the model [Formula: see text] (adjusted R2 = 48.9%). The ΔUDVA and ΔCDVA models were correct in 47.83% and 63.4% of the validation group within 0.20 logMAR, respectively. CONCLUSIONS: Potential predictive factors and models for ICRS-induced changes in visual acuity are proposed as adjunctive tools for clinicians. Such tools could be used for case selection and during counselling before ICRS implantation to maximize surgical outcomes.

Ocular involvement in melioidosis: a 23-year retrospective review.

BACKGROUND: Ocular involvement in melioidosis is rare and has devastating outcomes. Although there have been few reports on the condition, Khon Kaen, a city in northeast Thailand, has been called the "capital of melioidosis" due to the high prevalence of the condition in the region. We retrospectively reviewed all admitted cases of melioidosis with ocular involvement from the two largest hospitals in Khon Kaen. We reviewed cases from Srinagarind Hospital (a university hospital) of patients admitted between 1993 and 2016 and from Khon Kaen Hospital (a provincial hospital) of patients who presented from 2012 to 2016. RESULTS: We identified 16 cases of ocular involvement. Eight of these cases were proven from positive culture, and the remaining eight were implied from high melioidosis titer. The prevalence was estimated as being from 0.49 to 1.02%. Most patients had underlying diseases (14, 88%), of which diabetes mellitus was the most prevalent (12, 75%). Nine cases (56%) were part of disseminated septicemia. Patients suffered from blindness in 11 (73%) of the 15 cases in which visual acuity was recorded. Orbital cellulitis was the most common manifestation (7, 44%) followed by endophthalmitis (4, 25%). Interestingly, all patients with necrotizing fasciitis (100%) developed septic shock as a consequence. In most of the cases, patients underwent surgery (13, 81%) including incision and drainage, debridement, and pars plana vitrectomy. Despite appropriate management, the visual outcomes were disappointing (9, 64%). CONCLUSION: To summarize, ocular melioidosis is a highly destructive disease. Early detection and prompt surgical management may reduce morbidity and mortality from septic shock.